CONCEPTUAL RELEVANCE
JOSEPH GRONFELD
B.R. Gruner Publishing Co., Amsterdam, 1989
INTRODUCTION
Consistency is only c...
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CONCEPTUAL RELEVANCE
JOSEPH GRONFELD
B.R. Gruner Publishing Co., Amsterdam, 1989
INTRODUCTION
Consistency is only contextual. One of the fundamental constraints imposed upon accurate thought is the avoidance of mixing distinct semantic fields. Poorly resolved paradoxes that undernline set theory are there to remind the mathematician of the dangers that await him in the injudicious use of these seemingly innocent symbols. Quasi-empiricists view mathematics as a social product, and some have argued that the very search for foundations in mathematics is misguided. Mathen1aticians disagree, n1ake n1istakes and correct them, and are uncertain whether a proof is correct or not. The criterion of truth in mathematics, just as much as in physics, is success of our ideas in practice. As writing has changed the practice of mathematics, computers are likely further· to modify it more than we can envisage. Butchvaraov holds that the distinctness of material identicals (' 'x = y' ') is a fact about the world quite independent of language. But the power to impose identity enables us to focus on some perceptions while ignoring others as unnecessary and irrelevant; it makes concept formation a selective process. What Butchvarov takes to be the "foundational level of metaphysics," a world composed of units of whatever nature, is due to the way our language divides into selfcontained words and sentences. The verbal, piecemeal, and analytical mode of describing experience has blinded us to the fact that but for language, objects do not maintain their distinct existence either. Miller documents the gradual reduction of visualizability in theories of modern physics. There is less reliance on visual thinking and an awareness that in the subatomic domain we increasingly are unable to explain or even describe phenomena in a consistent fashion. Realism in truth-conditional semantics is the doctrine that the truth conditions of sentences, conditions that determine their meanings, can transcend speakers' capacities to obtain them. We do not know the limits of what we meaningfully can say anymore 9
than we know the limits of what we are capable of understanding. This is why we opt for realism in epistemology and in semantics. But since the information processing model of language mastery is itself largely metaphorical, some sort of antirealist view, involving nonassertion of bivalence, seems unavoidable. Pollock proposes an analysis of possible words in terms of maximal possible states of affairs. But while states of affairs are said to be de re, possible or maximal states of affairs remain inevitably de dicto. He fails thus to provide a workable notion of a possible world that is able to solve the problem of transworld identity. Since our intuitions do not settle this, it is misleading to talk about the "truth" of statements at possible worlds in the usual sense. In Hintikka's game theoretical semantics processes are conceptualized as games against a recalcitrant Nature that tries to frustrate my attempts. But this amounts to identifying Nature with a Cartesian "malignant demon," and under such conditions Hintikka's language game is no longer winnable in principle, i.e. it is not a game worth playing. What seems to be emerging from his assumption is a modernized version of Aristotle's doctrine of categories. It is not accidental, however, that Aristotle found it difficult to accommodate change and motion - as does Hintikka. Kelley cannot know either how reality operates behind the scenes to produce perception. Being real is thus a matter of degree and context. Objectivity consists not in any relations between our judgments and the world independently of them, but rather in a relation of coherence among our judgments. There is no way to get outside of our beliefs and our language so as to find some test other than coherence. Changing purposes and shifts in background knowledge result in an unstable environment for what we perceive and take to be real. Hacking argues that it is not thinking about the world bu~ changing it that in the end must make us realists. What counts in science is instrumental success, yet this is not anymore selfexplanatory than are representations. Thus the contrast that the word "real' makes in science remains problematic and controversial. What is taken to be real in science depends on specific theoretical assumptions, not mere background knowledge. We infer to the best explanation that the theory is true, and the question whether it is true finally cannot be separated from whether the ob-- -
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jects it refers to are real. Ackermann argues that as instruments are improved, a succession of data domains can be used as an objective standard for progress in science. Latet and more refined instruments are always preferable to older and primitive ones, and progress in science is thus largely a matter of technology. The historical character of data precludes anything like a logic of scientific research, since there is a sense in which we can understand a discovery only after its potential consequences have been realized. The present status of either fact or theory does not permit us to anticipate its future significallce. Facts in the history of science do not speak for themselves because they invariably depend on other relevant data and theories. Such domains of science are likely to be reevaluated radically only when more powerful instruments provide unanticipated findings. Glymour holds that hypotheticodeductivism is inadequate as a model of scientific method because it fails to account for the condition of relevance between hypotheses and evidence. Instances of a hypothesis in a theory, whether positive or negative are obtained by "bootstrapping," that is, by using the hypothesis itself (or conceivably some other) to make computations. What to retain and what to discard depends on what else we believe or disbelieve, and assessment of whether a theory provides more information, or whether we have more reason to believe it, is always made in the light of fuzzy background assumptions. Kripke questions the prevailing interpretation of Wittgenstein as a common sense philosopher who is anxious to defend our ordinary conceptions and dissolve traditional philosophical doubts. But only with reference to the Tractatus does it make sense to talk of "a skeptical solution to a skeptical paradox" in the manner of Kripke, while the later Wittgenstein most likely would have rejected all such talk as meaningless. In the Investigations, Wittgenstein never doubts that we can understand a language game merely by participating in it. Focusing on the intellectual environment, Toulmin treats science as a self-contained social ritual, subject only to internal constraints. But the rationality of a mature science cannot be separated efficiently from the specific language in which it is expressed and the logic that governs it. If a given context lacks both logical and syntactical consistency, we face a semantically segmented domain that is no longer coherent. Only if we admit 11
partial agreements between concepts does it become possible to link logic with historical method. Since Goodman's irrealism cannot prevent worlds from "melting" <jnto versions, it is not apparent how they are supposed to "make" worlds. It seems that this is largely a metaphor, which he somehow takes literally. Davidson's truth theory is also like an equation we know not to be satisfiable by standard logic, while he tries to extend the notion of satisfaction to cover such cases. His merging of meaning and belief into background knowledge prevents him from identifying either. In this manner the very idea of truth becomes metaphorical. The price to be paid for such "weak" logic lies in a diminished capacity to produce nontrivial results. According to Davidson, by just having reasons for acting in a certain way, I accept prima facie evaluative propositions. An allout judgment that some action is desirable is identical with the intention to perform it. But no matter how elaborately detaild an intention is, there are certain to be endless ways in which it could be realized that are unwanted and unintended by the agent. We are reduced to treat inconsistency as merely apparent and once more we are driven back to interpreting behavior by means of the normative idea of rationality. Brand cannot say to what extent his definition and analysis of desiring and intending reflect psychological reality, since what he calls "psychological reality" permits divergent interpretations in different theoretical terms. His very distinction between folk psychology and what he calls "scientific psychology" is thus questionable both with regard to content and method. It is mainly because of this that he fails to "naturalize" action theory. Notturno defends psychologism by accepting the justification of statements by sense perception as natural. Such as solution, however, is not unproblematic because it disregards the theory dependence of observation. Perceptions have to be interpreted, and how they are interpreted begs the question of rationality. Notturno's version of psychologism fails to explain how sense perceptions become reasons. Laudan agrees with Kuhn that at least some controversies in science cannot be resolved because of underdetermination of theories by data. While clashes between rival theories are for Kuhn always inconclusive, Laudan proposes a hierarchical model to provide a piecemeal justification of progress in science. It is designed to refute Kuhn's claim that advocates of one paradigm cannot 12
understand their rivals. But all Laudan offers us as an explanation of how consensus in science comes about is justification by hindsight. Niiniluoto proposes a theory of 'truthlikeness' that is close to Popper's notion of verisimilitude. He aims at accounting for progress across scientific revolutions by means of agreed upon meaning postulates that represent cluster concepts. However, since such a weak notion of progress cannot make any valid claims about particular cases, it seems to lack definite applications. Partial consistencies can be justified only by hindsight and they typically are expressed by means of metaphors. The crucial issue with all such talk is how to deal with inconsistencies and avoid becoming vacuous and pointless. While mathematics always has prohibited inconsistency altogether, some philosophers since Plato have opted for dialectics, that is, for conceptual relevance converging over time. The trouble with such arguments is that their final verdict is never in, and that even whether something is useful or works can be decided only contextually. Such background knowledge does, however, guide the invention of new hypotheses in science. Lacking a timeless conceptual framework, we go by contextual proximity, and as a result our standards of clarity and coherence vary. They reflect the relative entrenchment of a network of concepts subject to change even in mathematics. What Newton and Euler took for proof is frequently no longer acceptable today, and such shifts in standards reveal a surprising looseness in the metalanguage of even mathematical logic. What we take to be real in mathen1tics thus also becomes a manner of speaking. At the conceptual level, it is not the species-specific language capacity that is decisive but the particular idiom and culture in which we happen to grow up. Since these undergo continuous transformation, conceptual relevance is largely a matter of timing and becomes unpredictable. This accounts for the wellknown phenomenon of conceptual breakthrough in science and in the arts. The "softness" of such logic invites intuitionist interpretations where insight is relative to perspective, and conceptual relevance dominates understanding. Shifts in perspective may bring about conflicting interpretations because wl1at is accepted as a reason changes as well.
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CHAPTER I
QUASI-EMPIRICAL MATHEMATICS
Foundation studies have formed a major part of modern mathematics but more recently their very need has been called in question l • By the late 1930's, Wittgenstein 2 had developed a view of philosophy that simultaneously eliminated the idea of foundations and focused philosophical concern on the actual practice of mathematicians. By 1950 Quine had become skeptical of the very possibility of drawing a satisfactory distinction between mathematics and science. His point was that the contrast between analytic truths, statements true solely by virtue of their form or meaning, and synthetic statements, true in part because of facts about experienced reality, was untenable. Logic is in principle no less open to revision than quantum mechanics or the theory of relativity 3. The mathematician Polya argued that observation was an everyday feature in mathematical practice, which had many other features in common with natural science, features such as induction, plausible reasoning, guesses, and ambiguities 4 • Quasiempiricists like Putnam push Polya's analysis one step further and question the assumption of completely secure proofs 5 • According to the quasi-empiricists, it is our informal proofs, the kind investigated by Polya, that are often safer than any derivable for1. Thomas Tymoczko (editor), New Directions in the Philosophy of Mathematics, Birkhauser, Boston, Base, Stuttgart 1985, p. 95. 2. L. Wittgenstein, Philosophical Investigations, Oxford: Blackwell, 1951, sections 124-5. 3. W.V. Quine, Philosophy of Logic, Prentice Hall 1970, pp 98-9. 4. George Polya, How to Solve It, Princeton University Press 1945; Induction and Analogy in Mathematics, Princeton University Press, 1954. 5~ H. Putnam, "Mathematics Without Foundations," Journal of Philosophy 64 (1967), p. 5.
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malization of truth. The standards of plausible reasoning are fluid, and there is no theory of such reasoning that could be compared to demonstrative logic in clarity or could command a comparable consensus 6 • Mathematics in finished form appears as purely demonstrative, consisting of proofs only. But one has to guess a mathematical theorem before one proves it, and one has to combine observations and follow analogies to accomplish this. In plausible reasoning, the principal thing is to distinguish the more reasonable guess from the less reasonable one; there is, however, no foolproof method of learning how to guess. Plausible reasoning is a practical skill, and it is learned, as any other practical skill, by imitation and experience. Thus, these philosophers conclude that it is the practice of mathematics that holds the key to our philosophical perplexities. When philosophers and philosophically minded mathematicians reflect on ordinary proofs, they realize that such proofs are still far removed from idealized formal proofs that foundations require. But it is the ordinary proofs, the informal ones, that are the real focus of many familiar aspects of mathematical experience. Such basic concepts as lemma, counterexample, explanation, and development have their roots in ordinary proofs and apply only derivatively, if at all, to formal proofs. Since development or change is an essential aspect of informal proof, anyone who wants to understand mathematics must come to terms with them. Any serious attempt to understand the evolution of mathematics should begin by locating the practicing mathematician in a socia-historical context. No account of mathematics can be adequate if it leads to the conclusion that no one in the twentieth century knows any real mathematics. Any acceptable account of mathematics must explain the bulk of mathematical practice, and the most obvious characterization of mathematical practice is that it is essentially a justification of mathematicians' claims to knowledge. Many relevant features were ignored by the foundationalists, such as informal proofs, historical development, the possibility of mathematical error, mathematical explanation (in contrast to proofs), communication among mathematicians, and the use of computers in 6. G. Polya, From the Preface of Induction and Analogy in Mathematics, in Tymoczko, Ope cit. p. 100.
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modern mathematics. To foundationalists, the activity of mathematics was just the discovery of truths about sets, and the verification of formal proofs. Quasi-empiricists,~by contrast, view mathematics more as a social product, and Putnam has argued that the very search for foundations is misguided 7 • But Putnam's rejection of the search for foundations in mathematics ignores in effect a long-standing mathematical practice and to that extent is selfdefeating. In the nineteenth century, mathematicians were shifting from studying only "the natural Ilumbers given by God" to a consideration of arbitrary number systems, and from solving equations to solving groups. In order to make sense of these changes, nineteenth- and early twentieth-century mathematicians needed a new set of criteria for assessing mathematics and mathematical proof. Frege offered an alternative characterization of Aristotelian logic in terms of what we no'w call quantification theory, together with elements of type theory and set theory. His main point was that arithmetic, unlike geometry, needed no appeal to intuition it could be described solely from logical principles. But very early on Frege's system of logic was discovered to be inconsistent. Russell's paradox threatened the very concept of foundations for mathematics, and his goal was to reconstruct foundations in such a way as to avoid the paradoxes. Since, however, there is no one way of doing this, there resulted a proliferation of logical theories. An alternative to logicism was constructivism, which replaced Russell's characterization of logic with metamathematics, the logical manipulation of formal systems. According to such a formalism, mathematical theories are merely the results of logical deductions from arbitrary axioms. However, formalism's hope of finding the consistent and complete formal theory was dashed by Godel's discovery of the inevitable incompleteness of mathematical reasoning. Quine concluded that set theory is more conjectural than the classical mathematical superstructures that can be founded upon its. The so-called logical or set theoretical "foundations"
7. Putnam, Ope cit. 8. W.V. Quine, Elementary Logic, Revised edition, New York: Harper Torchbooks, 1965, p. 125.
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for number theory or any other well-established mathematical theory is explanatory rather than really foundational, exactly as in physics. Lakatos likewise pointed out that mathematical experience and induction (not only as regards the origin and n1ethod, but also the justification of n1athematics) is more alive and widespread than many seem to think. Classical epistemology has for two thousand years modeled its ideal of a theory, whether scientific or mathematical, on its conception of Euclidean geometry. It was a major shock for rationalism that science - in spite of immense efforts could not be organized in such Euclidean theorems. Scientific theories turned out to be arranged in inductive systems. A Euclidean theory may be claimed to be true, while a quasi-empirical theory will - at best - only be well-corroborated 9 At the beginning of this century, foundational studies unexpectedly led to the conclusion that a Euclidean reorganization of mathematics as a whole may well be impossible. It turned out that the sophisticated second generation of logical or set theoretical axioms designed to avoid the ~nown paradoxes - even if true - were not indubitably true, and not even indubitably consistent. Comprehensive logical systems cannot be proved either to be true or consistent; they can only be shown to be false or inconsistent. Comprehensive axiomatic set theories and systems of metamathematics can be, and indeed have been, refuted. The idea that logic must have a standard model, if it is to be ac~eptable as a framework for mathematical reasoning, is a vestige of the old idea that there is such a thing as absolute mathematical truth 1 o. The battle between rival mathematical theories most frequently is decided by their relative explanatory power l l • Theories that looked counterintuitive or even perverted when first proposed did nevertheless sometimes assume authority when they proved to be explanatorily fruitful. Hersch, therefore, proposes an explanation of the foundational concerns in terms of the historical development of mathematics. o
9. Imre Lakatos, "A Renaissance of Empiricism in the Recent Philosophy of Mathematics?" in Tymoczko, Ope cit, p. 34. 10. J.B. Rosser and H. Wang, "Non Standard Models for Formal Logics," Journal of Symbolic Logic, 15 (1950), PP 113-129. 11. Lakatos in Tymoczko, Ope cit. p. 43.
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To philosophize about mathematics, we begin with the ongoing concerns of mathematicians. It becomes, then, easier to see that mathematical knowledge is inherently fallible, and that no founda-, tion can make it infallible. Mathematical practice is essentially a public activity, not a private one. The focus on mathematical practice brings with it an emphasis on the mathematical community as the ultimate source of mathematical activity l2. Most writers on the subject, however, seem to agree that the typical "working mathematician" is a platonist. When he is doing mathematics, he is convinced that he is dealing with an objective reality whose properties he is attempting to determine. But when challenged to give a philosophical account of this reality, he finds it easier to pretend that he does not believe in it after all! 3. The question of what is interesting in mathematics is a practical question. At the same time, the dominant style of exposition in mathematical journals and texts has been to insist on precise details of definitions and proofs, and to exclude or minimize discussion why a particular method of proof is used. Until well into the nineteenth century, geometry was regarded as the foremost, most reliable branch of knowledge. It was the discovery of non-Euclidean geometries that revealed that there is more than just one possible geometry. When, therefore, analysis took the place of geometric intuition, this brought about a crisis because geometry had served since the time of Plato as the supreme example of the possibility of certainty in human knowledge. Dedekind and Weierstrass turned from geometry to arithmetic as the foundation of mathematics. But it gradually became apparent that in reducing the continuum to arithmetic, we require a kind of mathematics that had hitherto been unnoticed - set theory l4. Set theory first seemed to be identical with logic, and it was hoped that it could serve as the foundations for all of mathematics. But by the time set theory had been patched up to exclude the paradoxes, it had become a complicated structure that one
12. Reuben Hersch, "Some Proposals for Reviving the Philosophy of Mathematics," in Tymoczko, op. cit. p. 10. 13. ibid. p. 11. 14. ibid. p. 15.
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could no longer identify 'Nith "logic" in the philosophical sense of "rules of correct understanding." Hersch argues that we do not need either platonism or formalism once we abondon the search for absolute certainty in mathen1atics. The checking of an analytic algebraic proof as it is actually done by a mathematician is primarily a piece of intuitive reasoning. Mathematicians disagree, make mistakes and correct them, and are uncertain wether a proof is valid or not 15 • A doubtful proof does not become true by being formalized, and although there is no formal definition of "understandable," in practice it is understanding that verifies the correctness of formal computations - not only the other way around 16. The kinds of valid reasoning that are called "proof" are not universal; they differ from one branch of mathematics to another, and from one historical epoch to another 1 7. It was Putnam who termed ordinary mathematics, even number theory, "quasi-empricial." He concluded th·at the criteria of truth in mathematics, just as much as in physics, are success of our ideas in practice, and that mathematical knowledge is corrigible and not absolute 18 • What has been "verified" at a given time might later tllrn out to be false. Intuitively plausible, though not certain, analogies lead to results, which are then checked "empirically". It is important to realize just how much classical mathematics has been developed for physical application (the calculus, variational methods, the current intense work on nonlinear differential equations, etc.). Empirical and quasiempirical inferences support the claim that mathematics is largely true, and place constraints on interpretations under which it could be true. Proof has the advantage of not increasing the risk of contradiction, and for this reason proof will continue to be the primary method of mathematical verification. But we will have to face the fact that "empirical" versus "mathematical" is only a relative distinction, and that in a looser and more indirect way
15. 16. 17. 18. cit. p.
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ibid. p. 20. ibid. p. 21. ibid. p. 24. Hilary Putnam, "What is Mathematical Truth?" in Tymoczko, Ope 51.
much of mathematics is "empirical." 19 In the last few years the view has become prevalent that we just happen to live in a world that does not obey the laws of Boolean logic 20 • The fact is that if quantum logic is right, not only the propositional calculus used in physics is affected but also set theory itself. Thorn points out that an adequate philosophy of mathematics will have to deal with methods such as analogy, which are ignored by foundation studies. What foundations promise but never deliver is general rigor in mathematics realized once and for all. By contrast, what our experience actually reveals is local rigor - rigor as a local property of mathematical reasoning 21 • A proof is accepted as rigorous if it obtains the endorsement of the leading specialists. The axiomatic work resulting from Hilbert's Grundlagen der Geometrie has shown that the alleged rigor of the Elements of Euclid is in large part compromised by frequent appeals to intuition. As a consequence, the argument goes, it is better to avoid Euclidean geometry by developing the ideas of algebra in which a rigorous presentation is possible. But the argument of the utility of algebra is not as compelling as it appears, and with more complex situations the advantage of algebra tends to disappear. The strictly formal view fails - paradoxically for formal reasons associated with G6del's theorem. If mathematics is only an arbitrary game, how can we explain its unquestioned success in describing the universe? There is no rigorous definition of rigor that is essentially a local property of mathematical reasoning. No compelling argument has been advanced to discard the geometric continuum as fundamental. The naive belief that every deduction finds its model in set theoretic assumptions was shared by the neopositivists. But one of the fundamental constraints imposed by accurate thought is precisely the avoidance of mixing distinct semantic fields. Nicholas D. Goodman rightly concludes that each foundational
19. ibid. p. 63. 20. "The Laws of Quantum Mechanics," in H. Putnam, Philosophical Papers, Cambridge University Press, vol. 1. 1975, ch. 10. 21. Rene Thorn, "Modern Mathematics: An Educational and Philosophic Error," in Tymoczko, Ope cit. p. 67. 21.
theory is rooted in some deep asr:fect of mathematical experience: formalism in formal languages and symbol manipulation, intuitionism in the feasibility of certain constructions, logicism in the framework of logic, and platonism in the discovery of mathematical objects. The problem is that, as a foundation of mathematics, each theory claims to be exhaustive. Goodman argues that these claims require each theory to ignore and rule out some practically real aspect of mathematical experience 22 • Mathematics is a public activity that functions in a social context and has social consequences. Posing a problem, formulating a definition, proving a theorem are none of them private acts. A working mathematician is aware of the work of other mathematicians, has his work published, and expects other mathematicians to take his work into account. Goodman emphasizes that by embracing intuitionism, the mathematician is giving up the most powerful motive for his work - the search for publicly validated truth. Mathematics, after all, is part of science, and the main purpose of doing mathematics is to discover new truths. If that concepti9n is given up, mathematics is reduced to a kind of play. There is a sense in which intuitionisnl is inadequate on its own terms, for it overlookes what is introspectively obvious: that I am interested in any mathematical constructions not for their own sake but for the sake of new truths they enable me to find. Mathematical truth is not something I can hope to find by introspection, for a mathematical theory, like any other scientific theory, is a social product. It is created and developed by the dialectial interplay of many minds. It is an everyday occurrence that a mathematician knows "intuitively" that something must be the case but does not know how to go about proving it. Some of the axioms, such as the axiom of order, are so evident to the intuition that the need for them was not noticed until the nineteenth centruy. The reduction of all mathematics to set theory entails a narrowing of the subject matter of mathematics, and recently moreover set theory has encountered difficulties roughly of the same kind that geometry faced a hundred years ago. The prolifera-
22. Nicholas, D. Goodman, "Mathematics as an Objective Science," in Tymoczko, Ope cit. p. 79.
tion of non-standard models of set theory has made mathematicians realize how feeble their set theoretical intuition really is. Increasingly one hears the suggestion that there is not just one set theoretical universe but many. Wang shows that actual proofs (informal and usable proofs) must be "perspicuous," "surveyable," or capable of being taken in. The basic concepts, he suggests, will not be set or structure, but the existing body of mathematics, and as foundation serves the sociological fact that it is so accepted. That pencil and paper are indispensable to complicated calculations is certainly an important fact about the calculating activity. Logic is primarily interested in the analysis of a proof into as many different steps as possible, and not, as mathematics, in different methods of reasoning, which can produce remote consequences in one swoop or unravel an involved entanglement. We synthesize and abbreviate as we make progress. Definitions reveal new aspects and thereby help to direct the course of our thinking into certain channels. The word "can," "decidable," etc. mean different things in pure mathematics and in applied mathematics; in actual mathematical activities, and in the discussions of mathematical logicians. There is a great gap between what can be done in principle and between what can be done in practice. In broadening the scope of the latter, such techniques as the use of Arabic notation, logarithmic tables, and computing machines are important. A basic difficulty facing the attempt to reduce mathematics to logic is the accompallying increase in complexity. We understand arithmetic better than set theory since interpreting the axioms of set theory involves considerably greater conceptual difficulties. The view that identifies mathematics with set theory leaves unexplained why, for all possible consequences of set theory, we select only those that happen to be our mathematics today, and why certain mathematical concepts and results are more interesting than others. Relative to different concepts of set and proof one could reconstruct most of mathematics in several different ways23. Following Polya, Lakatos stresses the importance of informal
23. Hao Wang, "Theory and Practice in Mathematics," in Tymoczko, Ope cit. p. 148.
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proofs in mathematics. Such proofs are not infallible, for they occasionally are refuted by some hitherto unthought of possibility. Lakatos calls this common method of estabishing mathematical facts "thought experiments," a term that goes well with quasiempiricism 24 • He stresses that formal proofs do not eliminate the possibility of doubt and error. On the face of it, there should be no disagreement about mathematical proof, btlt in fact there is a considerable amount of controversy. Pure mathematicians disown the proofs of applied mathematicians, and logicians in turn reject those of pure mathematicians. Logicians do not allow the proof of formalists, and some intuitionists dismiss the proofs of both logicists and formalists 25 • Formalists look for criteria distinguishing those formal systems that are "interesting" or "acceptable," and so on, thus betraying their bad consciences in accepting the strict formalist view according to which mathematics is the set of all consistent formal systems. In a genuine preformal theory, proof cannot be defined, but while there may be no method of verification, there certainly is a method of falsification. We can point out some hitherto unthought of possibilities. Davis concludes that there is no perfect fidelity in mathematics, only sufficiently good approximations 26 • In the presence of potential error the methodology of a mathematical proof ceases to be absolute and becomes only probabilistic. The belief that mathematics exists apart from the human beings that do mathematics in thus an illusion. The arithmetic of excessively large numbers may be carried out only with diminishing fidelity. As we get away from trivial sums, mathematical operations become enveloped in uncertainty. Skipping invariably occurs in very long proofs as it becomes necessary to keep down their length. The inevitable conclusion is that the authority of mathematical proof is not absolute but only probabilistic. Proofs must not be too long, for else their probabilities go down, and they baffle the decision process. Conven-
24. Tymoczko, Ope cit. p. 153. 25. Imre Lakatos, "What does Mathematical Proof Prove?" in Tymoczko, Ope cit. p. 154. 26. Philip. J. Davis, "Fidelity in Mathematical Discourse: Is One and One Really Two?" in Tymoczko, Ope cit. p. 164.
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tional (precomputer) mathematics developed under conditions in which proof lenghts were suffiently short, so that fidelity could be considered absolute as long as the laws of information were irrelevant. But modern mathematics aquires more and more aspects of empirical science. In spite of all this, the typical mathematician regards his work as containing truth that will last forever. He relies on rigorous proof and believes that the difference between a correct proof and an incorrect one is an unmistakable and decisive difference. He is, however, unable to give a coherent explanation of what is meant by rigor, or of what is required to make a proof rigorous. To understand his proofs, one must be privy to a whole subculture of structured arguments, examples, habits of thought, and agreedupon modes of reasoning. While the mathematician usually assumes that his own view of himself is the only one that need be considered, to an outsider he seems to be engaged in an esoteric communication with friends 27 . Once we attend to mathematical practice, however, we can recognize that, like any other sophisticated human activity, it is largely a product of culture. Some of our philosophical perplexities can be resolved, Wilder argues, by learning how mathematics changes, how it came to be what it is today, given what it was in the past 28 " Such a view stands in sharp contrast with foundationalism whose central epistemological project is to justify mathematical knowledge once and for all starting from scratch. But as D.l. Struik has pointed out, mathematics has been influenced by agriculture, commerce and manufacture, by warfare, engineering and philosophy, by physics and by astronomy29. Even the mathematical genius can only carryon from the point that mathematical knowledge within his culture has already reached. Indeed, when a culture or a mathematical element has developed to a point where it is ready for important innovation, the latter is likely to emerge at more than one spot. The inter-
27. P.l. Davis and R. Hersch, "The Ideal Mathematician," in Tymoczko, Ope cit. p. 184. 28. Raymond L. Wilder, "The Cultural Basis of Mathematics," in Tymoczko, Ope cit. p. 185. 29. D.l. Struik, Concise History ofMathematics, New York: Dover 1967.
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national character of contemporary mathematics is due in a large measure to the standardization of symbols and procedures. But what was called mathematics in one culture hardly would be recognized as such in certain others. Mathematics is not a fixed entity; it is subject to constant change, and insofar as the search for satisfactory foundation theories aims at absolute criteria for truth in mathematics or at the fixation of mathematical method, it appears doomed to failure. While Kuhn 30 had exempted mathematics from his theory of revolution in science, Garbiner insists that there are revolutions in the history of mathematics as well. She points out that the shift in standards of rigor between eighteenth- and nineteenth-century mathematics amounts to a change of "world view." The need to avoid errors became more pressing as mathematicians developed more complex calculations. Teaching in a university also became an important component of mathematical practice, and brought with it more rigorous standards of mathematical explanation. There have been several major upheavals in the history of mathematics, such as the axiomatization of geometry in ancient Greece that transformed mathematics from an experimental science into an intellectual one. Another example is the history of non-Euclidean geometries and noncommutative algebras in the nineteenth century. These were revolutions that changed mathematicians views on the nature of mathematical truth, and about what could and should be proved 31 • The primary concern of eighteenth-century mathematics was to get results, but such results were often obtained in ways that today would be considered altogether illegitimate. The calculus was an instrument for deriving new results even though many mathematicians were not able to explain why this instrument worked 32 • The need to avoid errors became more important at the end of the eighteenth century, when there was increasing interest in complex functions, in functions of
30. T. Kuhn, The Structure of Scientific Revolutions, Chicago: University of Chicago Press 1962. 31. Judith V. Garbiner, "Is Mathematical Truth Time Dependent?" in Tymoczko, op. cit. p. 202. 32. ibid. p. 204.
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several variables, and in trigonometric series. In these subjects there are many plausible conjectures wh0se truth is difficult to decide. On the other hand, the discovery of non-Euclidean geometries did not force mathematicans to choose between them and Euclidean geometry. As in the natural sciences, the new observations were often concerned with some familiar phenomenon whose significance had not hitherto been appreciated 33. One difficulty for the historian had been the prevailing view that mathematics is a body of a priori knowledge because this diverted attention from rejected theories, plausible but not rigorous reasoning and intertheoretical struggles 34 • However, it can hardly be denied that vastly more of ancient mathematics than of ancient science has survived. Mathematics is commutative in a way natural science is not because threats of competition are often resolved by reinterpretation. Mathematical knowledge develops through a rational modification of mathematical practices. Such conceptual change is to be understood as the modification of reference potentional. One special feature of the concern about complex numbers was the felt need for a concrete interpretation of them. Natural number operations obtain their physical interpretation in the process of counting, and real number operations found theirs in the process of measurement. Proponents of complex numbers had ultimately to agree that the new operations shared with the original paradigm a susceptibility to construal in physical terms. Computers have been used in calculations for several decades. In the 1950s Wang programmed a computer to prove many elementary theorems of Principia Mathematica. Indeed, a few mathematical topics were relegated entirely to computers, such as the search for the highest known prime or the largest decimal expression of pP5. However, the mathematical legitimacy of computer use remained an open question. The practical setting of this debate changed dramatically in 1976 when K. Appel, W. Haken, and K.
33. Philip Kitcher, "Mathematical Change and Scientific Change," in Tymoczko, op. cit. p. 221. 34. ibid. p. 222. 35. Thomas Tymoczko, "The Four Color Problem and Its Philosophical Significance," in Tymoczko, op. cit. p. 243.
27
Koch 36 offered what was accepted as a proof of the four color conjecture - that four colors suffice to color every map in such a way that neighboring regions are never colored alike. The problem was that this theorem was essentially dependent on computer use. Tymoczko argues that the acceptance of such computer proofs forces us to adopt a quasi-empirical account of mathematics. As writing has changed the 'practice of mathematics, computers are likely to change it further and far more than we can envisage at present. If we accept the four color solution as a theorem, we are committed to change the sense of the relevant concept of "proof" . Modern high-speed computers were used to verify some crucial steps in an otherwise mathematically acceptable argument in favor of the four color theorem, and other computers were used to check the work of the first 37 • The most natural interpretation is that computer-assisted proofs introduce experimental methods into pure mathematics. Wittgenstein had all along argued that what makes a proof is that it is convincing to mathematicians, and that this is to be taken as a brute fact, something for which no explanation can be given and none is necessary. Still many philosophers felt that there must be some deeper characterization of mathematical proofs, e.g. that proofs are surveyable and that they are formalizable 38 • It is well-known, however, that no single theory isrsufficient to formalize every proof, and that given any sufficiently rich theory, we can find a surveyable proof of a statement of that theory, which has no formal proof. Since there is no one system in which any proof can be formalized, formalization is at best only a local characterization of proofs. We also know that there exist formal proofs, which cannot be surveyed because the proofs are too long or invoke formulas that are too long. At the same time, the mathematician can derive the existence of the required formal proof in effect by presenting a surveyable proof that the formal proof exists. Indeed, this sort of thing is standard practice in proof theory. 36. K. Appel,W. Haken, K. Koch, "Every Planar Map is Four Colorable," Illinois Journal of Mathematics, xxi 84 (September 1977), pp. 429-567. 37. Tymoczko,op. cit. p. 246. 38. ibid. p. 247.
28
The four color theorem, however, can be considered a wedge between the criteria of surveyability and formalizability. For there is no surveyable proof in the traditidnal sense of the four color theorem, nor is there likely to be one. The appeal to computer computation is ultimately a report on a successful experiment, and what makes the use of computers so dramatic is that it leads to a genuine extension of our knowledge of pure mathematics. But the fact that computer-based argument in favor of the four color theorem is convincing does not make it a proof. The four color theorem has no surveyable proof since it cannot be surveyed step by step. Thus, the appeal to computers is not a proof at all, and the mistaken view that it is a proof arises from a confusion between a proof and the mere description of a proof. The point is that surveyability is preserved in traditional descriptions of proof, but not in the appeal to compllters 39 • Tymoczko concludes that the appeal to computers does introduce a new method in mathematics; one in which the appeal is surveyable, but what it appeals to is not 40 • The work of the computer is not surveyable, for its truth depends on the reliability of the program. Even if we grant that the machine does what it is supposed to do - follow the program there remains the question of whether the program does what it is supposed to do, and this question may be difficult to answer. Programs are written in special "languages" and many of them can be quite complex. They may contain "bugs' and flaws that go unnoticed for a long time. The reliability of the computer rests ultimately on such diffuse grounds. It is natural for mathematicians, at least for those educated after the development of highspeed computers and pocket calculators, to accept the truth of the four color theorem. Its reliability, however, is not of the same degree as that guaranteed by traditional proofs, for this reliability rests on the assessment of a complex set of empirical factors 41 • While in the four color theorem we do understand the general shape of the computer proof, it is questionable whether we would be prepared to rely on computers even when we could not perceive
39. ibid. p. 256. 40. ibid. p. 257. 41. ibid. p. 258.
29
the general shape of their work. If, for example, a super computer were set to work on the consistency of Peano's arithmetic, and it registered a proof of consistency, but one that was so long and complex that no mathematician could understand it beyond the most general terms, it is unlikely that we would have sufficien~ faith in computers to accept such a proof. A widely shared conviction among philosophers is that there is a significant gulf between mathematical knowledge on the one hand and scientific knowledge on the other. Thoroughgoing empiricists like Mill have denied that such a gulf exists and have tried to explain mathematical truth as a very general kind of empirical truth. But such explanations have not been very persuasive, and most philosophers have characterized the different kinds of knowledge involved by some contrasting pair, like a prioriaposteriori, innate-learned, formal-empirical, analytic-synthetic, and the like. Thus, the four color theorem is an aposteriori truth, and such knowledge is always qualified by the uncertainty of our instruments, computers, and programs. Yet the four color theorem, we n1ight say, records an essential property of planar maps. It could be an example of an aposteriori necessary truth, and a counterexample to the claim that all necessary truths are known a priori 42 • Accepting the four color theorem forces us to modify our concept of proof, as such probabilistic arguments always admit the possibility of error, and because they can go wrong in ways strict proofs cannot 43 • The old idea that proof is a thought experiment again offers itself here. Describing proofs in terms of general features of mathematical practice, the suggestion is that program verification is more like engineering and less like mathematical logic than is usually supposed. Conviction in mathematics is obtained by a highly involved set of social processes. Indeed, we can argue they are actually more reliable than strictly formal proofs which often are quite long, lack perspicuity, and whose potential for error consequently might be quite· considerable. Contrary to what the name suggests, a proof is only one step in the direction of confidence, and in the end it is always a social process that determines whether mathematicians feel confi42. ibid. p. 261. 43. ibid. p. 263.
30
dent about a theorem. Insofar as program verification is successful, it is a social, informal, intuitive, human process - a community project. Russell showed in the Principia Mathematica what can be done in principle, but thereby he also unintentionally revealed what cannot be done in practice. The point is that n1athematicians' errors are corrected not by formal symbolic logic but by other mathematicians 44 • Proofs consisting entirely of calculations are not necessarily correct. The probabilist argues that since any very long proof can be at best only probably correct, we should state theorems probabilistically and give probabilistic proofs to begin with. This may even lead to a more plausible classical proof. Made in the real world, the kind of input-output specifications that accompany production of software are seldom simple. Even if alltomatic verification were feasible, the programmer does not know to what extent the program is reliable and safe, and what happens when he exceeds these limits. A program is a complex human artifact, and any human artifact of sufficient size and complexity is imperfect. Chaitin has applied the methods of thermodynamics and statistical mechanics to Godel's theorem, and uses such concepts as probability, randomness, entropy, and information in the study of incompleteness phenomena 45 • Revealing how widespread incompleteness is, he suggests that mathematics is more akin to physics than mathematicians have been willing to admit. Indeed Godel hin1self has expressed the view that axioms need not be evident in themselves, and that their justification lies (exactly as in physics) in the fact that they make it possible for "sense perceptions" to be derived. Under these conditions, mathematics may lose a great deal of its "absolute certainty," and under the influence of modern criticism this has indeed happened to a large extent 46 • 44. R.A. De Millo, R.J. Lipton and A.J. Perlis, "Social Processes and Proofs of Theorems and Programs," in Tymoczko, Ope cit. p. 270. 45. Gregory Chaitin, "G6del's Theorem and Inforn1ation," in Tymoczko, Ope cit. p. 301. 46. K. G6del, "What is Cantor's Continuum Problem?" in Philosophy oj Mathematics, ~. Benacerraf and H. Putnam (eds.), Prentice Hall, Englewood Cliffs, New Jersey, 1964, pp. 258-273.
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CHAPTER II
BUTCHVAROV ON IDENTITY
Russell l and Wittgenstein in the Tractatus 2 maintained that th apparent distinctness of material identicals (that is, " x = y" as opposed to formal identical, "x = x") arises out of certain features 0 language, and consequently explained material identity by considerations about language. Butchvarov, on the other hand, argues that such distinctions is a fact about the world, quite independent of language 3 • The difficulty in sustaining such a counterclaim lies in separating human perception from language. Quine has shown 4 that we cannot explain synonymy in purely behavioral terms but Butchvarov insists that this can be done for the noncoincidence of objects. Since he believes the distinctness of colors and of planets to be a matter of experience prior to language, he considers formal identity statements ("x:::: x") to be degenerates. Formal identity statements, though, are essential for logic, including the logic that establishes objects as separate entities. The formula "x = y" reflects not only the power of our perceptual apparatus to abstract from distinctness that are taken to be irrelevant; it also projects accepted distinctions by means of language as categories on further perceptions, and thus creates a "world." 1. B. Russell, Introduction to Mathematical Philosophy, New York, 1971, p. 175.
2. 2.242 and 5.533. 3. Panayot Butchvarov, "Identity," in Peter A. French, Theodore E. IUehling, Jr., and Hoard K. Wettstein (eds.), Contemporary Perspectives in (he Philosophy of Language, University of Minnesota Press, Minneapolis, 1979, p. 168.
I
4. W.V.O. Quine, The Ways of Paradox, Random House, New Yrok
11966, p. 122.
5. Butchvarov in French,
Ope
cit. p. 169.
33
Butchvarov has no room for self-contradictory concepts 6 ; he excludes internal developn1ent or change in the units out of which our world is composed. He rigidly separates perceptual indiscernibility from linguistic identity, but since different degrees of discernibility are admitted for different purposes and in different contexts, he cannot help feeling that material identity is somehow "imposed" on reality. As his world is not composed of some uniform identifiable stuff, he has to maintain ontological status for the principle of material identity. Leibniz had formulated the principle of the identity of indiscernibles according to which, if there were two objects qualitatively identical with one another, they are also numerically identical, that is, they are the same object. To suppose two indiscernible things is to suppose the same thing under two names. Even when a new instrument, such as a microscope is discovered, and a new set of facts is made accessible, what is revealed to us is that the dissimilarities are even greater than we had supposed 7 • Butchvarov retains Leibniz's model of a world composed of qualitatively heterogeneous units but does not accept Leibniz's preestablished harmony between them. That is why he requires ontological status for his principle of material identity, even when he has to impose it on recalcitrant objects, as it were. He recognizes that if we are indiscriminate in our application of the principle of identity, there will be no limits to our application of the concept of indiscriminability 8 either. It would t11us appear that indiscriminability and identity, or perception and language, presuppose each other in their application. Lacking the principle of identity, Butchvarov believes, we would be left without the idea of a world 9 • This amounts to saying that without a language in which perceptions are verbally represented, they must remain fragmentary and unstable. It comes thus to admitting how essential language is for anything we can call a human world. Before being verbalized, our perceptions retain a dreamlike quality, objects lack a stable identity and may change or disappear
6. ibid. 7. Ruth Lydia Saw, Leibniz, Penguin, London 1954, p. 55. 8. Butchvarov in French, Ope cit. p. 169. . 9. ibid.
34
without reason or cause. Only when it is expressed in language do we regard the world as "given," for only then can objects be singled out and repeatedly referred to. Another role of identity, according to Butchvarov, is "ontological simplification." 10 Without a conceptual framework, however, provided by some language (natural or mathematical), the notion of simplicity lacks any ascertainable meaning. An essential point in any such simplification is the "enforcement of indiscernibility. "11 Even with an improved microscope we have to stop making further distinctions at some point, not just for perceptual but for conceptual reasons. Our language ensures that complexity of concepts be kept at a manageable level. Our human world reflects thus not only what we are capable of perceiving (with or without instruments) but also the degree of complexity we can handle. To reject discernibility is to deprive ourselves of the primary tool of conceptual understanding; this, however, is always subject to the need for simplicity. The power to impose identity enables us to focus on some perceptions while ignoring others as unnecessary or irrelevant; it makes concept formation a selective process. Any verbal description of our experience is a choice out of a host of possible identifications; this is what makes the notion of a possible world plausible. There always remain unrealized identities that might have been imposed on the objects, and this amounts to saying that the objects themselves and the world composed out of them could have been different. Butchvarov rejects such an interpretation by arguing that material identity should not be regarded as a relation 12. Once, however, he accepts identity as imposed, he implicitly admits the possibility of divergent identities. What he takes to be the "foundational level of metaphysics," i.e. a world composed of units of whatever nature, is due to the way our language divides into self-contained words and sentences. Whatever we say of the world is composed of units that can be singled out and thus treated as entities. The domain of distinct objects, which Butchvarov takes to be the logically first picture of the
10. ibid. 11. ibid. 12. ibid.
35
_
world, is a projection of language. Our perceptions are not separate from our concepts; discernibility and identity are like two sides of the same coin in anything we can rightly call a human world. Butchvarov, on the other hand, considers the distinction between perceived objects and merely conceived entities to be "two sides of the frontier of c·onceptualization." This, he believes, is due not to any psychological, or phenomenological, or epistemological, or metaphysical arguments 13. But by thus rejecting any possible argument in support of his thesis, he is left with nothing more than a dogmatic assertion. Since he likewise repudiates any criterion for the identity of nonexistent objects 14 , no explanation in terms of a universe of discourse or possible world is open to him either. His "object" is "anything that might be referred to, singled out for our attention, whether in perception, thought, or discourse; it is anything that might be classified and is subject to conceptualization."15 All this, however, would be impossible without language; nothing can be conceptualized or be subject to logic apart from language. Neither can he draw the distinction between how we know an object and how we describe it. He claims that the classification achieved does not amount to a full recording or regrouping of the subject matter: it consists merely in our coming to see, to understand, what the concept is applied to in terms of some but not others, of the similarities and differences between it and other things 16. But lacking a language, not only would it be impossible to establish identity, there would likewise be no objects to be perceived as different. The verbal, piecemeal and analytic mode of describing our experience has blinded us to the fact that, but for language, objects do not exist separately.
13. 14. 15. 16.
36
ibid. p. 173. ibid. p. 170. ibid. p. 171. 173.
CHAPTER III
REDEFINING VISUALIZABILITY
Miller traces the origins of modern physics to its philosophical roots 1 • He shows that in accordance with his neo-Kantian premises, Poincare emphasized that if our experiences were different, our reflections would be different too. If there would be no solid bodies in nature, there would be no geometry 2. Like Poincare, Einstein started from a Kantian framework in maintaining that a good ~oncept is one that enables us to organize perceptions into knowledge. But although Einstein's "concepts" playa role analogous to Kant's categories, they are not unalterably fixed. The picture serves as an "ordering element" and this is what Einstein calls a "concept."3 Discoveries are never made by scientists focusing merely on the data at hand, and in the special relativity theory (1905) he demonstrated that only by disassociating our everyday perception from our concepts do we come to recognize the relativity of simultaneity. By taking seriously the high but finite velocity of light, he came to realize the limitations on some of our visual thinking. Even more fundamental and less intuitive was the second axiom of special relativity, which states that the velocity of light c is a definite velocity, no matter what the relative motion between the observer and the source of light is. Such modifications in our visual imagery changed in a fundamental way what we take physical reality to be. Einstein's principle of relativity rejects a
1. Arthur I. Miller, Imagery in Scientific Thought Creating 20th-Century Physics, Birkhauser, Boston, Basel, Stuttgart 1984. p. 5. 2. Henri Poincare, Science and Hypothesis, New York, Dover 1952. 3. Albert Einstein, "Autobiographical Notes," in P .A. Schilpp, (ed.), Albert Einstein: Philosopher - Scientist, Evanston, Illinois, 1949.
37
priori the possibility of detecting motion relative to the ether, and for this no reasons need to be given 4 • Taking rigid bodies as irreducible elements, he sets up a physics in which the failure of the ether shift need not be accounted for, nor are we required to explain why the measured velocity of light always turns out to be c. Contrary to Poincare, Einstein associated the concept of a practically rigid body with satisfying the meaning stipulation of axiomatic geometry, and in this manner his theory of knowledge became part of special relativity 5. A consequence of this approach is that simultaneity is at variance with our prescientific notions. Newton's mechanistic world picture had been widely influential, and the frequently expressed attitude was that science must not go beyond experience, and should introduce only such abstractions that can before long be tested by experience. Hertz and Boltzmann used the term "picture" or "image" to refer to the whole of Newtonian mechanics. But Hertz realized that in Newtonian mechanics we do not understand matter in motion merely by restricting ourselves to what directly can be observed 6 • Boltzmann likewise pointed out that what was really lacking was an argument that nature could be represented by such a picture 7 • Since he denied the existence of atoms, the long-range outcome of these discussions was to discredit the phenomenalists and to demonstrate the need to go beyond direct experience in formulating scientific theory. Boltzmann represented a visual style of thinking that was very prevalent at the beginning of this century among Germanspeaking scientists and engineers. Thus, he criticized deductivism for failing to produce an explanation of how the pictures in question come to be framed. It was Einstein who provided new images of simultaneity and time by means of thought experiments. These made him conclude that such issues could not be settled by means of ideal chronometers and imaginary reference systems as had been used by Boltzmann and Hertz 8 • Einstein pointed out that there is 4. Miller, Ope cit. p. 52. 5. ibid. p. 54. 6. Heinrich Hertz, The Principles ofMechanics, New York, Dover 1956. 7. Ludwig Boltzmann, Theoretical Physics and Philosophical Problems. B. McGuiness (ed.), Boston, Reidel 1974. 8. Miller, op. cit. p. 87.
