An A Priori Argument for Realism Colin McGinn The Journal of Philosophy, Vol. 76, No. 3. (Mar., 1979), pp. 113-133. Stable URL: http://links.jstor.org/sici?sici=0022-362X%28197903%2976%3A3%3C113%3AAAPAFR%3E2.0.CO%3B2-1 The Journal of Philosophy is currently published by Journal of Philosophy, Inc..
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THE JOURNAL OF PHILOSOPHY V O L U M E LXXVI, NO.
3, MARCH 1979
AN A PRIOR1 ARGUMENT FOR REALISM * XCEPT in the vulgar sense, one is not a realist tout court: one is a realist with respect to some or other type of subject matter-or better, with respect to particular classes of statements. Nor, similarly, is it feasible to be a n unqualified anti-realist. Nevertheless, specific realist and anti-realist theses are apt to exhibit certain interdependencies. For example: realism about scientifically posited theoretical entities is likely to go with realism about macroscopic material bodies; realism about values will naturally encompass both ethical and aesthetic values; realism about numbers may encourage a general acceptance of abstract objects; antirealism about the semantical and the mental may go hand in hand; and so on. T h a t is to say, particular philosophical arguments for or against realism with respect to specific areas may call for parallel conclusions in neigl2boring areas. Such interdependencies as those cited are, however, of a relatively local and unsurprising kind. T h e really interesting question to raise is how extensive such interdependencies might be; for it may turn out that philosophical investigation of apparently disparate areas will disclose interdependencies on a more global scale, and an appreciation of the lines of connection that define the scope and limits (if there be such) of global realism and anti-realism may help in the resolution of the dispute in particular areas. Thus we might inquire whether some preferred formulation of scientific realism requires mathematical realism or precludes it, whether insistence on the irreducibility of ethical or * T h i s paper was prompted by a n aside of Michael Dummett's in "The Reality of the Past," Proceedings of the Aristotelian Society, LXIX (1968/9): 239258, p. 250, and bears the mark of his discussions of realism throughout. I have also been influenced by unpublished work of Marie McGinn and Christopher Peacocke, and by conversations with Anita Avramides, W. D. Hart, and Arnold Zuboff. 0022-362X/79/7603/0113$02210
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aesthetic thought presupposes the reality of values, whether our ordinary understanding of the world of spatiotemporally distributed bodies requires realism about causal modalities,l and so forth. These are not, however, the questions I am going to discuss i n this paper; I mention them and the global question they instantiate in order to locate in a wider perspective the question I want to address. T h a t question is this: Can we discover interdependencies between realist and anti-realist conceptions of, on the one hand, the external world of material bodies and, on the other, the internal world of mental states and events-to put the matter tendentiously-such that we find ourselves compelled to adopt certain realist or anti-realist positions with respect to these two areas? I am going to argue that we can indeed expose such interconnections and that they force us to recognize that realism about both kinds of statement is the only viable position. T h e general structure and strategy of the argument is as follows. I n respect of our two classes of statements-which I shall for the sake of brevity hereafter designate as M- and P-statements, respectively-there are four possible combinations of view: (i) anti-realism about both M- and P-statements, (ii) anti-realism about M-statements combined with realism about P-statements, (iii) realism about M-statements combined with anti-realism about P-statements, (iv) realism about both M- and P-statements. I aim to show that (iv) is true by eliminating (i)-(iii) by appeal to global considerations designed to uncover the inconsistency of those positions. Since (i)-(iv) exhaust the alternatives and all save (iv) are inconsistent, we must acknowledge that (iv) is the only available position. T h e argument is thus indirect, like a proof by reductio, in that we set out to establish joint realism by supposing its negation, this giving three possibilities, each of which is claimed to embody a sort of inconsistency. No direct argument for realism in either area is essayed (though I think we shall see that the eventual upshot has a strong intuitive appeal): rather, certain interconnections are claimed and systematically exploited. T h e result is (intended as) an a priori argument for realism about M- and P-statements. I
T o proceed we need a preliminary formulation-to be refined later -of the general import of realist and anti-realist doctrines. Following Dummett, I shall take it that realism and anti-realism are best 1 As argued by Peacocke in "Causal hlodalities and Realism," forthcoming in Mark Platts, ed., Reference, Truth and Reality (Boston: Routledge 6 Kegan Paul, 1979).
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understood as contrary theses about the relation, with respect to various subject matters, between truth and the recognition of t r ~ t h . ~ That is, what distinguishes a realist from an anti-realist attitude toward the interpretation of a given class of statements is a difference in one's conception of how that in virtue of which the statements are true or false relates to the means or route by which we come to know their truth value. I n yet other words, what defines realism in contradistinction to anti-realism is a disagreement as to the relation between truth conditions and assertibility or verification conditions. T h e heart of a realist view of a given class of statements is that their truth conditions in a certain sense transcend-and so cannot be reduced to-their assertibility conditions. T h e anti-realist view, correspondingly, is that the subject matter of the given class does not thus transcend the grounds upon which the statements are asserted. Notice that, under that general formulation, realism and anti-realism, which are, strictly speaking, metaphysical or semantic theses, are already characterized in epistemological terms: for the content of realism is precisely that there obtain, or could obtain, recognition-transcendent facts, whereas that of anti-realism is that there could not. As will emerge, this epistemological formulation will play a crucial role in the argument I shall present. What I want now to register is that the statement of realism in terms of recognition-transcendence has the important consequence that a realist interpretation of a class of sentences inevitably introduces the possibility of a skeptical challenge concerning our knowledge of the propositions thereby expressed, whereas an anti-realist interpretation evades that challenge. Indeed, I think that a prima facie vulnerability to such a challenge should be regarded as a condition of adequacy which any formulation of realism is required to meet; and anti-realisms should correspondingly be seen manifestly to foreclose the threat of skepticism. I n respect of M- and P-statements, this general formulation may be specialized as follows: realism about M-statements is the thesis that the truth conditions of these statements transcend the experiential grounds on which they are asserted, whereas antirealism about M-statements denies this; and realism about P-statements is the thesis that the truth conditions of these statements transcend the behavioral grounds on which they are asserted, ZSee, for example, Dummett, "What Is a Theory of Meaning? (11)," in G . Evans and J. H. McDowell, eds., Truth and Meaning (Oxford: Clarendon Press, 1976).
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whereas anti-realism about P-statements denies this.3 T h e realist theses thus imply some sort of recognition-transcendence with respect to the truth of the statements in question, and it is precisely because of this epistemic gap between evidence and truth that the traditional skeptical problems as to the existence and nature of the external world and of other minds arise. Let us now, equipped with these rough preliminaries, turn to a criticism of the first of the combined positions I identified, namely joint anti-realism. I1
T h e anti-realist doctrines I wish to consider may be labeled-I take it with some historical precedent-phenomenalism and behaviorism. I shall understand the form of these doctrines to be defined by the thesis that M- and P-statements have the truth value they do have in virtue of the truth or falsity of statements drawn from certain other classes, not trivially different from the given ones: M- and P-statements are thus said to be subject to a reductive thesis. A reductive thesis is to this effect: a sentence s of a given class K is reducible to (true in virtue of) some sentence st of a class R if and only if necessarily s is true (false) just in case s' is true (false): it is a logically necessary and sufficient condition for a sentence of K to be true (false) that some sentence (or set of sentences) of R be true (false).4 Instantiating for M- and P-statements, the reductive anti-realist theses under consideration claim that these statements are true i n virtue of statements about experiences (E-statements) or statements about behavior (B-statements). We may gloss the reductive thesis definitive of phenomenalism as the claim that any language, such as our own, which contains both M- and P-statements exhibits a hierarchical ordering with respect to the relation of reducibility phenomenalism defines over its member statements. T h e basal statements of the hierarchy are the E-statements, a subclass of P-statements, and the distribution of truth values over these determines the truth value of any M-statement in the language (if it has one): the truth values of the M-statements cannot 3 I n saying that hl-statements are asserted upon experiential grounds and that P-statements are asserted upon behavioral grounds I do not deny that material objects (or indeed others' mental states) may be directly perceived. Direct perception is compatible with the beliefs thus formed being inferential in some sense: the significant point is that we shall be equally prone to forming M- and P-beliefs in nonveridical cases as we are in veridical cases. 4 A reductive relation between sentences may, for certain reductionist theses, hold a posteriori. Since anti-realism is a thesis about meaning, however, the reductions it advocates are better viewed as semantical and therefore knowable a priori; hence my use of the traditional phrase 'logically necessary and sufficient'.