38 _ - - - - - - - - - - - - - - - - - -
no inductive method that leads us to the basic physical concepts, and that failure to understand this was the fundamental philosophical error of nineteenth-century investigations 9 • He rejected mere accommodation of the facts as advocated by Mach, and concluded that only by means of speculation would: it be possible to make further progress 1 o. In his Science of Mechanics (1893) Mach had attacked the Newtonian concepts of absolute space and time. According to Newton, absolute space was the ultimate receptacle in which all phenomena occur, and absolute time flowed independently of what we measure by clocks. As a result, Mach also disagreed with Kant who in his Critique of Pure Reason (1781) had adopted Newton's absolute space and time as a priori forms of visuability (Formen der Anschauung) that precede all empirical knowledge. According to Kant, these intuitions serve as basic organizing principles that enable our nlinds to construct knowlegde from the medley of sense perceptions . Thus, we arrive at three-dimensional Euclidean geometry and the law of causality, and finally at such higher order organizing principles as Newton's physics. Although the discovery of non-Euclidean geometry in 1827 had dealt the Kantian view a serious blow, Kant's emphasis on the role of a priori organizing principles was considered essential to our understanding of how exact laws of nature are at all possible. A priori principles of this kind played a major role in the neoKantian system of such influential philosopher-scientists as Helmholtz, Hertz, and Poincare whose writings impressed Einstein no less than did Mach 11. Both Mach and Poincare considered time to be independent of motion, and they merely replaced Newton's motion in absolute space by motion relative to distant stars or relative to ether. But while in Newton's mechanics disturbances propagate instantaneously through empty space, according to Maxwell they spread at the very high but still finite velocity of light through ether-like ripples in a pond. So pervasive had Newton's physics 9. Albert Einstein, "Physics and Reality," Journal of the Franklin Institute, 221, pp. 313-347, (1936) 10. Letter to M. Besso, 8 October 1952, in Albert Einstein - Michele Besso, Correspondence 1903-1955, Paris: Hermann 1972. 11. Einstein, in Schilpp, Ope cit.
39
become that scientists attempted to reduce all physical theory to it and pursue a mechanical world picture. However, all such attempts were eclipsed by the success of Lorentz's electromagnetic theory. Thus in 1900 Wilhelm Wien proposed an electromagnetic basis for mechanics, i.e. an electromagnetic world picture derived from Lorentz's equations. An important result of this program was that the electron's mass originated in its own electromagnetic field, and was, therefore, a velocity relative quantity. Einstein's findings on the nature of light had convinced him that theories of matter could lead neither to exact explanations of the ether drift experiments nor to a consistent world picture 1 2 • The transformation rules for the laws of mechanics and electrodynamics were dependent on two different notions of time and Lorentz failed to combine the two. Thus, while most physicists in 1905 considered the tension between mechanics and electromagnetism to be due to the inability of mechanics to explain the measured velocity of light, Einstein came to the conclusion that current physics rendered mechanics and electromagnetism incompatible 13 • To his surprise he discovered that the very notion of time turned out to be problematic in the dynamics of moving bodies. Hume's analysis of causality helped him realize that the very high velocity of light relative to the velocities we are accustomed to in our daily activities, prevents us from realizing the relativity of simultaneity. Thus, Einstein's analysis of physical theory went far beyond science as it was generally understood. He pointed out that the customary notions of simultaneity and of time result in asymmetries, unobservable quantities and ad hoc hypotheses in physics. In the special relativity paper he concluded that the basic problem in physical theory was not the constitution of matter but realizing the equivalence in the points of view of different moving observers. By means of further thought experiments he demonstrated how imprecise the prevalent notions of time and distance were and thus revealed their accurate nature. Still, prior to Niels Bohr's 1913 atomic theory, all physical systems were taken to be based on perceptions as a matter of course and subject to the
12. Albert Einstein, The Principle of Relativity, New York, Dover 1952. 13. ibid.
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ordinary space and time categories. Allied with such visual thinking in physics was the realist view of atoms moving in space and changing over time in a continuous fashion. But by 1923 it generally was realized that such pictures do no(':apply to quantum theory. Nevertheless, the need for some sort of visualizability persisted even when in 1927 Heisenberg began to regard the mathematical formulations per se as representing the atomic entities. This consequently led to the highly controversial practice of denying in quantum mechanics the validity of maps and of pictures of any kind. It turned out that nothing less was at stake than the representation of physical reality beyond what we could perceive directly by our senses. The uniformity and continuity of laws in classical physics was replaced in Bohr's 1913 atomic theory by the Planck constant, which served both to set the scale of the atom and to account for the emission of homogeneous radiation 14. While classical mechanics cOllld be used to calculate the stationary states of the atom, the discontinuities inherent in atomic processes rendered classical electromagnetics inadequate. The symbols adopted from traditional mechanics permitted the atom in the stationary states to be visualizable as a miniature Copernican system. But the transitions of an atom between its "waiting states" was no longer visualizable 1 5. Einstein, on the other hand, regarded the probabilities that quantum mechanics produced as a weakness. Rutherford's law, for example, of how many of a large number of atoms will undergo radioactive decay during a given time is a statistical probability, and classical physics took such probabilities to reflect merely our ignorance of the true dynamics of individual processes. Physicists like Einstein, therefore, clung to the belief that somehow phenomena at every level should be described by a yet to be formulated version of classical physics that was based on the customary notions of causality and continuity 16. They tended to interpret Bohr's probability equations as a prescription for dealing 14. Niels Bohr, On the Constitution ofAtoms and Molecules, New York, Benjamin 1963. 15. Niels Bohr, The Theory of Spectra and Atomic Constitution, Cambridge University Press 1924. 16. Miller, Ope cit. p. 176, n 3.
41
with non visualizable quantum jumps whose causes were not known. Bohr's picture had to be abandoned anyway because it proved to be inadequate for atoms more complex than the hydrogen atom. The correlation of bound electrons with radiation could not be squared with continuous motion in Keplerian stationary states, nor with representation as Planckian oscillators. In Bohr's view, such difficulties were due to a mistaken model for the interaction of light and atoms 17 • By 1916 the usefulness of light quanta for discussing photoelectric effects had led some physicists to accept them as real, and this in turn led to various attempts to reconcile the particle and the wave models of light. Yet, by giving up a unified picture of light, it proved impossible to preserve the conservation laws of energy and momentum. Virtual oscillators emitted a field subject merely to probabilities of possible atomic transitions. Consistent with his realist view, Einstein did not want to give up strict causality 18. While Pauli opposed what he called the "virtualization of physics," Heisenberg opted for a redefinition of visualizability. Bound electrons lost the capacity to be visualized in the usual sense and free electrons were denied individuality altogether 19 , and such limiting of intuitiveness paid off. Bohr was able to show how electron spin was needed for a more adequate account of the properties of elements, even though the notion of an electron in the degenerative state could not be linked with any particular stationary state. Consequently the electron could not be uniquely assigned quantum numbers. By July)925 Heisenberg had given up not only the picture of Keplerian stationary states but also the image of a bound electron as a localized entity. He came to identify the electron by its radiations and the probabilities of transition, that is, the coefficients in its virtual oscillator expressions. Heisenberg admitted that the new theory labored under the disadvantage of there being no directly intllitive (anschaulich) geometrical interpretation since an electron in it could not be 17. Niels Bohr, "On the Application of Quantum Theory to Atomic Structure," Proc. Camb. Soc. 1924. 18. Letter to N. Bohr, 29 April 1924, in Max Born, The Born - Einstein Letters, New York: Walker 1971. 19. Miller, Ope cit. p. 137.
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described by the familiar space and time concepts 20 • Schrodinger consequently complained that it was "extremely difficult" to explain such processes as collision phenomena in terms of a theory of knowledge in which we suppress intuition (Anschauung) and operate only with abstract concepts such as transition probability, levels of energy, and the like. He preferred a continuum-based theory to the one of Heisenberg 21 , even though it turned out that such a theory did not provide a visualizable model. Schrodinger had to admit that his visual interpretation was inadequate for systems containing two or lTIOre electrons. Miller rightly points out how such personal differences about the meaning and visualizability of key terms such as energy levels and partition possibilities played a crucial role in the development of modern physics 22 • By 1926 there were two seen1ingly dissimilar theories. Wave mechanics was adopted by the more continuum-oriented physicists who were intent on preserving pictures of processes inside the atom and were clinging to classical realism (e.g. Einstein). On the other hand, Heisenberg emphasized that we simply cannot follow our ordinary perceptions or intuitions when dealing with penomena like the spinning electron 23 • Born likewise concluded that dealing with problems of scattering and transition requires new concepts, such as light quanta, which are subject to precise laws. He was, therefore, prepared to give up determinism when dealing with phenomena inside the atom. Since quantun1 jun1ps defy all attempts at visualization, it would seem that for such atomic transactions causality turned out to be meaningless 24 • Heisenberg 25 maintained that according to our 20. Werner Heisenberg, "Mehrkorperproblem und Resonanz in der Quantenmechanik," Zeitschrijt fur Physik, 38, pp. 411-426 (1926) 21. Erwin Schrodinger, "On the Relations of the Heisenberg - Born - Jordan Quantum Mechanics to My Own," in G. Ludwig, Wave Mechanics, New York: Pergamon 1968. 22. Miller, Ope cit. p. 144. 23. Heisenberg, Ope cit. 24. Max Born, "Physical Aspects of Quantum Mechanics," Nature. 119, pp. 354-357 (1927). 25. Werner Heisenberg, "Uber den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik," ZeitschriJt .rur Physik, 40, pp. 501-506 (1926).
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customary intuition both space and matter are imagined to be divisible into arbitrary small parts. Previously we had attributed to electrons the same kind of reality as to the objects of our ordinary sense experience. We visualized them as very small particles of known charge and mass but unknown internal structure that proceed according to iscoverable precise laws. They thus complied with the intuitions of familiar continuity in our ordinary space and time world. But this picture had to be given up when it turned out that the electron and atom do not possess the kind of physical reality we associate with the objects of our daily experience. The previous theory had the advantage of both visualizability and being subject to accepted physical laws. Since it admitted, however, relations that were not testable, Heisenberg rejected it and concluded that nature within the atom was not subject to our customary intuitions. But he realized that even this modified scheme in quantum mechanics led to contradictions in our intuitive interpretations, and that tllis was unacceptable. In a letter to Pauli he admitted that what the words "wave" and "corpuscle" mean we no longer kno\v 26 • Heisenberg quoted Einstein to the effect that it is the theory that finally decides what is visualizable. Since the product of the uncertainties in measurements of an electron's position and momentum is a small but non zero number (Planck's constant), the more precisely the electron's position is known, the less accurately can its momentum be ascertained. In this manner, uncertainty relations impose limits on the accuracy to which initial conditions can be determined. The uncertainty relations can no longer be criticized as being counterintuitive. Bohr, on the other hand, considered the wave-particle duality and not the unavoidable discontinuities to be the root of the problem. Unlike Heisenberg, Bohr did not permit the theory to determine what is visualizable, and by separating causality from the space-time description of the electron, he was able to regain perceptual imagery in a suitably restricted form. According to the principle ofcomplementanlty, the mathematical formulations cannot dictate what is to be t(\ken as intuitive, e.g. a formalism that
26. Wolfgang Pauli, Wissenschajtlicher Briejwechsel mit Bohr, Einstein, Heisenberg V.A., Berlin: Springer 1979.
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prefers discontinuities and particles over waves. Dirac in due course developed a form of quantum theory in which the wave and particle aspects of matter can be tranformed mathematically into one another, and yet remain essentially exlusive 27 • Within atomic dimensions, visualization is an act of cognition based upon Heisenberg's realization that our intuitions of uniformity cannot be extended to cover quantum mechanics 28 • While Bohr was at first uncomfortable with such a style of thinking, the notion of isotopic spin permitted Heisenberg to describe the nucleus as if it were composed of identical particles of spin. Thus, in Heisenberg's new formalism, which includes the image of migrating electrons, the neutron and positron are two different states of the nuclear particle or nucleon. Miller considers this an example of how in nuclear physics metaphor becomes physical reality 29. One reason why physicists accepted this metaphor was, of course, that Heisenberg's notion of a nuclear exchange force with something exchanged turned out to be fruitful. It led to Enrico Fermi's 1934 theory of beta decay, which rendered the existence of such exchange forces in the nucleus visualizable. According to Fermi, just as the light quantum emitted by an atom in an atomic transaction was not present in the atom prior to the transaction, neither was the electron present in the nucleus prior to beta decay 30. The new level of intuitivity achieved by complementarity became the basis for a correspondence principle in quantum electrodynamics and nuclear physics. In this manner the mental imagery of modern physicists underwent a variety of profound transformations. Classical physics fails for velocities approaching the speed of light, and for atomic dimensions where Planck's constant can no longer be ignored. One result is that terms like Schrodinger's picture, Heisenberg's picture, and interaction picture have no representation or image content in the usual sense - they refer on27. Paul A.M. Dirac, "The Physical Interpretation of Quantum Mechanics," in Julian Schwinger (ed.) Selected Papers in Quantum Electrodynamics, New York: Dover 1958. 28. Heisenberg,op. cit. 29. Miller, op. cit. p. 155. 30. Enrico Fermi, "Attempt of a Theory of Beta Radiation," in R. Beyer (ed.), Foundations oj Nuclear Physics, New York: Dover 1949.
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ly to symbols. According to quantum theory, the particles are representations of symmetry groups, and to that extent they resemble the symmetrical bodies of the Platonic doctrine 31 • In the mechanics of the atom intuition had to be abandoned, and Heisenberg adopted a more intellectual Platonic version of what can be visualized. His elementary particles are, like the regular solids of Plato's Timaeus, archetypes of the idea of matter 32 • Einstein's visual imagery was likewise an essential factor in his framing the special (1905) and general (1915) theories of relativitiy. The radical transformations these theories brought about in our concepts of space and time prepared the way for further changes due to Heisenberg's quantum mechanics. By 1925 all attempts to provide a plausible imagery for the new atomic theory had failed. We can in fact trace a successive reduction in visualizability from the sensual images of Poincare, to Einstein's intuitions based on objects that actually can be observed, to Bohr's restrictions on Einstein's imagery when reduced to subatomic dimensions, and finally to Heisenberg's visualizability that is restricted by the mathematics of subatomic particles. But since these mathematical symbols gain their meaning in a variety of different contexts, they still allow a number of diverse interpretations. The primitive image of a water wave is transformed into the picture of light as a wave phenomenon. In this manner Einstein can speculate how the nature of light affects our image of physical reality. But by rejecting the hypothetical medium of ether he liberated physicists from the primitive analogy of light as something requiring support in space like a wave in water or sound in air. At the same time, Bohr and Heisenberg provide an illuminating example of the scientist's persistent need for some sort of visualizability. Heisenberg demonstrated the failure of our customary intuitions when reduced to subatomic dimensions, and the inability of ordinary experience to guide us in such cases. His quantum mechanics restricts itself to quantities that actually can be measured, such as spectral lines, which serve to identify the atom,
31. Werner Heisenberg, "Was ist ein Elementarteilchen," Die Naturwissenschaften 63, pp. 1-7 (1976). 32. Werner Heisenberg, "The Part and the Whole," in A.J. Pomerans,
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and does away with unobservable electron orbits. However, without some sort of mental imagery about how the inside of the atom looks, physicists are at a loss how to proceed doing research. Schrodinger proposed a wave mechanics in which the intuition of waves is associated with electrons moving in orbit and refused to give up visualizability 33. It was Bohr who realized that the intuitions imposed by language on our capacity to form images for theories of the atom were due to our everyday language, and reflected inevitably a quite different experience. The high velocity of light produces unperceived effects under ordinary conditions, which turned out to be the key to Einstein's theory of relativity. Einstein was the first to realize that it was the high velocity of light that induces us mistakenly to accept simultaneity as instantaneous. Bohr similarly came to see that ordinary language and the intuitions it reflects is inadequate to deal with the discontinuity due to Planck's constant. In the subatomic domain Planck's constant can be said to combine wave and particle modes of representation into a wave-particle entity that is no longer visualizable 34 Bohr explained that such counterintuitiveness comes about because we inevitably formulate these entities in a language shaped by ordinary experiences since this is the only language we have. He concludes that pictures derived from ordinary experience do not apply to subatomic dimensions, and that consequently the laws of quantum mechanics are not visualizable in the usual sense 35 How such an atomic entity comes to be perceived depends on the experin1ental arrangements in use. Wave and particle models cannot be exhibited in a single arrangement; but while they exclude each other by our intuitive criteria, they still are demanded by the mathematics of quantum mechanics. Thus, it becomes evident that in the subatomic domain we are unable to describe and explain the phenomena in a fully consistent fashion. 0
0
Physics and Beyond, New York: Harper 1971. 33. Erwin Schr6dinger, Ope cit. 34. Niels Bohr, "The Quantum Postulate and the Recent Development of Atomic Theory," Nature, pp. 580-590 (1928). 35. ibid.
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CHAPTER IV
REALIST SEMANTICS
People say things without, in general, working out what has been said and how it was said. Ordinary linguistic competence is shown by unreflective appropriate verbal and nonverbal response to the behavior of others. Knowledge of the truth conditions attributed to competent English speakers in virtue of their understanding a sentence is such that they would not, even in principle, be recognized by any speaker as obtainable. Realism in truth-conditional semantics is the doctrine that the truth conditions of sentences, conditions that determine their meanings, can transcend speaker's capacities to obtain them. We can only have a partial knowledge of truth conditions that apply to an epistemologically independent reality. If there is intersubjective agreement or emergent consensus, there are many other possible explanations besides the realist one. The philosophic significance of Tarski's truth characterization is that it reduces the semantic notions to some others. It explains what it is for a sentence to be true in terms of the primitive components of the sentence - in terms of what is for a predicate to apply to something, and what it is for a function symbol to be fulfilled by some pair of things. Tarski's theory was restricted to languages in which the sense of every expression is determined unambiguously by its form. But natural languages are full of expressions that do not meet this requirement. This raises the question of whether Tarski's type of semantic theory is applicable to languages in which the sense is not determined by the form. For if the answer is no, then Davidson's project of giving a truth characterization for natural languages seems 49
doomed from the startle Tarksi required that the vocabulary of the language be fixed once and for all, but for natural. languages this is unnecessary; all that is required is that the general structure of the language be fixed, e.g. that the semantic categories (name, oneplace predicate, etc.) be held constant. In other words, if a language already contains proper names, the mention of a new name will not invalidate the old truth conditions, though the introduction of a name into a hitherto nameless language will. The notion of an adequate translation is a semantic notion that Tarski did not reduce to new semantic terms. On Tarski's view, we need translate adeqllately the object language into the metalanguage theory of truth. This means that the notion of an adequate translation is employed in the methodology of giving truth theories but it is not employed to the truth theories themselves 2 • Field concludes that empiricism has been empirically refuted; its heir is physicalism, which allows as basic not only facts about mechanics, but facts about the other branches of physics as well. The disagreement is between those who would look for a nonsemantic basis for terms in the theory of meaning and those who would follow Quine in simply throwing out those terms. To see what a theory looks like when all semantic terms are eliminated, we must appreciate how "satisfaction" is defined. The project is to explain how names refer, yet this is precisely to ignore Frege's distinction between use and mention. The notion of truth serves, of course, a great many purp9ses, but its original aim was to aid us in utilizing the utterances of others in drawing conclusions about the world. In order to make such inferences, we have to have a pretty good grasp of the circumstances under which what another says is likely to be true. Also, how to get from a belief in the truth of what one says to belief about the extra linguistic world 3 • These two features of truth are bound up intimately with the purposes to which the notion of truth is put: the attempt to tell
1. Hartry Field, "Tarski's Theory of Truth," in Mark Platts (ed.), Reference, Truth and Reality, Routledge & Kegan Paul, London, Boston and Henley, 1980, p. 87. 2. ibid. p. 90. 3. ibid. p. 103.
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the truth, and succes in doing so play in social institutions. Normally one is in a position to assert that a sentence is true in just those cases where one is in a position to assert the sentence or a paraphrase of it. The matter might thus be explained in terms of assertability conditions in the manner of Quine 4 • Our accounts of primitive reference and of truth are not to be thought of as something that could be given by philosophical reflection prior to scientific information. The reason why accounts of truth and of primitive reference are needed is not to tack our conceptual scheme onto reality from the outside; the case, rather, is that without such accounts our conceptual scheme breaks down from the inside.. Tarski claimed that his work on truth made semantics respectable from a physicalist standpoints. McDowell points out, however, that physicalism requires something more, which Tarski did not offer, namely, explanation of these primitive terms 6 • With quantification, the straightforward procedure is blocked since the constituents of complex sentences are no longer necessarily sentences. Tarski attempted to circumvent this obstacle with the concept of satisfaction, but as in all such attempts, there was an epistemological price to be paid. In the truth-functional case, the semantic impact of sentence forming operations is captured in a recursive characterization of truth itself. Truth as such is defined as satisfaction by, or relative to, every sequence whatever. With sufficient set theory, we could convert the recursive characterization of the auxiliary notion into a "normal" or eliminative definition 7 • But the result would still contain no suggestion for eliminating the evidently semantic terminology of "applies to," and "is fulfilled by."8 Tarski announced that he would not make use of his semantic concepts if he were not able previously to reduce them to other
4. W.V. Quine, From a Logical Point of View, New York, Harper and Row 1961, p. 138. 5. A Tarski, "The Establishment of Scientific Semantics," in Logic./ Semantics, Metamathematics, Oxford, Claredon 1956, p. 406. 6. John McDowell, "Physicalism and Primitive Denotation: Field on Tarski," in Reference, Truth and Reality, Ope cit. p. 111. 7. A. Tarski, "The Concept of Truth in Formalized Languages," in Logic, Semantics, Metamathematics, Ope cit. p. 193, n. 1. 8. John McDowell, "Physicalism," Ope cit. p. 114.
j1
concepts 9 , for only in this way would the notion of truth become respectable from a physicalist standpoint. But we are not told what it is for a simple expression to have semantic properties. Tarski has two prerequisites for acceptability in truth characterizations: formal correctness and material adequacylO. "Convention T" is his condition for material adequacy, but truth characterization could conform to convention T while being, because of sparseness of set theory, incurably recursive in its account of satisfaction. Two interlocking requirements, system and psychological adequacy, could form the fit between the truth characterization and the physical facts.. That requires locating it suitably against a background of propositional attitudes - beliefs and desires - in terms of which the behavior seems to make sense. The kinds of physical facts, then, which restrain the construction of a truth characterization for a language actually spoken are the structural properties that permit the language to be given a systematic description, and the complex relations between behavior and the environment that permit (some of) the behavior to be described and understood in intentional terms ll . It is at the level of its theories that a truth characterization makes contact with the hard physical facts. The distinctive apparatus used in describing the theorem needs no anchoring in the physical facts independently of the overall acceptability of the derived assignments of truth. We potentially are liberated from much bad philosophy about truth by seeing that sentences need no special extra linguistic items of their own (states of affairs, facts, or whatever) to be related to. Talk of facts is only a lacon de parler 12 .. The truth characterization has its relation to the realm of the physical governed by conditions that direct the relation of intentional to physical discourse. But the nature of these conditions makes it quite in1plausible that the relation of semantics to physics should be anything like the relation of chemistry to physics 13 • If we are 9. A. Tarski, "The Concept of Truth in Formalized Languages," Ope cit. pp. 152-3. 10. ibid. p. 256.
11. McDowell, "Physicalism," Ope cit. p. 122. 12. ibid. p. 129; n. 9. 13. ibid. p. 125.
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physicalists, we hold that physics can, in principle, give a complete account of all events. Intentional explanation, on the other hand, makes an action unsurprising, not a~1 an instance of the way the world works, but as something that the agent can be considered to have some point in going in for. Because of the different explanatory pretensions of the intentional and the physical, they do not compete directly. Assignments of truth conditions are partly confronted by the possibilities of belief ascription, and belief ascription is governed in part by principles about how the content of belief is sensitive to the causal impact of their subject matter. There need not be a physically describable relatioll that obtains between any occurrence of a name and its denotation. Any instance of denotation will have a physical realization, which will differ from one case to another. But the real question is about the principle on which the members of the set are collected. If the point of the grouping cannot be given in purely physical terms, then there is no justification for claiming that an induction has been offered 14. McDowell concludes that denotation is a nonphysical relation. Yet central to a theory of meaning is the task of explaining language and communication by appeal to simpler, or at least different, concepts. Truth clearly depends on the semantic features of the elements, and when the elements are names or predicates, reference seems to be the relevant feature. Such a truth theory does show how the truth conditions of each sentence are a ftinction of the semantic features of the items in the basic vocabulary. But this theory fails to explain the semantic features of the basic vocabulary. Satisfaction, in the opinion of Davidson, is much like reference for predicates: he defines the reference of a predicate as the class of those sentences that satisfy it ls • The problem is that, if one imagines a new predicate added to the language, the accounts of truth and satisfaction already given do not suggest how to go on to the next case. A Tarski-style theory of truth gives us no insight into the concept of truth itself. The reason convention
14. ibid. p. 127. 15. D. Davidson, "Reality Without Reference," in Reference, Truth and Reality, Ope cit. p. 133.
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T is acceptable as a criterion of theories is that T-sentences are clearly true (preanalytically) - something we can recognize only if we already (partly) understand the predicate "is true." The interest of a theory of truth viewed as an empirical theory of a natural language is not that it tells us what truth is in general, but that it reveals how the truth of every sentence of a particular language depends on its structure and constituents 16. Davidson emphasizes that the theory does not explain or analyze the concepts of reference. Like Quine, he attempts to provide a radical analysis of language and rejects the building block model in favor of an approach that makes the sentence the focus of empirical investigation 17. But such holism operates by a merely weak principle of individuation, which turns it often inconclusive. A proper theory of truth should let us answer the underlying question how communication by language is possible. What is essential is that the theory be related to behavior and attitudes described in terms not specific to the language or sentences involved. A Tarski-style truth theory establishes this relation by means of the T-sentences. The theory contains a recursion on concepts like satisfaction and reference similar to the logical forms attributed to sentences, and the whole machinery of terms, predicates, connectives and quantifiers. Davidson believes that none of this is open to direct confrontation with the evidence: the theory gives up reference as part of the cost of going empirical's. But the kind of empiricism to which we have been reduced after giving up reference remains at least in part undecidable. What Davidson seems to mean by "going empirical" is inevitably language-relative, and is, therefore, inadequate for revealing the structure of human communication as such. This study ignores the intentional quality of all meaning ascription in which reference plays a crucial role. To eliminate reference is to ignore not only what goes on between speakers but also to disregard the physical circumstances under which communication takes place. While Davidson's theory gives up reference, he is anxious to retain ontology'9, but it is difficult to see how he can do this. It is 16. 17. 18. 19.
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ibid. p. 134. ibid. p. 135. ibid. p. 138. ibid.
by no means clear how Davidson can relate a singular term to an object without assuming implicit reference. Neither can he tell which entities will satisfy each predicate without taking some sort of reference for granted. Davidson concludes that the relation between his theory and the evidence will not amount to anything approaching induction or definition 20 • But this makes his theory largely self-defeating, and he appeals, therefore, to a preanalytic notion of reference corresponding to Tarski's preanalytic notion of truth. Davidson postulates a "loose connection" between a name and its object or between a function and the range of variables that satisfy it, yet this inevitably begs the question. Without an adequate criterion of satisfaction, Davidson's T-sentences relativized to context do not meet even Tarski's test for adequacy. Davidson emphasizes that there is more than one way of ascribing entities to expressions that yield acceptable results with respect to the truth conditions of sentences. But if there are endless other ways that do as well, the very notion of satisfaction becomes highly problematic. The right way to investigate this question would be to ask whether the empirical and formal constraints on the truth theory sufficiently limit the range of acceptable theories. Davidson admits that different theories will assign different truth conditions to the same sentence, and this goes considerably farther than Quine's indeterminacy of translation, which, after all, assumes a common truth standard reflected in basic logic. Unlike Quine, Davidson makes the notion of truth itself recursive even at the metalanguage level. An interesting way to raise questions about the relation between language and reality is to ask: how would we state a theory of knowledge that would suffice for understanding a language? The point of the notion of sense is tied to an interest in understanding people's behavior. Frege's notion of sense belongs with understanding, but such understanding has the character of "knowing how" rather than of "knowing that." One has the ability to tell that a seen object is the bearer of a familiar name without having the slightest idea how one recognizes this. Understanding a language involves knowing what speakers of it are doing, even though such
20. ibid.
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knowledge cannot as a rule explicitly be formulated. A model for the sense of a word of some particular kind dos not seek to explain how we are able to use the word as we do: it merely forms part of an extended description of what that use consists of. Lacking such an explanation, we might not be able to see why speakers think fit to act as they do. To explain why they act intentionally in these ways presupposes a psychological mode of explanation. A person who knows the sense of a name must have some beliefs about its bearer. This second order belief is manifested by the subject's actions, not explained by his words. The Fregean view would have to seek its support in the idea that thought relates to objects with an essential indirectness. Davidson indeed emphasizes that we are asked to make sense of a judgment of synonymy between utterances, but not as a foundation for a theory of language. It is merely as an unanalyzed part of the content of the familiar idiom of indirect discourse that synonymy is introduced. When I say that Galileo said that the earth moves, I represent Galileo and myself as samesayers. To effect samesaying, I do not necessarily have to use his words, but I have to use words the same in import here and now as his then and there. Yet this is just what on the standard theory of quotation I cannot do. For the theory introduces the content sentence sealed in quotation marks, and on any standard theory of quotation this means that the content sentence is mentioned and not used. An utterance of a content sentence will not in general be an assertion. We cannot first construct a theory about conditions under which utterances are true, and then draw conclusions about what speakers are saying. Dealing with fornlal languages, Tarski . could take the notion of translation for granted, as determined by stipulation, and work from there to a characterization of truth. But we do not know independently what a truth characterization of the appropriate kind is, and cannot therefore use the intuition of such a truth characterization as a route to judgments of samesaying (judgments about what people are saying). Constructing a truth characterization of the appropriate kind, and putting oneself in a position systematically to interpret what people say are a single activity. If the identity of words depends on the identity of languag~s, then, as Quine has pointed out, words become problematic as objects of reference. From a Quinean standpoint, 56
languages as a kind of entity should be no more acceptable than meanings. Indeed, the ideas seem interdefinable: two speakers speak the same language when a sufficient number of their equation utterances have the same meaning. Intuitively speaking, quotation is a device for talking about words in abstraction from the circumstances in which the words happen to be produced. There is no way to explain what samesaying is except in terms of a prior intuition of meanings as objects of reference. Such a claim however does not survive appreciation of Quine's argument about translation 21 • We have no more an identification principle for languages than for meanings. In the familiar languages for which we know how to define truth, the basic iterative devices are reducible to the semantical connectives, the apparatus of quantification, and the description operator, if it is primitive. Adding to the list of logical constraints will increase the inventory of logical truths and consequence beyond anything a truth definition demands, and will, therefore, yield richer versions of logical form. Certain semantical purposes will suggest that we should attempt an external standpoint outside the logical predicament that Russell and Frege accepted as inevitable. Wiggings argues that it would be a great pity to talk ollrselves out of the unstructured natural language quantifier 22 , for example. To describe a natural language quantifier like "most" or "all" as starting_ from a preexisting unspecified mass of entities, one does not even need to treat it as a set or determinate totality of any kind. Wiggins concludes that truth-theoretical semantics cannot be a complete theory of meaning. Davidson likewise admits that metaphor is directed to what language is about. The point of the concept of linguistic meaning is to explain what can be done with words. But there are no restrictions for deriving metaphors and there is no manual for what a metaphor "means" or "says." There is no test of metaphor that does not call for taste. Davidson's analysis of metaphor - and
21. W.V. Quine, Word and Object, MIT Press, Cambridge, Mass, 1960, Ch.2. 22. David Wiggins, "Most and All," in Reference, Truth and Reality, Ope cit. p. 332.
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thus of truth-theoretical semantics - depends on the distinction between what words mean and what they are used to do. But while metaphor belongs exclusively to":: the domain of use, there are aspects of language that are not merely metaphorical. Literal meaning is at least partly independent of use, and this is what makes the device of quotation philosophically interesting. Literal meaning and literal truth conditions can be assigned to words and sentences apart from particular context of use. This is why adverting to them has genuine explanatory power 23 • The common error is to fasten on the contents of the thoughts a metaphor provokes, and to read these entities into the metaphor itself. What we attempt in paraphrasing a metaphor cannot be to give its meaning, for that lies on the surface; rather, we attempt to evoke what a metaphor brings to our attention. Yet it is hard to decide even in the case of the simplest metaphors exactly what the content is supposed to be. In fact, there is no limit to what a metaphor calls to our attention, since much of what we are called to notice is not propositional in character. When we try to say what a metaphor "means," we soon realize that there is no end to what we want to mention, and Davidson emphasizes that this is true for any use of language 24 • Peacocke consequently points out that we are required to make sense of the possibility that a counterfactual is well supported by the evidence but is nevertheless false. Our picture of the world is a representation not only of actual events but also of imaginary events that branch out from the actual ones. Logically speaking, the requirement that our beliefs be factually true leaves us free to characterize the imaginary events in any way we please. But in practice we limit our freedom by adopting principles of construction that apply to the whole picture 25 • Perception cannot fail to play an essential part in gaining knowledge about what is actually the case. The fact that perceptual sentences require for their truth some causally modalized sentences is linked with the
23. D. Davidson, "What Metaphors Mean," in Reference, Truth and Reality, Ope cit. p. 240. 24. ibid. p. 254; n. 16. 25. A.J. Ayer, Probability and Evidence, London, Macmillan, 1972, p.124.
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fact that to perceive an objct is a way of gaining knowledge of it. We form hypotheses about what is causally necessary and what is not on evidence much less than conclusive. A man can have a general belief, yet fail to instantiate it with respect to a particular object, much as he may fail to connect two of his beliefs that entail a third. In the case of counterfactuals, we do not obtain a condition that is decidable or can be observed to be true. What is actually the case fails to settle the truth of causally modal sentences but does not fail to settle those of universal generalization 26 • According to Michael Dummett, a truth condition theory of sense for a class of sentences is equivalent to realism with respect to their subject matter. The property of truth reflects the realist convention embodied in our customary linguistic practices that the world, or a given sector of it, determinably is constituted quite independently of any limitations on our capacity to come to know truth concerning it. Since, for the realist, truth value may thus transcend our power to discover its constitution, the principle of bivalence is regarded as generally assertable, whether or not we are equipped to determine even in principle what truth value a sentence has. Dummett holds that we must be able as theorists to relate to ascribed semantic knowledge the same specific practical capacity or capacities to use the language. Plainly, if sense is to fulfill its communication function, it must be a publicly ascribable entity. But then semantic knowledge must of necessity be manifestable in and recoverable from observable features of the language. What Dummett claims is that a theory of meaning framed in terms of a relative notion of truth precisely fails to forge the required connection 27 • It is clear that we cannot in general equate knowledge of truth conditions with the capacity simply to state these conditions. Dummett suggests that knowledge of truth conditions be identified or correlated with a certain kind of recognitional capacity, viz~ the 26. Christopher Peacocke, "Causal Modality and Realism," in Reference, Truth and Reality, op. cit. p. 59. 27. M. Dummett, "Truth," Proceedings of the Aristotelian Society, vol 59 (1958-59); "What is a Theory of Meaning?" in Mind and Language, edited by S. Guttenplan, Oxford, Claredon 1975; Elements of Intuitionism, Oxford, Claredon 1977.
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capacity to recognize, or come to know, the truth value of sentences. It is only because the possession of such an effective decision procedure for truth value is a practical capacity that it provides the needed link between the knowledge of sense and use. Trouble sets in, according to Dummett, when we inquire with what generality this account can be applied. Obviously in the case of undecidable sentences, an alleged grasp of transcendent truth conditions cannot be associated with possessing an effective method for handling truth value. Lacking that, Dummett concludes, a realist theory cannot represent sense as determining and being determined by use. But if truth and use fall thus apart, the sense of a sentence cannot consist in its having truth conditions subject to bivalence. It follows that the semantic content of a sentence .cannot represent conditions as they might obtain in some recognition transcedent reality, and so realism is false. We must, accordingly, only assign such conditions to sentences as deternlining their sense as are comprehensible by our actual recognitional capacities - e.g. verification conditions - and face the antirealist consequences 28 • McGinn argues against Dummett that speakers of what appears a common language may differ in their powers of truth recognition. Sentences concerning regions of space and time might be decidable for one speaker and undecidable for another, depending on how wellequipped they are to inspect the region in question. On such a view, it is not the individual speaker to whom we should look for a manifestation of his semantic knowledge; rather, we should require, for sense to be manifest, only that there should exist, within the community, some speakers whose powers of recognition match the truth conditions of the sentences in question. A truth conditions theory of sense for a language would then connect with sense only for the community as a whole. Since the individual speaker has to rely on the recognitional capacities of his co-speakers, a variability of semantic properties has to be acknowledged. But this involves crediting speakers with conceptions of states of affairs of a kind not available to them during the course of their linguistic training, and not such as to be manifestable in their linguistic prac-
28. Colin McGinn, "Truth and Use," in Reference, Truth and Reality, cit. p. 21.
Ope
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tice - it already concedes something to the realist 29 • It appears that the realist is unable to supply the appropriate recognitional capacity, and so, by Dummett's argument,~ cannot relate semantic knowledge to linguistic use 30 • The theory of sense consists in a recursive specification of truth conditions for sentences in the object language it represents: what it is a speaker knows in knowing the meaning of sentences. According to Dummett, it is not enough that a theory of language mastery merely records what a speaker knows - e.g. that "snow is white" if and only if snow is white - there is the further obligation reaching beyond pure description to supply an explanation of what possessing a language consists in; or else, it is claimed, no adequate mesh with use is achieved. We can think of such a complete routine for a whole sentence as constituting its direct method of verification. But knowing the truth conditions of sentences dealing with quantification over infinite or unsurveyable domains, past-tense sentences, reference to remote regions of space and time, and the like, does not confer upon speakers a practical grasp to establish their truth value . In this way, Dummett suggest, the realist cannot discharge his obligation to the theory of understanding. And this may reduce us to opt for a verificationist theory of meaning, according to which knowledge of a sentence just consists in a practical grasp of which states of information would warrant assertion of the sentence. It does not follow, however, that speakers cannot extract from their training conceptions that transcend these conditions, as McGinn has it 31 • What makes human language different from mere animal communication is precisely its creative potential, Le. the ability to use sentences and form concepts not previously encountered. We do not know the limits of what we meaningfully can say anymore than the limits of what we can know - and that is why we opt for realism in epistemology as well as in semantics. We grasp the meanings of our native tongue quite independently of a truth theory or a knowledge of truth conditions, however primitive. We
29. ibid. p. 22. 30. ibid. p. 23. 31. ibid. p. 26.
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cannot explain our actual use 'of language apart fronl its counterfactual components. But semantic realism, like epistemic realism generally, cannot explain undecidable sentences in ternlS of what it would be for a speaker to observe that they are true. The realist, accepting the presuppositions of Dummett's argument, finds himself forced to acknowledge that he cannot explain knowledge in the only way available. Like Hume, we wonder how there could be more to our "ideas" than can be extracted from our "impressions." McG-inn concludes that it is only an empirical dogma that makes us disposed to deny the possibility of acquiring conceptions of reality that transcend our recognitional capacities 32 • We cannot acquire a conception of reality that is separate from language because we do not know the lin1its of what we meaningfully can say or understand. The proper object of acquiring mastery of language and of knowing the meaning of sentences is communication, the business of interpreting the speech of others and of having one's own interpreted. It is not quite consistent to construe a theory of meaning as empirically testable, and at the same time underdetermined by the evidence, as Davidson proposes. The point is to sho\\' in what ways linguistic behavior interlocks with the psychological properties of the speaker and his dispositions to action. Since we cannot separate linguistic knowledge from other knowledge of a speaker, some sort of realist semantics seems to be called for. Linguistic theory forms an inseparable part of a more general theory of action of persons; a theory that relates meanings, propositional attitudes, and intentional behavior. One's knowledge of meaning is manifestable in one's capacity to interpret the speech behavior of others. A central ability is correctly ascribing beliefs to a speaker that agree, in combination with suitable devices, in explaining his behavior. But such reference may transcend recognition, as truth transcends recognition of truth. The cardinal principle of Dummett's conception of language mastery is that it consists solely in, and so cannot go beyond, sensitivity to the evidence. Yet what constitutes evidence in such circumstances is itself language relative. Quine's idea 33 that 32. ibid. p. 29. 33. W.V. Quine, "Epistemology Naturalized," in Ontological Relativity, New York, Columbia University Press 1969.
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the content of our general conceptionpf the world is underdetermined by the evidence can no longer be "considered empirical in the standard sense. Only under a realist interpretation of discourse (whether scientific or comn10nsense) is it possible to make sense of such underdetermination. That is why Quine accepts a realist semantics: undecidability is due to underdetermination. But McGinn rightly insists that the sensory underdeterminacy thesis is itself a form of antirealism about meaning 34 • One can see the underdeterminacy thesis as Quine's attempt to resolve the deep tension between a realist face value interpretation of scientific common sense discourse and his doctrine that there can be no more to meaning than is recoverable from dispositions to assent and dissent under sensory stimulation. What would take up the resulting slack is adherence to some form of mentalistic semantics, which repudiates the doctrine of empirical n1eaning altogether. Dummett finds it incredible that meaning should outrun linguistic dispositions and so prefers to relinquish realism, thereby restoring the exhaustive manifestability of sense. Both Quine and Dummett are motivated by the underlying assumption that the capacity to use a language must be represented fundamentally as the possesion of a complex of dispositions to verify and falsify sentences. Both take it for granted that knowing a language is an information processing capacity. But they ignore the fact that such a model is largely metaphorical. In consequence, some sort of antirealist view, involving nonassertion of bivalence seems to be unavoidable.
34. McGinn, Ope cit. p. 29.
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CHAPTER V
POLLOCK'S STATE OF AFFAIRS SEMANTICS
The basic tool of Pollock's philosophical semantics is the concept of a possible world. Carnap began it all by talking about state descriptions, but it was Kripke who made talk of possible worlds respectable in his 1959 completeness proof for modal talk 1. While possible world talk served originally heuristic purposes, it recently has been taken more seriously. Lewis 2 argues that possible worlds are real entities that actually exist and to which we can appeal in philosophical analysis. Pollock however believes that we should distinguish carefully between formal and realist semantics in such discussions. Realist semantics makes explicit appeal to possible worlds and identifies necessary truth with truth in all possible worlds. Formal semantics, by contrast, is carried on entirely within set theory. The basic tool of formal semantics is the concept of a model, which is a set theoretic structure. Models are said to "correspond to" possible worlds but it is by no means clear what this alleged correspondence amounts to. Thus, the philosophical foundations of formal semantics remain in doubt. There is no agreement on the nature of possible worlds and on how they are related to necessary truth, propositions or meaning. Pollock's philosophical semantics presupposes certain views about the nature of language, and the relationship between language and various logical entities like propositions as possible objects of belief. We want it to be the case that people believe the same thing if they believe the
1. S. Kripke, "A Completeness Theorem in Modal Logic," The Journal of Symbolic Logic, 24, (1959), pp. 1-14. 2. David Lewis, Counterfactuals, Cambridge, Harvard University Press, 1973.
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same proposition, but there is the obstacle that under different circumstances we adopt different criteria for believing the same thing. Pollock assumes that there must be a finest possible criterion for deciding that two people (or even one person in different situations) believe the same thing 3 • This, however, would require them to think of objects in precisely the same way, and to hold such beliefs at exactly the same time - and this is something we can never really know to be the case. Pollock therefore concludes that we can only identify more or less coarse-grained objects of belief with a given set of propositions. The resulting structure of such a semantics cannot be spelled out in any precise fashion. While objects involve some mode of representation, there is more than just one mode of representation available. What else should be included in an inventory of propositional designators remains a n1atter of dispute. Pollock maintains that we can think about an object without necessarily thinking about it under a description 4 , but the ways in which we refer to ourselves or to the present, for exan1ple, are certainly not invariant to the manner of description adopted. The view associated with Frege and Russell (perhaps unfairly) was that, when one makes a statement uttering a sentence containing a proper name, the function of the name is to express a definite description that becomes a constraint on the proposition asserted. Kripke s and Donnellan 6 , on the other hand, have argued persuasively that one can rarely find a definite description that is a plausible candidate for the sense of the use of a proper name. They instead have championed the historical connection theory according to which the referent of a name is determined by a chain of historical connections between particular uses of the name. They coupled this view of reference with the semantical thesis that sentences containing proper nan1es are used to express directly 3. John L. Pollock, The Foundations of Philosophical Semantics, Princeton University Press, Princeton, New Jersey, 1984, p. 9. 4. ibid. p. 11. 5. S. Kripke, "Naming and Necessity," in Davidson and Harman (eds.), Semantics of Natural Language, Dordrecht, Reidel 1972, pp. 253-335. 6. K. Donnellan, "Proper Names and Identifying Descriptions," in Semantics of Natural Language, Ope cit. pp. 356-379.
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referential properties, and this is known as the denotation theory 7. The claim that proper names are used. to state directly referential propositions means that it makes no difference how the speaker and his audience thi11k about the referent of a name. Members of the audience have understood the speaker just as long as they come to think of the correct object of the referent and understand what the speaker is saying about the object. The traditional view was that, for communication to be successful, the sent and received propositions must be the same. The denotation theory can be regarded as relaxing this requirement by pointing out that successful communication occurs just as long as the sent and received propositions are about the same object and attribute the same thing to its. The historical connection weakens our criteria of identity: we are no longer dealing with exactly the same object, merely with a coarse-grained resemblance adequate for ascribing belief. The ways in which speakers and hearers think about an object typically will reflect their idiosyncratic relationships to it and neither side will know exactly how the other side is thinking of the object. This does not preclude successful communication in most cases. There must be some connection between the sent and received propositions, but they need not be identical. Having specified the range of possible sent and received propositions, we can characterize only roughly the content of the communication or determine what statement has been made. Different features of the circumstances are invoked in determining the possible sent and acceptable received properties for different statements. Donnellan and Kripke argue that the historical connection theory provides a theory of reference, while the denotation theory represents a theory of meaning. Pollock points out, however, that these two theories are not really compatible. One would naturally expect internal and external necessity to coincide, but Pollock shows that they do not. He largely accepts the view of Kripke 9 and Putnam 10 that no distinction can be made between pl1ysical 1
7. Pollock, Ope cit. p. 20. 8. ibid. p. 21. 9. Kripke, "Nanling and Necessity," Ope cit. 10. H. Putnam, "The Meaning of "Meaning", in Boston Studies in the Philosophy of Science, vol 2, R. Cohen and M. Wartofsky (eds.) 1975, Humanities Press, pp. 205-222.
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necessity and logical necessity as they apply to "natural kinds." They have argued that if water is HzO (as a matter of physical necessity) there can be no possible world in which water is not HzO. Pollock identifies Kripke's epistemic necessity with internal necessity and external necessity with metaphysical necessity. But he admits that both internal end external necessity are species of de dicta necessity! I • The adverb "necessary" occurs in English as a de re modal operator when we say, "Two is necessarily the square root of four." While English provides us with devices for distinguishing between de re and de dicta necessity, there is the tendency to express de re necessity instead of de dicta necessity by ignoring the role our language plays in the identification of (especially abstract) objects. One way to make us sensitive to such background knowledge is to explain necessary truth in terms of truth in all possible worlds. Still, it has never been entirely clear just what possible worlds are supposed to be. David Lewis 1z argues that possible worlds are "ways things could have been,' and Saul Kripke describes possible worlds as "counterfactual situations."l3 While there is some intuitive appeal to such constructions, there is also considerable disagreement about how the concept of a possible world is to be understood. Lewis maintains that the concept is primitive and unanalyzable but this makes it of questionable utility in the analysis of other concepts. Pollock proposes an analysis interms of maximal possible state of affairs, which he identifies with maximal consistent sets of propositions 14. States of affairs are de re rather than de dicta, but possible or maximal states of affairs are inevitably de dicta. Pollock certainly does not solve the problem of transworld identity by postulating maximal possible states of affairs. He claims that no nonessentialist theory of transworld identity can be correct, while admitting that foundations are ultimately always de dicta. He fails thus to provide a workable notion of a possible world, for there is no way for him to identify objects across worlds in terms of qualities they have at worlds.
11. 12. 13. 14.
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Pollock, op. cit. p. 31. Lewis, op. cit. Kripke, "Naming and Necessity," op. cit. Pollock, op. cit. p. 43.
One alternative to this is to make the identity of an object part of the specification of the world as proposed by Kripke 15 • Pollock interprets this to mean the identification of possible worlds with maximal possible states of affairs l6 , but this introduces a concept that is used at the same time both de re and de dicto. States of affairs can never be literally true or false, for two distinct states of affairs are not logically equivalent. Pollock fails to show that one state of affairs obtains if and only if another obtains; his states of affairs semantics does not, therefore, satisfy the axioms of the propositional calculus. He wants only nontransient states of affairs to enter into the construction of a possible world, but this can be done only by stipulation. To be directly referential, states of affairs must be "maximal," Le. "combine descriptions of everything." 1 7 The trouble is that there cannot be a literal description of everything, and it is, th.erefore, misleading to talk about the "truth" of statements at possible worlds in the usual sense. Lacking an adequate principle of identification, Pollock permits possible or maximal states of affairs to be identified with their extensions l8 , and they thus become members of themselves and subject to the well-known set theoretical paradoxes. No such concept can be very helpful in analyzing necessary truth. The disagreement between Lewis and Pollock on whether possible worlds or necessity is to be regarded as primitive l 9, cannot be settled by an appeal to intuition, as Pollock proposes. While he maintains that the way things could have been are states of affairs and not just possible worlds, he is unable to tell at what point states of affairs become maximal or nontransient. When proposing states of affairs as primitive, he fails to give a noncircular account of necessity in terms of possible worlds. He wants necessary truth to be generated from a priori truth by closure conditions 20 while all such conditions remain strictly de dicto. His contention that possible worlds have
15. Kripke, "Naming and Necessity," Ope cit. 16. Pollock, Ope cit. p. 52. 17. ibid. p. 57. 18. ibid. p. 61. 19. ibid. p. 65. 20. ibid.