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vary if the assignment of truth values to the E-statements stays fixed. Similarly, behaviorism has it that the basal statements are uniformly M-statements, where any P-statement of the language is rendered true or false by some B-statement, these comprising a subclass of the M-statements; again, the truth values of the B-statements once determined, the truth values of the P-statements are thereby fixed. What distinguishes phenomenalism from behaviorism is thus a selection of distinct kinds of statement as reductively basic, i.e., a characteristic ordering of statements according to a particular reductive thesis. (The orderings preferred by the two doctrines often correlate with some relation of epistemological priority, but we need not go into this aspect of the doctrines now.) For both anti-realisms, then, the important point is that the truth of a statement of the given class consists in nothing other than the truth of some statement of the reducing class. Before indicating why it is that these positions are not jointly occupiable, it will be useful to distinguish three ways in which the reducibility relation defined over the relevant classes of statements may be understood. First, we might say that for any statement s of the given class (M- or P-statements) there is some statement s' of the reducing class (E- or B-statements) such that s reduces to s' and s is determinately either true or false; this reduction may or may not be translational, but it does (or would) preserve the law of bivalence for statements of the given class. Second, we may say that whenever a statement of the given class has a determinate truth value this is conferred upon it by some statement of the reducing class, but there is no presumption or guarantee that the former statements will be subject to bivalence: it may be that neither s nor its negation is made true by some reducing statement Third, it may be alleged that a reduction with this latter property obtains but that the proper response to it is that the sentences that suffer thus from truth-value gaps should be regarded as expressing no proposition, as strictly meaningless, so that bivalence is in effect respected. Which of these three positions one adopts will obviously depend upon the precise character of the anti-realism in question; but a main consideration here is what logical type of statement is assigned to the putative reducing class. Classically, phenomenalism and behaviorism have wished to include counterfactual subjunctive conditionals among their reduction statements, 5 This is Dummett's preferred formulation of anti-realism: see the works of his elsewhere cited in this paper.
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principally because of translational ambitions; for statements reporting the occurrence of actual sense experiences scarcely suffice to confer upon every M-statement a determinate truth value, and similarly for actual behavior and P-statements. There are a number of (by now) well-worn objections to such reductions which seem to me very powerful, but which need not be evaluated in detail at the level of generality set by this paper. For the record: it is hard to see how either the phenomenalist or the behaviorist reductions can succeed without tacit circularity, since the consequent of the subjunctive will not hold unless its antecedent introduces conditions of the very sort claimed to be reducible-material-object conditions or mental conditions, as the case may be; and, connectedly, one's strong conviction is that the proffered subjunctives are not barely true, i n Dummett's sense,7 but rather are true precisely in virtue of (in part) the categorical M- and P-statements they are designed by such objections, one might prefer to conto r e d u ~ e Impressed .~ fine the reducing class to suitable categoricals recording the occurrence (possibly for all times) of actual experiences and episodes of behavior, and then face the consequence that vastly many M- and P-statements will have no determinate truth value, thus taking up one or other of the second and third positions I distinguished. But, whichever option one takes, a claim of reductive ordering will be made, and that is my chief concern here. Once the general form of phenomenalistic and behavioristic antirealism is clearly set out, as above, it is, I think, pretty evident why it is that the doctrines cannot be jointly affirmed. T h e reason is simply that they offer competing proposals as to what statements comprise the basal truths: phenomenalism takes E-statements, a subclass of P-statements, as basic, while behaviorism takes B-statements, a subclass of M-statements, as basic. T h e result is that, where one reductive thesis represents a statement as not itself requiring 6 Gilbert H. Harman explains the point tersely in Thought (Princeton, N.J.: University Press, 1973), p. 10 f, and Peacocke makes much of it in Holistic E x planation, hitherto unpublished. 7 T h e notion is fully explained in "TVhat Is a Theory of Meaning? (11)," sec. III; roughly, it is the property of not being made true by some other (more basic) statement. 8 An interesting asymmetry of attitude is worth remarking here. Told that material objects are "permanent possibilities of experience," one readily suspects the claim to have dispensed with the objects, since it is extremely plausible that it is precisely their independent existence that sustains such possibilities; but the parallel claim for mental entities-they are "permanent possibilities of behavior," i.e., behavioral dispositions-has not been apt to provoke a parallel response. One would like to see a good reason for taking the cases differently, however.