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necessary existence is by no means universally shared, for he cannot decide whether possible wQrlds are internally or externally possible. Since he ascribes to states of affairs a directly referential character, their modal operators are more simple than for either propositions or statements 21 • But the price for such apparent simplicity is his inability to identify particular states of affairs. Pollock attempts to settle this by stipulation, that is, by arguing that in philosophy "property" has become a term of art, and that we consequently can have properties be anything we want them to be. Such an approach, however, becon1es useless for the purposes of semantical analysis, as when he permits (3 x) to range over merely possible worlds by stipulation. The appeal to intuition fails in such cases because it cannot tell us at what point merely possible objects become a possible world. He defends possibilism by permitting the philosopher (Le. himself) to speak a language significantly different from ordinary English. But in this manner his argument becomes circular. Philosophical analysis has to discover the constraints inherent in ordinary discourse, not simply to in1pose them, and the problem is that ordinary discourse lacks precise limits on the use of concepts dealing with what is possible or necessary. Pollock believes that it is only when we turn to sets built in part from contingently existent objects that the axiom scheme of replacement will fail for possibilistic set theory. He considers this to be only a minor failing 22 , while it plausibly may be argued that contingently existing sets reflect the "essence" of our actual world. It is indeed this fundamentally contingent character of the actual world that renders possible worlds and possible states of affairs de dicto. Possible worlds (Le. things that are possible at the actual world) either require that some currently existing objects do not exist, or that some additional objects exist. Being thus contingent, they are no longer "possible worlds" in Pollock's sense 23 • He take~ such modal knowledge to be of abstract entities 24 , but here everything depends on what we mean by "abstract." We
21. 22. 23. 24.
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ibid. ibid. ibid. ibid.
p. p. p. p.
71. 97. 100. 102.
know not only that all bachelors are unmarried but also that it is necessary that bachelors are unmarried. This latter kind of knowledge he believes to be not about (de dicto) propositions but about (de re) bachelors. However, when asked to explain why it is necessary that all bachelors are unmarried, he inevitably appeals to what the word "bachelor" means, Le. to the workings of our language. Thus, the foundation of our knowledge of (abstract as well as nonabstract) entities is finally always de dicto. Modal analysis cannot explain what (de re) numbers are, for the very question is obscure. All it can do is to explain what it is to be a real, irrational or transcendental number by describing their properties. Pollock wants all talk of abstract entities to be analyzable in terms of purely modal talk of nonabstract entities. But he proposes such an analysis not in terms of truth conditions but in terms of justification conditions 25 . All such justification, however, remains relative to what we take the trllth to be. To say, as Pollock does, that it is true that there are numbers (e.g. that there is a number between 1 and 3) and that no amount of logical analysis is going to make this fact go away26, is to adopt a position of logical intuitionism, which he claims to reject 27 . Similarily, to claim that states of affairs and possible worlds exist necessarily, may merely reflect the "fact" that our ordinary use of language takes such expressions for granted, and that we find it, therefore, difficult to imagine otherwise. The reason Pollock is dissatisfied with modal logic may be that his expectations of what a realist semantics can accomplish are really unrealistic. Most recent theories of counterfactuals are based on the idea that the nearest possible worlds are worlds resulting from minimally altering the actual world in order to accommodate possibilities being true. OUf final standard for doing this, however, remains the actual world and how we take it to be. The novelty in all such theories lies in how they make precise the notion of minimal alteration implicit in the concept of a possible world. The problem is that we have no intuitive standards for such minimal changes anymore
25. ibid. p. 102n. 26. ibid. p. 103. 27. ibid. p. 17.
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than for maximal states of affairs. Pollock emphasizes that in talking about the inclusion of such changes, we should not look at logical compounds (such as P and Q changing each other simultaneously) but at states of affairs that he takes to be logically simple 28 • It should be noted, however, that the whole point of talk in terms of possible worlds is largely its not being logically simple. On the one hand he believes that there are possible worlds that get closer and closer to the actual world without limit, while at the same time he has to admit that such limit assumptions fail for both minimal change and for comparative change. 29 Lewis argues that ordinarily counterfactuals require only a comparison of worlds with a great deal in common (from the standpoint of the worlds of the sort we might inhabit). The advocates of comparability of different worlds have to admit that the ordinary frame of reference of such talk is left underdetermined by linguistic practice and context. Practice and context determine the class of frames each.satisfying comparability, not a single frame that fails to satisfy it 30 • Pollock, by contrast, appeals to what gives intuitively correct truth values for the counterexamples in actual cases 31 ; and the trouble is that such intuitions do not seem to converge. Counterfactual conditionals tell us what would have been the case if something else had been the case, but this does not necessarily enable us to analyze them in terms of the nearest possible world. He takes states of affairs to be the most fundamental causal relation, while admitting that we have quite unclear intuitions about complicated cases of causation. Claiming that whether one state of affairs causes another cannot be relative to a frame of reference 32 , he realizes that causation is relative to the flow of time. We seem unable at this point to give any simple answer to the question of how formal semantics represents the notion of truth in all possible worlds. Likewise, there is no single right answer to what the notion of
28. ibid. p. 116. 29. ibid. p. 133.
30. David Lewis, "Ordering Semantics and Premise Semantics for Counterfactuals," Journal of Philosophical Logic, 10, (1981) pp. 217-234. 31. Pollock, Ope cit. p. 137. 32. ibid. p. 161.
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logical validity is supposed to be. It is apparent that formal semantics and the resulting logical theories can be intended to serve different purposes. A fruitful formulation of our concept of validity proceeds in terms of the interpretation of a language. But while the notion of a form of a proposition or of statement makes literal sense because of their having structure and constituents, we cannot make analogous sense of the notion of a form of a state of affairs or of a possible world. Pollock cannot show equivalent states of affairs to be identical. It is often thought that formal senlantics gives us insight into the logical concepts themselves, or that it provides us with an analysis of logical concepts. This claim is particularly prevalent in connection with possible world semantics. Models are thought of as simultaneously interpreting the language and as providing a possible world in which to evaluate the truth of a proposition, statement, or state of affairs. While the standard view is that models are formal surrogates of possible worlds, Pollock insists that a model should be regarded simultaneously as a formal surrogate and as an interpretation because it takes both to yield the truth value for a formal semantics. Contrary to what it usually claimed, Pollock points out that such relations do not correspond to pairs of possible worlds and interpretations. He rejects models as formal surrogates of possible worlds and insists that they are surrogates for ordered pairs (w,11) of possible worlds and interpretations, or in linguistic logics, for triplets, (w,l1, a)33. It is finally the interpretation that makes a formal semantics philosophically significant.
33. ibid. p. 229.
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CHAPTER VI
HINTIKKA'S GAME THEORETICAL SEMANTICS
Hintikka argues that the most interesting and succesful theories of meaning have been truth-conditional. The paradigm of such theories is usually taken to be Tarski's recursive characterization of truth for certain formal languages. I Davidson has sought to provide a foundation for truth-conditional semantics of the kind proposed by Tarski in the requirement of learnability of the language in question. 2 According to Davidson, theories of meaning for learnable languages are supposed to become so many truth theories for these languages. The mediating link between learnability and the recursive truth theory is what Davidson calls the Frege Principle, which says that the meaning of a complex expression is a function of the meaning of its constituent parts. Linguists know the Frege Principle as the principle of Compositionality. Learnability is supposed to bring us close to the Frege Principle, and the Frege Principle to make possible a Tarski type definition 3 • Hintikka insists, however, that compositionality fails in natural languages in a wide variety of ways. What the learnability requirement really brings about is a theory of truth different from Tarski's, and not subject to compositionality. The crucial step in this argument is the identification of the meanings of component part
1. A. Tarski, Logic, Semantics, Metamathematics, Claredon Press, Oxford 1956, pp. 152-278. 2. D. Davidson, "Theory of Meaning and Learnable Languages," in Y. Bar Hillel (ed.), Logic, Methodology and Philosophy of Science, Proceedings of the 1964 International Congress, North Holland, Amsterdam, 1966, pp. 383-394. 3. Jaakko Hintikka and Jack Kulas, The Game of Language, Reidel, Dordrecht 1983, p. 260.
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e with its contribution to the meanings of the larger complex expressions E in which it can occur. This ary.ounts to a reification of use into meaning. It is largely to safeguard this step that Frege introduced the other principle frequently associated with him, namely that a word or other simple grammatical expression has meaning only in context. Contrary to Davidson, Hintikka concludes that learnability is not sufficient to justify the Frege Principle. Hintikka, therefore, developes an alternative approach which he calls Ganle Theoretical Semantics (GTS), according to which the meaning of a complex expression E is typically analyzed in ternlS of the meanings of certain simple expressions El, E2 ... Ei. But these simpler expressions are obtained from E through certain game rules that are not always themselves parts (constitutive components) of E in any natural sense of the word. Hence, Game Theoretical Semantics violates the invariance thesis. At the same time, however, Hintikka seems to preserve the assumption of parallelism between the syntax and semantics of a natural language. 4 He believes that such parallelism is our best bet to approximate Tarski-type truth conditions. Hintikka shows how the English quantifier "allY" interacts with its context, and why we can expect to find counterexamples to cOlnpositionality in such contexts. Their explicit treatment depends on one's theory of anaphora. In a natural language, quantifier scopes extend arbitrarily far, and tend to branch instead of being hierarchically ordered. The most persuasive examples of branching 'quantifiers in natural languages deal with so called nonstandard quantifier words ("many," "few," "most," etc.) as distinguished from logicians' standard quantifiers (the existential and universal quantifier). It is significant that the counterexamples to the Frege Principle cover some of the most interesting and pervasive semantical phenomena. Hintikka emphasizes that the difficulties of translating natural languages into quantificational notation are much greater than most contemporary logicians and linguists realize. The failure of compositionality means that there are a large number of sentences in natural languages like English, for which no Tarski-type recursive characterization is possible. 4. ibid. p. 264.
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The paradigm problem for Game Theoretical Semantics is the treatment of quantifiers, primarily logicians' existential _and universal quantifiers. Hintikka argues thaNhe most natural way to make this terminology explicit is to envisage each choice of the value of an existentially bound variable to be my own move in a game, and each choice of the value of a universally bound variable a move in the same game by an imaginary opponent. The basic idea of Game Theoretical Semantics is introduced by reference to first order (quantificational) languages. We assume that L is an interpreted language, for otherwise we cannot meaningfully speak of the truth or falsity of its semantics. A two-person, zero-sum game, G(S), is associated with each well-formed sentence, S, of my language L. Hintikka calls the two players Myself (or I) and Nature. These games can be brought to bear on semantics by showing how they can be used to define the crucial concept of truth. GTS is truth-conditional, even though it works in a way different from Tarski-type theories. 5 The truth of a sentence S of L is defined by Hintikka as the existence of a winning strategy G(S) for Myself, i.e. a way of choosing my moves such that I end up winning no matter what Nature does. Falsity means that there is such a strategy for my opponent, Nature. The law of the excluded middle expresses the conviction that either one of us has a winning strategy. It is, of course, not a forgone conclusion that there should be a winning strategy for either one of the players in a zerosum, two-person game. Only where one exists can the game said to be determinate. Hintikka thinks of the players' strategies as being formed move by move and not once and for all. Classical logic presupposes that semantical games are characterized by perfect information. This assumption has to be modified, however, in the case of quantifier rules, and the result is a new kind of logic that has been independently studied: the logic of finite, partially ordered (e.g. branching) quantifiers. The usual Tarski-type truth definitions do not work in the case of partially ordered quantifiers. 6
5. ibid. p. 4. 6. ibid. p. 7.
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Since Hintikka's game rules are rules of semantical analysis, he cannot define truth recursively from the bottom up, as Tarski does, for there is no bottom on whi~h to build such a definition. This is no obstacle, however, to game theoretical truth definitions because it leaves open possibilities for setting up the definition of winning and losing (or neither) of such a game. However, the informative sets involved may not always be ordered transitively by class inclusion, and thus even branching structures may not suffice for many of such sentences. At each of the games, some sentence S' is being considered, on which the player's next move depends. Some primitive vocabulary is assumed to be given and itlterpreted, but contrary to Hintikka, the domain is not given 7 and turns out to be problematic, as we shall see. In formal languages, the sentence reached at a certain stage of a ganle always determines what happens next, while in natural languages, by contrast, several different rules may apply to the same sentence. The general ordering principles depend only on the syntactical structure ~f the sentence to which the rules are to be supplied, and the crucial issue in formulating general ordering principles concerns the way syntactical structure governs rule ordering. Hintikka's ordering conventions admit exceptions;8 they are considered approximations, which may be overruled by special conventions. A difference between formal and natural languages is that in the former the scope of each quantifier is indicated explicitly. In natural languages, on the other hand, the sort of ranges that belong to different quantifiers have to be gathered from diverse syntactical as well as semantical clues. Thus, some of our semantical rules apply much more widely than merely to well-formed (acceptable) strings of English words. Hintikka's GTS recognizes that syntactical wellformedness and semantical interpretability frequently do not go together, yet he nevertheless assumes a general parallelism between them. Since the set of acceptable English sentences is not recursively enumerable, it cannot be generated by grammar alone. In the opinion of Hintikka, this shows the limitations of Chomsky's generative grammar as a universal explanation of acceptability in
7. ibid. p. 11. 8. ibid. p. 29, n33.
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a striking fashion. While Chomsky has tried to shrug off such results as turning merely on various "imperfections" of natural languages, Hintikka insists that the absence of scope indicators implies that natural language discourse carfhot always be analyzed into components with notable meanings. That is why Hintikka rejects the Principle of Composionality (the Frege Principle) in the semantics of natural languages. Compositionality presupposes the kind of semantical context independence that would enable us to carry out the semantic analysis of a sentence from the inside out. Since the game rules of GTS operate from the outside in, they allow us to account for these context differences that violate compositionality. Among the approaches that rely on compositionality are Tarski-type truth definitions or so-called T-schema. Hintikka points out, however, that such approaches are unsatisfactory because they fail to account for bral1ching quantifiers. In formal languages there are, as Frege and Russell emphasized, at least four different counterparts to "is" in English. They include (1) the "is" of identity, exemplified by "Sue's brother is Jack," and formalized by" = "; (2) the 'is' of predication (the copula), exemplified by "Sue is blonde," and formalized by predicate juxtaposition; (3) the "is" of existence, exemplified by "There is money in the till," and formalized by the existential quantifier; (4) the "is" of general explication (or class inclusion), exemplified by "A whale is a mammal," and formalized in this example by (x) (x is a whale therefore x is a mammal).9 The Frege Russell ambiguity claim of "is" is codified in the usual formalism of first-order languages, and in this formalism the four a~legedly different senses of "is" are expressed in entirely different ways. Hence, all those who are using such first-order languages (quantification theory) as their framework of semantical representation are committed to the Frege - Russell ambiguity claim. This includes such diverse philosophers and linguists as Quine, Davidson and Chomsky. Hintikka nevertheless insists that the most central concepts of semantics - ambiguity and synonymy - turn out to be relative to a preferred framework of semantical representation. In
9. ibid. p. 15.
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GTS, too, distinctions have to be made between different kinds of primitive sentences containing "is." But such differences are not due to different meanings of 'is,' but to the diverse contexts in which it occurs. The importance that Russell ascribes to the different meanings of "is" can be realized in his Our Knowledge of the External World (1914) where it is introduced as the first serious advance in real logic since the time of the Greeks. This distinction is for Russell not just a 'feature of his notation but reflects important semantical and ontological differences. As a result of the formulation of Russell and Peano, and even to a greater extent through the notation of the Principia by Russell and Whitehead, this emphasis on the different meanings of "is" becomes a central part of contemporary first-order logic. Hintikka, on the other hand, rejects the distinction between the various meanings of "is" on the basis of his Game Theoretical Semantics. His game theoretical rules are said to correspond to recursive classes of a Tarski-type definition. The information a player has, or does not have, is seen by Hintikka as part of the specification of the situation. The problem is that such choices based on incomplete information do not always determine the course of a game, as Hintikka claims. 10 They may not be able to specify what it means for Myself or for Nature to win the semantical game because the game rules apply to sentences where truth values are subject to conflicting interpretations. It is thus questionable w11ether Hintikka can legitimately claim the benefit of the doubt, Le. that his conclusions are valid as soon as it is admitted that Game Theoretical Semantics is a possible framework, even if it is not the orl1y one. For what he claims to have established is not the incorrectness of Frege's multiplicitly of meanings of "is," but its idiosyncracy. Hintikka emphasizes that his Game Theoretical Semantics is much closer to traditional theories of logic than is Frege's notation. Many of the older treatments of "is" and its synonym go back ultimately to Aristotle, who in effect considered the difference between "=" and the copula to be an instance of his own distinction between essential and accidental predication, respectively. The most natural treatment of the traditional
10. ibid. p. 163.
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syllogism takes the form of some sort of calculus of equations of both identities and nonidentities between quantifier phrases. But the task of developing an account of syllogism along equational lines is impeded by the generic uses of some quantifier words in English, such as "any". Hintikka follows Kant in demanding that our ways of reasoning about existence be grounded in the human activities through which we come to know the existence of such individuals. But he thinks that Kant mistakenly located these activities in sense perception, and that in so doing, was following a tradition dating back to Aristotle. Hintikka points out that it is only in rare cases that we can wait until the· relevant individuals prove their existence by showing up in our passive sense perception. Since normally we do not look for them, the true basis of the logic of existence and universality lies in the human activities of seeking and finding Wittgenstein's "language games" - not in the structure of our sense perceptions. 11 Logical and mathematical inferences do not reflect the structure of our internal end external senses, as Kant mistakenly claimed, but the structure of our language games of seeking and finding. Such games, conceived against Nature, are Hintikka's model of semantical investigation. His basic idea is to focus on the activities through which we come to know the relevant propositions. These propositions are the ones studied in quantification theory, and the activities in question are our processes of verifying such propositions. What emerges is a modernized version of Aristotle's doctrine of categories. Aristotelian scholars have found the combination of different ideas in Aristotle's categories puzzling and some have argued that Aristotle's theory is based on the structures of the Geek language. Hintikka, in effect, aClJepts such an interpretation and extends it to natural languagt~' inV4 general. He rejects the Fregean version of logical type, wich has been central to modern mathematics and logic. But he admits that the individuals over wich quantifiers range can no longer be taken for granted. Thus, in Hintikka's Game Theoretical Semantics these verification processes are conceptualized as games against a recalcitrant
11. ibid. p. 33.
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Nature that tries to frustrate my attempts. 12 But this amounts to identifying Nature with a Cartesian "malignant demon,"13 and under such conditions Hintikka's semantical game is not winnable in principle, Le. it is a game no longer worth playing. To ascribe to Nature deliberate intentions to deceive us is a form of animism. The language Hintikka proposes cannot provide a foundation for the kind of semantics he is advocating because it remains an interlinguistic activity, it does not create or maintain the links between language and reality. He lacks a theory of concept formation that justifies his Game Theoretical Selnantics as a zero-sum, twoperson game. Strategies are determined by the features that tell the players how to move, given the earlier history of the game. If these theories are to be usable, they must be recursive, and Hintikka fails to show that they are. Following such a nonrecursive strategy amounts to having one's move not really determined at all. There are features in natural language semantics that have no counterpart in the semantics of the conventional formal languages, e.g. anaphora. Hintikka's treatment of the role of pronomial anaphora is admittedly incomplete, however. 14 By proceeding in his semantical analysis from the outside in, he has a more manageable translation problem than either Frege or Russell. But the price of such gain is a fatal weakening of the decision procedures of his semantical game. By making his negation rules more context sensitive, they lose logical bite. There are no exceptionless negation forming rules for all English sentences. To have something that amounts to a game, Hintikka has to assunle that the semantics of a natural language parallels its syntax, There is indeed a temptation to interpret the semantical equations of negation as a simple syntactical operation, and cases where such an interpretation is not possible are easily considered as deviant. 15. But in a natural language, such incomplete specification of negation rules do not amount to a parallelism of syntax and semantics, unless we assume
12. ibid. p. 34. 13. R. Descartes, Meditations I, Everyman's Library, London 1957, p.84. 14. Hintikka, Ope cit. p. viii. 15. ibid. p. 96.
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some sort of generative grammar in the manner of Chomsky and this is rejected by Hintikka. He in fact enlphasizes how differently negation is treated in formal anct natural languages. But if the negation rules by which he is playing his semantical game cannot be made explicit, the whole point of Game Theoretical Semantics becomes questionable. It has often been argued that natural languages are not logical because the rules that govern them are ambiguous anct admit of many exceptions. The applicability of semantical game rules ctepend on factors that are not purely syntactical. Hintikka's game rules leave open the question what player (Myself or Nature) is to make the next move because he claims that 'this is how our language works."16 The question then becomes what kind of game we are actually playing uncter such conditions. To ensure communication, Hintikka insists that Occam's razor applies to the kind of entities he assumes to exist,17 even when they become partly indeterminate. But it then becomes impossible to minimize the number of entities (or interpretations) of a given fragment of natural language discourse. Once Tarski's inside out procedure has been given up, standards of simplicity become blurred. The idea of logical form was introduced for the very purpose of uncovering, underneath the multiplicity of various grammatical forms, a unique structure that correctly displays 'the meaning of a sentence. For Hintikka, however, so-called logical form is merely a reflection of the semantical properties of sentences on the syntactical level. If these properties are conceptualized in a different way, our ideas of logical form will change correspondingly. At the same time, Hintikka emphasizes that his game theoretical treatment is closer to the intuitions of the man in the street, who would never say that "is" is ambiguous. He concludes that people's alleged intuitions reflect some semantical theory tacitly presupposed. He also emphasizes how easily affected, and, therefore, how frequently nlisleading, our so-called intuitions are. 18 In order to appreciate
16. ibid. p. 115. 17. ibid. p. 124. 18. ibid. p. 199, n39.
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the semantics of a word, or any other primitive expression, we should study its function in the rule-governed human activities that serve to connect the language with the world. In this sense, Game Theoretical Semantics claims to be an extension of Wittgenstein's language games, but a different kind of language would inevitably require different semantical game rules as well. Unlike Wittgenstein, Hintikka does not play his semantical game on the assumption that our language is "in order" because it reflects a certain life form. Our information about Nature, or lack of it, inevitably reflects the way we conceptualize a given scientific or philosophical problem. In languages with infinitely deep logics, i.e. languages where atomic sentences cannot be reached by a finite number of analytical steps, we cannot be said to know what kind of strategy to adopt. We simply no longer may be able to make any sense of the issue, and become unable to decide what our next step should be. Since the rules of such a game rapidly become uncertain and ineffective, it is only to a limited degree that partial information can be handled by a semantics of branching (partially ordered) quantifiers. 19 The language to which Hintikka's game rules apply is a formalized version of English, and in this manner the problenl of translating English into game theoretical notation crops up again. Such a version is closer to the surface forms of English than the usual canonical notations of logical symbolism,20 but the price for this is an increased complexity'and loss of applicability of the game rules. The behavior of "is" in Game Theoretical Semantics is seen by Hintikka to be merely a function of its status as an auxiliary in grammar. But English grammar is not directly formalizable because it is not recursive. If the primitives of such a model are taken as those of Eglish, and the expressions have the same surface form as those of a class of English expressions, the formal properties become unmanageable (as they are in Aristotle). The viability of Hintikka's model depends on the conceptual question of how precisely the limits of language are drawn. He treats the metalogical and metasemantical parts of English separately,
19. ibid. p. 203. 20. ibid. p. 204.
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while at the same time assuming a pre-established harmony between them. It was Tarski who realized that no coherent truth definition is possible for a natural language in its entirety, whereas Hintikka proposes a hierarchical structure as the basis for his semantical analysis of natural languages. 21 The trouble is that he cannot draw in natural languages a consistent demarcation line between the object language and the metalanguage anymore than Tarski. In the many-sorted logic Hintikka proposes for this purpose, the relationship between first-order logic (quantification theory) and the required higher order logics becomes itself manysorted, and, therefore, undecidable. He is thus unable, by means of his Game Theoretical Semantics, to capture the complexity of an actual natural language, anymore than Aristotle did by categories. What seems to be emerging as a consequence of Hintikka's assumptions is a modernized version of Aristotle's doctrine of categories. But Aristotle's scheme of a finite number of fixed, coordinated categories, largely because it fails to account adequately for change, is an inadequate model for a natural language. It was primarily the logic of relations and functions that led logicians to abandon Aristotelian categories. As Hintikka hin1self recognizes, it is not accidental that Aristotle found it difficult to accommodate cl1ange, and that the overthrow of his philosophy began with the analysis of motion. 22 This is where Frege and Russell have an edge over Hintikka.
21. ibid. p. 215. 22. ibid. p. 227.
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CHAPTER VII
KELLEY'S PERCEPTUAL· REALISM
Kelley maintains that in perception we directly are aware of physical objects and their properties, and that perceptual judgments are therefore self-evident. The integrative process that produces a percept is automatic; it is a preconceptual mode of direct awareness of physical objects. Thus, it provides adequate evidence or justification for our beliefs about these objects, even though such evidence is not propositional. He rejects the prevalent assumption that a belief can be justified only by another belief, judgment or other propositional state. The closest position to common sense about the nature of sense perception and its objects is realism 1. Realism holds that we perceive physical objects directly existing independently of the nlind, and that the senses are an open window in a world that is what it seems to be. But Kelley realizes that since Descartes realism has been a poor third (after idealism and representationalism) in terms of popularity among philosophers, and that most of them have accepted the philosophy of consciousness in some form. Trutll for Descartes consists in the correspondence between the ideas in the mind and the external objects , they represent. Only God's warranty provides an external link between ideas and their ultimate objects. The idealists of the nineteenth century relativized such forms of perception (e.g. the Kantian categories) and considered them as products of historical circumstances, pragmatic convenience or linguistic practice. Kelley points out, however, that if the objects of knowledge depend on the subject, the truth (if one retains that concept at all) must be
1. David Kelley, The Evidence of the Senses, A Realist Theory of Perception, Louisiana State University, Baton Rouge and London 1986, p. 2.
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something other than correspondence, and that idealists typically prefer some form of coherence theory of justification. Representationalists assumed that consciousness is metaphysically alltonomous, and that our mental life could go on exactly as it does even if there were no external reality. His thesis on the primacy of existence, on the other hand, emphasizes that however active consciousness may be in processing information, the mind can only work on information derived from its response to objects outside it. He denies that consciousness is in any sense an autonomous realm of inner content. Awareness essentially is directed toward external objects, and there is no way to have knowledge of consciousness before one has knowledge of the world. Kelley points out that a consciousness conscious of nothing but itself is a contradiction in terms, since before it could identify itself as something it has to be conscious of something 2 • He has to admit, however, that there is no way to prove realism, Le. to show that the objects of awareness exist independently of consciousness. The primacy of existence is not a conclusion but serves as an axiomatic foundation for any inquiry into the nature and function of our cognitive capacities 3 • All Kelley can really show is that it is possible to describe and explain the world in terms of the assumption of real objects. It is not possible to refute realism, but by the same token it is impossible to refute idealism or representationalism either. While the statement "the world is real" is presumed to be self-evident by Kelley 4, everything here depends on what he means by "real." As he himself recognizes, all that he claims for the primacy of existence also can be said about Descartes' cogito. It is one thing to argue that awareness is epistemologically relational, and quite another to draw conclusions from this about the nature of reality. The identity we ascribe to things we experience may be supplied by our language and social conventions. Whether something is taken to be an entity, a process or a relation depends on context and purpose. The idealist's claim that the objects of awareness depend on consciousness, or the
2. ibid. p. 29. 3. ibid. p. 30. 4. ibidem.
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skeptic's worry that they might so depend, are not any less intelligible than is Kelley's contention that reality exists "out there" independently of consciousness. There is no clear-cut phenomenological distinction to be drawn between what is real and what is not. What it makes sense to say depends on what is taken to be real, and vice versa. We know consciousness primarily from the inside as its subjects, and from this perspective our awareness of an object seems transparant. Unaware as we are of the way our cognitive faculties operate to produce our awareness, it seems as if nothing but the object itself determines the way we grasp it, the way it appears. It is the possibility of error that forces us to distinguish between appearance and reality. To preserve the primacy of existence, realists traditionally have resisted the facts of perceptual relativity. Idealists take the failure of this approach as a proof for the primacy fo consciousness, holding that consciousness creates its own contents. Kelley points out, however, that to do this they must step outside the confines of their theory to observe how consciousness operates behind the scenes. But by the same token, Kelley himself cannot know how reality operates behind the scenes anymore than the idealist can know this ab01Jt consciousness or the representationalist about representations. In defining awareness as relational he essentially attempts to sidestep the epistemological issue and this is why he cannot provide a theory of conceptual knowledge. He claims that to perceive an object is to discriminate it from other objects, to isolate its background as a unit, a distinct wholes. All this, however, may be due to mind or language, and to say that it is due to the "nature of things" is not really to offer an explanation at all. There can be little doubt that human perception is shaped at every turn not only by our physiological perceptual capacities but also by social and linguistic conventions. Kelley isn't able even to provide genuine examples of sensations as such 6 because sensations and perceptions are not phenomenologically different; they are merely diverse modes of describing and explaining what we experience. Entities are not given once and for all but
5. ibid. p. 45. 6. ibid. p. 47.
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change with our theories and terminology. What we are aware of is largely irrelevant to what we take to be real as we progress from common sense to scientific knowledge. This is why realism became increasingly discredited with the invention of powerful and sophisticated scientific instruments. In modern science, what is or is not real can no longer be settled by an appeal to common sense conventions. There is no way to separate interpretation from discrimination, since perceptual capacities invariably are integrated with other cognitive skills so that seemingly direct observations already contain some interpretative elements. Kelley has to admit that nothing we discover about the process could in itself show that personal awareness is indirect 7 • But by making the findings of perception irrefutable, he renders them altogether unscientific and ultimately incomprehensible from an experiental perspective. That is, of course, why the phenomenological grounds of perception are in dispute. Kelley denies that the relativity· of appearances can ever place the existence of an object in doubt, but he cannot tell us what the constancy conditions for an object are, or how illusions come about. Thus, nothing is either obviously normal or obviously real. The kind of phenomenalism he advocates would rightly have been rejected by Husserl as a species of dogmatic metaphysics. Claiming that when we perceive an object, it is the object itself that appears, Kelley reintroduces the diaphanous model of knowledge at the conceptual level once again. The metaphysical issues between idealism, representationalism, and realism cannot in any case be settled merely by epistemological arguments because such different theories of knowledge finally proceed from different assumptions. Normal perception cannot guarantee realism because what is taken to be normal is as controversial as what is taken to be real. The actual shape of an object can, therefore, never be known merely by inspection. Different forms of perception make different axes of similarity accessible at the perceptual level, so that perceivers with different sense organs will form different concepts and classify objects in different ways. They can, therefore, no longer be said to
7. ibid. p. 69.
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deal with the same "objective" reality in Kelley's sense. He likewise cannot show that "consciousness has no identity of its own" because such a statement lacks experiential significance. He claims to reject the naive realism that regards perception as the awareness of what exists independently of the perceivers, but by failing to provide a theory of conceptual knowledge he, in effect, retreats to some such position. Kelley simply postulates that it is the object that appears, the object we discriminate by means of its appearance 9 • However, that the subject may not be aware of the means by which he perceives the object may well be altogether irrelevant to the metaphysical issues connected with realism. Thus, he himself repeats the attempt to step out from behind our senses to see the world diaphanously, as it really is, and how it looks apart from any effect it might have on us. While he criticizes this attitude as the basic mistake of idealism and representationalism, his own kind of realism implicitly uses a diaphanous model to explain the conceptual level of knowledge. That colors do not exist as objects apart from us has been a common view since the Renaissance. This was formulated in Locke's distinction between primary and secondary qualities, and it is probably still shared by a majority of scientists and philosophers. Kelley on the other hand denies that color is in the mind because as with other relational properties, there is no reason to locate them at all 10 • But by the same token, if awareness is inherently a relational property, there would be no need to postulate realism to begin with. We cannot step out from behind our concepts anymore than from behind our percepts (or awareness) to determine how the world really is. Kelley thus cannot establish that we perceive the real shape of objects as quite similar to their apparent shapes, or that "objects are the way they appear in all respects." 11 Arguing in this manner he faces considerable difficulties in explaining how imagination, dreams, and hallucinations come about. According to his realist view, that of which we are directly aware of is the ex-
8. ibid. p. 104. 9. ibid. p. 108. 10. ibid. p. 110. 11. ibid. p. 119.
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ternal object itself. But this begs the question of what relation obtains between experience and its external object and turns the act of perception into a complete mysfery. Kelley's realism fails to account for the causal sequence of perception, Le. that in the case of seeing distant galaxies it may take millions of years for their light to reach us. This refutes the realist claim that we see things as they really are, because the things we see may no longer exist. Something is present to my perceptual awareness now, but it cannot be the galaxy because that galaxy may have disintegrated long ago. Modern science has largely discredited what Kelley takes to be normal experience and the kind of reality postulated by it. While he rejects a linguistic analysis of metaphysical issues, his own major argument in favor of realism is derived from the logic of conceptual justification. He argues that the claim that hallucinated objects are not real can only be understood and justified by contrast with the assumption that the objects of perception are real 12 • Yet Kelley himself admits that we can create new quasi-perceptual scenes in imagination, recognizing sensory materials from past perceptions, and experience them as more or less vivid images of things, as they might be or might have been 13 • Being real is thus a matter of degree and context. Olle is not always aware in imagination of making it up since the process of imagination routinely makes use of materials from past perception of objects whose reality may be in doubt. How the ways an object appears depend on the object itself is consequently left unexplained by Kelley. Neither is he successful in showing that what is perceived depends on what is there to be perceived 14 • What is real thus becomes a mystery. That our survival as a species proves the real existence of the environment we adjust to is likewise not a convincing argument because such adjustment remains forever incomplete. Indeed, there can be no local argument in favor of realism, and no particular perceptual phenomenon can in itself justify the realist model (or refute it, for that matter). All such phenomena presup-
12. ibid. p. 135. 13. ibid. p. 137. 14. ibid. p. 141.
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pose an interpretation that has already settled the issue of realism one way or another. Thus, Kelley regards the mind as a faculty for "grasping reality," yet this metaphor raises far more questions than he is able to answer. We may regard awareness as a relation, a process, or as an entity depending on text and purpose, and there is no intelligible answer to the question of what awareness "inherently" is. Neither idealism nor representationalism can be refuted by Kelley merely by the device of rejecting the diaphanous model of perception. He himself admits that we bring to perception an enormous amount of background knowledge l S but fails to realize that this effectively prevents him from isolating perceptions in the required manner. The history of what a person attends to affects what it is possible for him to perceive. A scientist and a layman may look at the same laboratory setup but the scientist will perceive much more than does the layman. Kelley declares attention to be noninterpretative l6 , an incorrigible intuition into what is real. But this is much less plausible than is the diaphanous model of knowledge. He claims that when one perceives an object, one's awareness of it does not depend on knowing its relation to other objects or facts 17. Yet supposedly isolated perceptions of this kind invariably are contaminated by background knowledge, and consequently no perception can be detached effectively from its context and purpose. What Kelley considers to be the direction of perception is the product of a sophisticated skill of abstraction due largely to language acquisition and the mastering of relevant concepts. This is how the child learns deliberately to concentrate on one object and ignore its background and context. It is this conceptual skill that enables Kelley to focus on entities and on what he takes to be essential. But having mastered it, we may focus equally on attributes, relationships or processes, and then we will regard entities as mere "snapshots" of such projections. Kelley has to admit that our awareness of entities is by no means uniformly clear and discriminatory, and that there are alternative ways of describing and explaining phenomena. It is thus our focus of attention
15. ibid. p. 147. 16. ibid. p. 149. 17. ibid. p. 150.
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that determines the relevant context, i.e. what is real, and not the other way round. There is no direct perception of features of entities as such. Kelley simply expects us to accept his version of "cognitive integration" without argument. His realism amounts to a decision to describe the world in a certain manner. But this manner is not mandatory, for idealism and representationalism remain as irrefutable as admittedly is realism. The substance-attribute relationship is not a product of sensory stimulation but a joint product of our senses and our concepts. Kelley appeals to common sense in denying that conceptual organization is due to language, and insists that the perception of things as things is given directly18. However, since the question about the nature of reality is not a common sense question, it naturally enough does not admit a common sense answer. What counts as an entity depends on what substance and sortal concept we have in mind. Since there are no discoverable units for what is possible, all awareness requires conceptual orgal1ization of some sort. This is very obvious in speech perception where the ability to pick out individual words from the optical or auditory array depends on and develops with an understanding of what the words mean. How we pick out units from the background very much depends on what we are looking for, and on what we intend to do. A prelinguistic awareness is unable to identify objects, and facts do not exist prior to being stated in language. That space must have three dimensions is taken for granted by common sense but this has to be revised when we deal with very small or very large objects. Different dimensions permit us to talk about different types or patterns of similarities, and thus of objects we would not perceive otherwise. It also permits us to detect the existence of novel sorts of lawful behavior. Such open-ended concepts alert us to the existence of other as yet unknown objects and facts. Apart from the conceptual framework, no entities of any kind can be said to be given in any absolute sense. Since our language is underdetermined by experience, our awareness of identity is not sharp, and there is often more than just one way to make sense of a statement. Kelley is not anymore successful than Descartes was in in-
18. ibid. p. 167.
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tegrating his internal and external perspectives of consciousness, and so he decides that it lacks identity. But in this manner he fails to provide answers to most of the traditioJlal concerns of justification of perceptual judgments. If we directly perceive external objects and sense their attributes as he claims, realism should be selfevident. Since this is clearly not the case, coherence theories hold that basic knowledge of this sort is neither possible nor necessary. It is not possible because any judgment can only be justified in the context of a conceptual framework, and it is not necessary because the real unit of justification is the context of the conceptual network itself. Kelley's claim that phenomenological knowledge is epistemologically prior to conceptual judgment is a species of discredited foundationalism. While rejecting a linguistic approach to these issues, his argument in favor of the priority of perception is based on the asymmetry in the logic of justification 19. He clain1s that in order to designate anything as "unreal," we have first to assume that some things are real. However, given the inherent ambiguity in designating anything as "real," suc11 an argument doesn't carry much force. What is taken to be real in one context may well turn out to be unreal in another context, and nothing is real under all conceivable circun1stances. Thus, from the way something appears to us, very little can be known about how it really is. Kelley's attempt to define what is real by reference to "normal" vision, therefore, begs the question. ·There are indeed good reasons for the prevalent view that knowledge does not have nor does it need incorrigible foundations. Such diverse thinkers as Wittgenstein, Quine, and Rorty agree that questions of justification, evidence, and truth arise only within Ollr conceptual scheme itself. The scheme is a social product, instilled in us chiefly through the process of learning a language. Objectivity consists not in any relation of correspondence between our judgments and the world independently of them, but rather in a relation of coherence among our judgments. The standards of coherence and of objectivity are set by the scheme itself. In spite of his proclaimed realism, Kelley conducts his conceptual analysis in terms of ideas, judgments, and
19. ibid. p. 182.
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conscious states. He rejects materialist and behaviorist views of the mind because they lead in his view ~to a reduction of the mind to pieces of linguistic behavior 20 • But while he regards the world as a framework of objects in terms of which we pursue our investigations, this can only mean that it is the set of things posited by theories not in question at tIle moment 21 • We cannot step out from behind our theories to achieve a diaphanous view of reality. Quine has shown that there is no way to establish the relation between any terms and items outside language altogether. It makes sense to apply' 'true" only to a sentence couched in terms of a given theory and seen from within the theory complete with its posited reality 22. Even Kelley has to admit that questions of justification, meaning, knowledge, and truth arise only where our utterances are seen as actions within a social practice governed by rules 23 • An utterance can be evaluated cognitively as meaningful and justified only by reference to the rules legislated by practice. The rules themselves have no basis in reality beyond the fact that the practice does legislate them. Outside human thought and speech there are no independent objective points of support, and meaning as· well as necessity are preserved only in the linguistic practices which embody them. There is no independent objective basis that will justifiy logical inference, and the only possible justification of it is that this is how people think and speak. Each mode of human thought is accepted on its own terms and justified by its own internal standards 24 • There is no way to get outside our beliefs and our language so as to find some test other than coherence. All such rules of justification are thus social, unstable, and pragmatic. As Rorty n1akes clear, all that language acquisition does is to let us enter a community where members exchange justifications of assertions and other actions with one another. What has happened is a shift inside the person, which now enables him to enter new
20. ibid. p. 186. 21. ibid. p. 188.
22. W.O. Quine, Word and Object, Cambridge, Mass. 1960, p. 24. 23. Kelley, Ope cit. p. 190. 24. David Pears. L. Wittgenstein, New York, 1970, pp. 179, 183, 184.
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relations 25 • Kelley points out, however, that these writers find it difficult to explain progress in science. Some have argued that although truth and justification are relative to conceptual schemes, there is nevertheless some sense in which our conceptual scheme is preferable to that of our predecessors and in which that of our successors will be preferable to our own. They thus implicitly take it for granted that conceptual schemes progress in the direction of greater adequacy to reality. Yet if there is no way for idealists to step outside our theories of the world to see their connection with the world itself, as Rorty maintains, there is, for the same reason, no way to step outside and see their relation to a transcendental knower. Kelley argues that, without assuming the primacy of existence, we cannot account for progress in any objective manner. Thus, on the one hand, he admits that any simple-minded realist theory that treats our knowledge as a mirror of reality can easily be shown to be false. On the other hand, he nevertheless insists that the conceptual identification of perceived objects as being of certain types or possessing certain properties is based directly on the perception of the objects themselves. While holding that perceptual awareness is direct, Kelley distinguishes it from conceptual awareness, and part of what he means by this is that it is not propositional in form, and that it does not involve the predication of the subject 26 • His realism, therefore, proceeds on the assumption of a nonverbal grasp of reality. But since justification takes place only at the propositional level of knowledge, perception, as Kelley understands it, cannot be a source of justification. Any answer to a request for justification has to be a statement, while no statement can in prin- . ciple justify realism. Kelley has to assume that basic noninferential knowledge is self-justificatory, and the very notion of such selfevident axiomatic truth has been exploded in modern non-Euclidean geometry and in non-Aristotelian logic. His phenomenological judgments, by contrast, claim self-justification and, therefore, infallibility 27, and they run thus counter to very deeply 25. R. Rorty, Philosophy and the Mirror of Nature, Princeton 1979, pp. 185, 187.
26. Kelley, op. cit. p. 197. 27. ibid. p. 199.
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entrenched trends in modern science. Kelley admits that the concept of justification requires that what justifies a statement must be something in the cognitive realm. Thus a noncognitive fact may be the object of some sort of knowledge but it cannot itself serve to justify. The mere rejection of the diaphanous model of perception, therefore, does not as such vindicate realism. Indeed, while repudiating the diaphanous model on the perceptual level, he in effect reintroduces it at the conceptual level of knowledge. At the same time he admits that he lacks a theory of knowledge to substantiate realism. His "synthetic" view of awareness is but a version of the idealist "spectator" or "mental eye" model of knowledge. Awareness is inevitably judgmental if it identifies knowledge with some sort of seeing, or as Kelley has it, as being inherently the relation to an object 28 • It should thus be possible to form a single judgment standing alone as an isolated cognition. Indeed, a world standing independently from us does not require any synthesizing on our part. Kelley has no theory of conceptual knowledge because he cannot explain why concepts are necessary for understanding reality in the first place. His notion of a nonpropositional and noninferential mode of justification 29 is much more problematic than is the diaphanous model of perception. He himself admits that in the absence of an adequate account of conceptual thinking he cannot even address the whole issue of realism. He fails to provide us with a theory of natural kinds, and cannot thus explain how he recognizes features directly and automatically, as he claims 30 • There is no such tIling as labeling an attribute by being directly aware of it, so that it does not require any further explanation. No belief about experimental states is incorrigible, and all phenomenal judgments presuppose some sort of conceptualization. To identify an object as red is to recognize it as possessing the same color in other objects one has seen. But given the existence of other shades of red, the object is at best similar to most of the other red things one has noticed. The recognition of it as red,
28. ibid. p. 205. 29. ibid. p. 207. 30. ibid. p. 220.
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therefore, involves the isolation of a relevant dimension of similarity. What we see depends on what we are able to identify and this, in tllrn, on the range of shades we call red. To be able to discriminate, we need to know what it is in the object that makes it an instance of the relevant attribute, yet what is relevant depends on what we are looking for. Dimensions of similarity change with our interest and perspective. The "nature of things" is what we have grouped together by means of language and social convention, and that is how properties come to be identified. As our theories change, so do also our ideas about what is real. l'lothing can be said a priori to be real, for there is no way to isolate the aspect of content that depends on the perceiver (or the conditions of perception) from those aspects that depend on the nature of the object. There is no privileged form of perception that has the unique capacity to reveal the object as it really is. Reality is inherently unstable because there is no norn1al set of conditions for any concept or sensory quality. Hun1an perception is conditioned not only by its specific physiological faculties but also by our social and linguistic conventions. Changing purposes and shifts in background knowledge result in an unstable environment for what we perceive and take to be real. Contrary to Kelley, perceiving is by no means "child's plaY,"31 and to assume this is to revert to the level of naive realism, which he supposedly rejects. Objects have identities that are not exl1austed by our conceptual knowledge of them, and this is how they can run counter to our expectations. Their coherence remains incomplete as is our evolutionary adaption to any specific environment. This tends to explain why such realist positions largely have been questioned by contemporary philosophers.
31. ibid. p. 244.
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CHAPTER VIII
HACKING'S INSTRUMENTAL REALISM
Hacking emphasizes that experimentation has a life of its own in science, interacting with speculation, calculation, model building, invention and technology. While the speculator, calculator and model builder can be antirealist, the experimenter must be a realist. Electrons become tools whose reality is taken for granted. It is not thinking about the world but changing it that in the end must make us scientific realist'sl. The more we come to understand some of the causal processes of electrons, the more we can build devices that achieve well-understood effects in other parts of nature. By the time we can use the electron to manipulate other parts of nature in a systematic way, the electron has ceased to be something hypothetical, something inferred. It has ceased to be theoretical and has become experimental 2 • The vast majority of experimental physicists are realists about the theoretical entities they use, and Hacking claims that they cannot help doing so. It is, however, questionable whether in the process they dispense with theoretical knowledge, as he claims 3 • To "read" what we see as an ion would seem to presuppose quite a lot of theory embedded in a specific conceptual framework. Thus, contrary to Hacking, the ways in which experimenters are scientific realists about entities is not essentially different from the manner they might be realists about theories. There are a lot of theories, models, approximations, pictures, formalisms, methods, and so on, involving electrons, and
1. Ian Hacking, Representing and Intervening, Cambridge University Press 1983, p. xiv. 2. ibid. p. 262. 3. ibid. p. 263.
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they presuppose shared beliefs that amount to implicitly held theories. Scientific teanlS tend to be forme,p from like-minded people, and there is necessarily some shared theoretical basis to their work. But like Kuhn, Hacking considers this to be a mere sociological fact 4 , while all the same arguing the realists case on just such a basis. Hacking disparages explanation in sciences, yet the fact remains that scientific experiments do not explain themselves. What is implicit in all experimental evidence remains always at least potentially controversial. Although realism and antirealism have been with us since antiquity, our present versions mostly started with debates about atomism at the end of the nineteenth century. Assumptions about the minute structure of matter could not be settled then (as they cannot be settled now), and the only possible proof is thus indirect, i.e. that the hypothesis seems to provide some explanation and helps to make good predictions. Hacking has to admit, however, that such inferences cannot produce conviction in the philosopher inclined to instrumentalism or some other brand of idealism 6 • To argue for scientific realism at the level of theory, testing, explanation, predictive success, and the like, is to be locked into a world of representations. That is why scientific antirealism has never been conclusively refuted. Hacking follows Dewey in attacking antirealism as a variant of the "spectator theory of knowledge."7 Skeptics have always challenged the complacent vision of accumulating human knowledge, but more recently they have taken ammunition from the details of scientific history largely under the influence of Kuhn. It was Kuhn who suggested that "truth" in'science is merely a social product with no claim to universal validity or even relevance. Hacking follows Kuhn and Feyerabend in disparaging the role of reason in science, but he fails in his attempt to isolate questions about what is real from those abollt what is rational. In The Structure of Scientific Revolutions (1962) Kuhn showed that there is no sharp distinction between observation and theory.
4. 5. 6. 7.
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ibid. ibid. ibid. ibid.
p. p. p. p.
264. 271. 273. 274.
Science is not cumulative, and a live science does not have a tight deductive structure. Rather there are lots of disconnected tools for various kinds of inquiry. The science§ are composed of a large number of loosely overlapping little disciplines, many of which in the course of time cannot even comprehend each other. Hacking accepts all this and yet wants to save scientific realism by an appeal to a pretheoretical awareness. According to Feyerabend 8 , there are many rationalities, many styles of reasoning, and also many good modes of life where nothing worth calling reason matters very much. On the other hand, Feyerabend does not preclude the use of any style of reasoning and he certainly has his own 9 • Hacking proposes realism as an alternative to rationalism in science. He agrees with Laudan that theory transitions are as a rule noncumulative. Theories are not usually rejected merely because they have anomalies, nor are they accepted simply because they are empirically confirmed. Changes in and debates about scientific theories often turn on conceptual issues rather than on questions of empirical support. The coexistence of rival theories is the rule rather than the exception 10 • While Hacking denies that we can compare problem-solving capacity, he also thinks that this does not matter much since rationality is of little moment in science anywayl!. What counts according to Hacking is instrumental success,and his notion of reality has more to do with what we do in the world than with what we think about it 12. Yet instrumental success in science is finally not anymore self-explanatory than are representions. We can never know that our present state of knowledge has got things right, or even that we are getting closer to the truth. Hacking claims to be a realist about entities but not about theories, while what entities are accepted as real cannot be isolated from our theoretical knowledge. He is an instrumentalist in his approach to reality, but
8. P.K. Feyerabend, Against Method, London 1977. 9. Hacking, Ope cit. p. 14. 10. L. Laudan, "A Problem Solving Approach to Scientific Progress," in I. Hacking, (ed.) Scientific Revolutions, Oxford 1981, p. 144f. 11. Hacking, Ope cit. p. 15. 12. ibid. p. 17
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he nevertheless insists that a satisfact~ry theoretical entity must be one that actually exists, and not merely one that is a handy intellectual tool. He believes that when we turn from representation to interaction, antirealism has somehow less of a grip, yet what "works" in science in this manner is inevitably also a matter of interpretation. J.L. Austin 13 pointed out that in discussing the word "real" we must not dismiss such Ilumble but familiar phrases as "not real cream." We must not look for one specifiable, always-tIle-same meaning. There need not be different kinds of reality just because the word "real" is used in so many ways. As Hume showed, we never really know why a certain type of event regularly produces an effect. Even when we use events of one kind to produce some effect, such understanding does not reveal to us any knowledge of some inner and necessary connection in reality. Instead, what our sophisticated instruments increasingly show is that the claimed regularities are merely features of the ways in which we C011struct theories in- order to think about phenomena. Hacking consequently is never able to use the word "real" in a way Austin claims is standard. The contrast that the word "real" is supposed to make in science remains problematic and controversial. Because of a new theory and the different context it created, such entities as "phlogiston" and "ether" no longer were considered to be real, and there is no way of knowing that the same might not happen to "electron" one day. The post-Newtonian attitude in science was that we should not seek causes in nature but only regillarities. We should not think of laws of nature as revealing what must happen in the universe but only what does happen. To say that we have found the explanation of an event is only to say that the event can be deduced from a general regularity 1 4 • Recently Van Fraassen convincingly has argued that there is no need to believe that either theories are true or that the entities they postulate are real. Theories are intellectual instruments for speculation and control I 5 • Hacking, on the other hand, downplays the role of explanation in
13. J.L. Austin, Sense and Sensibilia, Oxford 1963, ch. 7. 14. Hacking, Ope cit. p. 47. 15. B. Van Fraassen, The Scientific Image, 1980, p. 12.
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science and emphasizes how it is always relative to what we are interested in. The ground for believing a theory is its predictive success, not its explanatory power '6 • Yet this is not self evident either but requires theoretical justification. While some have argued that science is successful because it is converging on the truth 17, Hacking insists that the phenomenon of growth is at most a monotone increase in knowledge, not a convergence. His realism, however, should suggest otherwise, for not only the history of mathematics clearly reveals a convergence of underlying structure with the accumulation of specific knowledge, but so do the other mature sciences such as physics, chemistry and biology. He does, however, realize that there is a continuity in styles of scientific reasoning, which in fact readmits rationality into the history of science. We have indeed gradually amassed a host of methods, including the geometrical, the postulational, statistical, model building, hypothetico-deductive, genetic, evolutionary and historicist. Our talents of forming roughly the right expectations might be accounted for by the theory of evolution. If we regularly formed the wrong expectations, we would all be dead. This would seem to revive the assumption that we are rational people living in a rational universe after all. Peirce pointed out that what we mean by "real" is a conception that we must first have when we discovered that there was an unreal, an illusion, that is, when we first corrected ourselves 18. Peirce took it for granted that process and the possibility of progress are essential characterists of human knowledge. But while Hacking accepts this Hegelian doctrine, he attempts to reduce it to an instrumentalist level. Whereas Peirce believed that measurement in science converges, and that what it converges upon is true, Hacking, like Kuhn, denies this. Thus, contrary to Peirce, Hacking rejects the idea that inquiry continued long enough will lead to a stable opinion about any issue at hand. This is why he adopts Lakatos's strategy to substitute method for truth in order to save scientific objectivity. Unlike Peirce, Lakatos attends to the variety of scientific practices, and
16. Hacking, op. cit. p. 53. 17. W. Newton Smith, Rationality, 1982. 18. The Philosophy oj Peirce, J. Buchler (ed.) pp. 247f.
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so does not have the simplistic picture of knowledge settling down by a repeated process of trial and error 19 • But Hacking fails to reconcile his proclain1ed realism with his instrumentalism. The immediate challenge for his realism is Kuhn's treatment of science as a historical phenomenon. With each paradigm, Kuhn originally argued, not only do we see the world differently, but we actually come to live in a different world. Thus, we do not converge on the true picture of the world for there is none to be had. There is no progress towards the truth because successive and competing theories, even within the same domain, speak different languages. They cannot be compared strictly to each other or translated into each other. We pass from one world or one language to another by a gestalt switch, not be a process of understanding 20 • Hacking argues against Kuhn that while, for example, J .A. Millikan and Niels Bohr had quite different ideas about the electron, they were nevertheless talking about the same thing. Hacking agrees, however, with Kuhn that radical shifts in theory may turn earlier work unintelligible to a later scientific audience. Thus, an interesting proposition is in general true or false only if there is a style of reasoning that helps one to settle its value 21 • The historian discovers that old texts conceal from us the extent to which they are dissociated from our ways of thinking. "Planet" in Copernican theory does not mean the same as "planet" in Ptolemaic theory, for the sun is a planet for Ptolemy but not for Copernicus. Hacking considers the whole idea of meaning incommensurability incoherent. He admits than astronomy and genetics are incommensurable because they are about different domains. But he argues against Kuhn that competing or successive theories cannot be incommensurable because they would not be competing or successive if we did not recognize them as being about the same objects. Hacking, therefore, concludes that we need an alternative account of meaning, which allows that people holding competing or successive theories still may be talk-
19. Hacking, Ope cit. p. 90. 20. ibid. 21. I. Hacking, "Truth and Reason," in M. Hollis and S. Luke (eds.) Rationality and Relativism, Oxford 1982, pp. 48-66.
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ing about the same thing. But he does admit that meaning incommensurability creates difficulties for his version of scientific realism. The way in which speculation about electrons and experiments on electrons come to mesh is itself a matter of interpretation - and so, of course, is Hacking's defense of scientific realism as a whole. Practice is not anymore self-explanatory than are representation, and what in science (as distinct from common sense experience) is considered a natural kind inevitably is affected by current theory. Putnam riglltly points out that objects do not exist independently of conceptual schemes 22 • Hacking has finally to admit that his doctrine of scientific realism does not amount to a nontrivial general theory of the world. Neither is Hacking successful in his attempt to refute Quine's arguments in favor of the inscrutability of reference which, as Putnam points out, is bad for realism. Hacking simply claims that in order to refer, we need no theory of reference, but this hardly can be considered a philosophically adequate explanation. He agrees with Kuhn that we can never get outside our own system of thought while his own version of realism attempts to bring about something just like this. He realizes that new theories create novel objects and thus a different reality in which our prescientific categories and natural kinds are superseded. Thus, there is no uniquely right organization of any aspect of nature; the categories have changed in the past, and there is no reason to believe that they will not change further in the future. We cannot avoid approaching nature with our present categories, problems, systems of analysis, and evaluative technology. While we may think that we are using natural kinds, some historical reflection reveals that even the entities most acceptable to us may be replaced some day. In admitting that there is no right final representation of the world 23 , Hacking in effect renounces traditional realism. No more than Lakatos is he able to decide what would be reasonable to believe or to do right now in science. His attempts to change the world even when he is not being able to understand it are doomed to
22. H. Putnam, Realism, Truth and History, Cambridge 1982, p. 52. 23. Hacking, Ope cit. p. 110.
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failure because what is real in science is finally decided by hind sight. Hacking is unable to refute Kuhn's contention that knowledge changes by irrational conversions from one paradigm to another. Thus, while accepting Feyerabend's rejection of method, he retains an accumulation of "styles of reasoning" to preserve some sort of underlying historical continuity for science. But this amounts to a mere proliferation of conceptual tools, not a conceptual growth of knowledge or a general theory of truth and reality 24. Hacking agrees with Kuhn that there is no external way to evaluate our own tradition; he foregoes any epistemological justification of his realist ontology, and thus renders it a species of dogmatic philosophy. Rejecting what he takes to be a singleminded obsession with representation, thinking, and theory at the expense of interaction and experiment, he has to admit, however, that his concept of reality if after all a byproduct of a fact about human beings 25 • He thus fails to reconcile his instrumentalism with his scientific realism. While the basis of Hacking's realism is man as the maker of tools 26 , realism is, of course, precisely the doctrine that reality is not manmade. According to Hacking, as man's tools change, so does his reality; yet this is something never open to direct inspection. He argues that what is important in science is not what our theories say but what we do with them; however, these two aspects obviously are not unrelated. We may not always take our theories to be literally true, but when we work with them they have to be true as far as they go. Interaction with theoretical entities and their use inevitably depends on the way they come to be represented. Hacking's notion of reality is a second-order concept that remains parasitic on representation. Since there is no representation without style, Hacking's scientific reality is subject to fashion. It is a generalized notion of likeness, and he claims that we recognize human artifacts as likeness even when we do not know what they are likeness of27 • But this is not a likeness of some specific object
24. 25. 26. 27.
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ibid. ibid. ibid. ibid.
p. p. p. p.
128. 131. 132. 137.
or other and thus is useless for science. There can be in science no reality as such, separate from specific prq,cedures, yet governed by technology. Hacking treats "truth" in science as a metaphysical concept different from particular tradition and method, and achieved by an inarticulated observational skill. But if Feyerabend is right, and there is no rational method anywhere, nothing in science can be said to be real either. Still Hacking is out to refute Kuhn's contention that after a scientific revolution people come to inhabit "different worlds" a view that in the meantime Kuhn himself largely has abandoned. Hacking's realism can be taken as an attempt at a literal refutation of Kuhn's metaphor. This in turn leads Hacking to worry about the "inner constitution of things", which is somehow revealed in practice and is said to exist beyond mere theory and representation. It appears, however, that the study of nature provides us with alternative pictllres, and that neither prediction nor simplicity nor fertility are quite adequate to settle our choices among them. Duhem and Quine, therefore, concluded that there is simply no truth of the matter, while Hacking points out that they thereby fail to explain why some representations are nevertheless better than others. When science became the orthodoxy of the modern world, we were for a while made to believe that there is one truth at which we aim and which is the correct representation of the world. It turned out, however, that alternative representations could finally not be eliminated, and that is why Kuhn takes revolution as his model for science. Hacking, on the other hand, insists that how the world really is becomes something that we cannot fully articulate. Thus, in science there is no final truth, only a knowledge of more or less constructive representations. These are after all our own creations, and what we have made once in the past, we are free to remake or unmake later on. Moreover, reality as interaction did not even begin to mesh with reality as representation until the advent of modern science. It turns out, therefore, that Hacking's model of science is not any less historical than is Kuhn's, and while his realism claims to be derived from pretheoretical observation, it is at the same time supposed to mesh with modern experiment and technology. He admits that experimental work could not exist indepently of theory, yet insists that much fundamental research 109
precedes any relevant theory whatsoever 28 • He does realize, however, that a phenomenon is not noteworthy without some sort of theory. Like Lakatos, he is unable to predict how observation and theory are going to mesh,'iand thus to decide what is going to be acccepted as real in science. He emphasizes that technological inventions proceed at their own practical pace, but fails to see that they become relevant for science only after they mesh with theory. In Hacking's scheme, the role of observation in science is relatively unimportant. Observation is a skill that can be improved by training and practice; it is not merely the philosopher's reporting what one sees. Modern scientists usually observe objects and events by n1eans of instruments, and the things that are "seen" in twentieth-century science seldom can be observed by the unaided human senses 29 • Hacking rejects positivism because the positivist constructs the real to be observable; like Grover Maxwell, he considers the contrast between the observable and the merely theoretical to be vague. It often depends more on technology than on anything in the constitution of the wo.rld. Objects like genes, which once were theoretical, are transformed into observable entities; hence observability does not provide a good way to sort the objects of science into real and nonreal 30 • While Hacking agrees with N.R. Hanson 31 that we notice things only when we have expectations that will n1ake them seem interesting, he rejects the idea that all observation is theory-Ioaded 32 • Popper and Hanson include implicit and partly unconscious assumptions in their definition of theory while Hacking demands that theories be explicitly formulated. That is why he follows Lakatos in rejecting the simplistic form of Popper's falsificationism, which treats the theoryobservation distinction as unproblematic. Hacking emphasizes that there is no simple mechanism by which we propose theories 28. ibid. p. 158. 29. ibid. p. 168. 30. G. Maxwell, "The Ontological Status of Theoretical Entities in the Philosophy of Science," Minnesota Studies in the Philosophy of Science, 3 (1962), pp. 3-27. 31. N .R. Hanson, Patterns of Discovery, Cambridge University Press 1958. 32. Hacking, Ope cit. p. 172.
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and nature disposes of them. Observational propositions cannot be verified merely by looking at the facts, and no factual proposition can be proven directly from experience. Hacking attempts to sidestep that issue by arguing that experimenting is not stating or reporting but "doing". But what we do in science has invariably to be reported and explained, and the way it is reported and explained certainly makes a difference. He wants to reserve the word "theory" to a specific body of knowledge and to propositions with a definite subject matter 33 • However, what goes into a theory and what is merely background knowledge is by no means easy to determine. Hacking himself admits that unconscious expectation and hunches of all sorts playa significant role in discovery, yet he criticizes Feyerabend for using the word "theory" to denote all kinds of implicit or in1puted beliefs. If we call every belief that could be invented "a theory", the claim that beliefs are theory-loaded becomes insignificant. But his claim that important observations in the history of science have included no theoretical assumptions at all is certainly controversial. Thus, he denies that anyone who reports upon looking at a photographic plate, "this is a positron," is thereby employing or asserting a lot of theory 34. There can be little doubt, however, that different theoretical assumptions will make us "read" the same photographic plate quite differently. Indeed, if what we "see" by means of our equipment happens to conflict with our conscious or unconscious theories and expectations, we will as a rule tend to ignore it or explain it away. Hacking rejects what he considers Quine's displacement of observation by observation sentences 35 , but there is no denying that the manner in which we report our observations in science, the terminology or notation we use, do make a crucial difference. Shapere rightly points out that whether or not something is observable depends upon the current state of knowledge. Our views on the workings of receptors or the transmission of information by neutrinos all
33. ibid. p. 175. 34. ibid. p. 179. 35. W.V. Quine, The Roots of Reference, pp. 36-39.
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assume massive amounts of theory 36. For Hacking, on the other hand, it is precisely the diversity of science that allows us to observe, deploying one massive batch of theoretical assumptions to another aspect of nature about which we l1ave an unconnected bunch of ideas 37 • Hacking's argument depends thus crucially on the extent to which different domains of science can be said to be really separate. Inductive and inferential procedures cut across specific domains, and so does after all his own claim in favor of scientific realism. According to Hacking, first we "guess" that there is such and such a gene, and then we develop instruments to let us see it. At the same time he maintains that scientific invention is independent of theoretical development. He rejects the positivist contention that only theory makes us suppose that what the lens reveals is real, arguing that while you need theory to make a microscope, you do not need theory to use one 38 • But in scientific research, the theoretical knowledge of what a microscope can or cannot ~o is an integral part of our skill to use ito Theories about moleclLles are parf of the picture of what our equipment tells us about them. Visible displays will be interpreted differently as theory changes, and some data may be ignored altogether, as Kuhn has shown. What we see through the lens cannot thus be separated from how it is being interpreted. What is taken to be real in modern science crucially depends on specific theoretical assumptions, not mere background knowledge, as Hacking in effect argues. We infer to the best explanation that the theory is true, and the question whether it is true finally cannot be separated from whether the objects it refers to are real. Such entities as phlogiston and ether were abandoned largely because of theoretical and conceptual shifts. Similarly, we became convinced of the existence of genes because they fitted in well with the rest of our biological knowledge. Like Feyerabend, Hacking believes that the best way to maximize phenomena on the one hand, and have the simplest law on the other, is to have
36. D. Shapere, "The Concept of Observation in Science and Philosophy," Philosophy of Science 49 (1982), pp. 231-67. 37. Hacking, Ope cit. p. 183. 38. ibid. p. 191.
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the laws inconsistent with each other 39 • The trouble with this is that an inconsistent theory is useless not only for explanation but also for "changing the world." Thus, in science we are not only making the keys that unlock our knowledge of nature but also the locks in .which they turn. What Hacking calls "the experimenter's triumph"40 is never conclusive because all such data remain open to further interpretation.
39. ibid. p. 219. 40. ibid. p. 258.
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CHAPTER IX
ACKERMANN'S DIALECTICAL INSTRUMENTALISM
In the work of Popper, Kuhn und Lakatos, there is a tendency to Sl:lppose that theoretical attitudes must control the direction of experiment, and that the history of science revolves around these theoretical structures. Ackermann rejects this idea and offers a dialectic of instrumentalism as a model for scientific progress. He argues that the root failure of traditional methodologies was the attempt to trace scientific knowledge to the epistemological activities of the individual scientist. His philosophy of science, therefore, calls for a shift towards a more historical and sociological approach. Scientists are presented with both theories and complex data, and are required to fit the two together. Rationalism in the philosophy of science results when theory is thought primarily to guide data, and empiricism when data are said to determine theory. Ackermann admits that both fornls of guidance occur, but he insits that neither can be a conlplete characterization of progress in science. He maintains that it is scientific instruments that break the connection between theory and observation, and in this manner allow the dialectic of theory and data to take place. The use of instruments establishes data domains, which are what theories adapt tole But when new data domains are established by the use of modern instruments, older data domains and the theories that are adapted to them do not necessarily disappear. As instruments are improved, a succession of data domains can be used as an objective criterion for scientific progress, much as adaptive biological forms are selected out of the
1. Robert John Ackermann, Data, Instruments, and Theory, A Dialectical Approach to Understanding Science, Princeton University Press 1985, p. x.
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varieties of possibilities. The continuous adjustment of theory to data means that successful science may not be recognizable immediately. The attempt to fit resulta~t theory and data is a matter of trial and error, but the interaction of theory and data results in facts that have survived controversy and are not to be taken as an unchallenged access to the real world. Facts in science appear only as data text requiring interpretation. This means that facts and theories may equally be modified in the dialectic of progress; facts becoming irrelevant to new domains, and theories turning inadequate for the data domains for which they had been originally intended. Ackermann stresses that much of what scientists accept at any point is later found out to be modified or abandoned. In particular, he challenges the Cartesian assumption that the isolated scientist is the appropriate basis for understanding the nature and scope of scientific knowledge. The institutional character of science requires the rational scientist to react not only to the available evidence but also to what other scientists are doing in the field. Both rationalism and empiricism presuppose that a solitary individual isolated from his fellows could in principle observe the world and reason about it in terms of his own ideas. What neither can satisfactiorily explain are sufficiently rapid theoretical changes in the sciences (i.e. Kuhnian "scientific revolutions"). This is because both rationalism and empiricism consider the object of knowledge to be unaffected by the process of aquiring knowledge (that is, learning). Such epistemologies are serviceable only as long as the world studied by science remains stable, but when the perceived properties of the world change rapidly, both rationalism and empiricism turn out to be inadequate. The fit between established terminology and new scientific data constantly is disrupted by new information provided by improved technology. Ackermann thus rejects the rationalist assumption that knowledge can be grounded on clear and distinct ideas or be derived directly from sense perceptions. Only when language sufficiently often has been used successfully in interacting with the world, and thereby been modified to produce this success, do the ideas it expresses seem to reveal the precise structure of the real world. All that the Cartesian example and classical empiricism show is that our everyday language fits the world fairly well as a result of a long process 116
of adaption to human observations and interests. A great deal of knowledge about the world has already been coded by an evolutionary process into our vocabulary and the ways we use language. Early scientists required little more than this everyday language to describe the world and speculate about it since experimentation did not play any significant role in the advance of knowledge. Serious problems for rationalism and empiricism arose only with the rapid contemporary advances. The early positivists in the 1920s believed that science could be distinguished sharply from theology, common sense, and even logic and mathematics. They intended to show that science was superior as a means of acquiring empirical knowledge. Early positivists such as Neurath construed science as resting on paradigmatically clear, carefully prepared observation and experiment, and they tended consequently to downplay the role of imagination in theorizing. They were out to discredit the rational status of theology and aesthetics, and to restrict all knowledge to scientific knowledge. But since no one ever discovered an adequate way to draw that distinction, positivist philosophy of science in the end became self-defeating. Many positivist philosophers also drew a distinction between the context of discovery and the context of justification, claiming that their logical methods could be realized orlly within the context of justification. i.e. after sufficiently sharp statements of theory were available for logical treatment. In the heuristics of theory proposal, on the other hand, scientists were supposed to be free to draw on any sources, no matter how arbitrary or counterintuitive. The process of discovery was thus regarded to be impervious to rational argument. Ackermann by contrast emphasizes that the proposal of hypotheses is highly dependent on context at any given stage in the development of science. It is determined by the current state of scientific knowledge and the relevant space of scientific possibility. He argues that philosophical accounts of scientific explanation would be more illuminating if philosophers were to study the local contextual constraints rather than promoting an excessively idealized logical paradigm. Scientists as a rule are likely to assume that only a few explanatory possibilities exist, and discuss which of these is most likely, given the evidence. They are just as likely to try what has worked in what they see as similar situations. Ackermann 117
agrees with Kuhn that scientists are constrained by considerations of scientific plausibility, but points out that this constitutes a threat to scientific objectivity. That is also why many experimental scientists have been suspicious of all philosophical speculation to begin with. Kuhn's treatment of the history of science as a series of paradigms has been disliked by empiricists because it renounces the continuous accumulation of scientific data. It reduces facts to observations that are determined by background assumptions (i.e. paradigms). Ackermann rejects both Popper's falsifiability thesis that permits one single counterexample to overthrow an established theory, as well as Kuhn's model of scientific revolutions, which typically regards anomalies as sufficient ground for the adoption of a new paradigm. Both fail to account for the rapid accomodation of theory to experiment and of experiment to theory when scientific instruments are markedly improved. What a fact is will depend on the availability of theory to give it significance, and vice versa. Our discoveries describe the world most adequately at the rough level of ordinary experience and discourse, not at the level of the very large or the very small. That is why Ackermann rejects both ordinary realism and instrumentalism 2 and calls for a dialectical approach to science that focuses on historical data domains. As instruments become refined, so are the data, and our theories reflect such improvements. A good fit with the improved data constitutes success for a theory, and continued success of this kind is an objective criterion of progress in science. But such judgments will be possible only for specific domains, and more often either progress or falsification remain inconclusive because the significance of the relevant data will not always be apparent. When novel data are produced from improved instruments, a new domain may be created for which different kinds of theories are needed. In many cases, an observation is of no significance until a relevant theory has been developed that renders it meaningful. Such a theory constrains observation by determining what to look for, but the data are not determined in every detail by prior theory. Only the kind of data is specified by theoretical expectation. Ackermann argues that the advantage of a specific instrument is that it does not by itself modify theories; 2. ibid. p. 30.
11
the instrument will show the same reading, but now the scientist will no longer take it to be important, or he will consider it to be telling him something altogether different. Since the data text is not fixed before interpretation, a clash of interpretations can usually be resolved. Popper's hypothetico-deductive method fails to produce an adequate explanation of the interplay between theory and data. Because he takes the objectivity of data for granted, he always considers them to be the test of theory, but this considerably oversimplifies the actual process of how we judge scientific progress from a historical perspective. Ackermann concludes that the history of instrumentation provides us with a real standard of progress for science because later and more refined instruments are always preferable to older and primitive ones. The creation of data domains precedes that of scientific theory, and the real progress of science is largely due to improved technology. Ackermann denies that the internal practice of the great scientific innovators reveals any unifying theme. Scientists who disagree will often make quite different simplifying assumptions from which they draw their conflicting conclusions. Like members of any culture, the members of a research group cannot anticipate fully the sources of their unity of outlook, and this inevitably defeats all attempts to describe scientific practice in neutral terms. Following Kuhn, many philosophers no longer regard scientific practice as altogether rational and autonomous. What scientists see as plausible or relevant is determined by the space created by a paradigm, not by mere logic. Ackermann criticizes Kuhn's account, however, for making research groups seem more uniform internally and more distinct externally than the historical facts warrant. When anomalies pile up against a paradigm, a ,scientific revolution will not necessarily result, and rational communication across different paradigms still as a rule will be possible. The history of science, including its revolutionary shifts, has to be seen as a process in which scientists are not quite sure where they are going, or what the significance of their work really is. He emphasizes that a variety of divergent practitioners may be quite essential to the stimulation leading to creative advance 3 • Kuhn's
3. ibid. p. 47.
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account overemphasizes the power of a paradigm to shape scientific thought. If theory determines oDservation, and paradigm forms theory, how can anomalies be noted in the first place? The answer to this puzzle lies with the human ability to grasp and adhere to several paradigms simultaneously. Ackermann points out that what seems possible or impossible to scientists is linked to actual experiments and agreed upon results of thought experiments. Such constraints will not appear explicitly in the theories or publications of a research group, nor need they be agreed on by all members of that research group. An important feature of scientific instruments and of experimental techniques is that they reduce the variety and complexity of actual situations to a few manageable results, most of which can be recorded numerically. Instead of responding to a complex situation or process, the scientist will react to some numbers or features that he will accept in common with other scientists who may have quite different interpretations for them. Instruments and techniques assure scientists that they are talking about the same phenomenon even when they disagree. Better instruments and techniques tell us more about the same universe, and in this manner force changes in our theories when they reveal unanticipated facts or aspects of the world. But this also explains why progress in science is not always cumulative, and how past data may become irrelevant. Against Kuhn, Ackermann argues that the new paradigm need not arise from a revolutionary crisis and a break with older science. Rather, it typically will appear as a locus of new interest within an already established discipline. What in the end unites different scientists in considering the same theory is an orientation toward a certain range of data gathered in certain ways, and an agreement that the data constrain scientific thought along certain lines. The individuality of scientists explains why theories cannot be falsified easily by counterexamples or completely be eliminated even by a scientific revolution. While the majority may revise their views drastically, some will work at conservative revisions, thus preserving a wide potential variety of ideas. Ackermann, therefore, denies the existence of scientific method in the traditional sense. When a new piece of information is offered, it is not first known whether it can be fitted into the framework of existing science. Since the significance of scientific evidence is not open to immediate inspec120
tion, this provides a cognitive role to controversy. It is the struggle to establish that some new piece of information is significant, Le. that it deserves to play a role in the thinking of other scientists engaged in the same problem 4 • At any given time, apparently contradictory pieces of information may all be judged significant. An established body of techniques, instruments, theories and data may acquire new meaning and present new linkages because of a seemingly modest new theoretical outlook. In order to understand the succession of theories, one must take into account the data base to which these theories attempt adaptation. Ackermann points out that underlying the history of theory is the history of data text. What is accumulative in the history of science is the gradual refinement of scientific instruments once they have been introduced. A changing data environment for scientific theories is like a changing environment for biological species. Concentration on internal theoretical change cannot by itself lead to an adequate understanding of scientific progress, nor does mere focusing on the problems that such theories solve because it is impossible to inviduate problems properly and thus to assess their relative significance. Since there is no common core of rationality in the recognized achievements of the great scientists, instances of bad science or of pseudoscience cannot be identified merely by methodological criteria. Ackermann emphasizes that the historical character of science precludes anything like a logic of scientific research. The distinctions that we can locate in the past from our present perspective are not likely to be adequate representations of the past as it appeared to its participants. For the same reason, most revolutionary new theories were at first regarded as completely wrong by contemporaries. We, therefore, don't want a sharp boundary around what counts as science, since it is often impossible to tell of fledgling disciplines whether or not they are scientific. Such judgments only come later and largely are made by hindsight. Good science cannot be separated from bad merely by the logic of the situation because in the evaluation of a scientific theory or fact there is a time factor that cannot be ignored. While recognized
4. ibid. p. 66.
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groups define common problems and techniques, a perceived deviance at some time should not be taken as an indication that the deviant practice is unscientific. Ackermann emphasizes that we have to look to history to make these discriminations. Even deviant science sometimes can make contributions to the progress of genuine science. Traditional philosophy, on the other hand, has been dominated by a quest for certainty, the pursuit of permanent knowledge, and much of the prevalent philosophical picture of science tends to reflect this attitude. For such philosophers as Carnap, for example, the ideal scientist deals only with facts and calculations. Since achievement in contemporary science depends largely on the technology available to produce the data, it would be possible to write the history of science in terms of instruments that were at the disposal of scientists at the time. Philosophers of science, however, have as a rule tended to stress the independence of scientific knowledge from social, economic and technological conditions. While classical science indeed may have seemed to be largely autonon10us, modern science increasingly has been threatened by corporate and governmental funding. Ackermann emphasizes that there can be no altogether neutral description of the past, and that consequently philosophers of science have been too naive about history. There is a sense in which we can understand a discovery only after its potential consequences have been realized. At any given time there will be assimilated fact and theory, but also newly proposed facts and theories. Ackermann agrees with Popper that science is interested only in significant facts, he points out, however, that in this evaluative process neither fact nor theory will always have precedence. The present status of either fact or theory does not permit us to anticipate its future significance. Even the great scientific innovators at first could not grasp the full importance of their own discoveries since this comes only with the construction of related facts and theories. Both rationalism and empiricism wrongly assumed that we can describe contemporary events completely, and accepted, therefore, either theory or fact respectively to be settled. Ackermann argues, however, that the pool of all relevant historical data is neither identifiable nor surveyable. In his historical work even Kuhn takes it for granted that facts speak for themselves, and like Hume, he suppresses his philosophical doubts 122~
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to make room for a historical narrative:>. Ackermann, on the other hand, insists that facts in the history pf science do not speak for themselves because they depend on other relevant data and theories (Le.. "factual domains"). There is always the possibility that they be eliminated from a future history of science. While some areas clearly can be regarded as science, any attempt to separate sharply science from nonscience is based on the mistaken assumption that the significance of new work, its more permanent place is history, can be established at the time it is proposed. All such attempts ignore the essentially historical character of scientific progress. There can be no guarantee for the individual scientist that he has avoided error. He cannot know whether his new data are constant under slight perturbations of the experimental conditions, what exactly the relevant data are, and what is evidence for what. Since what is considered science takes on its familiar routines only after these issues have been settled, the craft activity of experimental practitioners is largely unnoticed by many philosphers of science who consider only what passes as scientific language. This is also why scientists are not as a rule much disturbed by philosophical attacks. At any given time, the set of possible facts will be enormous, and a theory typically will reduce this set by discriminating between relevant facts and features, and those it will ignore. Popper's theory of falsification turns out to be misleading to the extent that he ignores the historical and institutional character of scientific facts. An isolated fact typically will be insufficient to overthrow an established theory, and to accomplish this requires a great many adverse facts whose significance is taken for granted. The objectivity of certain features of the world is established in science as it is in ordinary experience by the robustness and repeatability of our perceptions. But telescopes and microscopes extend human vision, and provide Ilew objects that science can see, describe and theorize about. In this extended and argumented scientific field, neither the robustness nor the repeatability of data can be taken for granted as they are in common sense. Scientists with different interpreta-
5. Joseph Griinfeld, "On the Relation between Hume's Philosophical and Historical Writings," The Hebrew University, Jerusalem 1959.
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tions and theories will tend to see different things. There is in scientific perception no common-sense level at which everybody can be said to see the same thing, so that differences can be explained as variations of interpretation at this common level. The absolutely neutral observation of fact assumed by classical empiricism is shown by Ackermann to be an illusion. Especially at the growing edge of science, the data are usually in doubt and disputed, and, therefore in such cases perception can be seen to be guided by theory. An improvement in instrumentation will often remove such ambiguity, but what is then seen as a new kind of data, such as the data first revealed by a new instrument, must still be described graphically, as like what is already known. In this manner, instruments, data, theories and terminology tend to evolve in close consonance. But in such a process, instruments playa crucial role of initially separating data from tlleory. Instruments like eyeglasses are used to see things, but they tend not to be noticed unless they malfunction or break. What is seen through their use, however, takes an independent existence. The feel of such an instrument and an adequate explanation of its working are not easily accomplished verbally. Theory and data can be described, but one must learn to operate an instrument. It refines the kind of data it is possible to obtain, yet once the data have been legitimized, they tend to be taken for granted. How great a change is required before we recognize a new domain or a new theory is a matter of conceptional convenience. Galileo's use of the telescope clearly opened up a new domain in which, for example, the phases of Venus and the existence of sunspots called for new kinds of theory. The telescope thus makes a sharp break in our scientific knowledge and illuminates how what has been settled in science can again become unsettled. Ackermann shows that Kuhn's account misses the impact of new instruments on the historical development of science that create novel data domains. He likewise considers Feyerabend's call for new theories ,and research programs to be unrealistic in the absence of some perceived data domain. It is only the discovery of new entities that will change sufficiently the domain of what was thought to be understood. Domains of science are likely to be reevaluated radically only when more powerful and sophisticated instruments provide unanticipated findings. But once consonance of language 124
and fact has been achieved in science or mathematics through social legislation, it may seem quite marvellous that language should fit reality so closely. The traditional correspondence theories trade on the fit between ordinary language and the world, or between the contrived calculus and an idealized domain. In mathematics and science the process of achieving this consonance is more open to inspection because new data domains are always undergoing development. Both facts and the language in which they are described may become underdetermined when there are historical shifts in established data domains. In such a process of adaptation either theory or experiment may advance independently, and it is the consequent time lag that renders such a logical structure inexact. Ackermann, therefore, rejects the goal of unified science and the related view that there is only one way the world is as remnants of theology. But he then has difficulties to explain why the drive for more general theory plays such a dominant role in the evolution of science and mathematics.
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CHAPTER X
GLYMOUR'S BOOTSTRAPPING FUZZINESS
Glymour points out that hypothetico-deductivism is inadequate as a model of scientific method because it fails to account for the condition of relevance between hypotheses and evidence. Hempel's notion of instance confirmation comes closer to captivating the sorts of structured relations between evidence and hypotheses, which lies at the heart of theory testing l • But Hempel's original account was too narrow in not permitting hypotheses stated in theoretical terms to be combined with evidence stated in observationallanguage. Glymour proposes to remedy this defect with the idea of "bootstrapping": the basic relation of confirmation is three place (E confirms H relative to T) and auxilliary assumptions drawn from Tmay be used in deducing instances from E(x). While rejecting the traditional Bayesian approach, Glymour wants to combine bootstrapping relations with a partial knowledge of probabilities. What hypotheses mean has something important to do with what evidence is relevant to them, even though he rejects the suggestion that meaning is to be explained in terms of assertability conditions or confirmation conditions. Contrary to Quine, Glymour argues that no working scientist acts as though the entire sweep of scientific theory faces the tribunal of experience as a single undifferentiated whole, nor do we act in this manner with regard to our beliefs. Much of the scientist's business is to construct arguments that aim to show that a particular piece of observation or experiment bears on a particular piece of theory, and such arguments are among the most celebrated accomplishments in
1. Clark Glymour, Theory and Evidence, Princeton University Press, Princeton, New Jersey, 1980, pp. 26, 42.
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the history of our sciences. When we understand what went wrong with the positivist program, we cannot help but see that the same problems threaten to make the·,various systems of the "new fuzziness" either inadequate to save the phenomena, arbitrary, or incoherent 2 • Empiricist theories of knowledge during the first half of this century were vexed by the problem of how to make an inference from statements in the narrower sense to statements in the broader language. The hypothesis in the broader language cannot be confirmed in their instances. Much of the later methodologist work, therefore, focused on finding a precise criterion of empricist significance that could distinguish ordinary scientific discourse from metaphysics and nonsense. In the opinion of Glymour, however, what the positivists really sought in proposing a criterion for "empirical meaningfulness" were criteria for evidential relevance 3 • The bootstrap method holds that theoretical hypotheses are confirmed by deducing them, or positive instances of them, from observation statements. Because the vocabulary of the theory exerts beyond the vocabulary of the observation statements, the deduction requires hypotheses containing both theoretical and observational predicates. Typically these theories assume that there is a conditional probability for any hypothesis given any evidence statement. But Glymour claims that this makes an utter mystery of how it is that people are able to use theoretical expressions reliably and with mutual comprehension. It is important to realize the central function the notion of analytic truth played in positivist lore: analytic truth establishes the connection between evidence and theory, and thereby makes the confirmation or disconfirmation of the theory possible. Analytic truth prevents our hypotheses about the natural world from being underdetermined in principle by all possible evidence. It is no wonder, therefore, that as philosophers have come to reject analytic truth, they have come also to advocate holism, and to believe that even all possible evidence could fail to determine a unique theory.
2. ibid. p. 7. 3. ibid. p. 11.
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This point seems first to have been made by P. Duhem 4 who argued that theoretical claims are radically underdetermined by the evidence, so that theoretical sentences cannot be said to have such properties as truth or falsehood. Quine, following Duhem, attacked the doctrine that individual sentences determine a characteristic range of possible sensory events that could constitute evidence for or against them, and the related doctrine that pieces of evidence bear on individual sentences in isolation from vast domains of belief. The natural response to the difficulties that hypotheticodeductive approaches have with relevance is to suppose that there is some other kind of constraint on our theories besides these deductive constraints that require special logical connections with the evidence. Almost everyone believes nowadays that confirmation proceeds through the formation of conditional probabilities of hypotheses on evidence. Yet Glymour insists that probabilistic analyses remain at too great a distance from the history of scientific practice. We certainly have grades of belief, degrees that can have any value between zero and one, and that might, if we are rational, be representable by a probability function. Betting odds, however, would fail to measure degrees of belief for a variety of reasons; for example, we may place either a positive or a negative value on risk itself. Thus, what we want is an explanation of scientific argument, while what the Bayesians offer us is a theory of personal learning. It is not the case that scientists have their prior degrees of belief distributed to any plausible simplicity ordering, nor would it be rational for them to do so. There are always consequences to our theories that we do not know to be consequences. This lack of consistency was also discovered by KuhnS in the historical evidence. He questioned all scientific claims to knowledge that pretend to be independent of social context or convention. What is a good argument in one scientific tradition or epoch may not be considered to be one in another. Even scientists who share such values as simplicity, accuracy and consistency, may
4. P. Duhem, The Aim and Structure of Physical Theory, New York, Atheneum, 1974. 5. T. Kuhn, The Structure oj Scientific Revolutions, Chicago, University of Chicago Press 1962.
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ascribe different importance to each of the,Pl. But there is nevertheless in scientific work a central core of theory and practice that is the last to be touched by contrary evidence. That is why Kuhn's arguments throughout The Structure of Scientific Revolutions when dealing with historical cases, seem to appeal to a fairly standard hypothetico-deductive account of theory testing 6 • Glymour shows, however, that questions relating to evidential relevance are central to the claim of fuzziness. A satisfactory account must explain how it is possible to have grounds for theories at all, al1d it must be historically faithful. Glymour denies that there is a special privileged class of theoretical claims - the analytical truths or the coordinating definitions that connect evidence with theory. Any hypothesis can be used to deduce an instance, and the same hypothesis may be tested by means of different auxilliary hypotheses by different pieces of evidence. There is always some other theory with respect to which the evidence confirms or disconfirms the hypothesis. Instances of a hypothesis in a theory, whether positive or negative, are obtained by "bootstrapping," that is, by using the hypothesis of that theory (or conceivably some other) to make computations. A standard methodological principle is that a theory is better supported by a variety of evidence than by a narrow spectrum of facts. The substance of this principle is, however, unclear so long as we lack some account of what constitutes relevant variety. Glymour argues that if we reject the supposition that parts of our theories are analytic, truth by convention, then any of the definitions of which Quine writes 7 are simply further hypotheses, and not definitions at all. Although the bootstrap strategy is also holistic in its way, the heart of the matter is that the use of the strategy involves denying so radical a holism 8 • When scientists reject previously accepted theories, they often refuse to accept only parts of them, and retain other parts. Newton rejected Kepler's explanations while accepting his laws. Thus, beliefs forming a system or theory need not be accepted or rejected as a whole, and
6. Glymour, Ope cit. p. 95, n4. 7. W. Quine, Word and Object, Cambridge, Mass. MIT Press 1960, p. 21. 8. Glymouf, Ope cit. p. 145.
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Glymour finds it surprising that many prominent epistemologists hold views that seem to contradict such truisms. Kuhn writes of competing scientific theories as competing "paradigms" that are accepted or rejected as a whole, and between which ordinary criteria of evidence and support cannot be used to decide. Quine condemns what he calls the second dogma of empiricism, the dogma of reductionism that survives in the supposition that each statement taken in isolation can admit of confirmation or disconfirmation. His countersuggestion is that our statements about the external world face the tribunal of sense experience not individually but only as a corporate body9. Glymour points out, however, that different things mayor may not have to be taken as a whole. What hypotheses in a theory are tested by what pieces of evidence depends on the structure of the hypotheses, the theory, and the evidence I 0. Because our faith in the instances of any hypothesis depends on our faith in the linkages used in obtaining these instances, the hypotheses of a theory are interlocked, woven together. This does not mean, however, that a piece of evidence cannot bear on a piece of the theory without bearing on all of it. Nor does it mean that we cannot accept or reject part of a theory without accepting or rejecting it all. When something goes wrong, we may retain the best tested part of the theory and reject the rest. What to retain and what to discard depends on what else we believe or question. That we test our theories in the way described, explains a great deal about our historical practice, our methodology, and our judgments of relevance. What evidence bears on a claim depends on what other claims we make in a given context. Giving up analytic truth leads to holism, to the realization that we cannot assess hypotheses in a complex theory in isolation. from other hypotheses. Glymour concludes, therefore, that holism is true only in part l ). He points out that what makes a theory better is not something that can be measured appropriately on a single scale. Not all
9. W. Quine, "Two Dogmas of Empiricism," in From a Logical Point oj View, Cambridge, Mass. Harvard University Press 1953, pp. 40-41.
10. Glymour, op. cit. p. 151. 11. ibid. p. 152.
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hypotheses in a theory are of equal importance. There are at any time substantive beliefs about what kind of hypotheses are relevant to what kind of evidence. These beliefs~ are not due to the logical structure of hypotheses and evidence but are largely a matter of content. Textbook traditions have a tendency to eliminate such subleties, and as a result, arguments and discriminations that were framed quite differently come to be characterized in hypotheticodeductive terms. Indeed many of the difficulties of the hypothetico-deductive method could be eliminated if certain axiom systems could be characterized as "naturaL" But Glymour shows that the hypothetico-deductive method cannot itself provide such a description, and the bootstrap strategy suggests more than one such characterization as intuitively plausible. Newton's laws, for example, function in some contexts like definitions and in others like empirical generalizations. Glymour explains that the diffenrence is simply that in some contexts the law is being tested, while in other cases it is used to test other claims. Newton consistently maintained that this method was not hypothetico-deductive, yet most philosophers and critical historians of science have tended to reject this claim. Given Glymour's confirmation theory, however, Newton assertions begin to n1ake sense, for in his theory, confirmation is the coherent deduction of instances of hypotheses from observational data and other laws and theories. What Newton did, according to Glymour, was to pick a mathematically treatable description of data that was later corrected by theory - yet that was all the while compatible with the accepted observations. When dealing with the descriptions of such magnitudes, Duhem distinguishes between theoretical and what he calls "practical facts."I2. He contends that true precise quantitative descriptions of phenomena are, because of the complexity of nature, either unavailable or impossible to use. So science must do with theoretical facts, i.e. idealizations that are usually not compatible with ex;perimental error but that are justified in part by their logical attachability to scieIltific theories. Truth in description can be achieved only at the cost of vagueness, yet science demands
12. Duhem, Ope cit. pp. 132-138.
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precision. The problem is thus a species of curve fitting l3 • A theory is confirmed with respect to idealized, but strictly speaking, false data, even when it satisfies the hypothetico-deductive account or Glymour's bootstrap strategy of confirmation. But this is achieved only at the cost of idealized evidence, i.e. evidence simplified for theoretical convenience, and not consistent with observational error. Glymour concludes that the holism of Duhem and Quine is right in maintaining that hypotheses can be used jointly in a test, but mistaken in holding that the test is, therefore, an indescribable one of the entire set. Duhem argues that the evidence of positional astronomy did not offer grounds for preferring the Copernican over the Ptolemaic model of the universe. Glymour points out, however, that this conclusion was due to the hypothetico- deductive view, and that it was adopted by Duhem because he regarded it as the only rational one. The same holds for Kuhn's treatment of the Copernican revolution 14. Glymour emphasizes that the vagueness of the notion of simplicity adopted with the hypothetico-deductive view have led to a number of counterintuitive and conflicting consequences. To claim that we prefer the simplest hypothesis consistent with the data explains very little since observations and measurements are always open to error. One way to characterize error of measurements is to suppose that our measurements are uncertain but bound by error. But then the rule of simplicity fails to determine a unique curve from among the members of the simplest family of curves that fits the data. If our data consist not of exact points but rather of three regions, then there are an infinity of curves that pass through all these regions I 5. Glymour thus realizes that the principles of comparison are vague, and that we lack means to determine which of these considerations take precedence should they conflict, and how they are weighted. He
13. Ronald Laymon, "Newton's Demonstration of Universal Gravitation Philosophical Theories of Confirmation," in John Earman (ed.), Testing Scientific Theories, Minnesota Studies in the Philosophy of Science, vol x, University of Minnesota Press, Minneapolis 1983, p. 192. 14. T. Kuhn, The Copernican Revolution, Cambridge, Mass. Harvard University Press, 1957, p. 171. 15. Glymour, op. cit. p. 377. ~nd
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has to admit that his views about confirmation and theoretical equivalence do not guarantee that for a" given body of evidence there is a unique theory best confirmed by that evidence. Nor is there any assurance that with a definite class of competing theories there will be one that is best supported by the evidence. Glymour explains that if we had the probabilities of all things, good thinking would be apt calculation, and the proper subject of theories of good reasoning would be confined to artful and efficient assembling of judgmel1ts in accordance with the calculus of probabilities. In fact, however, we have the probabilities of very few things, and to account for inductive acceptance, we must construct theories that will explain how preferences among hypotheses may be established in the absence of such knowledge. The recent predominance of a personal and subjective interpretation of probability as a degree of rational belief requires only that belief intensities be so distributed as to satisfy the axioms of probability. Thus, when we reason about things in the absence of knowledge of objective chances, we still retain degrees of belief, and hence if we are rational, our reasoning is an application of the calculus of probability or of the principles of changing probabilities l6 • Yet philosophers of science concerned with theories and the nature of evidence tend to believe that there is a "logic" in the relation between theories and evidence. They largely have derived their inspiration from the historical criticism of Feyerabend, Hanson, Kuhn, and Toulmin. Partly because their roots tend to be in intellectual history, and partly in reaction to logical empiricism, they emphasize the evolution of scientific ideas and downplay the role of empirical data in the development of science. They reject the assumption that one can reduce the rationality of the scientific process to the rationality of individual agents. The rationality of science is to be found not so much in the heads of scientists as in the objective features of its methods and institutions l7 • The secret of the hypothetico-deductive method is to focus not on major logical relations between hypotheses and data, but in the
16. Glymour, "On Testing and Evidence," in Earman, Ope cit. p. 4. 17. Ronald N. Giere, "Testing Theoretical Hypotheses," in Earman, Ope cit. p. 270.