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the application of a reductive operation, the other insists that such a reduction be performed. Since a statement that is basal for one anti-realism is derivative for the other, it is plain enough that a vicious regress is generated by the conjunction of the two doctrines; and this, of course, effectively frustrates the reductive ambitions definitive of each anti-realist thesis. More explicitly, suppose we take a certain M-statement s. Then phenomenalism will deliver as its reducing statement some E-truth s'. But, since s' is a P-statement, behaviorism offers u p some B-statement s" as its reduction. Now s" is itself an M-statement; so it demands from phenomalism some further E-statement s"' to reduce it. And the cycle begins again, ad infnitum. So the two doctrines simply contradict each other on the crucial question of what statements make what other statements true.9 I t follows that position (i) is unoccupiable. And this already suggests a limitation on any would-be global anti-realism; it appears that there is going to be something irreducibly realist in our language and system of the world. I11
I imagine that the elimination of (i) will be fairly readily conceded: few philosophers would think idealism and (behavioristic) materialism compatible, and the reasons traditionally prompting the two views have not been such as to establish one of them if and only if they establish the other. What is not at all immediately apparent, however, is that (ii) and (iii) exhibit any hint of self-destructive internal tension. T o appreciate why it is that, as I claim, realism about one area requires realism about the other, let us articulate further the content of the realist interpretations of M- and Pstatements. T h e fundamental thesis of realism about the two classes of statements is captured in the notion of independence, i.e., the denial that the truth of suitable E- and B-statements constitutes logically Q Rudolf Carnap in T h e Logical Structure of the World, R. A. George, trans. (Berkeley: University of California Press, 1967), remarks en passant (in sec. 57) that it is possible to reduce all physical objects to psychological ones and also possible to reduce all psychological objects to physical ones. Since he does not confront the question which of these reductions is correct, the significance of his constructions is hard to assess. If my argument is right, neither can be correct. Nelson Goodman, too, in T h e Structure of Appearance (Indianapolis: Bobbs-Memill, 1966), p. 136 f, raises the topic of the competing claims of "phenomenalistic and physicalistic systems," but eschews the metaphysical question of which of them correctly characterizes the general nature of the world, and so again their philosophical significance remains uncertain. No doubt the pragmatic tone evinced by both writers reflects a familiar antipathy toward the metaphysical question of which, if any, is actually true.
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necessary and sufficient conditions for the truth of corresponding M- and P-statements, and similarly for falsity.1° I n other words, M-facts are not reducible to E-facts, and P-facts are not reducible to B-facts. T h e general notion of independence is reflected in a cluster of assumptions and practices which we customarily fall in with as uncritical realists and which would have to be abandoned, or at least radically re-interpreted, if the anti-realist were right. Thus the realist has it that it is possible for M-facts to obtain and no experiences be had as of their obtaining, so it is not a necessary condition for an M-statement to be true that some corresponding E-statement be true; and further, since no set of purely experiential statements ever logically entails the truth of some M-statement, it is not a suficient condition for an M-statement to be true that some corresponding E-statement be true. Similarly, in respect of P-statements the realist view is that it is possible for P-facts to obtain in a person and he not behave in some manifesting way, so it is not necessary for the truth of a P-statement that some appropriate Bstatement be true; and further, since no set of purely behavioral statements ever logically entails the truth of some P-statement, it is not suficient for a P-statement to be true that some corresponding B-statement be true. And if the truth of the relevant statements can come thus apart, there can be no possibility of reduction, of maintaining that one kind of statement is true in virtue of the other. (The being of an M-fact does not consist in its being perceived, and the being of a P-fact does not consist in its being behaved.) And it should be clear enough that this property of twoway logical independence from experiences and behavior on the part of M- and P-statements is precisely the source of the skeptical questions realism is prone to invite, on account of the alleged epistemic transcendence of subject matter (hence no necessity) and the correlative possibility of error (hence no sufficiency). As a natural corollary of the independence thesis your typical realist will hold to a certain conception of perception and action: viz., that a genuinely perceptual experience is caused by some external object ontologically distinct from the experience, and similarly that a piece of intentional behavior is caused by a mental l o Carnap formulates realism about material objects in the phrase "independence from the cognizing consciousness," op. cit. p. 281, and G. E. Moore employs the same style of formulation in "A Defence of Common Sense," sec. 11, Philosophical Papers (Reading, Mass.: Allen b+ Unwin, 1959). Hilary Putnam's realistic view of the mental is similarly stated in "Brains and Behaviour," reprinted in Mind, Language and Reality (New York: Cambridge, 1975).
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state or event from which it is ontologically distinct. Those are peculiarly realist theses because the causality claim implies the distinctness of the objects of perception from the perception itself, and of the mental antecedents of action from the caused action. Indeed, appropriate causation is plausibly regarded as criteria1 for whether an experience is a genuine perception or a piece of behavior a genuine action: these very distinctions are thus commonly drawn in terms of realist materials.ll Connected with this causality claim, and reinforcing the irreducibility consequent upon logical independence, is the activity of (causally) explaining the truth of certain E-statements by citing appropriate M-statements, as when we explain why a perceptual experience occurred and had the intentional-phenomenal character it had by saying that it was brought about by some external material object being thus and so; and similarly we have the practice of explaining the occurrence and properties of certain bodily movements by reference to presumed internal mental states and events. If the anti-realist views were correct, and the truth of M-statements just consisted in the truth of corresponding E-statements, while the truth of P-statements similarly reduced to the truth of corresponding B-statements, then it would be hard to see how statements of the former kinds could possibly explain statements of the latter kinds. So it appears that the ascription to M- and P-facts of such a causal-explanatory role v i s - h i s E- and B-facts is bound up with a realist conception of their status in the world. If those are some characteristically realist contentions about Mand P-statements, why should they imply the inconsistency of positions (ii) and (iii)? T h e first stage of my answer rests upon a simple observation. Consider M-statements first. I said that under a realist interpretation E-statements are neither necessary nor sufficient to fix their truth value; but if so, we can equally well say that hIstatements are neither necessary nor sufficient for E-statements-the independence is symmetrical. T o say that an M-fact is not necessary for an E-fact is to say that an E-fact is not sufficient for an M-fact (delusive experiences), and to say that an M-fact is not sufficient for an E-fact is to say that an E-fact is not necessary for an M-fact (unexperienced M-facts). T h e independence cuts both ways, and 11 Cf. H. P. Grice, "The Causal Theory of Perception," Proceedings of the Aristotelian Society, supp. vol. 35 (1961), and D. Davidson, "Agency," in R. Binkley, ed., Agent, Action and Reason (Toronto: University Press, 1971). I do not say that these authors explicitly view causal theories of perception and action as peculiarly realist.
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implies realism as much one way as the other. Similarly for P-statements. T o say that a P-fact is not necessary for a B-fact is to say that a B-fact is not sufficient for a P-fact (deceptive behavior), and to say that a P-fact is not sufficient for a B-fact is to say that a B-fact is not necessary for a P-fact (unbehaved P-facts). I n formulating the thesis that the truth of an M-statement does not consist in the truth of a corresponding E-statement we find ourselves saying-what is anyway hard to deny-that the E-statement is not true in virtue of the M-statement; and similarly for P- and B-statements. (Notice that this observation does not crucially depend upon the actual or possible occurrence of delusive experience or deceptive behavior, though I do think these are important in understanding the epistemological corollaries of realism; for no one would maintain that, when an experience is a genuine perception or an episode of behavior has a mental description, the truth of the corresponding E- and B-statements just reduces to the truth of the statements that report, as the realist asserts, their M- and P-causes.) So it begins to seem that realism about M- and P-statements implies realism about E- and B-statements, under the independence formulation. But now E- and B-facts are just subclasses of P- and M-facts, respectively; and if we are prepared to admit these in unreduced realist fashion, there can be no objection of general principle to admitting the rest.12 T h e same result issues from the causal-explanatory formulations of the two realisms: if material bodies must be distinct from the experiences they cause in episodes of perception, then the experiences are symmetrically distinct from the bodies; and if mental states and events must be distinct from the behavior they cause i n events of intentional action, then the behavior is symmetrically distinct from the mental antecedents-the effects must be as real, by this standard, as the causes. And parallel remarks apply to the explanatory relation, as the realist construes it, between M- and E-statements and P- and B-statements: explanandum cannot reduce to explanans. I n short, the formulation of each realism in terms of independence seems, on the face of it, to imply an equally realist interpretation of the statements that comprise the assertibility conditions of our given statements. This argument will certainly seem too swift; for, as stated, it 1 2 Cf. Gottlob Frege's attempted refutation of idealism in "The Thought," reprinted in P. F. Strawson, ed., Philosophical Logic (New York: Oxford, 1967), where he argues that there must be a t least one object that isn't a n idea, viz., the bearer of ideas, and so opens the door to the reality of all objects of thought.