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notion of a test of the hypothesis. We now tend to accept the idea that no empirical data possibly could determine with certainty that any theoretical hypothesis is true. Most students of scientific method would agree that the relevant notion of reliability is to be understood and explained using concepts of probability. But just what role probability plays is a matter of deep disagreement. At least some of the classical astronomers may be viewed as advocating a testing procedure that recommended calling a hypothesis true if and only if it "saves the phenomena." The defect of this procedure is that the changes of calling a false hypothesis true are simply not known. There are many, perhaps infinitely many, false hypotheses that could also save the phenomena. The scientific enterprise is not merely a matter of evaluating hypotheses in the light of available information, rather it is an active seeking out of information to answer definite questions 1 8 • What determines the satisfaction level is not a function of individuals but the institution of science. This institution decrees that tolerating some error is preferable to having no theoretical conclusions at all. It also appears that different fields, or even the same field at different stages of maturity, have different tolerances for the risk of error ,Garber points out that the Bayesian framework is intended, at least in part, as a formalization and systematization of the sort of reasoning that we all carry out at a rational level. One of the most attractive features of the Bayesian approach is the apparent ease and elegance with which it can deal with typical strategies for the confirmation of hypotheses in science. lJsing the apparatus of mathematical theory of probability, the Bayesian can show how the acquisition of evidence can result in increased confidence in accord with our best intuitions. Most of the objections have centered on the unrealistic nature of the assumptions required to establish the appropriateness of an in-' dividual's beliefs by way of a point-valued additive function. Glymour emphasizes that there is an important class of scientific arguments, cases in which we are dealing with the apparent confirn1ation of new hypotheses by old evidence, for which the Bayesian 0
18. ibid. p. 290.
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account of confirmation seems logically inadequate. The problem of old evidence is generated by the requirement that the Bayesian agent be logically omniscient, a requirement normally thought to follow from coherence. The basic concept for the Bayesian is that of degree of belief. The degree of belief that a person S has in the sentence P is a numerical measure of S's confidence in the truth of P, and is manifested in the choices S makes among bets, actions, etc. What differentiates the Bayesian account from idealized psychology is the imposition of rationality conditions on S's beliefs, Le. coherence. Garber points out that such a coherence condition amounts to a requirement of logical omniscience 19 • The fact is that we have to discover logical and mathematical relationships between hypotheses and evidence just as we have to find out what the empirical evidence is . Closely related to the problem of old evidence is the question how the Bayesian is to deal with the introduction of new theories. This is especially a problem for global Bayesianism (e.g. Carnap's) where the enterprise is to determine the changes that would occur in an ideally rational individual's degrees of belief as he acquires additional experience. Global Bayesianism assumes that the degrees of belief functions are defined over a maximally rich global language capable of explaining all possible evidence and hypotheses. The coherence of such a language seems to preclude the possibility of S's accepting a bet against logical truth. No hypothesis ever enters S's serious consideration without his knowing explicitly just which of his past observations it entails. What the problem of old evidence shows is that we cannot have a fully adequate theory of empirical reasoning either. The Bayesian account makes it irrational to be anything but logically omniscient, since the Bayesian agent who is not logically omniscient becomes inevitably incoherent. We might adopt an evolving probability model, but this requires a major change in the way we think about coherence. The best we can say is that an individual ought to regard coherence as an ultimate goal. However, if it is not required that an individual be
19. Daniel Garber, "Old Evidence and Logical Omniscience in Bayesian Confirmation Theory," in Earman, Ope cit. p. 128, n5.
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coherent at any given time, it would seem that nothing conclusive can be said about a rational individual's beliefs at any such time. Eliminating coherence as a condition of rational belief reduces the Bayesian framework to idealized psychology. This has the unfortunate consequence of allowing us to say nothing of interest about the characteristics that a rational person's beliefs would have to exhibit at any given time. Typically when scientists or decision makers apply Bayesian methods to the classification of inferential probabilities, they do so in a much more restricted scope than global Bayesianism suggests. To apply the Bayesian framework to some particular situation, we enter in only what we need to deal with in the context of the problem at hand, i.e. the particular sentences and beliefs (prior probabilities) we have with respect to these sentences 20 • Indeed one of Glymour's main complaints about the hypothetico-deductive method to be rectified by means of the bootstrap strategy is that it fosters a misleading and unnecessary holism. Horwich points out, however, that as far as relevance is concerned, bootstrapping is in the same boat as Bayesianism or the hypothetico-deductive method 21 • The core of these views it that a system of rational beliefs must confirm to the probability calculus. But it seems unlikely that coherence on its own is sufficient for establishing rationality. Further constraints are needed to characterize completely our inductive practice, and until they are supplied, the Bayesian approach cannot do much better than the competition in systematically accounting for our intuitions of relevance. Thus, confirmation turns out to be neither necessary nor sufficient for the enhancement of credibility. Glymour's chief objection to hypothetico-deductivism and Bayesian approaches is that they are too liberal, admitting as confirming items of evidence some that we should not admit as such. A similar previous attempt to show that Bayesian methodology is too liberal comes from Popper. His chief criticism is that Bayesians cannot account for the demand of content. For if high probability is the aim of inquiry, it is best attained by putting forward
20. ibid. p. 111. 21. Paul Horwich, "Explanations of Irrelevance," in Earman, Ope cit. p. 62.
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theories of low content that run minimum risk of exposure to contrary and falsifying evidence. Rosenkrantz argues that this criticism applies equally to the Hempelian instance confirmation that Glymour adopts 22 • For if consistency with our hypotheses is all we demand, then confirmation is easy to come by. We complicate a theory when we enlarge its stock of adjustable parameters, for each parameter we add extends the range of possible findings that they can accommodate. Granted that probability is the yardstick by which Bayesians compare rival conjectures, it does not follow that high probability is the goal of scientific inquiry. Highly truthlike theories are just those that combine a high degree of content with a high degree of accuracy. Contrary to Popper, Rosenkrantz claims that Bayesian confirmation or support is not easily obtained, for it requires both accuracy and simplicity. Bayesians may, therefore, legitimately speak of support reducing changes in the theory. One is interested at bottom in the hypothesis that there exists a (not unduly complicated) theory of such and such a form capable of accomodating the data from a certain class of experiments, only some of which have already been performed. A good theory can explain the salient facts without recourse to special assumptions of an arbitrary kind. Although most criticism of Bayesianism focuses on the alleged arbitrariness of prior probabilities of theoretical hypotheses, the real difficulty more frequently is to compute the relevant likelihoods. In case in which likelihoods cannot be computed, we may still have an intuitive rank ordering of experimental outcomes as agreeing more or less well with the theoretical conjecture and interest. As for prior probabilities, admittedly they are of little importance in preliminary investigations where we lack a sharply determined set of theoretical alternatives. But informal counterparts of these major elements of formal Bayesian analysis - prior probabilities, likelihoods, and alternative hypotheses - figure importantly in nearly all informal assessments of evidence. Jeffrey emphasizes that the emergence of probability during the mid-seventeenth century was part of a general appearance of concepts and theories that made essential
22. Roger Rosenkrantz, "Why Glymour Is a Bayesian," in Earman, op. cit. p. 73.
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use of what came to be recognized as real variables. These concepts and theories were quite alien to ancientJhought, and even today this sort of mathematical probabilistic thinking remains less natural than reasoning from definite hypotheses. Thus, one reasons about estimates of truth values, i.e. probabilities, in many situations in which an argument in terms of truth values is unproductive. The step from two-valued functions (zero and one) to probability functions, and hence to estimates of functions that need not be two valued, brings with it a very considerable increase in range and sublety. To take full advantage of the scope, one must resist the temptation to suppose that a probability statement that is not a unity set must be a blurry representation of a sharp state of belief23 • Assessment of whether a theory provides more information or whether we have more reason to believe it, is always made in the light of background assumptions. Van Fraassen points out that there is in general a conflict between the need for information and the desire for truth. Thus, the problem of theory acceptance has the structure of a practical decision making problem in which conflicting considerations must be weighted against each other 24 • Since we never get a truly universal scope and completeness in our theories, a belief that a theory is empirically adequate will not lead necessarily to a commitment to the use of the theory's conceptual scheme. It may be more natural to pursue a theory that is capable of being tested in the short run or capable of being combined with other theories already being pursued.
23. Richard Jeffrey, Bayesianism with a Human Face," in Earman, Ope
cit. p. 155. 24. Bas C. van Fraassen, "Glymour on Evidence and Explanation," in Earman, Ope cit. p. 168.
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CHAPTER XI
KRIPKE ON WITTGENSTEIN AS A SKEPTIC
Kripke claims that in the Philosophical Investigations Wittgenstein has raised a new "skeptical paradox." According to Wittgenstein, we follow a rule as we do, without reason or justification. This Kripke considers to be similar to the strategy followed by Hume in explaining causation by "custom," since custom is something we follow blindly. Consequently, "we have no choice left but between a false reason and none at all." 1 Kripke points out, however, that there are two areas in which the form both of the paradox and its solution are most likely to be ignored, and with respect to which Wittgenstein's basic approach is most likely to remain unconvincing. One such area is the notion of mathematical rule, such as the rule of addition. The other is our talk of our inner experience of sensations and other inner states. In Philosophical Investigations Wittgenstein says, "this is our paradox: no course of action could be determined by a rule because every course of action can be made to accord with a rule." 2 This "paradox" is in the opinion of Kripke the central problem of Philosophical Investigations. He takes it to be a new form of philosophical skeptisffi. 3 Following Wittgenstein, Kripke develops this problem initially with respect to a mathematical example, thougl1 the relevant skeptical problem applies to al meaningfull rules of language. Like
1. David Hume, A Treatise of Human Nature, L.A. Selby-Bigge ed, Oxford, Clarendon 1955, p. 268. 2. Ludwig Wittgenstein, Philosophical Investigations, Oxford, Blackwell 1953, par. 201. 3. Saul A. Kripke, Wittgenstein on Rules and Private Language, Harvard University Press 1982, p. 7.
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almost all English speakers, we use the word "plus" and the symbol "+" to denote the well-kno~n mathematical function, addition. This function is defined for all pairs of positive integers. Although I myself have computed only finitely many sums in the past, the rule determines my answer in infinitely many sums that I have never previously considered. This is the whole point of the notion that in learning to add, I grasp a rule. Now according to Kripke, the skeptic's hypothesis is that it is not logically impossible that in the past I used "plus" and "+" to denote a function he calls "quus" and symbolizes (±). It is defined by x(±)y == x + y if x, y < 57, and otherwise x + y == 5. If this hypothesis is false, there must be some fact about my past usage that can be cited to refute it. For although the hypothesis is wild it does not seem a priori impossible 4 • In computing' '68 + 57" as I do, I do not simply make an unjustified leap in the dark. I follow directions I previously gave myself which uniquely determine that in this new instance I should say" 125" because I am confident that this answer also accords with what I meant. Neither the accuracy of my computation nor of my meaning is under dispute. Kripke emphasizes that the "directions" determing what I should do in such instance must somehow be "contained" in my candidate for the fact as to what I meant. Otherwise the skeptic has not been answered when he holds that my present response is arbitrary. In order for the skeptic to converse with me at all, we must have a common language. He merely questions whether my present usage agrees with my past usage, whether presently I am conforming to my previous linguistic intentions. If the skeptic is right, there can be no fact about which particular function I meant in the past', and there can be none in the present either. The evidence is not to be confused, however, with that available to an external observer who can observe my overt behavior but not my internal mental states. While Wittgenstein's philosophy of mind has often been characterized as behavioristic, Kripke emphasizes that no hostility to the "inner" on the part of Wittgenstein need to be assumed as a premise; at most it may be argued as a conclusion. This feature of Wittgenstein contrasts with Quine's discussion of the indeter-
4. ibid. p. 9.
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minacy of translation. 5 Quine is more content to assume that only behavioral evidence is to be admitted into his discussion. Wittgenstein by contrast undertakes an extensive introspective investigation. He makes use in his discussion of our own memories and knowledge of our "inner" experiences 6 , whereas Quine posits the problem of meaning in terms of the linguist, trying to guess what someone else means by his words on the basis of his behavior. Wittgenstein's challenge can be presented to me as a question about myself. The skeptic can question my present interpretation of my past usage of "count" as he did with "plus." It is indeed tempting to answer the skeptic by appealing from one rule to another more basic rule. But Kripke shows that the skeptical move can be repeated at the more basic level also. Eventually the process must stop - "justification come to an end somewhere" - and I am left with a rule that is completely unreduced to any other. 7 However, it would seem that such rules may support each other partially as do definitions in a dictionary. If this is correct, Kripke's skeptical problem no longer arises, for I then no longer follow a rule altogether blindly. His "paradox" is that there can be no fact as to what I mean by "plus" or by any other word at the time. There is no fact about me that distinguishes between my meaning a definite function by "plus" (which determines my responses in new cases) and my meaning nothing at all. 8 In this manner the crucial idea of meaning vanishes altogether, and this would render pointless Wittgenstein's discussion of both following a rule and of the impossibility of a private language. Kripke attempts to meet this objection by arguing that the dispositional account misconstrues the skeptic's problem. His point is that the intelligibility of the notion of "competence" is dependent on our understanding of the idea of "following a rule." The relation of meaning and intention to future action is normative, not descriptive. 9 The skeptic's problem is not merely
5. W.V. Quine, Word and Object, MIT Cambridge, Mass. 160, ch. 2. 6. Kripke, op. cit. p. 14, nIl. 7. ibid. p. 17. 8. ibid. p. 21. 9. ibid. p. 37.
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epistemic; rather he argues that there is no fact as to what I meant by addition, whether plus or quus. Against such a claim, issues of behavior are irrelevant. The skeptic does not argue that our limitations of access to the facts prevent us from knowing something hidden. Rather he claims that there is no fact to be known that differentiates between the plus and the quus hypotheses. It is, however, possible to argue that meaning addition by "plus" denotes an irreducible experience with its own special quale known directly to each of us by introspection (headaches, tickles, nausea are experiences of inner states with such qualia). This type of view is characteristic of Hume's philosophy 1 0 • The idea that each of my inner states - including presumably what I mean by "plus" - has its special discernible quality is indeed one of the cornerstones of classical empiricisn1. Kripke denies that the alleged quale could be relevant to the question at hand, 11 since such a picture suggests that the association of an image with a word (paradigmatically a visual one) determines its meaning. He emphasizes that this need not be the case because the skeptic could suggest that the image be used in nonstandard ways. No internal impression with a quale could possibly tell me in itself how it is to be applied in future cases. Nor can any number of such impressions thought of as rules for interpreting how to do the job. But if meaning vanishes altogether, the skeptic's question, "What tells me how I am to apply a given rule in a new case?" has no point either. It no longer can be raised meaningfully from "outside" n1Y images or qualitative mental states. While Wittgenstein extensively argues that the supposed special experience of meaning (addition by "plus", etc.) does not exist, Kripke considers the view of meaning as an introspective experience to be most natural and fundamental. Wittgenstein's and related arguments (such as Ryle's) have done much to discredit the Cartesian and Humean pictures of the concept of mind. But the naturalistic-behavioristic views that ignore the problem of mental states altogether are rejected by Kripke l2 • An experienced reader simply calls the words out and is aware of no special conscious experience of "deriving the words from the page." Usually there will 10. ibid. p. 41, n26. 11 ~ ibid. p. 42. 12. ibid. p. 44.
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not be an identifiable moment when"he can be said to have learned to read. The teacher will judge of a given pupil that he has learned to "read" if he passes tests for reading often enough. There may or may not be an identifiable moment when the pupil first felt, "Now I am reading," but the presence of such an experience is neither a necessary nor a sufficient condition for a teacher to judge of him that he is reading. 13 It is by examples like these that Wittgenstein judges the supposed special "experiences" associated with rule following to be chimerical. But while he denies that there is any particular "qualitative" experience like a headache present when and only when we see a word with a certain meaning, he does acknowledge a certain "feel" to our meaningful use of a word that may under certain circumstances be lost (e.g. when we repeat it as a mantra, and the like). Kripke stresses this ambivalence in Wittgenstein: whatever the "experience of being guided" (in reading) may be, it is not (contrary to Hume) something with an identifiable introspective character like a headache. In particular cases of reading, we may have definite introspective experiences, but they are different and distinct experiences, particular to each individual, not a single experience present in all cases of reading. The presence or absence of the elusive feeling of being guided is not constitutive of whether I am reading or not. Kripke enlphasizes, however, that Wittgenstein's method of investigation is deeply introspective; it is the kind of investigation a strict philosophical behaviorist would reject. While Wittgenstein has important affinities to behaviorism, he insists at the same time that anyone who does not think of me as conscious is wrong about the facts. Understanding is not a mental process as a pain growing more or less, or the hearing of a tune or sentence are mental processes. Kripke's point is that Wittgenstein's real concern is not with image but with philosophical terminology. Thinking of understanding as a mental process leads to misleading philosophical pictures but Kripke concludes that this does not mean necessarily that they are wrong 14 • On the other hand, mathematical realists have emphasized the nonmental nature of
13. ibid. p. 46. 14. ibid. p. 50, n13.
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mathematical entities. The addition function is not in any particular mind, nor is it a common<property of all minds; it has an independent "objective" existence. The proof that the addition function contains such a triple (68, 57, 125) belongs to mathematics, and has nothing to do with meaning and intention 15 • Kripke insits, however, that ultimately the skeptic's problem must be faced by the mathematical realist, and it consists precisely in the question how the existence in my mind of any mental entity can constitute "grasping" one particular sense rather than another. For Wittgenstein, Platonism is largely an unhelpful evasion of the problem of how our finite minds can give rules that are supposed to apply to an infinity of cases. Platonic objects may need no interpretation, but ultimately there must be some mental entity involved, which raises the skeptic's problem in the opinion of Kripke. He insists that the skeptic's problem remains unanswered - there can be no such thing as meaning anything by a word. Each new application we make is a leap in the dark, and any present intuition could be interpreted so as to accord with anything I choose to do. So there can be neither accord nor conflict. Kripke emphasizes the analogy between what he takes to be Wittgenstein's skeptical problem and Quine's indeterminacy of translation and the inscrutability of reference. Quine also questions whether there are any objective facts as to what we mean. But Quine bases his argument from the outset on behavioristic premises. Since he is not interested in introspective thought experiments in the manner of Wittgenstein, he does not regard views that posit a private inner world in need of elaborate refutation. For Quine, the untenability of such views should be obvious to anyone who accepts a modern scientific outlook. Because Quine sees the philosophy of language within a hypothetical framework of behavioristic psychology, he thinks of problems about meaning as problems of disposition to behavior. On the other l1and, the important point for Wittgenstein is that any present mental state does not appear to determine what I ought to do in the future. Although I may feel now that something in my head corresponding to the word "plus" mandates a definite response to any new pair of
15. ibid. p. 54.
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arguments, in fact nothing in my head does so. For Quine, since any fact as to whether I mean plus OI,~ quus will show up in my behavior, there is no question, given my disposition, as to what I mean 16. But Kripke finds such a formulation of the issues inadequate. He points out that my actual dispositions are not infallible nor do they cover all of the infinitely many cases of the addition table. In Philosophical Investigations para. 243, Wittgenstein emphasizes that without some external check on my identification of my own sensations, I would have no way of knowing that I have identified a given sensation correctly (in accord with my previous intentions). To the extent that I rely on my impressions or memories of what I meant by various sensation signs for support, I have no way of quelling my doubts. Only others who recognize the correctness of my identification through my external behavior, can provide an appropriate external check 17. Kripke points out, however, that if I really were in doubt as to whether I could identify my sensations correctly, the identification of my sensations with external behavior would not be of any help either. My capacity to identify external phenomena rests on my ability to identify relevant sensory (especially visual) impressions. If I were to doubt my ability to identify any of my own mental states, it would be impo-ssible to escape from it l8 • The recognition of anything public rests on the recognition of my inner states. Unless there is something one is allowed to recognize, no test can ever be completed. It is through hearing what other people say, or through reading what they write, or by observing their movements, that I am able to conclude that their use of a word agrees with nline. But if without further ado I can recognize such noises or shapes or movements, why cannot I also recognize a private sensation?19. In the opinion of Kripke, the main problem is not, "How can I show private language to be impossible?" rather it is, "How can we show any language (private or public) to be possible?" Wittgenstein appears to have shown all language, all concept forma-
16. 17. 18. 19.
ibid. ibid. ibid. ibid.
p. p. p. p.
57. 60, n47. 61, n47. 62, n47.
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tion, to be impossible, indeed unintelligible. 20 But Kripke does not use this as an argument against Wittgenstein; instead he constructs him to hold that there is no fact of the matter. It is a case of language running idle and as a consequence lacking meaning. Kripke's point is that the notion of following a rule is presupposed in any such argument. However, that we have to take following a rule ultimately for granted \vollid not have been regarded by Wittgenstein as a skeptical paradox. Indeed it is most likely that he would have considered Kripke's interpretation as a specimen of language running idle. That our explanation has to stop somewhere is the standard reply of common sense philosophers against Humean doubts. Once we have explained the social circumstances of adding, for example, there is nothing more to explain, and all further questions miss the point. Hume is thus the prime source of those ideas on the nature of mental states that Wittgenstein is most concerned to attack. Kripke has to admit that Wittgenstein would never have avowed the label of skeptic as Hume explicitly did 21 • Kripke questions the prevailing interpretation of Wittgenstein as a common sense philosopher anxious to defend our ordinary conceptions and dissolving traditional philosophical doubts. He rejects Wittgenstein's claim of a "philosop'hical misllnderstanding of common language," and his argument that the ordinary man means nothing at all when following a rule 22 • In particular, Kripke questions Wittgenstein's contention that traditional philosophers are like savages, primitive people, who hear the expressions of civilized men, put a false interpretation on them and then draw the queerest conclusions from it 23 • .Kripke rightly points out that, as a philosophical doctrine, this becomes self defeating. He has to admit, however, that his own hypothesis that we mean quus by addition cannot be maintained seriously. Indeed, what Wittgenstein considers a primitive misrepresentation of language, Kripke finds quite attractive 24 • Witt-
20. ibid. p. 62. 21. ibid. p. 63. 22. Philosophical Investigations, Ope cit. par. 183-93.
23. ibid. par. 194. 24. Kripke, Ope cit. p. 66.
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genstein does not wish to deny tbat when people speak of themselves and others as meaning something by their words, or following rules, they do so with perfect right. "The sentence only seems queer when one imagines a different language game for it than the one in which we actually use it. "25 Philosophically our difficulties arise when we try to give a precise formulation of exactly what it is we are denying - what "erroneous" interpretation our opponent is placing on ordinary means of expression. Kripke concludes that it may be hard to do this without producing yet another statement that, we must admit, is still "perfectly all right, properly understood." 26 In this manner, however, some major part of Wittgenstein's philosophical investigations becomes inconclusive. The skeptical·paradox as presented by Kripke leads one to the conclusion that the workings of language are ultimately mysterious and this is precisely why Wittgenstein denies being a skeptic. Against Wittgenstein's later philosophy in the Investigations, Kripke argues that the simplest and most basic idea of the Tractatus hardly can be disn1issed - that a declarative sentence gets its meaning by virtue of its correspondence to the facts that must obtain if it is true. In place of this view, Wittgenst~in proposes an alternative rough general picture according to which we have different activities related to each other in various ways. Wittgenstein replaces the question, "What must be the case for this sentence to be true?" by two others. First, "Under what circumstances may this form appropriately be asserted (or denied)?" Second, given an answer to the first question, "What is the role and the utility in our lives of our practice of asserting (or denying) the form of words under these conditions?"27 Wittgenstein does not confine himself to declarative sentences, and hence to assertion and denial. On the contrary, in the Philosophical Investigations he is out to deny any special primacy to assertion or to sentences in the indicative mood. This in itself plays an important role in his repudiation of the classical realist picture. The picture of language he proposes is based not on trllth conditions but on assertion conditions or on
25. Philosophical Investigations, par. 195. 26. Kripke, Ope cit. p. 70. 27. ibid. p. 73.
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justification conditions. Consequently, for Wittgenstein there is an important class of cases where a use of language properly has no independent justification other than the speaker's inclination to speak thus on that occasion (e.g. saying that he is in pain). It is essential to our working of language that in some cases such a use is perfectly proper. In other words, there are cases when Wittgenstein would say there is no justification. But even then a role must exist in our lives for this use, for otherwise this aspect of a language game becomes idle. Likewise, against the Platonic conception of mathematical entities Wittgenstein asks that we discard any a priori conceptions and look at the circumstances under which numeral assertions are actually made, and what roles such assertions play in our lives. His conclusion is that no facts, no truth conditions, correspond to statements such as "Jones means addition by '+'." But Kripke points out that from such a skeptical position it will follow that assertions of anyone ever meaning anything are themselves meaningless. In Philosophical Investigations Wittgenstein merely indicates that no supposition of facts "corresponding" to assertion is needed. He does not find a useful role in our lives for a language game that someone "means" suchand-such, and that his present application of a word "accords" with what he meant in the past. It is very likely that Wittgenstein would have rejected Kripke's construal of a "skeptical paradox" by pointing out that there is no room in our lives for the quus hypothesis of addition. Wittgenstein emphasizes that ostensive definitions are always capable of being misunderstood. How someone understands a word is established in the way he goes on, "the use he makes, of the word defined." One may go on in the right way given a minimal explanation, and on the other hand, one may go on in another way, no matter how many detailed clarifications are added, since they too can be misunderstood. Much of Wittgenstein's argument is directed against the view of a special qualitative unique experience of understanding the ostensive definition in the right way28. Wittgenstein's earlier work had taken for granted a
28. Philosophical Investigations, par. 33-6.
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natural relation of interpretation between the thought in someone's mind and the "fact" it depicts. The relation was supposed to consist· in an isomorphism between mental events and facts in the world and it is Wittgenstein's rejection in the Investigations of this idea that Kripke finds to be "paradoxicaL" It is important to realize that we are not looking for meaning and" sufficient truth conditions for following a rule, or an analysis of what such a rulefollowing consists in. No one actually hesitates to produce an answer to an addition problem. But we do so without justification. The entire point of the skeptical argument is that ultimately we reach a level where we can act withollt any reason in terms of which we can justify our action. We act unhesitatingly but blindly29. It is part of our language game of speaking of rules that a speaker may, without giving any justification, follow his own confident inclination that this way (say, responding "125") is the right way to respond to "68 + 57," rather than another way (e.g. "5"). If we confine ourselves to looking at one person alone, his psychological states, and his external behavior, this is as far as we can go. The whole point of the skeptical argument is that there can be no facts about him in virtue of which he accords with his intuitions or not. But Kripke points out that this is not our usual concept of following a rule. Only as long as we regard an individual as following a rule' 'privately," so that we pay attention to his justification conditions alone, can we say that he is licensed to follow the rule as it strikes him. The situation is very different, however, if we widen our gaze and allow ourselves to consider him as interacting with a wider community. Others will then have justification conditions for attributing correct or incorrect rule following to the subject, and there will not be simply that the subject's own allthority is unconditionally to be accepted. When I say that "the teacher judges that, for certain cases, the pupil must give the "right" answer, I mean that the child has given the same answer he himself would give. Something quite similar happens in the case of adults. Any individual will be judged to have mastered the concept of ad-
29. Kripke, Ope cit. p. 87.
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dition by the community if his particular responses agree with those of the community in enough cases': especially the simple cases (and if his "wrong" answers are not bizarrely wrong, as in "5" for "68 + 57", but seem to agree with ours in procedure even when he makes a conceptual mistake). An individual who passes such tests is admitted into the community as having mastered addition, and an individual who passes such tests in enough other cases is admitted as a normal speaker of the language, and as a member of the community. Those who deviate are corrected (casually, as children) that they have not grasped the concept of addition. One who is a incorrigible deviant in enough respects simply cannot participate in the life of the community and in communication 30 • The customer, when he deals with the grocer and asks for five apples, expects the grocer to count as he does, not according to sonle bizarre nonstandard rule. OUf entire lives depend on countless such interactions and on the "game" of attributing to others the mastery of certain concepts or rules, thereby showing that we expect them to behave as we d0 31 • Since this expectation is not always fulfilled, it places a substantive restriction on the behavior of each individual, and is not compatible with just any behavior. In this respect it differs considerably from the case where we considered a person alone. When the community denies of someone that he is following certain rules, it excludes him from various transactions, such as the one between the grocer and the customer. Wittgenstein in effect argues that we do not all say 12 + 7 = 19, and the like, because we all grasp the concept of addition; rather we all grasp the concept of addition because we all say 12 + 7 = 19, and the like. Kripke on the other hand, rejects this argument 32 ; he points out that if Jones does not come up with "125" when asked about "68 + 57," we cannot assert that he means addition by "+ ." If, however, we ascribe to Jones the conventional concept of addition, we do not expect him to exhibit a pattern of bizarre, quus-like behavior. Wittgenstein claims that it makes no sense to ask why in practice such divergent behavior rarely occurs. But
30. ibid. p. 92. 31. ibid. p. 93. 32. ibid. p. 94, n76.
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Kripke rightly considers this a perfectly legitimate question. The fact that almost all of us, after sufficient training, respond with roughly the same procedures to concrete addition problems remains mysterious in Wittgenstein's philosophy. Beings who agreed in consistently giving bizarre quus-like responses would share another form of life. By definition, such another form of life would be bizarre and incomprehensible to us. However, if we can imagine the abstract possibility of another form of life (and no a priori argument would seem to exclude this), the members of a con1munity sharing such a quus-like life form would play the game of attributing rules and concepts to each other much as we do. Be this as it may, there is no objective fact - that we all mean addition by " + " or even that a given individual does - that explains our agreement in particular cases. Rather our license to say of each other that we mean addition by " + " is part of a language game that sustains itself only because of the brute fact that we generally agree 33 • It is this counterintuitive doctrine that renders Wittgenstein a skeptic in the eyes of Kripke, for to ask why we generally agree seems to Kripke a quite legitimate question. Contrary to his claims, Wittgenstein questions the intuitions of ordinary people. Nor does he seriously expect such basic agreement to break down because it would then become impossible to talk of a "language game" in the first place. Kripke raises the interesting question whether we can imagine creatures who follow rules in a bizarre quus-like fashion. He points out that there is a tension in Wittgenstein's philosophy between two unreconciled attitudes. On the one hand, there is for Wittgenstein no a priori reason why a creature could not follow a quus-like rule, and in this sense we ought to regard such creatures as conceivable. But at the same time it is supposed to be part of our very form of life that we find it natural and indeed inevitable to follow a rule for addition in the particular way we do. It therefore seems that we should be unable to understand "from the inside" how a creature could follow a quus-like rule. We can, of course, define the quus function, introduce a symbol for it, and follow the ap-
33. ibid. p. 97.
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propriate rule for computing its values - as Kripke in fact does. What it seems might be unintelligible to us is how an intelligent creature could get the very training we have for the addition function, and yet grasp the appropriate function in a quus-like way34. Kripke himself thus has to admit that the skeptical paradox he is ascribing to Wittgenstein may not be intelligible after all. For if the quus function were intelligible, we would not find it inevitable to apply the plus function as we do. To talk of a life form and to say at the same time that it cannot be questioned seems an arbitrary postulate on the part of Wittgenstein. Indeed, it is only this dogmatic assertion that a life form cannot be questioned that sustains Kripke's skeptical paradox. It would seem, however, that in Wittgenstein's view only the basic fact of agreement has to be accepted as given, while agreement or disagreement in particular cases of testing is not given in advance, and has to be decided according to circumstances. Kripke's skeptical problem turns on the idea that each person who claims following a rule can be checked by others. But at the same time he denies that outward behavior be regarded as conclusive evidence for what goes on in our mind. What complicates evaluating Kripke's skeptical paradox is his admission that he is suppressing his disagreements with Wittgenstein 35 . He does, however, reject the view that an inner process always has outward criteria as empirically mistaken. Kripke thus questions not only the behaviorism of Quine but also that of Wittgenstein in some of its crucial aspects. Kripke's Humean interpretation of Wittgenstein stresses introspection as a legitimate philosophical method. Kripke points out that we have sensations or sensation qualia we can identify that have no "natural" external manifestations. While he tries to retain irltrospection as a tool for philosophical analysis, this crucially calls in question Wittgenstein's whole idea of a life form. By admitting the identification of private sensations 36 , Kripke in effect accepts both a private language and the private following of a rule - and this is, of course, precisely what Wittgenstein was out to deny. His
34. ibid. p. 98, n78. 35. ibid. p. 103, n83. 36. ibid. p. 103.
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language game of attributing concepts to others depends on agreement, while no such agreement can ever b;e conclusive according to Kripke's interpretation. In mathematics, likewise, we judge that someone has mastered various concepts from the fact that he agrees with us in enough particular cases of mathematical judgment, and that when he disagrees, we are operating with a common paradigm. By means of Kripke's skeptical paradox, we are supposed to realize that it is no help to ask whether he has mastered the concept of addition. But in some sense, at least this seems a perfectly legitimate question. For Wittgenstein, Kripke's quus interpretation of addition would simply not be part of our life form, and, therefore, incomprehensible. Kripke by contrast insists that mathematical finitists and psychological behaviorists make parallel unacceptable moves when they deny the legitimacy of infinite mathematical objects or inner states. He rejects such views as misguided because they are an attempt to repudiate our ordinary language game. In this game, we are allowed for certain purposes to assert statements about "inner states" or infinite mathematical functions under certain circumstances 37 • What Wittgenstein rejects is their metaphysical interpretation (e.g. the existence of an ego, or the reification of time, and the like). The ways language misleads us are manifold and subtle, and by no means easy to detect, let alone eliminate. Any statement about how language misleads us is necessarily itself in language and, therefore, open to the same kinds of objections as is the original statement. What constitutes a life form, and what makes sense to say under such-and-such conditions is the very opposite of "primitive," as Wittgenstein's Philosophical Investigations amply demonstrate. Even such an apparently uncomplicated rule as addition permits a quus interpretation in the opinion of Kripke. He, therefore, concludes that Wittgenstein's refutation in the Investigations of his previous Tractatus position remains incomplete at best. Kripke shows that if nothing I have done determines future ap~ plications, language no longer serves communication and becomes incomprehensible. To dismiss, as Wittgenstein does, such ques-
37. ibid. p. 107.
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tions as illegitimate does not[~constitute a solution because our criteria for what it makes sense to say are themselves controversial. Wittgenstein would never have considered himself a skeptic in Kripke's sense because he never would have doubted that we can understand such language games as addition. Hume's dissatisfaction with mere common sense 38 is an essential part of his skepticism, while Wittgensteirt regards Hume's skepticism as pointless as long as it fails to have publicly observable consequences. Wittgenstein would have rejected Kripke's quus hypothesis of addition for a similar reason. He would have pointed out that we must look at the circumstances under which assertions of addition are introduced into discourse, and their role and utility in our lives. But for Kripke such a procedure remains inconclusive. Contrary to Wittgenstein, Kripke does not regard agreement as unproblematic mainly because the judgment we make by observing an individual's behavior may admit a different interpretation when looked at "from the inside." Wittgenstein's test is simply that an individual does as we do, so that the very notion of following a rule is fictitious. The rule is not something abstract; rather it characterizes a certain kind of behavior. If an individual does not as we do in enough cases, he is no longer considered a member of the community, but whether we consider him a member of our community is primitive and not open to further clarification. Kripke points out, however, that what may be primitive in one language game, may not be primitive in another, and what is open to clarification even in the same life form is not a priori given. As Russell pointed out, the appeal to utility is not anymore self-evident than is the appeal to facts or to observable behavior. Only with reference to the Tractatus does it make sense to talk of Kripke's "skeptical solution of a skeptical paradox," while the later Wittgenstein would have rejected all such talk as meaningless. In the Investigations, Wittgenstein never dou'bts that we can "see" how language works.
38. Hume, Treatise, Ope cit. p. 271.
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CHAPTER XII
TOULMIN'S INTELLECTUAL ECOLOGY
Toulmin argues that evolutionary changes do not display any single long term direction - still less that it is their business to harmonize with the larger cosmic purpose l • Darwin's theories were built from the very beginning around the novel conception of organic species as modifiable populations possessing not a specific essence but a statistical distribution of properties and of the "peak" or "mean" of these populations as shifting in the face of ecological changes. When the Origin oj Species first appeared in 1859, the general intellectual debate was not ready to absorb the new populational mode of thought. At that time, the term "evolution" had other quite different implications of providential progressivist change. Within the whole German tradition of historicism - both in its idealist Hegelian and materialist Marxist forms - great stress was laid on the rationality of the historical process. Toulmin, by contrast, interprets evolution in biological Darwinist terms as concerned with questions of adaptiveness or adequacy. He rejects the theological implications of dialectics by emphasizing that in practice we can judge rational adequacy of organic or social change only relatively to the needs of particular problem situations as they occur. Ideological principles of a totally general or cosmic kind give us no precise criteria of judgment. In social and political history, as in the history of scientific thought, the "dialectic" lies primarily in our writing of history rather than in the historical events about which we write 2 • An organic species,
1. Stephen Toulmin, Human Understanding, Princeton University Press, New Jersey, 1972, p. 323. 2. ibid. p. 330.
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however, is not a permanent entity defined by unchanging essential characteristics; yet neither are its Tepresentative exemplars associated merely by our own verbal decisions. The same is true of a society, a culture, or a language: each is a historical entity, i.e. an individual whose component elements are at all times subject to classification. Toulmin not only rejects Aristotelian essences but also all "systematicity" in such conceptual change. The point to note, however, is that these two factors are epistemologically independent; the metaphysical doctrine of permanent essences drew empirical support from the success of Aristotle's theory of fixed species, which was its most convenient application to our actual experience of the world. Darwin, on the other hand, demonstrated that Aristotle's most favored examples failed to support the metaphysical assumptions on which his natural philosophy had been based. Species were not, after all, permanent entities; their typological and essentialist taxonomy inherited from Aristotle misrepresent the long-term history of living beings. As we now understand it, nothing in the empirical world possesses the permanent unchanging identity that Greek philosophers presupposed as the ultimate elements of nature. This tradition proved difficult to dislocate. Kant still believed that it was possible to judge the rationality of theoretical concepts and of practical procedures once and for all. He took it for granted that our everyday ways of handling spatio-temporal ideas, subjectpredicate logic, arid even Newton's dynamic and gravitational concepts represe"nted the one and only rationally coherent treatment of experience. But from an evolutionary perspective Kant's "necessary forms of judgment," or, for that matter, Chomsky's "structures of deep grammar" have to be regarded as the current end products of a long historical development. Kant's unqualified acceptance of Euclid's theorems and of some of Newton's ideas became increasingly an embarrassment. So nowadays more weight is placed on the indispensability of our basic concepts for the organization of language and practice than on the logical necessity of any particular proposition. Psychologists like Piaget and Kohlberg are committed to the idea that certain very general patterns of thougl1t or action are indispensable in all genuine experience and knowledge. These patterns are regarded as the universal long-term goals of intellectual and moral development. But in 158
problematic situations it simply may be misleading to describe the experience of infants or men from other milieus entirely in our language. Toulmin argues that the "deep structure of all language" is consequence, not of our genetic properties alone, but also of the typical interplay between human beings and the practical tasks on which they have occasion to exercise them 3 • The trouble is that such similarities in the environment are much more difficult to identify than are those of genetic structure. He believes that the historical and cultural diversity of our concepts gives rise to intractable problems only so long as we continue to think of "rationality" as the characteristic of a particular system of propositions and concepts. In other words, he treats science as if it were a Wittgensteinian "life form." Against Popper and Lakatos he argues that what has to be demonstrated is not that rational procedures of scientific inquiry have, after all, a kind of "logic" of their own. Rather, we need to explain how the formal structures of propositional logic are put to work in the service of rational interpretations at a1l 4 • Focusing on the intellectual environment, Toulmin treats science as a self-contained social ritual, subject only to "internal" constraints. But the rationality of a mature science cannot be separated from a discussion of the specific terminology in which theories have been formulated. The much greater accuracy and predictive power of such theories is largely due to an improved quality of instruments. What caused Galileo's ideas finally tc prevail was the invention of the telescope. Darwin's theories, by contrast, required only a conceptual adjustment capable of dealing with much larger time spans. Darwin faced the additional problem of having to decide what is sufficiently alike to be capable of being rationally compared. The "facts" of evolution are a matter of theoretical construction; they cannot be established by simple inspection. That we are all men, and live the lives of men, does not by itself constitute a standard of comparison among different milieus, because what constitutes this commop "human nature" is precisely the issue. To appeal to "scientific understanding in general," as Toulmin does,s is really question3. ibid. p. 467. 4. ibid. p. 479. 5. ibid. p. 495.
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begging. Arguing that men face some general and common problems regardless of milieu, and that these shared problems call for the development of corresponding sets of techniques, concepts, and procedures, he in effect appeals to precisely the kind of logic and systematicity he ostensibly has rejected. In historical terms, he proposes to judge rational compatibility by the "long enough run,"6 even though he can know this only by hindsig11t. Whether the atomism of Democritus and Epicurus can be compared rationally with that of Boyle and Rutherford very much depends on our theory of the atom being speculative or empirical. Such a distinction, however, is itself by no means obvious or clear-cut. Lacking criteria of consistency, Toulmin's "intellectual ecology" is no more than a metaphor. Change of belief considered as mere adjustment does not become rational without "external" criteria. Structural problems of this kind cannot be settled on empirical grounds alone, because what the relevant facts are depends partly on our theories. It makes all the difference whether we regard stability as such to be intelligible, or deny this, as Toulmin does, on a priori grounds. Only if we are convinced that conceptual change is both inevitable and universal does it make sense to prefer historical method to "logic" in spite of its inconclusive character. But even in this case, syntactical consistency will still be necessary in our descriptive language. Toulmin's "intellectual ecology" finally turns around the· question what is to be taken as science. If a given context lacks both logical and syntactical consistency, we face a semantically segmented domain, which may no longer be coherent. Radical incomprehension among the segments may indeed be unavoidable under such conditions. A science can tolerate some degree of inconsistency amo11g its theories, but not isolated conceptual domains, for these no longer share the common intellectual purposes that make up a discipline. Toulmin proposes Darwin's populational theory of variation and natural selection as a general model of explanation in the history of science. The problematic questions now have to do with the circumstances under which advantageous variants selectively can be perpetuated.
6. ibid. p. 498.
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Darwin's zoological use of terms like "selection" and "advantage" invoke an implicit metaphor of choice."'Yet his theory of evolution precisely denies the foresight in such choise. Toulmin's theory of "intellectual ecology" depends upon an interlocking set of assumptions that turn out to be largely circular and, therefore, inconclusive. Denying logical criteria, he is unable to establish valid comparisons between the evolution of organisms and the gradual transformation of concepts. To discuss "intellectual ecology" in terms of variation and natural selection, we have to explain why certain ideas did not survive, Le. to offer an argument. Moreover, the explanations given must be cumulative and not merely ad hoc. Even when a history of science deals with specific events, this is always part of a more general picture. The "facts" of science do not speak for themselves, they are theory dependent and to that extent subject to the logic governing those theories. Toulmin realizes that problems in science emerge by comparison of "ideas" with "experience, "7 but he fails to see that the ideas in question are linked logically by relevant theories. It is one thing to reject a single ideal of explanation such as Plato and Descartes found in formal geon1etry, and quite another to deny even syntactical consistency to our descriptive language. Toulmin finds himself unable to generalize about the relevant criteria of evolutionary "merit," "succes," or "superioritY,"8 and this effectively prevents him from writing any history of science at all. In terms of mere intellectual ecology he cannot distinguish between prejudiced beliefs and rationally prefered concepts. He argues that we are justified in trusting our ideas only because - and to the extend that - they have proven their worth in competition with alternatives 9 But without a shared logic, neither alternatives nor competition between them can be identified. Thus, no history of science can be written in terms of mere local intellectual ecologieso Evolutionary theories have a narrow biological and an extended philosophical scope. Yet contrary to Toul0
7. ibid. p. 151. 8. ibid. p. 315. 9. Stephen Toulmin, Foresight and Understanding, Harper Torchbooks, New York, 1961, p. 102.
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min,IO it is the original speculative meaning of evolution that still plays a decisive role even in Darwinist theories. When Darwin abandoned the idea that the scale of nature is fixed, this had farreaching ideological consequences. Toulmin insists that such cosmological questions have nothing to do with the ultimate importance of our mundane affairs. But by denying the privileged position of man in the natural order of things, Darwin changed our historical perspective in a radical manner. Contrary to Toulmin, there are quite legitimate reasons for rejecting certain world views. 11 He himself emphasizes that the Darwinist theory of evolution is altogether incompatible with a progressivist or teleological understanding of the world. Once we take Darwin seriously, we are no longer at liberty to view the cosmic process in whatever light we please, as Toulmin maintains. 12 Part of the ambiguity inherent in such terms as. "evolution" is due to the difficulty of applying a static Aristotelian logic to changing entities. While Toulmin claims such stability for the genetic code that controls the hereditary process, he denies it to the rational observer. Yet this crucially depends on how demanding our standards of consistency are. Once we admit partial agreement between concepts, it becomes possible logically to link deductive logic with historical method. It was his commitment to a static ontology and taxonomy by which Aristotle was able to make formal logic the prime instrument of scientific explanation. With an evolutionary world view by contrast, no such description can be trusted to hold indefinitely. A proper evolutionary way of dealing with experience obliges us to recognize that no event or object has any single unan1biguous description. Conceptually, however, such transformations ensure continuity by a partial overlapping of meanings. Lacking such continuity, we may not even have a recognizable subject matter to deal with, and all arguments based on intellectual ecology remain inconclusive.
10. Press, 11. 12.
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Stephen Toulmin, The Return oj Cosmology, University of California Berkeley, Los Angeles, London, 1982, p. 28. ibid. p. 64. ibid. p. 138.
CHAPTER XIII
GOODMAN'S METAPHORICAL TRUTH
Goodman attempts to reconcile his radical relativism with making valid distinctions between right and wrong theories, interpretations and works of art. Stressing the cognitive functions of emotion, he rejects realism in favor of irrealism I and dismisses as naive the idea that science seeks truth while art seeks beauty. He emphasizes that science seeks relevant, significant and illuminating principles, and that we often set aside trivial and oversimplified truth in favor of powerfull unifying approximations. Stylistic affinities and differences we do not discern by rational analysis alone but by means of perceptions and feelings sharpened in practice. Cognition is involved not merely in understanding the works themselves but in "making" tl1e several worlds - of perception, sense, practice - that we live in. A symbol may inform in as many ways as there are contexts and systems of appreciation 2 • He, therefore, 'concludes that the question what we are seeing actually, or natively, or partly, or without interpretation is vacuous 3 • Under different frames of reference, the earth moves, and the earth stands still. While we are tempted to say that the facts are detern1ined when the framework is chosen, Goodman insists that the facts and the framework differ only in scope. There is no one correct way of describing or picturing or perceiving "the World"; rather there are many equivalent right but conflicting ways ~ and thus in effect many actual worlds. Nothing is fixed completely and
1. Nelson Goodman, Of Mind and Other Matters, Harvard University Press, Cambridge, London 1984, Preface. 2. ibid. p. 12. 3. ibid. p. 13.
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finally. The search is no longer fof a raw given or final or fixed form of the understanding or a unique mandatory system of categories. Goodman emphasizes that thinking is not in words alone, and that we can think in pictures as we think in words 4 • The forms and the laws in our worlds are not ready-made to be discovered but are imposed by world versions we contrive - in the sciences, the arts, perception, and everyday practice. How the earth moves, whether a w.orld is composed of particles or waves of phenomena are matters decided not by passive observation but by painstaking fabrication. Species do not come prepackaged; they depend on the relative weight put on certain features for given purposes. What or even whether I perceive depends on my state of perceptual readiness. Habit, context, explicit instruction of all kinds can blind or activate perception. Far from .only recording what is before us, perception participates in making what we perceive. The problems of judging or perceiving a symbol are by no means independent of the forms of what we think in. He concludes that what there is consists in what we make, and rejects the idea that anything at all is "given." But in this way the very distinction between appearance and reality is lost, which seems to be crucial for doing work both in the sciences and in the arts. Since Goodman's irrealism cannot prevent worlds from' 'melting" into versions 5 , the precise manner in which a version "makes" a world becomes obscure. It seems that this is largely metaphor, which Goodlnan somehow takes literally. In spite of his protestations to the contrary, his criteria for what makes a version "right" and a world "well-built" turn out to be not logical but ultimately aesthetic. At the same time, he rejects platonism as a legitimate method of making a world version, even though as an irrealist he legitimately cannot claim individuals to be any more real than are classes. Try as he might, he is unable to get away from an implicit assumption of one real world since this is deeply entrenched in all our ordinary ways of talking. That is how he "understands" that in any true world version there is only one earth, and that this earth is not flat. Goodman's postulated plurali-
4. ibid. p. 20. 5. ibid. p. 29.
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ty of worlds is not less fictive than is the real world he claims to reject. To say that "we live in diff~rent worlds at the same time" is no more than a metaphor, Le. the application of a name or description to an object to which it is not literally applicable (e.g. a glaring error). We reject mixed metaphors to the extend that they remain dependent on their original literal meanings, and this depends upon context, which often is not decidable logically. To speak of "true" metaphor is misleading because the appropriateness or inappropriateness of a metaphor is not merely logical but at least partly aesthetic. Goodman's metaphor of a multiplicity of worlds is not a construction in space and time but only a grammatical construction, a figure of speech. Logically, worlds are totalities and to postulate a multiplicity of totalities is prima facie self-contradictory as long as it is taken literally. To shift our point of view or frame of reference from the earth to the sun does not, therefore, make a new world literally, only metaphorically. As Goodman becomes aware of the logical problems he has created, he is forced to restrict his discussion to differing world versions each of which does not yet constitute a full-fledged world. But now he has to explain how a version becomes a world, and why some versions are transformed into worlds while others are not. If nothing is "out there," as Goodman insists, what is it that prevents us from creating versions any way we like? Goodman believes that we can make the earth move and the sun stop by verbal convention 6 but it is one thing to argue that we create kinds as relevant classes in this manner, and quite another that we literally create the objects by verbal stipulation. What Goodman calls a "well-made version" is really a class of objects belonging together, and thus something a consistent nominalist should reject. He argues that the differences between worlds should not be thought of as differences in grouping 7 , while insisting that what makes a category "right" is its adoption in inductive practice, which takes some such sorting for granted. He fails to explain why certain practices become entrenched while others do not. He attempts to justify his distinction between truth and accep-
6. ibid. p. 34. 7. ibid. p. 36 n.