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ignores a crucial maneuver open to the partial realist. Consider again the realist who desires his basal statements to be uniformly material; i.e., he wishes to be a behaviorist and a realist about the external world. His response to the foregoing observations will be as follows: begin by formulating realism about M-statements in terms of independence, causality, and explanation, thus introducing the required E-statements; then claim, anti-realistically in respect of such statements, that they are to be construed as true in virtue of appropriate B-statements-so that the E-statements needed to formulate realism about M-statements at large are in turn reduced to a subclass of M-statements. Analogously, the realist about P-statements who wishes his basal statements to be uniformly psychological will initially state his mental realism in terms of independence from B-statements, but then go on to subject the introduced B-statements to a phenomenalistic reduction, thus rendering them true in virtue of appropriate E-statements. T h e first philosopher is a behavioristic realist about the external world, the second a phenomenalistic realist about the internal world. Are these not perfectly consistent positions? I think that ultimately they are not, but the reason is somewhat subtle. I t is tempting to suppose that these reductive reformulations of the realist's characteristic claims are vulnerable to a regress argument, along the following lines. Suppose the realist about M-statements and anti-realist about P-statements were to present us with his reductive B-statements. T h e n we would be entitled to put to him the question, in what his realism about these B-statements consists. T o be constant he is obliged to offer an independence formulation, thus introducing a new range of as yet unreduced E-statements. H e now proposes to reduce these to further B-statements, and inevitably invites a repetition of the question. Evidently this process of question and answer generates a chain of alternating E- and B-statements with no determinate upper bound. Again, suppose the realist about P-statements and anti-realist about M-statements were to present us with his reductive E-statements. T h e n we can ask him in what his realism about these E-statements consists. Constancy requires an answer framed in terms of independence from further B-statements. These would then in turn call for phenomenalist reduction, and the cycle recurs, thus generating an indefinitely extended series of B- and E-statements. However, the resulting series, though in a certain sense regressive, do not seem viciously so, since there is nothing in the general position of the
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differential realist to prevent him, at any arbitrary stage in the series, from producing the reductive statement demanded by his anti-realism as that in virtue of which the E- or B-statement yielded by his realist half is true. T h e case is unlike that of the joint antirealist, because there we were presented with incompatible claims as to what constitutes reductive bedrock; but in the case of positions (ii) and (iii) the realist component need not, for all that has so far been said, insist upon the irreducibility of the statements from which independence is alleged. I think, however, that the intuition that encourages one erroneously to suspect straightforward vicious regress here does have considerable force. Part of its force can be brought out by means of the following argument against the proposed reformulations. I t was remarked earlier that realism implies a gulf between truth conditions and verification conditions-between truth and the recognition of truth-and that this gulf is what allows skepticism to get purchase on the area in question. I n respect of the external world, this involves the idea that how experience represents the world as being may not coincide with how it really is-appearance and reality may fail to match. I n respect of the mental, realism implies that what a true P-statement corresponds to transcends, and so may diverge from, the behavioral evidence on the strength of which we make psychological judgments. Thus it is that skepticism about the external world and other minds arises. Now our question must be: do the suggested reformulations of realism adequately preserve those epistemological corollaries? For if they do not, they fail to capture the content of the intended realist theses. T h e quickest way to see that they fail in this is to negate the realist views as thus reformulated and then test whether the resulting propositions fulfill our conditions on an adequate formulation of anti-realism for the two areas. I n the case of M-statements, then, the reformulated anti-realism would be to the effect (strange as it is) that statements about external material bodies reduce to statements about behavior-a sort of behavioristic phenomenalism. For P-statements the reformulated anti-realism about them would be that they are true in virtue of statements reporting experiences as of behaving in a certain way-a sort of phenomenalistic behaviorism. Just as we are advised under the reformulations to state realism about each area in a uniform vocabulary, so we state the corresponding antirealisms in that very vocabulary. But clearly these formulations of the two anti-realisms do not have the epistemological consequences
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we expect of anti-realism about material objects and about mental states. For, first, anti-realism about M-statements should have the consequence, enjoyed by standard phenomenalism, that our knowledge of the external world has a firm and skepticism-free characterization; but behavioral facts are in no way epistemologically privileged among M-facts at large, and so cannot afford the epistemologically unproblematic foundation that anti-realism characteristically promises us. And, second, anti-realism about P-statements should have the consequence that our knowledge of other minds is innocent of illicit inference precisely because P-statements are seen, upon reductive analysis, not to go beyond the publicly accessible facts of behavior; but if behavioral facts are reduced to experiential facts no epistemological progress of the sort desired by the anti-realist about the mental is made, since these are just as private and inaccessible as the P-statements they are intended to reduce. So negating the proposed reformulations of realism about M- and P-statements does not lead to an adequate and consistent statement of anti-realism for the two domains. Unsurprisingly, the suggested reformulations also misrepresent the epistemological predicament of the realist about each area: for if we permit ourselves unproblematic epistemological access to behavioral facts as the surrogates for statements about how things appear in immediate experience, then we must already have resolved the question of our knowledge of the external world-or else we simply deprive ourselves of the materials with which to raise that question. O n the other hand, if we try to construe all B-facts as ultimately experiential, then we fail to capture the idea, essential to a realist view of the mental, that P-facts transcend and are distinct from the publicly accessible facts of overt behavior: for, under such a reduction, the assertibility conditions for P-statements turn out to be themselves as private and subjective as the statements whose truth they evidence. We cannot really claim to retain the distinctive features of the realist conception of the relation between mental states and behavior if we insist upon reducing the latter to suitable experiences; room must be made for the public. T h e underlying point in both cases can be put as follows. According to realism about the external world, M-facts transcend their assertibility conditions in such a way that information about the totality of E-truths does not decisively settle what M-statements are true, or indeed whether any are; someone possessed of this information can still ask skeptical questions concerning M-statements. Similarly, knowledge of the
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totality of B-truths should not preempt the skeptical question whether there really are any mental states responsible for the observed behavior. Even an ideal observer, in something like the position of God, could raise these skeptical questions given only information about assertibility conditions. But, if we reduce E-facts to B-facts, this no longer holds, since knowledge of E-facts will just consist i n knowledge of appropriate B-facts, and so will presuppose unproblematic access to a range of M-facts. Similarly, if our ideal observer were in receipt of all the B-facts and these reduced to corresponding E-facts, then he would already have settled the question of whether the world contains mental states over and above material objects. So neither reduction would have the required consequence that the truth conditions of M- and P-statements genuinely transcend their usual assertibility conditions; neither, therefore, gives an adequate characterization of that in which the reality of M- and P-facts consists. T h e simple truth is-and I shall have more to say on this later-that a proper statement of realism about material bodies requires unreduced acceptance of experiences as that from which the external world is allegedly independent, and that a proper understanding of realism about the mental requires unreduced acceptance of episodes of behavior as that from which the internal world is independent. This point is just made more vivid by tracing out the epistemological consequences required of an adequate formulation of realism for the two areas. So I think that in the end our initial crude argument from independence must be accepted and positions (ii) and (iii) declared unoccupiable. But first a certain line of objection to the whole set-up must be disposed of.13 IV
Anxious to avoid compulsory occupation of position (iv), someone might try to question the very idea of formulating realism in terms 13 I should perhaps make i t explicit that this paper does not, officially at any rate, address the question of solipsism. Solipsism is not realist about P-statements, in my sense, because it regards non-first-person ascriptions (what Carnap calls the "heteropsychologica1") anti-realistically-other minds are logical constructions out of my experiences (the "autopsychological")-and thus it takes all statements to be true in virtue of first-person P-statements. On the contrary, I assume the existence of a plurality of persons and ask after the relation between their experiences and the material world, and their behavior and mental states. You might helpfully conceive of the issue as a very general question of radical interpretation: given that a speaker's language contains M- and P-statements, what metaphysical schemes of interpretation are possible, as represented by positions (i)-(iv)? My thesis is, then, that only scheme (iv) is consistent. Refuting solipsism would demand further considerations.