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tability by claiming truth to be constant and acceptability merely transients. But what makes a world unreal is precisely the fact that nothing in it is constant. All entrenchment is only a matter of habit, which may change at a moments notice for no apparent reason. Like Hume, he considers habit as an integral part of truth, yet unlike Hume he insists that we also create the context in which habit is reinforced. Thus, even what is altogether acceptable at the moment may later on become unacceptable, and what makes a world version true or false remains altogether mysterious. Considered as a mere version of appropriateness, truth can be no more than a transitory form of entrenchment. What is right or appropriate cannot be decided from inside the system and thus becomes arbitrary in the last resort. The irony is that, following Quine, Goodman rejects the very distinction between internal and external questions 9 • The issue whether different world versions are cOlnmensurable or consistent no longer arises once they are taken as due to "external" decisions. All we can do, according to Goodman, is follow our intuitions, and there is finally nothing to reconcile conflicting insights, as those that separate him from Quine. Since anything may be taken as an individual, a world may be composed in any conceivable manner. Even simplicity does not constitute an effective guiding principle because, according to Goodman, it is up to us to make any world version as simple or as complex as we wish. He finds himself unable to draw a line between world features that are discourse dependent and those that are not. Thus, he concludes that all such features are metaphorical. But in this manner Goodman has no longer any effective defense against the relativization of truth. While we may make world versions as simple or as complex as we wish, it is not meaningless to ask whether or to what extent any of our versions refers to or reflects the real world. He admits materialism to be one legitimate way of explaining phenomena (while rejecting its absolutist claims) but he repudiates platonism as unnecessary and confusing. This, however, is done finally on aesthetic grounds - he simply does not like to talk that way while admitting that Quine may have what for
8. ibid. p. 38. 9. ibid. p. 95.
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him are valid reasons for giving up nominalism. It is certainly not obvious why platonism is not at least one legitimate way of understanding the world; after all, in mathematics platonism is doubtless well-entrenched, and has a long and flourishing tradition. Given Goodman's insistence that nothing real is involved in all this, it seems quite arbitrary on l1is part to insist that world versions must be made up of individuals, or that the mechanism of classes must be avoided at all cost. At the root of these difficulties lies Goodman's complicated notion of reference, which he takes to be primitive. Being metaphorical, his ways of reference are largely hybrid and indeterminate. Whether and to what extent a symbol is "iconic" or factually depicts its subject matter may vary without change in the symbol or what it denoted. However, an examination of how close an analogy to verbal quotation we have in painting or music will bring out plainly the decisive differences between literal truth and metaphorical appropriateness. A symbol may denote metaphorically what it does not refer to literally. Such n1etaphor arises by transferring a schema of labels for sorting a given realm (or the same realm in a different way) under the guidance or influence of the earlier sorting. Goodman insists that the new sorting, while being different, is as genuine as is the original "factual" one 10 , but all he succeeds showing is that one is as groundless as is the other. It is to ignore that metaphorical statements are as a rule factually false. Indeed, Goodman's decision to treat the literal and factual as a subspecies of the metaphorical inevitably creates a host of formidable paradoxes. Even if one agrees with Goodman that there is no such thing as a reality consisting of objects, events or kinds established independently of discourse, it does not follow that language literally creates reality. What we normally call "real" precisely constrains discourse in ways we cannot otherwise justify or predict. To say, therefore, that "the earth stands still, revolves about the sun, and runs many another course all at the same time" 11 should be regarded not as literal truth but as metaphor. It is likewise misleading to maintain that discourse creates reality, if this is taken literally.
10. ibid. p. 61. 11. ibid. p. 30.
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Thus, what makes Goodman's world versions collapse are mere changes in our manner of speal\ing. Unlike literal truth, a metaphor may lose its dominance for no reason at all, and it cannot, therefore, be falsified conclusively either. A metaphor may replace "natural kinds" with novel and illuminating categories, but it does not contrive new facts literally or create different . worlds. Since metaphorical appropriateness is compatible with literal falsity, Goodman's world versions can factually neither be verified nor refuted. What makes a metaphor differ from literal ambiguity is that literal application precedes and influences its correlative metaphorical use. Contrary to Davidson 12, Goodman insists on retaining the notions of metaphorical "truth" and "falsity. " But what makes metaphors apt is often not a matter of logic but of aesthetics. Even when metaphorical applications seem quite clear, they work by analogy rather than by identity or nonidentity. While words combine with other words to make statements that can be falsified, metaphorical similarities and dissimilarities often cannot be settled. Only literal statements offer us logical truth or falsehood and, therefore, decidability. To take metaphorical aptness as logically equivalent to literal truth amounts to a category mistake. Ordinary language is, of course, always partly metaphorical, face such language is, on the face of it, quite different from the literal statements and theories stated in the language. But to know a language is to understand at least initially the literal statements expressed in it, for it is only after we understand the literal applications that we are in a position to phrase metaphors. Thus, by treating literal truth as a species of metaphorical appropriateness, Goodman reduces his logical criteria to the level of aesthetic preferences. He is then no longer in a position to decide what belongs to a particular world version, and what, if anything, has the power to "unmake" it. To take a metaphorical world version as appropriate is to treat it as dominant but this is not done merely on logical grounds. To evade such difficulties, he prefers a language that is nondeclarative; however,
12. D. Davidson, "What Metaphors Mean," Critical Inquiry, 5 (1978), pp.31-47.
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a nondeclarative language is as incapable of handling metaphors as it is literal statements. To the extent that he makes his language nondeclarative, he renders his statements inconclusive. He realizes that metaphorical statements sometimes subsume truth and sometimes compete with it 13 , but even to do this much they have to be declarative. Thus, instead of eliminating contradictions, he renders inoperative the criteria for recognizing them. For two texts to tell the same story, it is necessary that they be intertranslatable. Metaphor permits us to manipulate the order of recording, and with time running backwards for example, we no longer have the same story to tell. While he admits that enough twisting of the tale will leave us without one 14 , he is at a loss to decide when this is going to happen. Since the order of telling the story is related only metaphorically to the events told, it does not follow that the events told occured in a given order or even that there are any such events. This holds equally when the order of what is told is only implicit rather than explicit. The realms to which the metaphor refers are at least partly indefinite. To say that the geocentric and heliocentric versions refer to "different worlds" is merely a metaphor, and as a statement of fact it is demonstrably false. On the one hand Goodman holds that the different kinds of motion have the same or virtually the same meaning, and on the other that there is no such thing as the meaning of a term. Thus, he speaks of several versions of the same or virtually the same story, while denying that there is anything to give the story identity. His irrealisn1 is as unable to establish identity for nonfiction as it is for fiction. As a radical nominalist, Goodman insists that there is nothing nonactual, no n1erely possible or impossible worlds. Worlds, like individuals, are either actual or they are nothing at all. It is not clear, however, what it is for fiction to be actual. In rejecting the idea of possible worlds, Goodman denies that any world version can be merely contingent, Le. that it could be different from the way it is. Every world version is, therefore, unique; it is necessarily the way it happens to be or it is nothing at all. Because every world version is unique, it becomes incommensurable with any other
13. Goodman, Ope cit. p. 98. 14. ibid. p. 122.
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world version, but in this manner Goodman's original problem of conflicting world versions vanishes. The problem is that the notion of independent multiple world versions~runs counter to deeply entrenched convictions inherent in common sense discourse. We may agree with Goodman that we cannot describe or depict the world apart from our language or other symbolic representation. But if no single world version is anymore real than any other, all this does not matter much. Treating literal statements as mere metaphors, Goodman is unable to eliminate even bizarre and devious categories and predicates. Thus, his language becomes inadequate for scientific prediction and control. What finally distinguishes the arts from the sciences is not their respective symbol systems but their different purpose and method. Yet the kind of "understanding" Goodman provides cannot justify what makes certain works of art adequate or superior either. Since he lacks reliable standards for sensitivity, almost any procedure in art education will appear to be effective. He believes that "hard looking and intelligent seeing" can settle such differences 15 while rejecting the "innocent eye" as a myth.
15. ibid. p. 173.
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CHAPTER XIV
DAVIDSON: TRUTH AS METAPHOR
Davidson emphasizes that interpreting an agent's intentions, his beliefs and his words are part of a single project. While the speaker of a language normally cannot provide an explicit finite theory of his own language, he can test a proposed theory because he can tell whether it yields correct interpretations when applied to particular utterances l • Thus, Davidson cannot supply more than correct sam.ples for his theory of radical interpretation (which he develops along the lines of Quine's radical translation but in a semantically more explicit manner). Davidson's proposed truth theory fails to provide adequate explanations not only of meaning and synonymy but also for the notion of interpretation itself. His criteria for what is intelligible rest on the idea that understanding our own language neither allows nor needs an explanation. But if this is accepted, there remains little for a truth theory to do. It was Quine who proposed the translation manual as a device for studying problems in the philosophy of language. While following Quine in basing a theory of interpretation on translation procedures, Davidson rejects Quine's preference for canonical notation. Davidson wants to extract from Tarski's T - sentences extended to the indexical devices of a natural language a procedure for establishing literal meaning. But he denies that truth is a single property that attaches or fails to attach to individual sentences. The evidence for his theory of radical interpretation already presupposes a system of beliefs very much like our own. Since such beliefs cannot be identified in any detailed manner without a shared language, he is
1. Donald Davidson, Inquiries into Truth and Interpretation, Clarendon Press, Oxford 1984, p.128.
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unable to tell what the best fit is between his own language and that of the alien speaker. The principle of charity, which Quine had restricted to the identification of (pure) semantical connectives, is applied by Davidson across the board 2 • But without a language-independent logic he cannot assign definite truth conditions to alien sentences, nor can he specify what makes native speakers know their own language. Davidson's global principie of charity turns out to be no less selfdefeating than is the sweeping imputation of error and unreasonableness to everybody. With too much charity in interpretation, the very possibility of philosophical analysis is in doubt, for all such analysis depends on the assumption that certain concepts are clearer or more basic epistemologically or ontologically. Starting with Tarski's criteria of truth and satisfaction, Davidson is only able to formulate a partially interpreted theory 3. His modified T - structure fixes the truth value of individual sentences to certain conditions but is unable to conclude that the object sentence is true when these conditions obtain. Davidson's demand that the totality of T - sentences optimally should fit the evidence cannot be realized without canonical notation. The holistic constraints he imposes are too weak to insure that each sentence yields an acceptable interpretation. Indeed, the resulting indeterminacy of translation may prevent the theory as a whole fron1 attaining a nonambiguous interpretation even after having passed Tarski's tests. It is one thing to say that we always must assume to undertand our own language, and quite another that we understand what is implied in such knowledge. Davidson is thus unable to answer the original question of how we know that a particular interpretation is true. Because of his global principle of charity, he can,riot separate the theory from the evidence he needs to support it. His problem is to show that the partial understanding he offers 'yields results that are more than trivial or empty. While nobody doubts that we are endowed by nature or evolution with the ability to use language, to understand all that is involved in such skills in quite another matter.
2. ibid. p. 136. 3. ibid. p. 137.
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Making detailed sense of a speaker's intentions and beliefs cannot be separate from making sense of his utterances. Davidson cannot fix unambiguously the circumstances under which such utterances are true. Nor is his notion of partial understanding reducible to probable truth since in order to know the preferences of an agent it is essential to describe his options in a language we already understand. Two descriptions of what the experimenter takes to be the same option may elicit quite different responses from the subject. Davidson's truth theory is like an equation we know not to be satisfiable, yet he tries to extend the meaning of "satisfaction" to cover such cases. The kind of understanding he offers or what he considers to be intelligible is based on a preanalytic notion of truth for which his theory cannot account. His use of such terms as meaning, translation or synonymy heavily relies on the unanalyzed idea that we understand our own language. But such a truth concept does not provide adequate constraints to yield a uniform interpretation. Because of the indeterminacy of translation there is no systematic way of matching predicates of the metalanguage to the primitive predicates of the object language. Davidson is unable to reduce Tarskian T - sentences to the point where they yield an acceptable theory of nonquestion-begging constraints. He lacks an evidential base concerning the circumstances under which speakers hold sentences in their own language true, let alone those in an alien tongue. Since this typically involves complicated situations, such 'evidence does not settle the issue between meaning and belief and assumes in fact their partial identity. In his truth theory Davidson is thus unable to make the crucial distinction between what is true and what is merely believed to be true. Neither can he explain why speakers are allowed to differ more often and more radically with respect to some beliefs than others. Quine can1e to realize that we cannot give up logic without impairing communication, while Davidson maintains that similarity in beliefs is by itself enough to ensure communication. But his merging of meaning and belief into background knowledge prevents him from identifying either. By extending Quine's idea of logic to cover basic belief, Davidson has given up truth as an objective standard. The price he pays for extending across the board Quine's principle of charity is a diminished capacity to make relevant distinctions. To be able to talk about what is new, surprising 173
or disputed, we need a language that is understood, i.e. one whose conventions are not questioned. Davidson maintains that two speakers can interpret each other's utterances without there being in any ordinary sense a common language 4 • But what constitutes a common language under such circumstances is precisely the issue. His contention that we can comminicate with alien speakers by means of a shared system of beliefs begs the question since we cannot identify such beliefs without a shared language. Davidson's truth theory fails to provide a convincing argument for the very possibility of radical translation or interpretation. Even given the sentences a man accepts as true under certain circumstances, we normally will not be able to determine what his beliefs are or what his words mean. Unlike Tarski, therefore, Davidson cannot take either translation or interpretation as primitive without begging the question of the empirical character of his truth concept. Whether such weaker standards are adequate depends on what we are trying to accomplish. All the standard ways of testing theories under uncertainty already presuppose the understanding of an appropriate language. Even when we eliminate verbal expressions on the part of the subject and take him to have expressed preference by taking action, we are still faced with the task of identifying what he has chosen. We can do this by means of an understood language and the largely unanalyzed truth concept that goes with it. Since the attribution of decisions and beliefs (and other thoughts) goes hand in hand with the interpretation of speech, neither a decision theory nor a theory of interpretation can be provided without a previous understanding of the language. As long as we cannot identify the meaning of words and sentences, we cannot make the fine distinctions that are essential for the ascription of beliefs and desires. Intensionality in the attribution of thought is very hard to make sense of when speech is not present. Knowing the language does not normally imply understanding the conditions under which sentences in the language are held true . A sentence is held true because of what the speaker takes the sentence to mean and because of what he thinks is the case. Davidson cannot hold one of these factors steady while investigating the other.
4. ibid. p. 157.
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False beliefs undermine the intelligibility of a subject matter, and thus the knowledge of its truth conditions. He dismisses the possibility of massive error in our beliefs, yet this does not provide him with a workable truth theory. What a standard truth theory provides is knowledge of the conditions under which a given sentence is true. He, therefore, means by "truth" something quite different from either Tarski or Quine: Davidson's truth theory is largely powerless to eliminate error. He cannot settle whether two speakers have the same or even similar standards of interpretation. Disagreement about how things look or appear is less tolerable to Davidson than is disagreement about how things ares, since he no longer can make a valid distinction between appearance and reality in his truth theory. That things look different to people beyond their power of comprehension is something his truth theory cannot accomodate. What to most people sharing a language or a system of beliefs seems true will be accepted by Davidson as true for us. These difficulties become evident when we apply his version of partial understanding to unobserved or counterfactual cases. Conceptual schemes or ways of organizing experience play a central role in his truth theory. Conceptual schemes are by definition untranslatable, but that something is untranslatable cannot be established conclusively and is not even intelligible according to Davidson. Languages that have evolved at different times and places may differ extensively in their resources for dealing with one or another range of phenomena. But difficulties in translation are at the same time never so extensive that changes and contrasts may not be described and explained using the equivalent of a single language. While different points of view make sense only if there is a common coordinate system in which to put them, Davidson's idea of language does not provide any such coordination. What we need is son1e idea of the considerations that set the limits to conceptual contrast. While conceptual schemes differ, so do languages, yet speakers of different, languages share a conceptual scheme provided there is a way of translating one language into another. The background knowledge into which he makes belief and meaning merge cannot be identified directly by Davidson. He
5. ibid. p. 169.
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emphasized that nobody can take up a vantage point for comparing conceptual schemes tempora:lily by shedding his own. His problem, however, is to make sense of partial translation by treating such differences as empirical. Since he has given up· in effect the contrast between scheme and content, of organizing systems and something to be organized 6 , there remains nothing distinctive to be called empirical. He has thus to settle on translatability into his own language as the criterion of languagehood, even though he admits that this is an unsatisfactory solution 7 • If this is what is meant by partial understanding of how language works, everything depends on the as yet unspecified consequences of such a theory. Davidson rejects the building block model of interpretation but his holistic approach is no adequate substitute. The partial understanding he provides by means of it remains largely inoperative in determining the truth content of individual sentences. He admits that enough translation difficulties may add up to an untranslatable one, and at the same time he insits that total untranslatability is incomprehensible. In maintaining that there is at most one worlds, he fails to provide an argument for either the thesis that there is one world or for its rejection. But in this manner the very idea of a conceptual scheme becomes metaphorical. Having given up language-independent logic, he no longer can make a valid distinction between the object language and the metalanguage of the argument. He emphasizes that we can be clear about a breakdown in translation only if it is local enough, since only a background of generally successful translation provides what is needed to make failures intelligible 9 - yet this is something the unidentified conceptual resources of his own language cannot settle. He lacks criteria for what it means to fit into the totality of all possible experience because he cannot compare or contrast this with anything else. He maintains that what renders sentences true is that experience takes the course it does 1o • To make
6. ibid. p. 189. 7. ibid. p. 186. 8. ibid. p. 187. 9. ibid. p. 193. 10. ibid. p. 194.
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this intelligible, however, he has to identify an alternative hypothetical course of all possible experience, Le. a radically different conceptual scheme, and this by his own admission he cannot do. Davidson rejects what he takes to be the metaphor of a single space within which each sentence has a position and provides a point of view l l • At the same time he does accept the notion of a common language within which all intelligible discourse takes place. Unlike a coordinate system, such a language makes allowances for partial failure in communication, and thus for the possibility of meaning changes and contrasts in conceptual schemes. Davidson postulates a common ground that makes contrasts only partially intelligible: what makes different conceptual schemes intelligible is their common part 12, but this common part is merely the background knowledge he cannot identify positively. When he appeals to the general features of language or reality, this merely reflects his inability to make further relevant distinctions. The trouble is that by means of such weak consistency Davidson is unable to derive a workable semantics. He admits that a'detailed knowledge of beliefs con1es only with the ability to interpret words, and so he assumes a general agreement of beliefs with which to begin. He emphasizes that if we want to understand others, we must count them right in most cases. This means that we can translate only languages pretty much like our own. What we recognize as a language must be something of which can make sense. But what Davidson can make sense of is by no means a priori given. In his view, it does not make sense to say that all speakers of a language share a conceptual schemel 3 • At the same tin1e he maintains that in sharing a language, in whatever sense this is required for communication, we share a picture of the world that largely must be true. Davidson is not even able to claim that his own truth concept is the only legitimate one. Thus while stressing the relativity of all logic to language, he still hopes, to formalize natural language along the lines of Tarskian semantics. His notion of truth is identified largely with background knowledge,
11. ibid. p. 195. 12. ibid. 13. ibid. p. 198.
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something that in principle cannot be elaborated further. To evade such self-defeating consequences, Qui!Je decided to tie his ontology to canonical notation. Since Davidson rejects the idea of a language-invariant logic, he lacks criteria for judging all-over fit between different conceptual schemes. He recursively characterizes truth for each of the sentences by means of "satisfaction" relativized to specific events. But his method does not suggest what truths are to be counted as logical. Davidson empasizes that a very large number of ordinary claims about the world cannot be true unless there are events 14. He is unable, however, to identify such events and at the same time to generalize about them in a nontrivial fashion. All semantics requires an explanation of meaning in simpler or at least different terms. While accepting Quine's teachings on the inscrutability of reference, Davidson admits that satisfaction is like reference for predicates: the reference of a predicate is the class of those entities that satisfy it 15. However, if one imagines a new predicate added to the language, Davidson's account of satisfaction does not suggest how to go on to the next case. He considers "reduce" and "analyze" to be too strong as terms when applied to semantic concepts, but this converts his own theory into a metaphor. The price for such "weak" logic lies in a diminished capacity to produce nontrivial results. Without an adequate principle of individuation, no empirical account of synonymy, translation or interpretation can be given by Davidson. While his theory of truth conditions takes sentences for granted as units of literal meaning, he is unable to provide adequate criteria for sentencehood. But a translation manual is no more than a method of going from sentences in one language to sentences in another. By giving up language-independent logic and accepting reference as inscrutable, Davidson's truth theory becomes largely metaphorical. He no longer can make the crucial distinction between explanations within the theory and explanations of the theory, Le. the al1~ important difference between the object language and the metalanguage of the argument. His partial understanding of how lan-
14. ibid. p. 214. 15. ibid. p. 217.
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guage works does not cover an explanation of how such language is learnable. What is invariant as between different acceptable theories is meaning, and Davidson remains unable to identify it. His attempts to compensate for the paucity of information at each single point by appealing to the potential infinity of points 16 fails because he cannot demonstrate convergence in the truth content of different sentences. He does not produce actual evidence for the meaning of words and sentences but merely considers possible evidence for a theory of the language to which the word or sentence belongs. Contrary to Quine, Davidson insists that two satisfying theories may differ in what they count as singular terms or quantifiers, and even with respect to the underlying logic itself l 7. This prevents him from fixing literal meaning to singular expressions, and he himself realizes that we explain what words mean in metaphor only by supposing they have the same meanings they do in nonfigurative contexts l8 • He identifies "satisfaction" with the resources one is certain to credit a natural language with 19 - but this is precisely what is at issue. Davidson agrees with Quine that all the evidence for or against a theory of truth (interpretation, translation) comes in the form of facts about what events cause, or could cause, speakers to assent or dissent from someone's repertoire. Davidson, however, rejects Quine's behaviorist criteria for deciding the truth content of sentences, and emphasizes instead intensional attitudes - above all the attitude of holding a sentence true. Thus, while Quine relativized reference to translation manuals, Davidson links it to the general features of language, and the trouble is that he cannot identify these general featllres of language anymore than a conceptual scheme, for there is nothing with which to compare or contrast them. He rejects the idea that there is a unique language to which a given utterance belongs, yet maintains that truth may be relative to an object language but not to the metalanguage of the argument. The evidence allows choice between languages only
16. ibid. p. 225. 17. ibid. p. 228. 18. ibid. p. xix. 19. ibid. p. 229.
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because we can balance any g~ven option by an appropriate selection of beliefs and attitudes. 4bavidson denies that we have nontranslatable conceptual schemes as well as the opposing view that conceptual schemes are fully translatable. But partially translatable conceptual schemes lack identifiable meaning and are posited as a result in a metaphorical manner. This rules out all hope of responsible theory and our ability to account for metaphor itself. In such a language, statements are no longer decidable. Unlike Tarski's truth theory, Davidson's modified proposal cannot be tested by comparing some of its consequences with the / facts. Such a theory reveals little that is new about the conditions under which a sentence is true for it cannot make these conditions more explicit than the original sentence. The weak empirical character of the theory is inadequate to recover the complexities of a natural language. Nor can it attain insight into likely equivalences between our own language and that of the alien. Davidson's "logical form" reflects the largely indefinite features of languagehood", not something that amounts to a Chomskian transformational grammar. In suggesting that an acceptable theory of radical translation take the form of a recursive characterization, Davidson goes beyond Quine. Among logicians, philosophers of language and linguists, Davidson is almost alone in suggesting that it is possible to constrllct a formal semantic theory of natural language. With ingenuity, he believes, one could overcome both the semantic paradoxes and the amorphic character of natural language 2o • But such "ingenuity" appeals to precisely the kind of conceptual resources in his own language he cannot identify. He starts with a weak holistic notion of truth, as what we always seem to grasp in understanding the language of another 21 , yet what this is he cannot tell. Logicians seem to agree with philosophers of language critical of formal methods that semantics and logic are incapable of dealing with demonstratives. Part of understanding demonstratives is to know the rules by which they adjust their reference to circumstances. Davidson has to admit that his proposed truth theory fails to do justice to the logical form of
20. ibid. p. 51. 21. ibid. p. 29.
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counterfactual or subjunctive semantics, to probabilistic or causal relations. Nor is he able to make'+:~logical sense of adverbs, mass terms like "snow" (as Tarski did), sentences about belief, perception, or words of action that imply purpose 22 • While he largely shares Quine's views on the inscrutability of reference, Davidson nevertheless attempts to formulate truth in terms of satisfaction between the major features of language and the world. But lacking a principle for the individuation of sense, he cannot account for literal meaning of either words or sentences in a natural language. A semantic theory of truth tells the story for a particular sentence by running through the steps of the recursive account of satisfaction. Davidson, however, remains unable to identify the facts that correspond to the sentence in this manner; what he provides amounts merely to a paraphrase of the sentence. His focusing on the general features of language has the consequence that the relation of correspondence (or picturing) can no longer maintain the distinction between object language and metalanguage of the argument. He cannot pack anything into the entities to which sentences correspond (such as events) for the simple reason that he denies their existence. But neither can he define sentencehood or grammaticalness by which natural languages differ from formalized ones. In spite of all this, he hopes that the notion of "satisfaction" will play the same role reference plays in standard semantics. However, when Tarski's convention T is revised by Davidson to make its truth sensitive to context, most of its logical bite is lost in the process. His trutl1 theory can no longer deal with such issues as consistency, completeness or decidability. By evading these problems, Davidson no longer accounts for most of the constraints successful communication imposes on speakers. In defining sentencehood, what we capture is the idea of an independently meaningful expression 23 , for Davidson there is more than just one way to abstract a natural lal1guage or formalize its syntax. He welcomes alternative readings provided they are a'dequately clear, yet what he considers adequately clear depends on the conceptual resources of his own language for which his truth
22. ibid. pp. 35-36. 23. ibid. p. 60.
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theory cannot account. Quine, in his later work, came to realize that we must stick to the basic lo'gic of our language no matter what in order to prevent such self-defeating consequences of too much charity. Unlike Tarski or Quine, Davidson lacks criteria to judge the fitness of a translation or interpretation. We cannot test his truth theory as long as we do not know what each sentence means. Davidson has to admit that a number of significantly different theories will fit the evidence equally we1l 24 • The evidence to which he appeals is truth value under transformation, but having given up language-independent logic, such evidence is no longer available to him. A theory of truth patterned after Tarski's type of truth definition and relativized for natural language does not tell us what we want to know about sense.
24. ibid. p. 62.
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CHAPTER XV
DAVIDSON ON INTENDING
Davidson maintains that intentional action is action that is explainable in the appropriate way by appeal to the agent's reason for action. The reasons that explain intentional action are appropriate pairs of the agent's desires (and other pro-attitudes) and beliefs. When one acts for a certain reason, an appropriate desirebelief pair causes one's action. But eve11 granted that when I act for a reason, my reason is a cause for my action, there will also be some sort of logical relation between my reason and my action. In "How is Weakness of the Will Possible?"l Davidson characterizes this logical relation in terms of a general conception of practical reasoning. The guiding idea is that the reason for which I act provides me with premises from which I could have reasoned to a conclusion that corresponds to my action 2 • Davidson's main idea is to treat "prima facie" as relating premises to conclusions of practical syllogisms. But he also understands the major premises of such practical syllogisms as using the concept of prima facie analogies as that of statistical probability. The problem is that our notions of probability sometimes conflict with those of practical causality. Bratman emphasizes that a theory of intentional action cannot stand alone. It needs to be related to a plausible conception of future intention - intending now to do something later. According to Davidson, in just having reasons for acting in a certain
1. Donald Davidson, Essays on Actions and Events, Oxford 1980, pp. 21-42. 2. Michael Bratman, "Davidson's Theory of Intention," in Essays on Davidson, Actions and Events, edited by Bruce Vermazen and Merrill B. Hintikka, Clarendon Press, Oxford 1985, p. 14.
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way, I accept certain prima facie evaluative propositions. My future intentions are conditioned: by my beliefs 3 • But having said this, it remains unclear just what these beliefs must be. In Davidson's view, mere enabling conditions are not bona fide conditions, not genuine conditional intentions, for they are not reasons for action that are contemporary with the intention. The availability of tickets is by itself no reason for my going to the concert, though it is an enabling condition for my going. Davidson's picture seems to be that the basis for practical reasoning about what to do - either now or later - will just be the agent's desires and beliefs. Such reasoning, when concerned with the future, can issue in future intentions. But these intentions are fundamentally different sort of states from the desires and beliefs on which they are based. The problem is that there is no significant further role for those intentions to playas input into one's practical thinking. Future intentions are mere spin-offs of practical reasoning concerning the future 4 • A theory of future intentions needs to explain why we ever bother to fornl them. Why do we not just cross our bridges when we come to them? Our answer is the we want to avoid the need for deliberation at the tinle of action. But, more importantly, we form future intentions as parts of larger plans whose role is to aid coordination of our activities over time. We do not adopt these plans in all their detail all at once; rather, as time goes on, we add to and adjust our plans. This means that they playa significant role in our further practical thinking in the ongoing creation and adjustment of our plans - a role Davidson rejects s • Bratman argues that Davidson's difficulties with agglomerativity and Buridan's problems are symptoms of a deeper perplexity. They are symptoms of an overly limited conception of the role of intentions and plans in rational motivation and practical reasoning. Davidson, not surprisingly, denies this. In "How is Weakness of the Will Possible?" he claims that action corresponds to "all-out" judgments, and that such judgments do not follow by ordinary
3. "Intending," EAE p. 100. 4. Bratman in Vermazen, Ope cit. p. 24. 5. ib. p. 25.
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logic from the premises provided by our desires and beliefs 6 • The all-out judgment has no simple relation to the reasons on which it is based. We are stuck with states of intending, which are independent of our reasons for intending and our actions. The independence of intentions is logical: it does not follow from the existence of reasons for an action. An all-out judgment that some action is desirable is not different from the intention with which it is identical. But no matter how elaborately detailed an intention is, there are certain to be endless ways in which it could be realized that are unwanted and unintended by the agent. All actions, past present and future, have properties of which their agents are ignorant. The alternatives or options that matter to intention are those an agent believes are available to him, not those actually available. One cannot intend what is inconsistent with one's beliefs; this means that there are often things an agent can do that he can't, given his beliefs, intend to do. While all of an agent's beliefs form the context in which he evaluates possible actions and forms his intentions, only some of his beliefs enter directly into practical reasoning. The question is how beliefs condition evaluations and intentions. What a person intends, Davidson argues, must be consistent with what the person believes, but this merely includes the number of alternatives to be considered, it does not help select one. The value an agent puts on a contemplated action depends on the values he places on the various ways he thinks the world may turn our to be, given the action and how problematic he thinks the various outcomes are. This is what makes an all-out judgment of the desirability of an action plausible. It would be wrong to say that this process of weighting is usually conscious, or that people always base their all-out judgments (or intentions or actions) on a rational survey of alternatives. A rational judgment is one that takes account of all all agent's relevant beliefs, and these will include beliefs about other intentions an agent has. My intentions are based on my present view of the situation. Only if an agent values one line of action more highly than any alternative does he act intentionally in the present or harbor an intention for the future.
6. Davidson in Vermazen, op.cit. p. 196.
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According to Davidson's "How is Weakness of the Will Possible?" an incontinent act is in effect an act done intentionally, an alternative to which is both open to the agent and judged by him to be, all things consid-ered, better than the act in question. Davidson's views seem to lead him to maintaining also that if an action is done intentionally, it is done for a reason'. In incontinence it is always the case that desire or passion makes us act against our better judgment. In incontinence, what our better judgment calls for is always action in line with duty or morality; it is always duty or morality that is the loser. G-rice and Baker emphasize the problematic nature of Davidson's use of "all things considered." There is a genuine distinction between "relative to the available evidence," and "all things considered." We should not ignore the possibility that _a man in his deliberations might regard the evidence at present available to him as adequate, in which case it would seem inappropriate to suppose him to be ready to make the judgment that, "all things considered," a is better than b (as "all things considered" is normally understood). One might seek to understand the idea of an "all things considered" judgment as being the idea of a judgment that something is probable or prima facie better than something else, relative to some totality of supporting facts many of which would in a normal case be unavailable to the judger, at least at the time of judging, and possibly at any time. The crucial stage in probabilistic or practical reasoning would be the stage at which we are entitled in the light of the judgment that the qualificatory conditions obtain, actually to judge, as opposed merely to conjecture, that an ideal totality could support a certain conclusion. But now it is not clear what useful function the "all things considered" judgment, so understood, can be supposed to fulfill. The typical incontinent man (who does not do a though in a sense he thinks he should) reaches only a not fully present "all things before me" judgment in favor of a, which he combines with a fully present unconditional judgment against a, and (consequently) with an intention against a. Davidson points out that many philosophers, including
7. Paul Grice and Judith Baker, "Davidson on Weakness of the Will," in Vermazen, Ope cit. p. 28.
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Socrates, could not see how it was possible for someone to act contrary to his own best judgment. According to the story, Socrates decided it really wasn't possible, so that only ignorance could explain wrong action. Others though have been certain there are cases of acting against one's best judgment. In "How is Weakness of the Will Possible?" Davidson suggests a way of resolving the problem by distinguishing between prima facie or conditional evaluation judgments and "all-out," or unconditional ones. Our "best judgments," he argues, naturally could be taken to be those conditioned on all the considerations deemed relevant by the agent, but action is geared to unconditional judgments. Grice and Baker do not reject Davidson's distinction between conditional and unconditional evaluative judgments, but they question Davidson's use of the "all things considered" judgments. They argue that there is no way to construe such judgments that is both consistent with what Davidson says about conditional judgments generally, and that yields a satisfying analysis of inconti,nence. There are many constraints each of which defines a different form of irrationality. But is a man irrational in going against his own best judgment if he is not aware that this is what he is doing? Davidson maintains that he is irrational in one sense but not in another. He does not want to explain incontinence like making a logical mistake. One can know one ought to be continent and fail 8 • To have a desire is not to have an intention, and it is an intention that the weak-willed person has. The duality is one of desire and intention, but actually we need further the agent's own view of the rationality of an action relative to a given set of reasons he has for or against an action. The weak-willed person is irrational because he intentionally does something for which he has some reason, but there is a wider set of reasons he has relative to which he does not judge what he does to be rational 9 • Clearly it need not be true that in doing a intentionally the agent judges that a will best satisfy all his desires and values over his whole life; many who smoke intentionally do not believe this of their smoking. There are many ex-
8. Davidson in Vermazen, op. cit. p. 206. 9. Christopher Peacocke, "Intention and Akrasia," in Vermazen, op. cit. p.52.
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amples in which an agent plans to act, knowing his chances of success to be very low; in such cases he does not have belief that he will succeed. Peacocke concludes that intending to do something is not to be identified with any particular judgment, belief, or something held to be the case by the agent. Davidson rejects Peacocke's analogy between the probability of a statement and its desirability or status as an object of intention. He prefers a weaker analogy between subjective probability or degree of belief, and intention or desire. He insists that we must distinguish between what someone expresses by uttering a certain sentence, and what the sentence expresses. It is usually assumed that the future of factual belief is part of the essence of intending. However, Davidson has made the suggestion that the connection between factual belief and intending is looser than this. Future belief is not built into the essence of intending but is only a feature of communicating intensions, and that is why it can be cancelled lo . When A tells B that he likes him, the implication is partly based on the fact that attention necessarily tends to produce good treatment. Hence B is entitled to believe that A shares this belief. Davidson rightly rejects the idea that "I intend" works like "I promise," which is governed by the convention that it gives the entitlement directlyl!. He does however leave a gap in this theory, a question unanswered: on what is B's entitlement to his belief based when A tells him that he intends to do something? It seems that it must be based partly on the necessary connection between an intention and the tendency to produce the intended action, just as his entitlement to the other belief was based partly on the necessary connection between personal affection and the tendency to produce good treatment!2. If the belief would be given a fairly weak content, the counterexamples might be avoided. Then it would be possible to preserve the traditional theory that the belief necessarily is connected with the intention itself rather than cancelably connected with its announcement. I can intend to perform an action without believing that I shall do
10. D.F. Pears, "Intention and Belief," in Vermazen, op. cit. 75. 11. EAE pp. 90-91. 12. Pears in Vermazen, op. cit. 76.
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so. This is a powerfull counterexample to the thesis that intention essentially invokes future belief. It might be argued that a minimal future factual belief is an essential part of every intention. The probability may be very low, but the agent must believe that it exists and that his intention confers it on his performance. If he explicitly disassociates his intention from his minimal belief, he announces it as something completely ineffective, and so as something more properly called "a wish."13 If we are looking for a futllre factual belief that is an essential part of every intention, we have to pitch it very low. For an agent can intend to do something that he assesses as son1ething extremely difficult, and he can announce his intention without qualifying it in any way. The reason why he must have a positive belief has nothing to do with announcing his intention to anyone else. It is simply that it is an essential part of the intention itself. The explanation why its precise content varies from case to case is that the agent's other beliefs may affect his estimates of the stepwise probabilities. Never mind that this is only a model and that in real life the assumed probability seldom will be very definite. Because the future is uncertain, and we need to be able to rely on future factual implication, it may be that the agent's estimate of the probability of performance is high when he annouces his intention in advance, but less high when his action actually has been performed and he says that his performance was intentional. We often say things like "1 intend to do it if I can," and there are evidently cancellations of some elements in the associated future factual belief. So we need to know what the belief would be if it remained uncanceled, what is canceled, and what (if anything) cannot be canceled. 14 The answer to the last question is that minimal belief cannot be canceled, but the answers to the first two questions are less easy to give. Though this provides us with a theory of rational intention-based belief, it does not give us a theory of implication because the agent's credence usually will be unaware of his other relevant beliefs. What is needed is shared standards of prob-
13. ib. p. 79. 14. ib. p. 84.
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abilities that will serve as a starting point. The theory allows us to regard the varying probabilities of intention-based beliefs as a kind of sliding peg. The concept of intending does not allow the peg to move down to zero. Confusion has occured because it has not been appreciated that an essential part of all relations is necessarily minimal. The doubts are about the precise position of the sliding peg of probability and the exact conversational constraints on the words needed to communicate the intention. Davidson agrees with Pears that there is a conceptual connection between intending to do something and a belief that one will do it. This connection explains, at least in part, why it is that in saying one intends to do something an agent entitles a hearer to believe the agent has some degree of confidence that he will do what he intends. The rival theories were theories that identified intentions with actions of some sort, and those that identified intentions with beliefs. Davidson opts for a third view, one that identifies with certain "all-out" or unconditional evaluative attitudes. He repeatedly insists that an agent cannot intend to do something unless he believes he can do it. This "connection" is a logical implication, and so cannot be canceled by a verbal performance. It must be said, however, that the belief Davidson insisted the intending agent must have, namely the belief that what he "intends" to do it is possible for him to do, is not the same as the belief that if it is possible, he will do it. For there are many things a person is sure he could do, 11e is equally sure he will not do (at least intentionally). There is a perfectly general conceptual connection between beliefs and intentions, and it explains why our intentions entail that the agent must believe that he has some ch~nce of achieving what he intends. If, as Davidson thinks, intentions are "all-out" positive evaluations of a way of acting, it is clear why an intention requires some degree of belief in success; for if an agent believes his action has no chance of succes, the value he assigns to his action will be the value of the desired outcome multiplied by zero lS • There is an obvious conceptual connection between pro-attitudes and action. s
15. Davidson in Vermazen, Ope cit. p. 214.
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Still, Bruce Vermazen points out that there are negative acts: if I intentionally pass up a chance to win at cards by laying down the ten of clubs, I have done somethIng - performed an act describable as not laying down the ten of clubs and as not bringing about my winnig. What we count when we establish a negative act to a person is what he intends not to be doing. Vermazen believes that omissions, failures and neglectings that are not intentional are not acts at all. They correctly are attributed to agents in virtue of the inhibiting role played by the appropriate pro-attitude, but they are not themselves events 16. But Davidson points out that actions are events, and th'at adverbal modific~tions provide a lead for understanding what actions and events are, and how they are inviduated. Adjectives have a standard predictive use bilt many of the difficulties are connected with the individuation of sentences and events l7 • The tragedy of Oedipus was that he insisted on such invalid inferences: because he intentionally struck an old man and married Jacosta, he felt as guilty as if he intentionally had married his mother and killed his father l8 • The solution that recommends itself is to take such words and phrases as "intentionally," "inadvertedly," and "on pupose" as making semantically opaque contexts, on a par with "possibly" and "probably." If this is right, then such adverbs are not to be treated as predicates of events or actions as well. To say someone did something unintentionally is not to speak of a manner of doing but of a wayan agent reviews his action. It is not surprising that the light in which an action recommends itself to an agent should not provide the only way of describing the action 19. Either we give up simple inferences like the one that takes us from "Oedipus married Jacosta, and Jacosta was his mother" to "Oedipus married his, mother," or we recognize that being intended, alleged or inadvertent are not properties of action, and so cannot serve to inviduate· then1 20 • The analysis of sentences containing rules of action and adverbs has
16. Bruce Vermazen, "Negative Acts," in Vermazen, Ope cit. p. 103. 17. Davidson in Vermazen, Ope cit. p. 233. 18. ib. p. 234. 19. ib. p. 235. 20. ibid. 191
some obvious ontological consequences. Not only must there be particular actions and events if any ordinary sentences are to have truth value, but we also can draw conclusions about the inviduation of actions. We cannot speak of the action as an action that has that consequence until the time of the consequence arrives. But the arrival of the consequence does not change the cause. It merely changes what we can, at the present time, say of it. We can say of a man that he is president, or a grandfather at some times and not at others; yet he remains the same man. A is not a grandfather of B until B is born, yet A may be dead by the time he is a grandfather. Davidson explains that causal relations are reported by extensional sentences the truth of which is not affected by how the related events happen to be described. To claim, however, that causal relations are de re is to ignore that there may not be widespread agreement on any particular causal relation. This is why the category of causation largely has been abandoned in modern science. What Davidson means by an action or event "under a description" is that Oedipus striking the old man was "intentional" under one description but not under another 21 • "The storm explains the flood" implies the existence of the events mentioned, even though such sentences can change in truth value when the same events are described differently. The distinction between causality and explanation is drawn in ordinary language between intentions that show intensionality and those that do not 22 • Davidson points out, however, that events are as much caught up in this net of concepts as are objects 23 • OUf belief in supervenience is largely and often a combination of metaphysical convictions and methogological considerations. There is the familiar risk of vacuity, but if we assume that the proposition can be given a nonvacuous formulation, it has interesting metaphysical implications. The notion of supervenience, as Davidson uses it, is best thougl1t of as a relation between a predicate and a set of predicates in a language. Supervenience guarantees a very general
21. EAE p. 195. 22. Davidson in Vermazen, op. cit. p. 226. 23. ib. p. 227.
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and so weak a concept of reduction that it might be called ontological reduction. The fallacy is to reason from ontological to a stronger fornl of reductionism, or simply to conflate the two. Reliable prediction of human behavior can come only fronl scientific psychology, which avoids reference to intensional states. But we cannot ascribe too much inconsistency and other forms of irrationality to the foreigner. As Davidson says, global confusion leaves nothing to be confused about 24 , and translation depends on a constitutive idea of rationality 25. We might ask, however, whether people actually may not be approximately rational and consistent in their patterns of belief and desire. A person's actions clearly depend not just on the intensity of his desires but also on the state of his beliefs. The upshot of all this is that we are induced to treat inconsistency as merely apparent, and once'more we are driven back to interpreting behavior by means of the constitutive idea of rationality. Davidson holds that Ramsey's problem of sorting out values as probabilities is really the same prQblem as that of radical interpretation of language. A man's beliefs, he says, cannot be ascertained unless we understand his language, but equally we cannot understand his language unless we ascribe beliefs to hinl. The basic reason the mental concepts connected with propositional attitudes ca'nnot be incorporated in a system of exceptionless laws is the normative character of these mental concepts. If attitudes can be identified at all, they must be found largely to be consistent with one another (because of their semantic properties). Smart wonders what prevents us from assuming that people are approximately rational and consistent in their patterns of belief and desire. But in Donaldson's view this cannot be a factual question: if a creature has propositional attitudes, then that creature is approximately rationa1 26 • Rationality is a normative notion that by its nature resists regimentation in accord with a single public standard. Even the individual interpreter has trouble deciding on the best way to understand another person when he finds what seem to be serious deviations from his own norms of internal coherence
24. "Mental E,:pnts," EAE, p. 221. 25. ib. p. 223. 26. "Rational Animals," Dialectica, 36 (1982), 317-327.
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and outward correspondence with the truth 27. It is at this point that the indeterminacy that results from the lack of a clear line between the analytic and the synthetic becomes relevant. Only a shared area is indicated by the assignment of propositional content to sentences and attitudes of a speaker, and within this area there is, as Quine insists, no fact of the matter. We draw the line as best as we can, tailoring one theory to the multiple demands of "charity." The application of the principle of charity is an application of normative considerations (among others)28. Strict laws do not deploy disposition terms nor do they use causal concepts. It is just when the relevant mechanisms are unknown that diseases are defined by their causes or their symptoms. An intentional action is an action caused by states or events that internalize it; it is a basic aspect of a belief ora desire that it will cause certain sorts of action under appropriate conditions. There are, Davidson, insists, irreducible aspects of reasons/explanations, and a sense that tries to eliminate the causal element from these concepts will succeed only in changing the subject, for here causality is connected with the normative elements of rationality29. Suppes questions Davidson's contention that animals have no belief because they lack language. A variety of data shows indisputably that -only gradually does the child master either language comprehension or language production, while his intentional motor behavior is well-developed much earlier. As the child learns to crawl about, he early develops beliefs concerning what is and what is not feasible, what can be wanted and what not. On the holistic theory of language advanced in "The Material Mind,"30 it is not easy to see how a child could acquire beliefs at all. Suppes denies that experimental tests of decision theory require an interpretation of speech 31 . If we take Davidson literally, we would not be able to make inferences of a definite belief about the
27. Davidson in Vermazen, Ope cit. p. 245. 28. ibid. 29. ib. p. 246. 30. pp. 256-257. 31. Patrick Suppes, "Davidson's Views on Psychology as a Science," in Vermazen, Ope cit. p. 191.
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preferences of animals (about kinds of food, and the like) because we are not able to relate the agent or subject to utterances potential or actual. But what Davidson actually contends is that thought in any moderately sophisticated sense depends on language. When rationality is at stake, it is bound to be a pressing question whether what the experimenter takes to be rationality is not better understood as a failure of communication. The appropriate constraints are, Davidson suggests, to be given by a theory of verbal interpretation 32 • We identify and discriminate between beliefs, desires and meanings of sentences by attaching propositions to them (or sentences of our own, which we understand). In trying to understand you, I match up my own sentences or propositions with your utterances and attitudes. My sentences are related to one another by logic, inductive and deductive, and are hooked to the world in various ways. I cannot ignore the properties of my propositions in interpreting you, since these are the properties that individuate the identity of properties. But given the multitude of considerations and the richness of the field of propositions, there will not be one best way for me to interpret you. So choices among alternative systems of interpretation have no empirical significance. It is only when the machinery of quantification is present that questions of ontology have a clear application.
32. Davidson in Vermazen, op. cit. p. 251.
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CHAPTER XVI
BRAND'S ACTION THEORY
The old-time volitional theory holds out the promise of translating action talk into nonaction talk. From a commom sense viewpoint persons are primarily responsible for their actions. But Brand emphasizes that although wanting and believing appear to play some role in the motivation of action, they are not the kind of events that directly cause action. Rather, the best candidate for proximate cause of action is intention. Common sense or folk psychology appear to recommend a notion of planned activity, one that is rooted in cognitive psychology and related disciplines that do not require conscious deliberations. Brand sees the fundamental problem in philosophical action theory to specify adequately the nature of the proximate cause of action. He follows Sellars in taking the initiatory cause of action to be an intending and denies that intending is reducible to desiring (or wanting) plus believing l • An adequate account of intending the proximate cause of action, involves specifying its internal structure. Davidson 2 suggests that primary reasons are causes of action. He maintains that a primary reason is a combination of a pro-attitude towards actions of a certain kind and a belief that this kind of action can be performed. But Brand follows Sellars 3 in maintaining that Davidson has failed to specify the mental statements adequately. Davidson rejects the idea that there is a peculiar kind of mental event that causes action.
1. Myles Brand, Intending and Acting, Toward a Naturalized Action Theory, Bradford, MIT Press, Cambridge, London 1984, p. 33. 2 Donald Davidson, "Actions, Reasons, and Causes," Journal of Philosophy, 60, (1963) pp. 985-700. 3. Wilfried Sellars, "Actions and Events," Nous 7, (1973), pp. 179-202.
1 7
Brand, on the other hand, points out that in taking a pro-attitude in a wide sense to cause action David~on has not specified the proximate cause. He has, in Sellars' terms, only given us the "mental background" preceding the proximate event causing the action 4 • Sellars' view is that the proximate cause of an action is an intention to do here and now. It is a fundamental problem in action theory to explain why one type of mental event proximately causes action while others do not, no matter how fully they occupy consciousness. The fundamental problem is to identify the nature of "immediate intention" as an event type. Brand emphasizes that an action is intentional only when it is planned. Sellars takes intention to be primitive and analyzes other types of mental events in terms of it, while Brand insists that only immediate intention causes action. Sellars' account trivializes the role of intention; cognitive features are part of the proximate cause of action, but they are not the whole of it. The person must also be moved to act, and without conative features action could not begin. Our proximate cause is immediate intention. But mental events of this sort are not distinct entities; they are not like members of a set. Brand thus fails to show that desiring and intending are irreducibly distinct. It is impossible for him to become quite clear about the properties of the mental event proximately causing action. Some mental events, such as believing, do not initiate action directly but indirectly may do so. Thus, Brand's distinction between believing and intending is not sharp; his criteria for what can or cannot be conceptualized are by no means obvious or clear-cut. Ordinary English does not have a standard form of expressing de re attitudes. Brand cannot say to what extent his definition and analysis of desiring and intending reflect psychological reality, since what he calls "psychological reality" permits divergent interpretations in different theoretical terms. While he rejects behaviorism without argument, such theoretical assumptions finally dominate psychological reality at the expense of empirical ones. Since there are different theoretical frameworks, there is no one correct analysis. De re belief is said by Brand to be generated by a normal perceptual process, but what
4. Brand, Ope cit. p. 35.
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is to count as "normal" is by no means uncontroversial. His attempt to "naturalize" action theory must, therefore, be considered a failure. Such de re attitudes are conceptual claims that underlie psychological theory, but whether they are compatible with psychological reality, as he claims 5 , cannot be settled. Factual constraints of this sort remain inconclusive because they are themselves dependent upon changing theories and manners of conceptualization. Brand claims that a person can have a de re attitude only toward that which exists 6 , but whether and in what sense (e.g. a dream) "exists" is precisely the question. Thus, while de re attitudes are themselves problematic, Brand attempts to analyze his de dicto attitudes in terms of them. De dicto belief is common in scientific reasoning; someone has a de dicto belief if he attributes the semantical value of truth to the positional object of such belief. Brand argues that it is possible for a normal person to have incompatible desires but not incompatible intentions 7 while folk psychology accepts conflicting intentions as commonsensical. He thus uses "intention" as a technical term. Brand rejects Davidson's8 contention that it is the onslaught or coming into existence of a dispositional desire (plus belief) that is causally efficacious. Comparative preference is primitive in these analyses and there is some temptation to identify preference and expected utility in the manner of von Neumann and Morgenstern. But while expected utility is partially a function of the subject's beliefs, preference as understood by Brand is independent of the subject's raw attitudes. The totality of pre-analytic contentions do not form a consistent unified whole. Brand emphasizes that intending is not sufficient for acting intentionally: to act intentionally is to act according to a plan, and not everything we do is according to a plan 9 • But in the more complex attitudes, folk psychology does not sanction Brand's distinctions. Folk psychology associates predicting that one will succeed with intending to do it, while Brand em-
5. ibid. p. 107. 6. ibid. p. 108.
7. ibid. p. 125. 8. Davidson, Ope cit. 9. Brand, Ope cit. p. 143.
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phasizes that one can intend without thinking that one will succeed. Believing that one will try to do something is consistent with believing that one will fail. Brand admits, however, that for a certain class of actions a person is said to do something only if he makes a genuine effort. Now the notion of making a genuine effort is extremely difficult to explicate in causal terms. Contrary to Davidson, Brand maintains that someone might intend to do something despite believing that the world is unfriendly, on the whole, toward that which he considers desirable. The major difficulty with Davidson's proposal, like the earlier folk psychological ones, is that it fails to detail the mental representation a person has when initiating an action. Brand considers Davidson's proposal to be an improvement over folk psychology in that it makes reference to a person's beliefs about the environment rather than merely to his subjective estimates of success. But Davidson still formulates his proposal in terms of the folk psychological notion of belief, which permits only a limited complexity content. Thus, the cognitive con1ponent of intention is son~ething other than folk psychological belief 1o • There are, however, no established constraints on the permissible complexity of common sense beliefs either, and Brand indeed realizes that the unpacking of apparently simple folk psychological notions reveals considerable complexity in many cases. While a comprehension of ordinary speech is hindered by excessive complexity, what degree of complexity is to be considered as excessive is by no means given. Brand's very distinction between folk psychology and what he calls "scientific psychology" is thus questionable both with regard to content and method. It is mainly because of this that he fails to "naturalize" action theory; he does not succeed to formulate it in a testable form or even to render it conceptually coherent. His reconstruction of folk psychology, even when supported by the evidence, suffers from vagueness and cannot be determined uniquely. The qualification "all things being equal," does not provide a precise formulation; rather this qualification has the force of saying that a precise formulation cannot be given. The theories he provides are no more than rules of thumb that do not fix boundary
10. ibid. p. 153.
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conditions. The experimental data underdeternline action theory; such empirical import is correlated to testability: the higher the empirical import of a statement, the more likely it is to be testable by experimental procedures. But Brand's conceptual claims have neither empirical nor precise theoretical import. He cannot substantiate his conceptual judgments; since the degree to which they are based on evidence remains indefinite, the role they play in forming theories is not determinate either. He claims that his model is antipositivistic but this merely means that he cannot provide an adequate distinction between theoretical and empirical statements. While he considers empirical testability a matter of degree, he fails to make his own version of action theory more testable. Brand's explanation of intention claims to go beyond mere folk psychology. In his opinion even Davidson's pro-attitude fails to capture the conative aspect of the mental antecedent. Brand insists that intention concerns the completion of actions with a plan in progress. Plans are not intended; rather it is actions within plans that are intended. To be intentional, an action has to be part of a plan and plans are programs. Persons are always engaged in one activity or another, but the central problem for a dynamic theory is not to explain why persons act, rather it is to define why they perform the particular actions they do. Brand points out that even dynamic theories fail to do justice to human action because they do not distinguish actions from other activities in which persons are engaged. Clearly persons are not constantly performing actions; they are not acting when sitting quietly and daydreaming or when asleep. Knowledge of alternatives is not sufficient for action ll • Brand follows Schank and Abelson's theory 12 of intentional action, which has also been used in computer. simulation models. Characteristic of this model is that information about intermediate steps and about goals of the actors is reinstated and must be inferred. Understanding a story describing action consists in being able to provide an account of these missing steps. The
11. ibid. p. 187. 12. Schank, Roger and Robert Abelson, Scripts, Plans, Goals and Understanding, Hillsdale, N.J. Lawrence Erlbaum 1977.
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leading idea about Schank and Abelson's model is that the unit of analysis is a script. A script is a complex routine; it is a predetermined and stereotyped sequence of actions that defines a wellknown situation 13. Scripts have internal complexity and are divided into scenes. The main advantage of organizing actions into scripts is that it permits representation without attention to the myriad details. If a person attended to all the detailed actions when thinking about a script, he would be overloaded with information and could not represent to himself the larger situation of which the script is a part. A person can, however, focus on a scene and thereby access the details 14. But Brand points out that there is nothing in Schank and Abelson's model that says a subject thinks of himself in a first person, self-referential way. This issue is critical because the model is used to depict the cognitive antecedent to intentional action. There is a great deal of information not stated but normally understood to be implicit, and these psychological mechanisms for self-referentiality are largely a matter of language and semantics. A terminal goal for one activity can be an instrumental goal for another. Goals are related intimately to intentions: a goal is an intention to do something in the future. But the relationship between instrumental and terminal goals can be a matter of undesirable complexity. Scripted actions are not planned explicitly but are part of a pattern of planned activity. Brand argues that even though the subject may not always be aware of what is involved in opting for a certain course of action, actions that are formed by virtue of following a script are intentional 15 • To say, however, that an action is intentional even though not preconceived in some sense is to deviate from the common sense of folk psychology. What we normally understand by an intentional action is that it is perceived to be part of some story. One reason to appeal to scripts and plans is that they seen1 to provide the correct "chunking" structure. But there are indefinitely many events that take place when someone follows a script. The most plausible suggestion concerning the con-
13. ibid. p. 41.
14. Brand, op. cit. p. 205. 15. ibid. p. 215.
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stitutive atomic units of scripts and plans is that they are representations of basic event types. The units must be types rather than tokens, since types are needed to capture general meaning and future action. Representation of such event types, it would seem, proceeds by family resemblance l6 • Scripts are stored as unified wholes, and they consist of scenes that are serially (that is, temporally) ordered. Similar chunking judgments also are made in planning, but script theory continues to undergo change and there is not now a definite version. The units of analysis have changed from large-scale scripts and plans to smaller and more abstract ones, and these units typically are ordered hierarchically. Central processing, however, including memory and plan formation is not well-understood. The more global an intention is the less we understand it, and to the extent that the output system overlaps with the central system, it is not amenable to scientific explanation. Thus, in order to understand prospective intention, Brand has to turn to folk psychology despite its known limitations. The need for a conative component of the cause of action is generated by the conceptual base of folk psychology. A cognitive representation of a possible future course of activity, no matter how well-articulated, and no matter how well attended to, is not sufficient to initiate action. But there is presently no tenable scientific theory into which this folk psychological concept can be translated. Brand's key idea is that an action is performed only when the agent is moved to act, and this mental event is an intention 17 • Still there is no conclusive argument that folk psychology is committed to such ways of talking. There is, however, in folk psychology a fundamental distinction between intentional and nonintentional action. Brand explains that intentional action falls within the pattern of a plan while nonintentional action does not. Following a plan is more complex that acting according to a rule: the person must instantiate a hierarchical structure of action types, and he must be aware in some sense of what he is doing. In nonintentional action, on the other hand, the con-
16. ibid. p. 233. 17. ibid. p. 238.
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ative feature of the antecedent mental. event is independent of all plans the subject follows. An example of nonintentional acting is putting one's hands forward to break a fall. This type of action has survival value, but there is no realistic hope that complex human action can be explained solely in terms of input stimulus and output response l8 • Brand concludes that the subject's cognitive awareness of success and failure is best understood in terms of mental happenings 19. A set of interlocked expectations serves to guide a subject through his environment, and the subject has a "cognitive map" of the environment. Brand argues that there has been an overemphasis on cognitive processes to the neglect of conative ones. It is a misplaced Aristotelianism that all of us have our goals nicely ordered in some hierarchy. Scripts are like generalized cognitive maps, and as such they do not transmit motivation; a set of interlocking rules is required for that. But Brand has to admit that there is at present no extant theory adequate to transform fully the folk psychological concept of conation into a scientific one 20 . The central problem concerns the plasticity of human action; there seems to be an enormous nUITlber of ways to behave that can count as, say, greed. Actions motivated by greed cannot be described or catagorized topologically21, and the same applies to achievement or moral fairness. Persons can be moved to achieve or to act from greed or to have moral concerns only within a social context. Thus, a psychological theory containing only natural kind terms referring to the topological behavior of single individuals cannot explain motivation.
18. viz. Noam Chomsky, "Review of B.F. Skinner's Verbal Behavior,
"Language 35 (1959), pp. 26-58. 19. Brand, Ope cit. p. 248. 20. ibid. p. 263. 21. ibid. p. 268.
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CHAPTER XVII
NOTTURNO'S DEFENSE OF PSYCHOLOGISM
Notturno attempts to justify psychologism by regarding it as part of a twentieth-century paradigm shift. The previous traditional paradigm considered scientific and philosophical inquiry as a quest for absolute and objective certainty. Hence, knowledge was taken as justified true belief, and the objectivity of this belief was thought to be guaranteed by identifying justification with logical proof. To defend the concepts of objective knowledge, justification and rationality against skepticism or relativism, traditional epistemologists found it necessary to separate the objects of knowledge from the natural world - this because the objects of the natural world are in no sense absolute but decidedly temporal and decaying. Notturno emphasizes, however, that philosophy and science assume an entirely different character within the framework of contemporary epistemology, which begins with the assumption that objective certainty is, strictly speaking, unobtainable. Fallibility is accepted, and whatever knowledge is obtained is thought to be both temporal and uncertain by its very nature, evolutionary and subject to revision. Thus, there is little clarity as to exactly what is being charged when an author labels a theory "psychologistic," and psychologism is used in the philosophical literature as a term of ill repute. John Wild locates the essence of psychologism in its characterization of reason as in some way dependent upon something nonrational in character l • As such psychologism should not be understood as a particular thesis but
1. John Wild, "Husserl's Critique of Psycho!ogisID," in Philosophical Essays in Memory oj Edmund Husserl, ed. M. Farber, Greenwood Press, New York 1968, p. 20.
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as a tendency that motivates a wide range of theories, e.g. relativism, skepticism, idealism "and subjectivism. The ground of psychologism is not a commitment to the primacy of psychological methods of inquiry but to empirical justification. It implies the denial of a priori truth and tends to depreciate or deny distinctions between epistemology and metaphysics on the one hand and psychology on the other. Antipsychologism by contrast is the tendency to keep such alleged distinctions sharply in focus. In Frege's view, logic is a normative and not a descriptive or natural science, and meaning or senses are third-realm entities as are numbers. Questions of justification are different from questions of discovery, and statements concerning the psychological genesis of a belief are irrelevant for its justification. The hup of Frege's antipsychologism is that truth and knowledge are in some literal sense objective. Notturno points out, however, that we could not really know what would count as a demonstration that psychologism is true'or that it. is false 2 • Justification by our revised modern standards is thought either to be unnecessary or to be given in the survey. Since the context of justification cannot be separated completely from the context of discovery, epistemology continues to be concerned with the extralogical factors that influence the acceptance or rejection of a theory. This leads to the repudiation of the traditional identification of justification with logical proof. Antipsychologism denies that truth is dependent upon the judging subject, but Notturno argues that Frege's failure to explain the mechanism of apprehension makes his hypothesis of third-realm entities less plausible. For it was in part the mysteriousness of our supposed ability to grasp objective and timeless truths that led empiricists to limit the sources of human knowledge to sensuous intuition in the first place 3 • Notturno argues that fallibilism makes antipsychologism insignificant, for all we know, psychology may be "deeper" than
2. Mark Amadeus Notturno, Objectivity, Rationality and the Third Realm.' Justification and the Grounds of Psychologism , A Study of Frege and Popper, Martinus Nijhoff Publishers, Dordrecht/Boston/Lancaster 1985, p, 24.
3. Ope cit. p. 69.
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logic, and not vice versa as traditional epistemology assumed. But whether logic or psychology comes first is a transcendental problem and as such not decidable. Human+'~beings do in fact reason according to inference forms that deviate from the valid norms of classical logic. Thus, we can no longer accept Frege's antipsychologism, which rejected such deviant inference as irrational 4 • Frege considered self-evidence an objective rather than a psychological property but such a construal of self-evidence would no longer be acceptable today. Popper, therefore, attempted to combine antipsychologism with a thoroughgoing fallibilisn1. The central thesis of Popper's antipsychologism is his rejection of justification as a criterion of knowledge. While, he admits that the very idea of error implies one of truth as the standard of wl1ich we may fall short, Popper does not restrict his antipsychologism to logic and mathematics but extends it over the entire domain of science. His philosophical doctrine is that scientific knowledge is not justified true belief. Popper follows Hume in rejecting both a priori valid statements and induction as logically valid inference, but he repudiates Hume's skepticism or his irrationalist epistemology. This, however, is nothing but Hume's psychologism in the opinion of Notturno, for Hume believed that judgments are justified, but justified not logically by an appeal to reason; they are justified psychologically by an appeal to sense perception and to memories of sense perceptions. Popper by contrast regards scientific knowledge as rational and objective - objective because it can be formulated and communicated in language; rational because such formulation makes logical criticism possible. He en1phasizes that knowledge can grow and that science can progress - just because we can learn from our mistakes 5 • This conception of scientific knowledge as rational and objective, albeit fallible, is often considered to be the central tenet in Popper's philosophy. He denies that scientific statements need
4. Gottlob Frege, The Basic Laws of Arithmetic, M. Furth translation, University of California Press, Los Angeles 1967, p. 14. 5. Karl Popper, Conjectures and Refutations: The Growth of Scientific Knowledge, Harper & Row, New York 1963, p. vii.
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to be justified to qualify as knowledge; for him, it is the demand for justification that leads to skepticism by continually frustrating expectations. Nagel argued that the most natural way to facilitate the shift from traditional to a more realistic modern epistemology is to retain the justified true belief theory of knowledge while weakening the requirement of justification 6 • In Popper's view however, such claims of probability remain relative to a nonexistent truth criterion, and he preferred, therefore, to abandon justification altogether. Nagel maintains that the reliability of a theory can be established through verification by observation and experiment. Rationality for Nagel is teleological and the rationality of behavior is to be assessed by its ability to achieve the goals for which it has been designed. He accuses Popper's philosophy of science of being excessively formalistic in its evaluation of theories 7 • Popper insists, however, that the quest for objectivity demands that knowledge be considered as something other than a species of belief. This is why Popper introduces subjectless knowledge and the third realm. But in addition·to mathematical entities he includes in his world 3 such objects as tools, scientific problems, social institutions, and works of art 8 , none of which can be said to have truth value in a logical sense. Popper emphasizes that the genesis of World 3 objects in no way compromises the timelessness of truth 9 • Frege regarded objective knowledge as a discovery of man, while for Popper it is a product of the human mind. Theories according to Popper are not discovered but invented; yet World 3 ohjects are nevertheless autonomous in the sense that once they are created, they may have unforeseen consequences that can themselves be discovered 10. What impresses Popper as the scientific character of Einstein's
6. Ernest Nagel, Teleology Revisited, Columbia University Press, New York 1979, pp. 64-83. 7. Ernest Nagel, "The Quest for Certainty," in Ope cit. pp. 76-77. 8. Karl Popper and John Eccles, The Self and Its Brain, Springer, New York 1977, p. 38. 9. Paul A. Schilpp, ed. The Philosophy of Karl Popper, Open Court, La Salle, Ill. 1974 p. 148. 10. Karl Popper, Objective Knowledge, Oxford University Press, New York 1972. pp. 160-161.
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theory of gravitation is not that Einstein believed it to be true (which he did not) but that by formuLating its consequences in language he presented the theory for criticism and thereby assumed the risk of refutation 1 I • Indeed, much of what Popper considers to be objective knowledge is, strictly speaking, false. Such false knowledge is essential for his conception of the growth of knowledge, which is changed in the hope of approaching nearer to the truth 12. Prior to Popper, falsehood could be of no interest to the antipsychologist because he accepted knowledge as justified true belief. But for Popper final states of understanding do not exist since they depend solely on the subject's willingness to curb his curiosity and rest content with an interpretation. Popper's point is that statements cannot be justified psychologically because sense perceptions are not reasons. Musgrave nevertheless criticizes Popper's thesis that the degree of corroboration of a hypothesis depends in part upon the severity of the tests to which it has been subjected as psychologistic l3 • The problem here is in explaining what consitutes a severe test. Notturno rightly points out that facts about the expectations of a tester seem every bit as psychological as facts about his sincerity l4. In this way, criticism is shown to be no less psychological than is justification. Popper's method of conjecture and refutation consists essentially in criticizing universal theories by counterexamples. But there is the problem of recognizing a counterexample as a counterexample. Any such observation presupposes a theory and this theory is merely a conjecture that we may be trying to refute. Notturno emphasizes that the appeal to dogmatism in criticism is as problematic as it is in justification. By denying the possibility of justification, Popper himself has indeed introduced something of the magnitude of an epistemological paradigm shift. But while Popper's argument against justificationism is based logically, his alignment of rationality with
11. Popper, Conjectures and Refutations, op. cit. pp. 34-36. 12. Popper, Objective Knowledge, op. cit. p. 71. 13. A. Musgrave, "The Objectivism of Popper's Epistemology," in Schilpp, op. cit. pp. 576-581. 14. Notturno, op. cit. p. 161.
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criticism is not. What it reflects is a, normative nonhistorical approach to the goals of inquiry and the nature of scientific knowledge. Contrary to Popper, Kuhn denied that paradigms can be falsified conclusively. For even when the test of a paradigm yields a universally acknowledged counterexample, the wealth of background knowledge not included in the paradigm but implicit in its test is too rich to determine conclusively that the theory is false. Such debates about paradigms concern the foundations of rational inquiry, but they leave little common ground for nonquestionbegging comparison of theories. So-called paradigm sl1ifts occur not as a result of reasoned argument but by a bandwagon process of ideological or political allegiance, somewhat like religious conversion. Such paradigm shifts usually involve a revision of ontological commitments. New terms are introduced into the semantic structure to denote entities not recognized by the old theory, and familiar terms are redefined and acquire a different meaning. As a result, it is often difficult to express the propositions of a new theory in the language of the old paradigm. Hence Kuhn's celebrated thesis that competing scientific paradigms are incommensurable. Notturno bases his psychologism on what Popper and Kuhn allegedly have in common. Both deny that science progresses through the accumulation and generalization of facts. Instead, they emphasize the logical and psychological priority of theory to observation. For both the sharp distinction between observation and theory is philosophically untenable. New theories are generated primarily in response to recalcitrant problems that confront older theories when they are applied in new and unfamiliar contexts. Notturno concludes that scientific progress cannot be understood by means of logical analysis alone; one must also be sensitive to the common values and goals that govern the context within which scientific problems arise. His interpretation of fallibilism is not logical like Popper's but is psychological; it amounts merely to a repudiation of the view that science aims or can achieve absolute or justified certainty. Notturno sees the differences between Popper and Kuhn as due to a disagreement concerning the aim of science, the notion of rationality, and the role of truth in scientific inquiry. Kuhn interprets Popper's position as an allegiance to logical analysis but Notturno shows that Popper's approach is fundamentally ambiguous. Popper attempts to justify 210
his preference for falsification by an appeal to logic, but he cannot establish in this manner that art alleged f~lsification is ever compelling. So Popper's basic commitment is not to logic but to fallibilism and to a critical attitude, which are at least partly psychological. What Popper criticizes is not simply the logical form of metaphysical statements but the unwillingness of metaphysicians to adopt a critical attitude he regards as essential for rational discourse. In Popper's view, Kuhn's incommensurability thesis is tantamount to what Popper calls the "Myth of the Framework," Le. the view that different theories are like mutually untranslatable languages 15 • Were competing paradigms like untranslatable languages, they would not admit the kind of critical comparison that Popper considers essential for rational discourse. But while Kuhn accepts the analogy between paradigms and linguistic frameworks, he does not regard competing paradigms to be untranslatable 16. Rather, Kuhn's claim is that when paradigms compete, the parties to such disputes inevitably see differently certain aspects of an experimental or observational situation., Since the vocabularies in which they discuss such situations consist predominantly of the same terms, these terms must have different meanings for them, and their communication is, therefore, only partial and incomplete. As a result, the superiority of one doctrine over another is, not something that can be proved in debate. Instead, each party must try by persuasion to convert the other 17 • Kuhn does not deny the translatability of paradigms, but he rejects the existence of a theory that provides a basis for nonquestionbegging cornparison of theories. While Popper is explicitly skeptical of a theory-neutral observation language, Notturno agrees with Kuhn that Popper's epistemology commits him to one 18 • Not~
15. Popper, "Normal Science and Its Dangers, in Criticism and the Growth of Knowledge, I. Lakatos and A. Musgrave eds. Cambridge University Press 1970, p. 56. 16. Thomas Kuhn, "Reflections on My Critics," in Refutations and the Growth of Knowledge, Ope cit. p. 267. 17. Thomas Kuhn, The Structure of Scientific Revolutions, "Postscript 1969," Chicago, University of Chicago Press, 1970. 18. Notturno, Ope cit. p. 199, n23.
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turno considers the idea of a rational argument requiring the existence of a theory-neutral observation language to be yet another residue from the antiquated quest for certainty. He refers to Quine's indeterminacy of meaning in radical translation as making a similar point 19 • Notturno argues that once we give up traditional epistemology, there is no'longer any reason to think that falsification must be conslusive. Thus, from the denial of a theory-neutral observation language it does not follow that competing paradigms are untranslatable because neither translation nor communication can ever be perfect. Popper and Kuhn disagree about the value of a critical attitude in science. What Kuhn looks for are not conclusive experiments, justifications and falsifications, but ideological or political affiliations. Popper, on the other hand, insists that scientists should make a commitment to the tradition of critical rationalism. The heart of the issue between Kuhn and Popper is the role of truth in inquiry or the limits of rationality. While Popper claims to believe in objective truth, this is qualified in Tarski's sense, Le. it is taken relative to a given framework or language 2o • The belief that the truth of a statement can be determined independently of its theoretical context is a familiar compo11ent of the traditional quest for certainty. To admit, therefore, that the determination of truth is theory dependent is to argue against this epistemological tradition. The great revolutions in modern science, in particular the decline of Euclidean geometry and of Newtonian mechanics, have left philosophers skeptical about the absolute, i.e. contextindependent truth. The view gradually emerged that one cannot speak of truth per se but only as related to a conceptual framework of a particular theory or language,. Since such external questions are answered only by a decision to adopt a particular framework, this language or theory cannot itself be considered either true or false. Instead, nonjustificationist epistemology generally appealed to such criteria as practicality, fertility, simplicity or convenience
19. Willard Quine, Word and Object, MIT 1960. 20. Alfred Tarski, "The Scientific Conception of Truth and the Foundations of Semantics," Philosophy and Phenomenological Research, vol 4, pp. 341-376.
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as standards that govern theory choice 21 • The problem, however, is that if the truth of a statement can only be determined within the conceptual framework of a given theory, it becomes impossible to determine the truth of competing theories. In this way, a rational inquiry into foundational problems becomes undecidable as it involves begging the question at issue. The inescapable conclusion seems to be that all rational inquiry is based or arbitrary assumptions. Popper's antijustificationism escapes this foundational relativism by denying that there are foundations about which to be relativistic. But Notturno questions whether only justificationists crave finality while Popper's doctrine of criticism does not. What Notturno emphasizes is that Popper cannot in this fashion escape relativism. There can be little doubt that, from a perspective of traditional epistemology, all such nonjustificationist theories of knowledge are relativistic. Traditionally, philosophers opposed' relativism because they feared that it would lead to a general breakdown of social institutions. This fear was based on the conviction that social bonds could be forged by a community of beliefs. So long as it was accepted that such beliefs could be justified by reason, the rationalist tradition was thought to be the best defense against relativism. Bllt when further logical analysis revealed that all inference depends upon statements that cannot themselves further be justified, this assumption was shown to be deficient. According to Popper, it is only a rationalist critical attitude that can prevent the segmentation of scientists into heterogeneous subcommunities unable to communicate because of their commitment to different paradigms. But Notturno believes that psychologism is another such possibility of partial communication. Many contemporary philosophers have either consciously or unconsciously en1braced psychologism by asking for justification in such terms. Only pro forma did they reject psychologism. The early Wittgenstein, Carnap, and the Logical Positivists were anxious to reveal the genetic and psychological "fallacies" and sought to eliminate all psychological (Le. subjective or arbitrary) elements from philosophical analysis, while using
21. Notturno, Ope cit. p. 190.
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all kinds of psychological arguments in doing so. In this manner, foundational problems came to be regarded as either analytically undecidable or as neither true nor false - n1ere conventions to be accepted or rejected on the basis of "pragmatic," that is, psychological considerations. One such result is Quine's extension of falliblism to logic as manifested in the pragmatic denial of the analytic/synthetic distinction 22 • More recently, however, even Quine seems to have taken a more conservative stance with regard to the laws of logic. The possibility of revising logic is left open, but he still considers it "bad practice" to assume a deviant logic in the translation of others for primarily psychological reasons. Notturno points out that the acceptance of psychologism does not mean that we can never be in a position to assess the rationality of beliefs or actions. Like Isaac Levi 23 , he questions the psychologistic/antipsychologistic dichotomy itself and prefers a Tarskian solution of objective but context-dependent truth. Notturno concludes that psychologism as commonly understood is unavoidable bllt that this is no cause for alarm. The fundamental human situation is one in which men disagree even with regard to the most basic beliefs, and these alternatives leave us without nonquestion-begging grounds for justification. While Popper still hoped that theories can be refuted conclusively, Notturno follows Kuhn in denying this. Such a revised epistemology usually has been accommodated by attempts (like that of Nagel) to weaken the criteria of justification. But further analysis reveals that probability goes the way of logical self-evidence. Notturno thus defends psychologism by accepting the justification of statements by sense perception as "natural." 24 Such a solution, however, is not unproblematic either mainly because it disregards the theory dependence of observation. Perceptions have to be interpreted, ana how they are interpreted begs the question of rationality. Notturno's version of psychologism fails to explain how sense perceptions become reasons. 22. Willard Quine, "Two Dogmas of Empiricism, in From a Logical Point of View, Harper & Row, New York 1953, pp. 42-43. 23. Isaac Levi, The Enterprise of Knowledge, MIT Cambridge, Mass. 1980, p. 428. 24. Notturno, Ope cit. p. 131.
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CHAPTER XVIII
LAUDAN'S JUSTIFICATION BY HINDSIGHT
Students of development in science, whether sociologists or philosophers, have been occupied alternatively with explaining consensus or with describing disagreement and divergence. In the opinion of Laudan, neither approach has shown itself capable of dealing with both. The more recent models leave us largely in the dark about how scientists ever could resolve their differences reasonablyl. So impressed were many philosophers and sociologists by the extent of agreement in science that they took it to be the central and defining epistemic and cognitive feature of science. What makes this broad consensus even more perplexing is the fact that the theories around which agreement forms do themselves sometimes rapidly change. Moreover, all such modifications usually occur at a variety of levels. The central problems of the discipline vary, and the basic explanatory hypotheses shift as do the methods of investigation. Philosophers, however, have generally retained the Leibnizian ideal that all disputes about matters of fact can be impartially resolved by invoking appropriate rules of evidence. Thus, they to-ok it for granted that there are rules of scientific methodology, which are responsible for producing consensus in science. Sociologists like Robert Merton likewise argued that scientific communities share the values of "universalism, communism, disinterestedness, and organized skepticism" 2. The review process along with other features of its
1. Larry Laudan, Science and Values, University of California Press, Berkeley, Los Angeles, London 1984, p. 3. 2. Robert Merton, "The Normative Structure of Science," in Sociology of Science, Chicago, University of Chicago Press 1973.
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reward system manages to institutionalize and to internalize professional norms. Both sociologists and philosophers believed that agreement among scientists about the "facts of the matter" was the natural state of affairs. Laudan, on the other hand, argues that this consensual view of philosophers and sociologists during the 1950s and 1960s fundamentally was mistaken. Scientists have disagreed too often and about too many important matters for us to treat scientific disagreements as minor deviations from a consensual norm. We now understand how deeply the data of science, especially at the research frontier, can underdetermine choice between theories. He consequently rejects the logical empiricist view that scientists have all subscribed to the same evaluative standards. Prolonged disagreements in the past were not merely quarrels about words between empirically equivalent theories. Rather, they were controversies between profoundly different rival frameworks that appeared at the time to be equally well-supported by the evidence. Laudan agrees with Kuhn 3 that at least some controversies in science cannot be resolved because of the underdetermination of theories by data. This also explains how revolutions in science can become successful. But while clashes between rival paradigms are for Kuhn always inconclusive, Laudan proposes a hierarchical model to provide a piecemeal explanation of progress in science. It is designed, among other things, to refute Kuhn's claim that advocates of one paradigm literally cannot understand their rivals. After all, the historical record shows that most such controversies get resolved when one paradigm is replaced by another. Kuhn, on the other hand, was never able to explain how consensus comes about in science, and without such agreement, the onset of "normal" science becomes entirely unintelligible. He tends to explain the transition to a rival paradigm by invoking external factors, like the older generation of scientists dying off. Laudan argues that, even if true, this provides no answer to the original question, for it Jails to explain why the younger generation of scientists are able to agree that one particular rival to the orthodoxy is preferable to
3. Thomas Kuhn, The Structure of Scientific Revolutions, Chicago, University of Chicago Press 1962.
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others 4 • All Kuhn can offer as an explanation of how consensus comes about in science is justificatipn by hindsight. At the lowest level of Laudan's hierarchical model are disputes about matters of fact, including claims about theoretical or unobservable entities. Scientists resolve such disagreements and reach consensus by moving one step up the hierarchy to the level of shared methodological rules. Decisions between competing theories may be likened to the way in which our courts settle civil disputes. Sometimes, however, scientists disagree also about the appropriateness of the proposed rules of evidence or procedure to be applied to the case at hand. Such controversies are in turn resolved by reference to shared aims or goals in science. Laudan admits that methodological rules will not always pick out one factual claim to the exclusion of all its possible rivals. He points out, however, that long-standing stand-offs are only a tiny minority of cases, and that the great majority of disagreements get settled routinedly as the historical record shows. Thus, even when a rule underdetermines a choice in the abstract, it may still dictate a comparable preference among the available alternatives 5 • But Laudan is unable to identify the relevant rules that are said to govern a given decision. Even arbitrary or random choices tend to become plausible by hindsight. His standards for what is rational do not provide a decision procedure to settle which theory or method is superior. If there is more than one set of rules available, it may indeed be quite reasonable to disagree on how to proceed. Laudan rejects the notion of scientific method altogether 6 while trying to preserve the ideal of rational progress. He rejects Kuhn's claim that every paradigm has its own set of cognitive standards or ain1s that are unique to it. Instead, Laudan focuses on the common background assumptions by which such disputes are sometimes resolved. He can, however, identify them only by hindsight. He argues that the historical record disproves Kuhn's claim that there are alternative forms of science each legitimate in its own right. But he has to admit that, in the past, we have often regarded
4. Laudan, op. cit. p. 18. 5. ibid. p. 29. 6. ibid. p. 36.
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something as physically or even logically impossible, which in the end has turned out to be feasible after all. Such familiar cognitive goals as simplicity or elegance fail to impose effective constraints on scientists because few of those who claim to subscribe to them have anything very specific in mind'. Like the rest of us, scientists are largely unaware of the consequences of their choices, which sometimes become evident only long after the event. In this manner, Laudan imputes to scientists motives that are shaped by consequences unforeseen by them, for he can tell what these implicit assumptions are only by hindsight. He believes that what brought about the shift to the "hypothetical method" (first formulated by George Lesage in his article for the French Encyclopedie) was the growing recognition that the explicit claims of empiricism were fundamentally at odds with the implicit aims of scientists to make their theories work. He likewise claims that the Cartesian standard of clear and distinct ideas was abandoned by scientists because they realized that it could not be attained 8 • However, while factual beliefs in one way or another shape our views about which methods and goals are appropriate or attainable, the tendency to mathematize has increased its momentum in modern science. While Laudan rejects all realist clailns for· a gradual realization of truth, his own criteria for what is rational cannot establish valid standards for progress in science. No more that Kuhn is he able to provide a point at which it becomes unreasonable to hold on to the old paradigm rather than accept the new one. He has no plausible explanation for consensus formation, let alone for scientific revolutions. His "reticulated" n10del merely notes consensus formation as a historical fact and mistakenly takes this as some sort of justification. While he realizes that no such judgments are final, he accepts them as prima facie valid. But rejecting pragn1atic criteria as irrelevant, he is in no position to explain why nineteenthcentury physics revived the ancient speculations of Leucippus and Democritus. When he denies that pragmatic success has anythiIlg to do with such epistemological conversions 9 , they inevitably
7. ibid. p. 52. 8. ibid. p. 61. 9. ibid. p. 82.
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become themselves irrational and mysterious. He realizes that seventeenth-century scientists ceased to insist on observable entities in their theories only when all such attempts consistently had failed, yet does not consider this to be a pragmatic judgment. There can be little doubt, however, that giving up in empirical science the ancient and venerable ideals of certainty and proof amounts to a pragmatic decision. What Laudan rejects as "utopian" is clearly a judgment resulting from lack of success, and such significant changes in our beliefs about what is possible will induce us to modify our scientific goals. When theories are underdetermined by a set of rules, Laudan's appeal to internal consistency is bound to turn inconclusive. Referring to background knowledge, his hierarchical model no longer can distinguish effectively between facts, theories, methods and goals. Changes as profound as those from creationist biology to natural selection or from Aristotelian to atomistic views of matte~ very often involve all three levels simultaneously. The triumph of atomism was not just a matter of ontology but led, among other things, to the introduction of statistical methods into empirical science while discouraging teleological explanations. Theory appraisal, therefore, usually involves besides disagreement on facts also controversy abollt which goals are attainable. While Laudan emphasizes that even rival theories often share important background assumptions 10 , he has to admit that in many instances it is impossible to bring such disagreements to a rational conclusion. His attempt at a piecemeal clarification of this process fails to produce a decision procedure because he can identify problems and their solution only by hindsight. Laudan admits that the rules and principles of scientific appraisal underdetermine theory choice, but he nevertheless believes that their normative power suffices to eliminate such pseudosciences as creationist biology or astrology. Because he refuses, however, to evaluate his background assumptions by whether they are successful or not, he can judge them only ex post facto. He opposes Kuhn's view that a scientist can always interpret the ap-
10. ibid. p. 87.
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plicable standards of appraisal so,~as to rationalize his own preferences, but his own historical model inevitably is based on what has succeeded in the past. Since he agrees with Kuhn that the shared values are implicit and ambiguous, he has to admit that two scientists may subscribe to what they consider to be the same standards and yet endorse different views on how to proceed. Because he deals with background knowledge, Laudan cannot specify effectively the shared objective criteria that Sllpposedly warrant a particular preference. He mistakenly takes the fact that such a choice has been made as an indication that it was made rationally. He fails to take seriously the possibility of random or irrational choices in science, even though he agrees with Kuhn on the existence of conflicting paradigms. Laudan concludes that scientific rationality resides in the power of science to resolve problems 11 but fails to show that this is historically cumulative. By identifying problems by hindsight, he in effect uses present knowledge to solve past scientific problems. Laudan rejects prevailing realist assumptions concerning scientific methods and aims. He is skeptical about what they take to be the best explanation and points out that all such judgments are historically relative. The realist aim of attaining ever truer theories about the world may not be attainable for all we know. Neither can we establish that scientific theories in the mature sciences are approximately true, or that more recent theories are closer to the truth than are older theories in the same domain 12. Yet in judging by hindsight, Laudan in effect takes progress in science implicitly for granted. How successful science is taken to be depends, of course, on our standards, but in spite of his protestations to the contrary, Laudan cannot help being pragmatic abollt this. He holds that a theory is successful as long as it has worked well in a variety of explanatory contexts, has led to several confirmed predictions, and has been of broad explanatory scope. How all this is different from "reference to the best explanation" is by no means clear. What he mainly objects to is the realist contention that reference explains success. In Putnam's account, for example,
11. ibid. p. 97. 12. ibid. p. 106.
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Bohr's "electron," Newton's "mass," Mendel's "gene," and Dalton's "atom" are all referring terms~, while "phlogiston" and "ether" are not 13 • Laudan denies that theories whose central terms genuinely refer are necessarily or even generally successful. A theory might be approximately true (in the sense tilat its truth content is higher than its falsity content), and yet be such that all its so far tested consequences are false. Since such estimated truthfulness is parasitic on existing evidence and available conceptual systems,it is not related necessarily to genuine verisimilitude in the opinion of Laudan 14. The point to note, however, is that such estimated truthfulness cannot be established by historical hindsight either If truthfulness is unrelated to success in science, Laudan can only record what has happened, he cannot explain it rationally. His antirealist claim that a theory is approximately true just as long as its directly testable consequences are close to the observable results is unmistakably instrumentalist and pragmatic. He concludes that after the epistemological and methodological battles about science during the last three hundred years it should be clear that science at its face value implies no particular epistemologyls. And yet he ends by offering us another such hierarchical model in the theory of knowledge. He insists that realists have got their history wrong when they imagine that cumulative retention of truth has prevailed in science. Be this as it may, he himself is unable to provide us with an explanation of why we have been successful in science. He considers tIle notion of approximate truth to be too vague to permit one to make rational judgments of progress. But if we cannot tell even that we are getting closer to truth, the very attempt to explain scientific consensus would seem to become epistemologically pointless. 0
13. Hilary Putnam, Meaning and the Moral Sciences, London, Routledge & Kegan Paul 1978, pp. 20-22.
14. Laudan, Ope cit. p. 119n. 15. ibid. p. 12611.
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CHAPTER XIX
NIINILUOTO ON PROGRESS IN SCIENCE
Niiniluoto follows Peirce in taking the essence of science to be a method of self-correction 1. But more recently Popper, Kuhn and Feyerabend have called attention to the discontinuities in the development of science. Niiniluoto points out, however, that the idea of making progress in science does not presuppose universal neutral frameworks 2 • What is needed is a _method of balancing the strength of our evidence against the risks or benefits of contemplated acts. Niiniluoto prefers a Bayesian analysis of rational decision making under uncertainty to Popper's account 3 • Whewell, Peirce and Popper share the view that there are criteria for the evaluation of hypotheses even before they are tested, and such criteria may be said to constitute a "logic of discovery." The term "logic" is used here in a weak sense as referring to an attempt to conceptualize in general terms some recurring patterns of reasoning involved in scientific discovery. For Popper, the main element in this logic is the informative content of a hypothesis. But Popper argues as if it were always fairly easy to find a great number of rival explanations, so that the problem of prior evaluation is that of finding the most trustworthy among them. Kepler's laborious process of discovery, however, serves well to remind us of the extraordinary efforts and difficulties that the hitting upon even one satisfactory explanation may involve. Niiniluoto concludes that
1. C.S. Peirce, Collected Papers, edited by C. Hartshorne and P. Weiss, Harvard University Press, Cambridge, 1931-35, vol. 5, para. 575. 2. Ilkka Niiniluoto, Is Science Progressive? Reidel, Dordrecht, Boston, Lancaster 1984, p. 16, n7. 3. ibid. p. 30.
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there is more "logic" in scientific discovery than Popper has ever ventured to suggest. Contrary to Popper, Niiniluoto emphasizes that the bolder a hypothesis we falsify, the less information we gainthereby. Popper regards all scientific theories as merely conjectural, but during the last one hundred years much work has been based on the assumption that rational estimates can be made of the degree in which the available evidence supports the claim that some particular item of scientific knowledge is true. Suc11 degrees of evidence are expressions of subjective probabilities of our hypotheses. In the selfcorrecting interpretation of progress it is emphasized that scientific knowledge does not merely grow factually, but that its findings are also replaced by novel theories and laws. Thus, while in the empirical sciences we can never claim that we have·actually attained the truth, we do have reasonably good arguments that we have made progress toward the truth 4 • The novelty of Popper's methodology lies in his idea of degrees of empirical content. But he belittles the cognitive value of science by claiming that we usually miss the truth by a wide margin. In a literal application of biological theories to epistemology, knowledge formation is viewed by Popper as a process in which human beings acquire information about the world, i.e. as part of the activities by which we adapt to our environment. Niiniluoto argues, however, that while science may well have started as a continuation to man's adaptation to his environment, contemporary science is an exceedingly complex social and cultural institution. That is why an instrumentalist approach that measures the value of scientific knowledge exclusively in practical terms becomes inadequate. In the instrumentalist view, the question whether science is true does not arise, and does not even make senseS. On the other hand, Niiniluoto finds the idea that scientific method is structurally similar to Darwinian selection to be largely plausible. Following Lakatos, he emphasizes that there is an important inductive (and indeed Lamarckian) ele-
4. K. Popper, Objective Knowledge, Oxford University Press 1972, pp. 57-8. 5. Niiniluoto, Ope cit. p. 62.
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ment in Popper's account of scientific method 6 • It was Kuhn who pointed out that the development of science is not evolution towards anything. The evolution of science should not be viewed as a process culmin-ating in one full objective and true account of the world. Niiniluoto contends, however, that there is a sense in which one can say that biological evolution is goal oriented; in the sense namely, that species adapt themselves to their environment. Whether science makes progress in this sense becomes, therefore, a factual questiol1. The trouble is that such factual investigations are often confused with either epistemological or semantical issues. Progress is a normative or goaloriented rather than descriptive term, and this requires a specification of the goals of science. An essential ingredient in the traditional view of progress has been the idea that scientific knowledge grows in a cumulative fashion. Associated with Bacon's naive methodological optimism and Cartesian rationalism was the conviction that scientific method properly used grows by accumulating reliably established knowledge. Such a view of progress, however, is 110wadays criticized as an inadequate oversimplification by Kuhn and Feyerabend. While this belief may still be justifiable in some branches of mathematics or during periods of what Kuhn calls "normal science," it does not take sufficient account of the discontinuities due to scientific revolutions. Niiniluoto, therefore, proposes a theory of truthlikeness that is close to Popper's notion of verisimilitude which aims at accounting for progress across scientific revolutions. To acconlplish this, he appeals to a Tarskian correspondence theory of truth. He points out that, while there may be no unique, ideally adequate, conceptual frameworks for describing the world, there is a comparative notion of truth relative to each chosen framework for describing the world 7 • Niiniluoto follows Lakatos in suggesting that some weak conjectural principle of induction be assumed to connect scientific standards with versimilitude 8 • He proposes a rational system of inductive pro~ 6. ibid. p. 67. 7. ibid. p. 89. 8. I.Lakatos, "Popper on Demarcation and Induction," in P.A. Schilpp (ed.), The Philosophy of Karl Popper, Open Court, LaSalle 1974, pp.260-262.
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babilities P(Ci/e) for the constituents 9 , and maintains, contrary to Popper, that degrees of corrobor~Jion may serve as an indication of scientific progress 10. For comparative purposes, degrees of truthlikeness are taken to be relative to agreed upon meaning postulates. Niiniluoto agrees with Kuhn that there is no one unique goal of science. But While Kuhn considered the matching of the ontology of a theory with its counterpart in nature to be illusoryll, Niiniluoto emphasizes that most philosophers would agree that science does make progress in the scope of its practical applications. Why science is pragmatically successful has indeed puzzled both Kuhn 12 and Laudan 13 • Niiniluoto claims that his realist theory is able to explain such progress. He argues that pragmatically successful theories have a higher degree of estimated truthlikeness. Their continued success is explained by the hypothesis that they are actually close to the truth, at least in the relevant aspects. This idea that scientific progress can be defined in terms of a prqblemsolving capacity has been further developed by Laudan in his Progress and Its Problems. For Laudan science is a problem-solving rather than truth seeking process l4 . He defines progress in science without appealing to either "truth" or "confirmation." Progress occurs if and only if the succession of scientific theories in a domain exhibits an increasing degree of problem solving effectiveness. But Niiniluoto points out that the problem solving capacity of theories is inevitably connected with their truthlikeness. The less structure one can put into the description of a theory, the more difficult it becomes to distinguish between different types of theory change. Still, Stegmiiller's approach can be used in situations where the class of intended applications is an "open class," i.e. a
9. Niiniluoto, op. cit. p. 105, n65. 10. ibid. p. 105, n66. 11. T.S. Kuhn, The Structure ofScientific Revolutions, 2nd ed. University of Chicago Press 1970, pp. 206-207. 12. T.S. Kuhn, The Essential Tension, University of Chicago Press 1978, pp. 332-333. 13. L. Laudan, Progress and Its Problems, Routledge and Kegan Paul, London 1977, p. 224. 14. ibid. pp. 7, 70.
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class defined by paradigmatic examples. One gives a list of some typical cases that are sufficiently sim!lar to these examples 15. As this sort of openness was exemplified by Wittgenstein, one may say that the need for a pragmatic nonstatement approach to progress arises from the Wittgensteinian character of concept formation in science 16 • Another approach stressing multiple intended applications of theories is based on the idea of theories as tools. But while inquiries are in this sense "local," theories are not restricted to any one single problem. Niiniluoto favors the method of paradigmatic examples in the formation of open concepts, and a pragmatic emphasis on the local aim of inquiries, without committing himself, however, to the instrumentalist view of theories. But he admits that this is a philosophical position that cannot be justified by any simple argument l7 • Stegmiiller's account of progress has the advantage of covering scientific revolutions as well because he is able to explain the immunity of theories to recalcitrant experience. He rejects the idea that there is only one single source of scientific rationality l8. If scientists change some of the essential elements, they are no longer working with the original paradigm or disciplinary matrix, and thus no longer belong to the same tradition 19. Niiniluoto maintains that even the demand that the core remain constant throughout the whole course of the historical development of a theory is too strict. Such a constraint prohibits all conceptual change at the core of normal science no matter how trivial. To be applicable in historical and sociological contexts, we must allow some flexibility even in what passes as the basic meanings. We must treat temporal slices of a research tradition as if they were dominated by cluster concepts. Instead of giving necessary and sufficient conditions for being a Newtonian at time t, we should say that a scientist is part of the Newtonian tradition as
15. W. Stegmiiller, The Structure and Dynamics oj Theories, Springer, New York, Heidelberg, Berlin 1976, pp. 170-185. 16. Niiniluoto, op. cit. 135. 17. ibid. p. 137. 18. W. Stegmiiller, "Logical Understanding and the Dynamics of Theories," Collected Papers, II, Reidel, Dordrecht 1977, p. 272. 19. Niiniluoto, op. cit. p. 139.
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long as he satisfies a sufficient number of criteria that are simultaneously relevant to that tra.dition. Thus, Niiniluoto concludes that Kuhn fails to account for the problem-generating and problem-determining character of a disciplinary matrix. Such partial models or functions permit a range of diverse and even conflicting interpretations. Often instrumentalists indeed have seen nothing wrong in a scientist using conflicting theories for his purposes. But Kuhn cannot pernlit such an inconsistent use of paradigms, because a paradigm change amounts to a gestalt switch, which brings about a scientific revolution. In Niiniluoto's view, by contrast, traditions are characterized by means of cluster concepts, and the successive elements within a tradition bear only a family resemblance. His structuralist analysis rejects Kuhn's contention that in normal science failure to support a paradigm discredits the scientist rather than the theory. Niiniluoto emphasizes that Kuhn's explanation of normal science remains inconlplete as long as he fails to provide a theory of belief formation in scientific communities, that is, an account of how members of a community are influenced by their peers, and how they actually reach a consensus. To the extent to which scientists are able to accomodate diverse meaning postulates, communication even across different paradigms becomes possible. Thus, J. Sneed and W. Stegmiiller use reduction to account for theory change. Reduction is possible even between elements that employ dissimilar conceptual frameworks. D. Pearce 20 shows how a reduction between two cores can generate a translation between their respective languages. In this manner, Niiniluoto attempts to bridge Kuhn's dichotomy between normal science and scientific revolutions. An important feature of such an account of scientific development is the possibility of progress branching. Like Kuhn. and Stegmiiller, Niiniluoto consequently rejects the teleological myth of progress, i.e. the claim of defining progress in terms of getting. closer to the truth. Instead, he agrees with Laudan's
20. D. Pearce, "Is There Any Theoretical Justification for a Non-statement View of Theories?" Synthese 46, 1981 pp. 1-40; also D. Pearce, "Logical Properties of the Structuralist Concept of Reduction," Erkenntnis 18, 1982, pp. 307-333.
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evaluation of theories by their problem-solving capacities. But he emphasizes that such a criterion permits not only an instrumentalist but also a realist interpretation. While instrumentalism denies that truth is part of what we mean by a problem, Niiniluoto maintains that problems presuppose a criterion of truth or at least of truthlikeness. He elaborates on some of the pragmatic aspects of Popper's criterion of verisimilitud_e, but he realizes that Popper's insistence on the Darwinian features of progress in science inevitably lead to the Kuhnian position where progress can be recognized only within the context of a shared paradigm. Niiniluoto, therefore, attempts to define progress across scientific revolutions as a cluster concept. This, however, amounts to no more than a partial family resemblance of the new and the previous paradigms, and such a criterion of progress cannot make any valid claims about specific cases nor can it predict future developments. All it shows is how certain scientific solutions adapt to a changing context but it fails to provide any more general explanation of how or why this happens. It thus becomes questionable whether such a weak criterion of progress has any definite applications in science. Niiniluoto's theory of truthlikeness amounts to the claim that the development of science is at least partly cumulative when it corrects earlier results or replaces old theories with a conceptually different theoretical framework. Truthlikeness is a combination of truth and information, and while we cannot know about having gotten close to the truth, we do know about increasing information about the world we live in. But such information would be useless .or worse if it were not true. If attaining the truth is an impossible ideal in science, Niiniluoto's criterion of truthlikeness cannot become operative either. The new theory must be able to explain the relative success of its predecessors, and this is something that Popper's criterion of verisimilitude notably fails to d0 21 • Kuhn's account is a compromise between the cumulative and the non-
21. cf D. Miller, "Popper's Qualitative Theory of Verisimilitide," The British Journal ofthe Philosophy ofScience, 25, 1974, pp. 166-177; A. Grilnbauffi, "Can A Theory Answer More Questions than One of its Rivals?" The British Journal for the Philosophy of Science, 27, 1976, pp. 1-23.
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cumulative view of scientific progress; he holds that while the paradigm based normal science is cumulative, periods of normal science end in a crisis and in a conceptual revolution by which the old paradigm is replaced by a new one. According to-Kuhn, different paradigms are incommensurable, and for that reason theories after a scientific revolution cannot be said to be closer to the truth than theories belonging to the previous paradigm. Niiniluoto by contrast argues that, even scientific revolutions can be progressive as long as the paradigm preserves the problemsolving capacities of its predecessors. Such progress, however,is not necessarily cumulative because some of the problems that the old paradigm managed to solve are no longer meaningful within the new paradigm. The result is that science is not defined anymore in cognitive terms that presuppose the criterion of truth, and that theories come to be regarded merely as instruments for problem solving 22 • For instrumentalists, theories are conceptual tools for performing such tasks as prediction, control, and the like, and scientific progress is defined by how theories manage these tasks. Most instrumentalists find nothing objectionable in scientific revolutions, and can thus accept Niiniluoto's weak consistency of a cluster concept. But even those who admit that progress in science is noncumulative believe that there is at least some sort of progress across scientific rev·olutions. Theory change thus becomes a matter of degree. Laudan objects that in view of the notorious difficulties with the notions of approximate truth at both the epistemic and the semantic level, progress in terms of increasing trllthlikeness prevents us from viewing science as a rational activity 23. Niiniluoto argues, however, that a theory of truthlikeness is no less well-understood than the problem-solving account of progress. As most scientific questions are either truth-using or truth-seeking or both, the problem-solving account of scientific change requires ultimately assumptions of truth or truthlikeness 24 • A theory gets credit only 22. Niiniluoto, Ope cit. p. 162. 23. L. Laudan, "A Problem Solving Approach to Scientific Progress," in I. Hacking (ed), Scientific Revolutions, Oxford University Press, 1981, pp. 144-5. 24. Niiniluoto, Ope cit. p. 164.
230
after its predictions have been verified - and this makes science inevitably a truth-seeking enterprise. Laudan demands that successful theories also entail novel facts;: but Niiniluoto points out that such facts are states of affairs expressed in true sentences. Facts are semilinguistic entities that presuppose not only a conceptual framework but also a given technology. Like Popper, he prefers a Tarskian version of the correspondence theory according to which truth is a relation between sentences in a language Land any structure of the type WL. Which sentences are true in WL is not determined by the frame L but by the way the world is. There is nothing either metaphysical or even epistemic about this account; it merely tells us what it means for a sentence h to be true when a structure WL and the interpretation of the vocabulary of L in the domain of WL are given. In most cases, however, where the conceptual system L is given, the structure of WL remains unknown - and this is precisely why scientists have conceptual problems with the formation of tl1eir theories. A primitive realism keeps truth altogether separate from our practice. Yet the success of empirical predictions in science crucially depends on the quality of our instruments and thus upon technology. It need not be the case that such predictions are strictly true, and they are actually often false. Niiniluoto emphasizes, however, that even if they happen to be false, they cannot be at a great distance from the truth. If a theory is' successful to a merely limited degree, the relative success of h is explained by the assumption that it is truthlike to some degree. Thus, the phlogiston hypothesis was not generally true, but it did have some empirical success. Niiniluoto emphasizes that human knowledge is not only theory-laden but that it depends on a given level of technology. Thus, the language in which progress is defined is itself subject to change. Our ideas of what constitutes scientific knowledge have changed considerably in the twentieth century. As a consequence, the procedure of solving cognitive problems is more likely to be represented in terms of decision making 25 • If a theory were merely a symbolic device that does not have any truth value, as some instrumentalists claims, its persistent practical success would be nothing short of a miracle. Niiniluoto,
25. cf. I. Levi, Gambling with Truth, Alfred A. Knopf, New York 1976.
231
therefore, concludes that it is compatible with scientific realisn1 to treat science as a problem-solving activity. As soon as we admit that our theories are expected to yield correct interpretations of nature, we acknowledge that science is a truth-seeking enterprise 26 • He emphasizes that there are genuine steps of scientific progress discoveries of new theories and facts that are more truthlike than their predecesors even if they do not have any practical applications. The mistake of instrumentalism is to think that all sciences are basically technological. Bacon's methodological optimism has turned out to be mistaken, but it would be wrong to blame science for the detrimental effects of technology since they are primarily the result of prevailing societal values.
26. Niiniluoto, Ope cit. p. 255.
232
INDEX
Abelson, R. 201n; 202 Abstract 33, 38, 43, 70, 71, 93, 153, 181,203,217 Ackermann, R. 11, 115-125 Action 12, 56, 62, 96, 141, 143, 151, 174, 181, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 197-204, 223 Aesthetic 164, 165, 166, 168 Analogy 16, 20, 21, 46, 73, 146, 167, 168, 183, 188, 211 Analysis 12, 15, 19, 23, 40, 54, 56, 57, 65, 68, 69, 70, 71, 72, 73, 76, 78, 79, 82, 85, 92, 95, 107, 129, 138, 151, 154, 163, 172, 173, 174, 178, 187, 191, 198, 199, 202, 203, 210, 213, 214, 223, 228 Analytic 16, 20, 30, 36, 54, 55, 84, 128, 130, 131, 194, 199 Appel, K. 27, 28n Aristotle 10, 17, 81, 85, 97, 158, 162, 204, 219 Arithmetic 16, 19, 23, 24, 30 Atom 40, 41, 42, 43, 44, 45, 46, 47, 102, 160, 203, 219, 221
Austin, J .L. 104n Axiom 17, 18,21,22,23,26, 31, 37, 38, 69, 70, 88, 97, 132, 134 Ayer, A.J. 58n Background 10,11,12,13, 52, 68, 89, 93, 94, 99, 111, 112, 118, 139, 173, 175, 176, 177, 198,210,217, 219, 220 Bacon, F. 225, 232 Baker, J. 186n, 187 Bayes, T. 127, 129, 135, 136, 137, 138, 223 Behavior 12, 33, 49, 52, 54, 55, 62, 94, 96, 142, 143, 144, 145, 146, 147, 151, 152, 154, 155, 156, 179, 193, 198, 204, 208 Belief 10, 11, 12,24,31,41, 50, 52, 53, 56, 58, 59, 62, 65, 66, 67, 71, 72, 87, 96, 98, 102, 104, 105, 107, 109, 117, 127, 128, 129, 130, 131, 132, 134, 135, 136, 137, 139, 158, 159, 160, 161, 170, 171, 173, 174, 175, 177, 180, 181, 183, 184, 185, 187, 188, 189,
233
190, 193, 194, 197, 198, 199, 200, 205, 206, 207, 208, 209, 212, 213, 214, 216, 218, 219, 225, 228, 230 Bivalence 10, 59, 60, 63 Bohr, N. 40, 41n, 42n, 44, 45, 46, 47n, 106, 221 Boltzmann, L. 38n Boole, G. 21 Born, M. 43n Boyle, R. 160 Brand, M. 12, 197-204 Bratman, M. 183n, 184n Buridal1, J. 184 Butchvarov, P. 9, 33-37 Carnap, R. 65, 122, 136, 213 Category 81, 85, 87, 107, 164, 165, 168, 170, 192, 204 Cause 72, 101, 104, 159, 179, 181, 183, 187, 192, 194, 197, 198, 199, 200, 203 Chaitin, G. 31n Change 72, 85, 90, 101, 103, 107, 108, 112, 113, 116, 120, 124, 135, 136, 138, 157, 158, 160, 162, 167, 168, 175, 177, 190, 191, 192, 194, 199, 203, 209, 215, 219, 226,227, 228, 229, 230, 231 Chomsky, N. 78, 79, 83, 158, 180, 204n Classification 36, 90, 130, 134, 137, 138, 150, 158, 164, 165, 157, 178,200, 226, 227 234
Coherence 11, 13, 25, 85, 88, 95, 96, 99, 106, 128, 136, 137, 158, 160, 193, 200 Common Sense 11, 63, 87, 90, 94, 107, 117, 123, 124, 148, 156, 170, 197, 199 Complexity 23,26, 27, 29, 30, 31, 35,42,51,52,63, 75, 76, 84, 85, 115, 120, 131, 132, 138, 155, 166, 167, 173, 180, 199, 200, 202, 203, 224 Computation 9, 16, 25, 27, 28, 29, 30, 138, 142, 154, 201 Concept 9, 10, 12, 23, ·27, 28, 30, 31, 34, 35, 36, 37, 38, 39, 43, 46, 51, 52, 53, 54, 57, 60, 61, 62, 63, 65, 68, 69, 71, 73, 77, 79, 81, 82, 83, 84, 87, 89, 90, 91, 92, 93, 94, 95, 97, 98, 99, 101, 103, 107, 108, 109, 112, 124, 135, 138, 139, 144, 147, 148, 150, 151, 152, 153, 155, 157, 158, 159, 160, 161, 162, 172, 173, 174, 175, 176, 177, 178, 180, 181, 183, 184, 190, 192, 193, 194, 198, 199, 200, 201, 203, 204, 205, 207, 209, 213, 221, 223, 225, 227, 228, 229, 230, 231 Concrete 27, 153 Consistency 9, 118, 129, 161, 177, 181, 193, 199, 219 Content 56, 58, 60, 63, 67, 88, 89, 99, 132, 137, 138,
176, 179, 188, 189, 194, 200, 221, 223, 224 Context 10, 11, 13, 16, 22, 34, 46, 55~ 58, 72, 76, 79, 80, 82, 88, 92, 93, 94, 95, 104, 117, 129, 131, 132, 137, 160, 163, 164, 165, 166, 179, 181, 185, 191, 204, 206, 210, 214, 220, 227, 229 Convention 24, 52, 59, 78, 82, 88, 89, 90, 99, 129, 130, 152, 165, 174, 181, 188, 214 Copernicus, N. 41, 106, 133 Criterion 9, 26, 29, 36, 47, 54,55,66,67, 115, 118, 121, 128, 131, 154, 156, 157, 160, 161, 164, 168, 169, 171, 172, 176, 179, 182, 198, 207, 208, 212, 214, 218, 223, 228, 229 Critical 132, 134, 138, 207, 209, 210, 211, 212, 213, 225 Culture 13, 25, 26, 119, 158, 159, 224 Dalton, J. 221 Darwin, C. 157, 159, 160, 161, 162, 224, 229 Data 11, 12,37, 112, 113, 115, 116, 118, 119, 120, 121, 122, 123, 124, 125, 132, 133, 134, 135, 138, 194, 201, 216 Davidson, D. 12, 49, 53n, 54, 55n, 56, 57, 58n, 62, 75n, 76, 79, 168n, 171-182,
183-195, 197n, 199n, 200 Davis, J. 24n Decision 59, 60, 62, 66, 70n, 84, 94, 95, 107, 108, 110, 131, 137, 139, 154, 158, 164, 165, 166, 168, 169, 174, 179, 180, 181, 187, 193, 194, 207, 212, 213, 214, 217, 219, 223, 231 Dedekind, R. 19 Deduction 11, 17, 21, 24, 38, 53, 57, 103, 104, 105, 119, 127, 128, 129, 130, 132, 133, 137, 162 Definition 12, 21, 22, 23, 37-47, 50, 51, 55, 75, 77, 80, 85, 89, 95, 110, 122, 130, 132, 136, 142, 143, 150, 153, 175, 181, 182, 187, 194, 198, 201, 202, 215, 226, 228, 229, 230, 231 De Millo, R.A. 31n Democritus 160, 218 Descartes, R. 10, 82n, 87, 88, 94,116,144,161,218,225 Description 35, 43, 52, 53, 56, 57, 61, 65, 66, 69, 93, 94, 117, 122, 123, 124, 125, 131, 132, 143, 159, 160, 161, 162, 163, 165, 170, 173, 175, 191, 192, 201, 204, 206, 215, 225, 226 Development 16, 18, 22, 25, 26, 34, 76, 81, 84, 112, 117, 124, 125, 134, 158, 160, 194, 215, 223, 225, 226, 227, 228, 229 Dewey, J. 102 235
Dialectic 22, 115-125, 157 Dirac, P. 45n Discourse 52, 56, 63, 70, 79, 83, 118, 128, 156, 166, 167, 170, 177,211 Discovery 11, 37, 59, 90, 94, 106, 111, 117, 118, 122, 124, 129, 164, 206, 208, 223, 224, 232 Domain 11,47,61, 112, 115, 116, 118, 119, 123, 124, 125, 129, 160, 207, 220, 226, 231 Donnellan, K. 66n, 67 Duhem, P. 109, 129n, 132n, 133 Dummett, M. 59n, 60, 61, 62n, 63 Eccles, J. 208n Einstein, A. 37n, 38, 39n, 40n, 41n, 42n, 43, 44, 46, 47, 208, 209 E!llpirical 15-31, 39, 50, 54, 55, 62, 63, 103, 116, 117, 118, 122, 124, 128, 131, 132, 134, 135, 139, 144, 15 4, 158, 160, 174, 176, 178, 180, 195, 198,201, 206, 216, 218, 219, 224, 231 Entity 35, 42, 57, 58, 59, 65, 70, 71, 88, 89, 93, 94, 101, 103, 104, 107, 108, 110, 146, 150, 158, 162, 178, 181, 198, 206, 208, 210, 217, 219, 231 Epicufus 160 Epistemology 10, 25, 36, 43, 1
236
49, 51, 61,62, 68, 88, 89, 90, 95, 108, 115, 116, 131, 144, 158, 172, 205, 206, 207, 208, 209, 211, 212, 213, 214, 215, 218, 221, 224, 225, 230, 231 Euclid 158, 212 Euler, L. 13 Event 58, 104, 110, 122, 129, 151, 161, 162, 167, 169, 178, 179, 181, 191, 192, 197, 198, 202, 203, 204, 218 Evidence 11, 51, 54, 55, 58, 59, 62, 63, 87, 95, 97, 102, 105, 116, 117, 120, 123, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 138, 142, 143, 154, 171, 172, 173, 175, 179, 182, 186, 189, 200,201, 207, 215, 216, 218, 221, 223, 224 Existence 28, 36, 38, 45, 60, 65, 70, 71, 77,78, 81, 88, 89, 90, 91, 92, 94, 97, 98, 104, 107, 109, 112, 120, 124, 138, 144, 146, 150, 155, 181, 185, 189, 192, 199, 208, 209, 211, 212, 220, 221 Experience 9, 16, 18, 22, 33 35, 36, 37, 38, 44, 46, 47, 88,89,90,92, 107, 111, 123, 127, 136, 141, 143, 144, 145, 150, 158, 159, 161, 162, 175, 176, 177, 227 Experiment 24, 26, 29, 38,
40, 47, 98, 101, 102, 107, 108, 109, 111, 113, 115, 117, 118, 120, 123, 125, 127, 132, 138, 146, 195, 201, 208, 211, 212 Explanation 10, 13, 16, 18, 23, 26, 28, 30, 33, 36, 38, 40, 43, 47, 49, 51, 52, 53, 54, 56, 57, 58, 61, 62, 71, 78, 89, 91, 92, 93, 97, 98, 99, 102, 103, 104, 105, 107, 109, 111, 112, 113 , 116, 117, 119, 120, 124, 125, 127, 129, 130, 131, 133, 134, 135, 138, 141, 148, 150, 153, 159, 160, 161, 165, 166, 171, 175, 178, 179, 183, 184, 187, 189, 190, 192, 194, 198, 201, 203, 20.4, 206, 214, 215, 216, 217, 218,219,220, 221, 223, 226,227, 228, 229 Expression 66, 71, 75, 76, 84, 148, 149, 179, 188 Fact 11, 15, 23, 24, 28, 33, 34, 39, 50, 52, 58, 59, 62, 63, 68, 71, 72, 89, 93, 94, 98, 102, 108, 111, 116, 118, 119, 120, 121, 122, 123, 124, 125, 130, 132, 138, 142, 143, 144, 145, 146, 147, 148, 149, 151, 153, 154, 155, 156, 159, 160, 161, 163, 166, 167, 168, 175, 179, 180, 181, 186, 188, 189, 193, 194, 199, 207, 209, 210, 215, 216,
217, 218, 219, 224,225, 231, 232 Falsification 24, 110, 224 Fermi, E. 45n Feyerabend, P. 102, 103n, 108, 109, 112, 124, 134, 223, 225 Field, H. 50n Form 15, 20, 21, 24, 28, 29, 30, 31, 33, 44, 45, 49, 55, 56, 57, 65, 72, 73, 75, 78, 79, 82, 83, 84, 97, 99, 101, 135, 138, 141, 149, 153, 154, 155, 156, 157, 158, 159, 161, 162, 164, 166, 177, 179, 180, 181, 184, 192, 193, 198, 200, 207, 208,209,211,217,227, 228, 231 Foundation 16, 17, 18, 19, 21, 23, 25, 26, 35, 56, 68, 71, 82, 88, 95, 213, 214 Framework 13, 18, 21, 35, 37, 72, 79, 80, 94, 95, 96, 101, 120, 135, 137, 146, 163, 165, 198, 205, 211, 212, 213, 216, 223, 225, 228, 229, 231 Frege, G. 17,50,55,56,57, 66, 75, 76, 79, 80, 81, 82, 85, 206, 207n Galileo, G. 56, 124, 159 Game 10, 75-85, 149, 150, 151, 152, 153, 155, 156 Garber, D. 135, 136n Garbiner, J. 26n Geometry 18, 19, 21, 22, 26, 27, 37, 38, 39,42, 97, 105, 237
161 Giere, R. 134n Glymour, C. 11, 127-139 Godel, K. 17, 21, 31n Goodman, Nelson 12, 163-170 Goodman, Nicholas D. 21, 22n Grice, P. 186n, 187 Griinfeld, J. 123n Hacking, I, 10, 101-113 Haken, W. 27, 28n Hanson, N.R. lIOn, 134 Hegel, G. 157 Heisenberg, W. 41, 42, 43n, 44, 45n, 46n Helmholtz, H. 39 Hempel, C.G. 127, 138 Hersch, R. 18, 19n, 20n, 25n Hertz 38n, 39 Hilbert, D. 21 Hintikka, J. 10, 75-85 History 11, 12, 16, 18,26, 27,66,67,82,87,93,102, 105, 106, 107, 108, 109, 111, 115, 118, 119, 121, 122, 123, 124, 125, 128, 129, 130, 131, 132, 134, 157, 158, 159, 160, 161, 162, 210, 216, 217, 218, 220, 221, 227 Horwich, P. 137n Hume, D. 40, 62, 104, 122, 141n, 144, 145, 148, 156n, 166, 207 Husserl, E. 90 Hypothesis 11, 13, 101, 102, 105, 117, 119, 127, 128, 238
129, 134, 139, 150, 215,
130, 135, 142, 156, 218,
131, 136, 144, 177, 223,
132, 137, 146, 206, 224,
133, 138, 148, 209, 226.
Identity 9, 33-37, 67, 68, 69, 73,79, 81, 88, 94, 95, 98, 99, 147, 158, 161, 168, 169, 172, 173, 174, 176, 177, 178, 179, 180, 181, 193, 198, 199, 205, 206, 217 Imagination 37, 46, 58, 77, 91, 92, 117, 149, 153, 178, 221 Individual 54, 81, 115, 116, 120, 123, 129, 134, 135, 136, 137, 145, 151, 152, 153, 156, 158, 166, 167, 171, 172, 178, 181, 191, 192, 193, 195, 204 Induction 15, 18, 39, 53, 55, 134, 137, 165,207, 224, 225 Inference 81, 96, 97, 101, 102, 191, 194,207, 213 Infinity 61, 142, 146, 147, 155, 179 Information 10, 11,25,31, 51,61, 63, 77,78, 80, 84, 88, 111, 116, 120, 121, 135, 139, 179, 201, 202, 223, 224,229 Instrumental 10, 11, 34, 35, 101-113, 115-125, 202, 221, 224, 227, 228, 229, 230, 231, 232 Intention, 52, 53, 54, 56, 57, 62, 73, 82, 94, 142, 143,
146, 147, 171, 173, 174, 179, 183-195, 197, 198, 199, 201, 202, 203, 226, 227 Interpretation 12, 13, 23, 27, 28, 35, 42, 43, 44, 46, 56, 62, 63, 69, 73, 78, 81, 82, 83,90,93,104,107,112, 113, 116, 119, 120, 123, 124, 134, 143, 144, 146, 158, 149, 151, 155, 157, 159, 163, 171, 172, 173, 174, 177, 178, 179, 181, 193, 194, 195, 198, 209, 210, 214, 219, 224, 228, 229, 231, 232 Intuition 10, 12, 13, 17, 18, 19, 20, 21, 22, 23, 24, 31, 37, 39, 42, 43, 44, 45, 46, 47, 56, 68, 69, 70, 71, 72, 83, 93, 117, 132, 133, 135, 137, 138, 146, 151, 153 , 166, 206 Invention 13, 90, 110 Jeffrey, R. 138, 139n Judgment 10, 12, 56, 87, 95, 97, 98, 118, 119, 121, 131, 134, 145, 151, 155, 156, 157, 158, 160, 164, 182, 184, 185, 186, 187, 188, 201, 203, 206, 207, 218, 219, 220, 221 Justification 12, 13, 16, 18, 25,31,53,71,76,82,88, 92, 95, 96, 97, 98, 105, 108, 117, 132, 141, 143, 150, 151, 161, 165, 167, 170, 180, 201, 205, 206,
207, 208, 209, 210, 212, ";'213, 214, 215-221, 225, 227 Kant, I. 37, 39, 81, 87, 158 Kelley, D. 10, 87-99 Kepler, J. 42, 130, 223 Kitcher, P. 27n Knowledge 10, 12~ 13, 16, 19, 25, 27, 29, 30, 37, 38, 39, 47, 55, 56, 58, 59, 60, 61, 62, 63, 66, 67, 68, 70, 71, 81, 84, 87, 88, 89, 90, 91, 93, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 108, 109, 111, 112, 113 , 11 7, 120, 122, 123, 124, 127, 128, 129, 134, 135, 136, 143, 144, 147, 158, 172, 173, 175, 177, 182, 187, 188, 189, 194, 201, 202, 203, 205, 206, 207, 208, 209, 210, 213, 219, 221, 224, 225, 229, 231 Koch, K. 27, 28n Kohlberg, L. 158 Kripke, S. 11, 65n, 66, 67n, 68n, 69n, 141-156 Kuhn, T. 12, 26n, 102, 105, 106, 107, 108, 109, 115, 116, 118, 119, 120, 122, 124, 129n, 130, 131, 133n, 134, 210, 211n, 212, 214, 216n, 217, 218, 220, 223, 224, 225, 226n, 228, 229, 230 Lakatos, I. 18n, 23, 24n, 105, 107, 110, 115, 159, 224, 225n 239
Lamarck, J .B. 224 Language 9, 10, 11, 13,21, 29, 33, 34, 35, 36, 47, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 68, 70, 71, 72, 73, 75, 76, 77, 78, 79, 81, 83, 84, 85, 87, 88, 89, 92, 93, 94, 95, 96,99, 106, 116, 117, 123, 124, 128, 136, 141, 142, 143, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 158, 159, 160, 161, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 192, 193, 194, 195, 202, 207, 209, 210, 211, 212, 228, 231 Laudan, L. 12, 13, 103n, 215-221, 226n, 228, 230n, 231 Laymon, R. 133n Learning 16, 75, 76, 95, 116, 124, 129, 142, 145, 179 Leibniz, G. 34, 215 Leucippus 218 Levi, I. 214n, 231n Lewis, D. 65n, 68n, 69, 72n Lipton, R.J. 31n Locke, J. 91 Logic 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 23, 24, 30, 31,33,35,54,55,57,58, 65, 68, 69, 71, 72, 73, 76, 77, 80, 81, 83, 84, 85, 92, 95, 117, 119, 121, 125, 129, 132, 134, 136, 142, 158, 159, 160, 161, 164, 165, 240
168, 172, 173, 176, 178, 179, 180, 181, 183, 185, 187, 190, 206, 207, 209, 210, 213, 214, 216, 218, 224 Lorentz H.A. 40
177, 182, 205, 211, 223,
Mach, E. 39 Marx, K. 157 Mathematics 9, 13, 15-31, 44, 45,46,47,81, 105, 117, 125, 132, 135, 139, 141, 142, 145, 146, 150, 155, 167, 207, 208, 218, 225 Maxwell, G. 29, lIOn McDowell, J. 51n, 52n, 53n McGinn, C. 60n, 61n, 620, 63n Meaning 9, 11, 13, 15, 23, 38, 43, 46, 47, 50, 53, 54, 57, 58, 59, 61, 62, 63, 65, 67, 75, 76, 77, 79, 80, 83, 94, 96, 104, 106, 107, 118, 121, 127, 131, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 153, 156, 162, 165, 166, 169, 171, 173, 174, 175, 176, 177,178,179,180,181, 182, 192, 201, 203, 206, 210, 211, 212, 226, 227, 228, 230, 231 Mendel, G. 221 Merton, R. 215n Metaphor 10, 12, 13, 45, 57, 58, 63, 93, 109, 160, 161, 163-170, 171-182 Metaphysics 9, 35, 36, 68, 88,
90, 91, 92, 109, 128, 155, 158, 192,206,211,231 Method 12, 16, 18, 19, 21, 23, 24, 26, 28, 39, 50, 60, 61, 101, 105, 108, 109, 115, 117, 119, 120, 121, 127, 128, 130, 131, 132, 134, 135, 137, 145, 154, 160, 162, 164, 170, 178, 180, 192, 200, 206, 209, 215, 21 7, 218, 219, 220, 221, 223, 224, 225, 227, 232 Mill, 1.S. 30 Miller, A.l. 9, 37n, 38n, 43n, 45n Miller, D. 229n Millikan, 1.A. 106 Modality 59, 65, 66, 70, 71, 89, 98, 103, 149, 157 Model 10, 18, 21, 23, 34, 43, 47, 54, 56, 63, 65, 73, 81, 84, 85, 90, 91, 92, 93, 98, 101, 105, 109, 115, 118, 127, 133, 160, 176, 189, 201, 202, 215, 216, 217, 218, 219, 220, 221, 222, 228 Morgenstern, O. 199 Musgrave, A. 209n Nagel, E. 208n, 214 Name 34, 50, 53, 55, 56, 66, 67, 165 Necessity 68, 69, 70, 71, 190 Network 13, 95, 192 Neumann, 1. 199 Neurath, O. 117 Newton, I. 13, 38, 104, 130, 132, 158, 212, 227
Newton Smith, W. 105n Niiniluoto, I. 13, 223-232 Norm, 12, 95, 99, 143, 152, 186, 193, 194, 198, 199, 202, 206, 207, 210, 216, 225, 227, 228, 229 Notturno, M.A. 12, 205-212 Number 16, 17,20, 24, 27, 41, 71, 136, 144, 150, 178, 182, 185, 206, 223, 228 Object 11, 22, 33, 34, 35, 36, 44, 46, 50, 55, 56, 57, 58, 61, 66, 67, 68, 69, 70, 85, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 106, 107, 108, 110, 112, 116, 123, 146, 155, 162, 165, 167,172,178,179,181, 188, 192, 199, 205, 208 Objective 10, 11, 19,91,96, 97, 105, 115, 118, 119, 123, 134, 146, 153, 173, 205, 206, 207, 208, 214, 220, 225 Observation 12, 37, 38, 40, 47, 59, 62, 89, 90, 102, 109, 110, 111, 112, 115, 117, 118, 120, 124, 127, 128, 132, 133, 136, 142, 147, 156, 162, 164, 175, 208, 209, 210, 211, 212, 214, 219, 221 Occam, W. 83 Oedipus 191, 192 Ontology 34, 35, 54, 80, 108, 162, 172, 178, 192, 193, 195, 210, 219, 226 Order 22, 37, 73, 76, 77, 78, 241
84, 129, 138, 162, 169, 182, 203 Paradigm 12, 27, 75, 77, 106, 108, 117, 118, 119, 120, 131, 144, 155, 205, 209, 210, 211, 212, 213, 316, 217, 218, 220, 227, 228, 229, 230 Paradox 11, 17, 18, 19,69, 141, 143, 148, 149, 150, 151, 154, 155, 156, 167, 180 Pauli, W. 42, 44n Peacocke, C. 58, 59n, 187n, 188 Peano, G. 30, 80 Pearce, D. 228n Pears, D.F. I88n, 190 Peirce, C.S. 105, 223n Perception 58, 59, 87-99, 123, 124, 163, 164, 181, 198, 207, 209, 214 Perlis, A.J. 31n Phenomenon 36, 38, 89, 90, 95, 97, 110, 112, 120, 128, 135, 147, 164, 166, 175 Philosophy 15, 16, 19, 20, 21, 25, 28, 30, 37, 39,49, 51, 52, 58, 65, 70, 73, 84, 85, 87, 91, 99, 102, 107, 108, 110, 115, 117, 118, 119, 122, 123, 128, 132, 134, 141, 142, 144, 145, 146, 147, 148, 149, 153, 154, 158, 161, 171, 172, 180, 186, 197, 205, 207, 208, 210, 212, 213, 215, 216, 226, 227 242
Physics 9, 18, 20, 21, 25, 31, 37, 38, 39, 40, 41, 42, 43, 4:5, 46, 47, 50, 51, 52, 53, 67, 87, 101, 105, 218 Piaget, J. 158 Picture 35, 37, 38, 40, 41,42, 43, 44, 45,46, 47, 58, 101, 106, 109, 112, 122, 144, 145, 149, 161, 163, 164, 170, 177, 181,202 Planck, M. 41, 42, 44, 45, 47 Plato, 13, 19, 20, 21, 46, 146, 150, 161, 164, 166, 167 Play, 22, 82, 150, 153, 162, 191, 197, 201 Poincare, H. 37n, 38, 39, 46 Pollock, J.L. 10, 65-73 Polya, G. 15n, 16n, 23 Popper, K. 13, 110, 115, 118, 119, 122, 123, 137, 138, 159, 207n, 208n, 209n, 210, 211n, 212, 213, 214, 223, 224n, 225, 226, 229, 231 Positivism 21, 110, 112, 117, 128, 177, 189, 201, 213 Possibility 23, 24, 30, 35, 36, 38, 42, 43, 49, 53, 58, 62, 63, 66, 67, 68, 69, 70, 71, 78, 82, 88, 89, 93, 94, 95, 96,98, 102, 116, 117, 121, 123, 124, 129, 130, 132, 136, 138, 142, 143, 144, 147, 148, 158, 162, 169, 172, 174, 175, 176, 177, 179, 180, 183, 185, 186, 187, 188, 190, 191, 199, 203, 207, 209, 213, 214, 217, 218, 219, 220, 228, 229
Possible World 10, 35, 36, 65, 68, 69, 70, 71, 72, 73, 169 Practice 16, 17, 19,23,25, 26, 28, 30, 31, 41, 58, 59, 60, 61, 72, 96, 105, 107, 109, 110, 119, 121, 123, 129, 130, 131, 132, 137, 139, 157, 158, 159, 163, 164, 165, 183, 184, 185, 186, 214, 224, 226, 231, 232 Pragmatism 87, 214, 218, 219, 220, 221, 226, 229 Probability 24, 31, 41, 42, 43, 91, 98, 127, 128, 129, 134, 135, 136, 137, 138, 139, 173, 181, 183, 186, 188, 189, 190, 191, 193, 208, 214, 224, 226 Problem 10, 28, 40, 43, 44, 55, 56, 68, 70, 71, 77, 78, 80,84, 103, 104, 107, 110, 117, 121, 122, 128, 133, 136, 137, 139, 141, 143, 144, 146, 147, 151, 153, 154, 156, 157, 159, 160, 161, 164, 165, 170, 171 , 172, 176, 181, 183, 184, 185, 186, 187, 193, 197, 198, 199, 201, 204, 208, 209, 210, 212, 213, 214, 215, 219, 220, 223, 226, 227, 228, 229, 230, 231, 232 Process 9, 27, 30, 31, 41, 43, 63, 87, 88, 90, 93, 95, 101, 106, 116, 117, 119, 120, 124, 125, 134, 143, 145,
157, 162, 181, 185, 198, 203, 204, 210, 215, 220, 223, 224, 225, 226 Progress 11, 12, 13,23, 39, 90,97, 106, 115, 116, 118, 119, 120, 122, 123,201, 207, 210, 216, 217, 218, 220, 221, 223-232 Proof 15, 16, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 65, 89, 102, 111, 146, 161, 205,211,219 Psychology 12, 36, 52, 56, 62, 136, 137, 146, 151, 155, 158, 193, 197, 198, 199, 200, 201, 202, 203, 204, 205-212 Ptolemy, C. 106, 133 Purpose 10, 88, 93, 99, 157, 160, 170, 181, 191 Putnam, H. 15n, 17n, 20n, 21n, 67n, 107n, 221n Quine, W. 15n, 17n, 33n, 50, 51n, 54, 55, 56, 57n, 62n, 63, 79, 95, 96n, 107, Illn, 127, 129, 130n, 131n, 132, 142, 143n, 146, 147, 154, 166, 171, 172, 173, 175, 178, 179, 180, 181, 182, 194, 212n, 214n Ramsey, F.P. 193 Rational 11, 12, 18,27, 102, 103, 105, 109, 115, 116, 117, 119, 121, 122, 129, 133, 134, 135, 136, 137, 157, 158, 159, 160, 161, 162, 163, 184, 185, 187, 243
189, 193, 194, 195, 205, 207, 208, 209, 210, 211, 212, 213, 214, 217, 218, 219, 220, 221, 223, 224, 225, 227, 230 Realism 9, 10, 11, 12, 13,41, 42, 43, 49-63, 65, 71, 87-99, 101-113, 118, 124, 135, 145, 146, 149, 163, 164, 169, 208, 220, 221, 226, 229, 231,232 Reality 19, 34, 37, 41, 43, 44, 45, 46, 49, 55, 60, 62, 71, 82, 88, 89, 90,91, 92, 93, 94, 95, 96, 97, 99, 102, 103, 104, 108, 109, 110, 112, 116, 119, 139, 164, 165, 166, 167, 170, 177, 189, 198, 199 R~ason 12, 13, 15, 16, 18, 20, 21, 23, 25,27, 38, 81, 102, 103, 108, 116, 134, 135, 136, 139, 141, 151, 153, 162, 166, 167, 168, 172, 181, 183, 184, 185, 186, 187, 189, 193, 194, 197, 199, 202, 205, 207, 209, 210, 212, 213, 214, 215, 217, 218, 223, 224, 230 Reference 27, 38, 45, 51, 53, 54, 55, 56, 57, 61, 62, 66, 67, 69, 70, 72, 77, 95, 96, 107, 112, 146, 156, 163, 165, 167, 169, 178, 180, 181, 193, 200, 202, 217, 219, 220, 221 Relation 10, 35, 44, 52, 54, 55, 56, 65, 67, 72, 73, 85, 88, 89, 91, 92, 93, 94, 95, 244
96, 97, 98, 108, 122, 127, 129, 130, 134, 143, 144, 149, 151, 169, 181, 183, 185, 190, 192, 195, 197, 202, 212, 221, 231 Relative 20, 37, 38, 39, 40, 46, 47, 51, 55, 59, 71, 79, 87, 89, 90, 97, 105, 121, 157, 163, 164, 166, 177, 178, 179, 182, 186, 187, 192, 205, 206, 208, 213, 225, 226, 229, 231 Relevance 10, 13, 28, 81, 93, 94, 99, 110, 117, 118, 119, 120, 122, 123, 127, 128, 129, 130, 131, 132, 135, 137, 138, 141, 144, 147, 160, 161, 165, 173, 177, 185, 187, 189, 194, 206, 217, 226, 228 Representation 66, 79, 107, 108, 109, 121, 148 Research 10,47,109,112, 119, 120, 121, 124, 216, 227 Revolution 13, 116, 118, 119, 120, 227, 228, 229, 230 Rorty, R. 95, 97n Rosenkrantz, R. 138n Rosser, J.B. 18n Rule 76, 77, 79, 80, 83,84, 96, 103, 133, 141, 142, 143, 144, 145, 146, 148, 149, 151, 152, 153, 154, 180, 200, 203, 204, 215, 217, 219 Russell, B. 17, 31, 33n, 57, 66, 79, 80, 82, 85, 156 Rutherford, E. 41, 160
Ryle, G. 144 Satisfaction 50, 51, 52, 53, 54, 55, 72, 135, 172, 173, 178, 179, 181 Saw, R.L. 34n Schlank, R. 201n, 202 Schrodinger, E. 43n, 45, 47n Science 10, 11, 12, 13, 15, 16, 18, 22, 26, 27, 30, 37, 38, 39, 40, 46, 51, 63, 84, 90, 91, 92, 93, 97, 98, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 127, 128, 129, 130, 131, 132, 134, 135, 137, 138, 146, 157, 159, 160, 161, 163, 164, 170, 192, 193, 199, 204, 206, 207, 208, 210, 212, 213, 216, 217, 218, 219, 220, 221, 223-232 Sellars, W. 197n, 198 Semantics 9, 10, 11,21, 49-63, 65-73, 75-85, 160, 171, 172, 177, 178, 180, 181, 191, 193, 199, 202, 210, 225, 230 Sense 11, 12, 17,20,28,29, 31, 41, 44, 47, 49, 52, 55, 56, 58, 59, 60, 63, 66, 69, 70, 73, 76, 81, 84, 87, 88, 89, 91, 94, 95, 96, 99, 110, 116, 120, 128, 131, 132, 141, 146, 147, 152, 155, 156, 163, 173, 174, 175, 176, 177, 180, 181, 182,
187, 194, 195, 197, 198, 199, 202, 203, 205, 206, 207, 208, 209, 214, 221, 223, 224, 225, 227 Sentence 9, 35, 49, 51, 52, 53, 54, 55, 56, 58, 59, 60, 61, 62, 63, 66, 76, 77, 78, 80,82,83, 111, 129, 136, 137, 149, 171, 172, 173, 174, 176, 177, 178, 179, 180,181,182,188,191, 192, 194, 231 Set 17, 18,21,22,23,24,51, 52, 53, 57, 65, 69, 70, 96, 133, 161, 187, 192, 198, 204 Shapere, D. 111, 112n Simplicity 35, 72, 76, 83, 106, 109, 110, 112, 119, 129, 132, 133, 138, 142, 149, 151, 152, 159, 163, 166, 178, 181, 185, 189, 191, 193, 212, 218, 225 Situation 66,80,137,173, 185,202,211,214,226 Smart, J. 193 Sneed, J. 228 Social 22, 30, 31, 88, 89, 95, 96, 99, 102, 115, 122, 125, 129, 148, 157, 159, 204, 213, 224 Socrates 187 Standard 11, 12, 13, 15, 18, 23, 25, 26, 28, 55, 56, 63, 71, 73, 76, 83, 96, 104, 119, 130, 144, 148, 152, 159, 170, 173, 174, 175, 181, 189, 191, 193, 198, 206, 207, 213, 216, 217, 245
217, 220, 225 Statement 10, 12, 15, 28, 33, 66, 67, 70, 73, 88, 91, 94, 97, 98, 117, 128, 131, 139, 149, 150, 155, 167, 168, 169, 170, 180, 188, 197, 201, 202, 206, 207, 209, 211,212, 213, 214, 227 Stegmiiller, W. 226, 227n, 228 Structure 23, 50, 52, 54, 65, 66, 73, 78, 81, 83, 85, 102, 105, 115, 125, 127, 131, 132, 139, 158, 159, 160, 172, 197, 202, 203, 210, 224, 226, 228, 231 Struik, D. 25n Style 38, 45, 103, 105, 106, 108, 163 Suppes, P. 194n Symbol 22, 26, 31, 46, 49, 84, 142, 153, 163, 164, 167, 170,231 Synonymy 33, 56, 79, 171, 173, 178 Syntax 11, 78, 82, 83, 160, 161, 181 System 17, 18,24,28,38,41, 43, 52, 101, 107, 128, 130, 132, 135, 137, 158, 159, 160, 163, 164, 166, 170, 171, 173, 174, 176, 177, 193, 195,203,216,221, 225, 231 Tarski, A. 49, 50, 51n, 52n, 53, 54, 55, 56, 75n, 76, 77, 78, 80, 83, 85, 171, 172, 173, 174, 175, 177, 189, 246
181, 182, 212n, 214, 225, 231 Test 10, 62, 130, 131, 132, 133, 134, 135, 147, 152, 154, 156, 171, 172, 180, 182, 200, 201, 210, 221, 223 Theory 9, 10, 11, 12, 13, 16, 17, 18, 19, 21, 22, 23, 26, 27, 28, 37, 38, 40, 41, 42, 43, 44, 45, 46,47, 49, 50, 51,52, 53,54,55,56,57, 58, 59, 60, 61, 62, 65, 66, 67, 69, 70, 71, 73, 75-85, 88, 89, 90, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 138, 139, 157, 158, 159, 160, 161, 162, 163, 168, 171, 172, 173, 174, 175, 176, 179, 180, 181, 182, 183, 184, 188, 189, 190, 194, 195, 197-204, 205, 206, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 224, 225, 226, 227, 228, 229, 230, 231, 232 Thinking 9, 10, 23, 24, 30, 36, 37, 38,40,41,45, 56, 58, 61, 66, 67, 77, 96, 98, 101, 103, 106, 107, 108, 120, 121, 136, 139, 144, 145, 146, 151, 157, 159,
164, 165, 174, 184, 185, 190, 195, 200, 202, 205, 206, 212, 213, 232 Thorn, R. 21n Toulrnin, S. 11, 134, 157-170 Translation 50, 55, 56, 76, 82, 84, 106, 143, 146, 169, 171, 174, 175, 176, 177, 178, 179, 180, 182, 193, 194,203,211,212,214, 228 Truth 9, 10, 12, 13, 15, 16, 18, 20, 22, 24, 26, 29, 30, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 65, 68, 69, 71, 72, 73, 75, 77, 78, 79, 85, 87, 95, 96, 97, 102, 103, 105, 106, 108, 109, 128, 129, 130, 131, 132, 135, 136, 138, 139, 149, 150, 151, 158, 163-170, 171-182, 192, 194, 199, 205, 206, 207, 208, 209, 210, 212, 213, 214, 218, 220, 221, 224, 225, 226, 228, 229, 230, 231, 232 Tyrnoczko, T. 27n, 28n, 29n Understanding 10,11,13,16, 20, 23, 25, 27, 29, 35, 36, 38, 39, 49, 52, 54, 55, 61, 62, 67, 68, 92, 94, 98, 101, 104, 106, 107, 121, 122, 124, 127, 135, 143, 145, 149, 150, 153, 156, 158, 159, 163, 164, 167, 168, 170, 171, 172, 173, 174, 175, 176, 177, 180, 183,
186, 191, 193, 195, 199, 201, 202, 203, 204, 205, 209, 210,. 214, 216, 230 Use 56, 58, 61, 62, 63, 66, 67, 71, 76, 77, 79, 81, 82, 92, 101, 103, 104, 107, 109, 111, 112, 115, 116, 117, 124, 130, 131, 132, 135, 139, 142, 143, 144, 145, 147, 148, 149, 150, 161, 168, 172, 173, 175, 183, 186, 187, 192, 194,201, 205, 213, 220, 223, 226, 228, 229, 230 Utility 13, 21, 23, 42, 50, 56, 68, 70, 149, 156, 186, 199 Validity 73, 80, 102, 163, 175, 176, 207, 218, 229 Value 59,60, 61, 72, 80, 106, 129, 139, 154, 172, 182, 184, 185, 187, 190, 192, 193, 199, 204, 210, 212, 215, 216, 219, 221, 223, 224, 229, 231, 232 Van Fraassen, B. 104n, 139n Verbal 34, 35, 36, 49, 148, 165, 167, 174, 195 Verrnazen, B. 191n Verification 24, 28, 30, 31, 60, 61, 63, 81, 111, 231 Visual, 37-47 Wang, H. 18n, 23n, 27 Weierstrass, K. 19 Whewell, W. 223 Whitehead, A.N. 80 Wilder, R. 25n Wien, W. 40 247
Wiggins, D. 57n Wild, J. 205n Wittgenstein, L. 11, 15n, 28, 33n, 81, 84, 95, 141-156, 159, 213, 227 Word 9, 10, 23, 35, 56, 57, 58, 71, 76, 81, 84, 104, 111, 143, 144, 145, 146, 149, 150, 164, 168, 171, 174, 177, 179, 181, 190, 191, 216 World 10, 12, 26, 31, 33, 34, 35, 38, 40, 44, 50, 52, 58, 59, 63, 68, 69, 70, 71, 72, 84, 87, 88, 91, 94, 95, 96, 97,98,101,102,103,106, 107, 109, 110, 113, 116, 118, 120, 123, 125, 128, 131, 146, 151, 158, 162, 163, 164, 165, 166, 167, 168, 169, 170, 176, 177, 178, 181, 185, 195, 200, 205, 208, 220, 224, 225, 229, 231
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