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of independence from E- and B-statements. T h e hope would be to formulate realism for M- and P-statements in such a way that 110 symmetrical condition on E- and B-statements results. T h e claim I now wish to defend is that such alternative conceptions of realism for the two areas as I can produce fail systematically either to provide necessary or sufficient conditions for an intuitive formulation of realism. A first proposal for doing away with explicit allusion to E- and B-statements for a realist interpretation of a class of statements might require that the class meet the following two conditions: (a) the statements obey the law of bivalence, and (b) there is no class of statements, genuinely distinct from the given one, such that statements of the given class are true in virtue of statements of that other class, i.e., statements of the given class are barely true. There are two objections to this formulation of realism. First, it fails our requirement that an adequate formulation display the distinctive epistemological properties of the statements in question, in particular, the way in which the gap between truth and recognition of truth is apt to invite skeptical challenge. This failure is especially apparent if one tries to obtain a characterization of the intended anti-realisms by negating the realist formulation: the operation does not yield the specific doctrines of phenomenalism and behaviorism. Only if we instantiate the existentially general condition (b) with experiential and behavioral statements do we get the right results, but of course this just takes us back to my initial argument. But second, failure of the given class to meet the condition of bare truth is not sufficient to indicate an anti-realist interpretation. For consider physicalism with respect to mental states, and elementaryparticle micro-reduction with respect to macroscopic material bodies. Whether true or false, such theses are intuitively realist about Pand M-statements; not all reductionism is anti-realist.14 These doctrines are intuitively realist, I would say, because they do not deny a cleavage between truth and the recognition of truth. Unlike phenomenalism and behaviorism, they do not embody a purported reduction to assertibility conditions. So, because bare truth is not a necessary condition for a realist interpretation, independence from all other classes of statements is too strong a requirement for such an interpretation. I n reply to this objection someone might propose weakening the 1 4 AS Dummett himself insists in "The Reality of the Past," op. cit., and in "Common Sense and Physics," forthcoming in a Festschrift for A. J . Ayer.
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formulation by omitting condition (b) altogether. There would still be the objection from epistemology, but there would now be the problem that the resulting formulation is too weak. T h a t mere conformity to bivalence is insufficient for realism is shown by recalling the first and third of the anti-realist doctrines I distinguished in section 11. Surely classical reductionist phenomenalism and behaviorism, with their invocation of subjunctive conditionals, count as anti-realist, yet both seek to retain bivalence; and the positivistic third view a fortiori rates as anti-realist. (It seems to me, incidentally, that these positions show Dummett's rather monolithic formulation of realism-across-the-board in terms of conformity to bivalence to be deficient; l5 one needs to say something specific about the relation of the statements in question to their distinctive assertibility conditions.) And if we ask in what the contrast between such doctrines and the realist reductions I just mentioned consists, I think the answer must be that the former deny, whereas the latter do not, the features of logical independence, causal relations, and explanatory role that I earlier set forth as definitive of a realist view of M- and P-statements. This leads me to conclude that my initial formulation in terms of these features uniquely captures the content of the realist conception of the two types of statement. But if the argument that starts from that style of formulation is sound, we are left with global realism as the only really viable position. Realism and anti-realism about 1CI- and P-statements are theses about the kind of meaning possessed by these statements, i.e., about what their truth conditions consist in. According to realism, their truth conditions are such as to transcend the conditions that we recognize as verifying or falsifying the statements in question; this, to repeat, is precisely why skepticism about the external world and other minds seems in order. I t is thus clear that the task of defending realism about a class of statements is an enterprise quite distinct from rebutting skepticism concerning that class: one is not yet in the business of answering the skeptic unless one has already assumed a realist interpretation of the statements. T h a t these are distinct questions is apt to be disguised by the fact that anti-realism 15 See the articles by him I have cited. I think, in fact, that the formulation of realism in terms of irreducibility to assertibility conditions lies behind the bivalence formulation: it is just that there seems no necessity for the assertibility conditions of a given class of statements to be incomplete with respect to the assertion of each statement of the given class-complete assertibility is quite compatible with anti-realism.
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is at one stroke a theory of meaning and an account of how statements endowed with a meaning so characterized are known. Now I have claimed to establish realism about M- and P-statements on the basis of an a priori argument, by an appeal to definition indeed. This goes against the grain of the currently dominant view sometimes labeled "empirical realism," this being some such thesis as that metaphysical realism should be grounded upon much the same considerations as realism about theoretical entities, or indeed a realistic view of particular kinds of theoretical entities, viz. some sort of simplicity or inference to the best explanation.16 That is to say, one should adopt something like an a posteriori scientific approach to the realism/anti-realism dispute. I strongly suspect that such an attitude arises at least in part from a conflation of the questions of realism and skepticism. I t is perhaps to be expected that our knowledge of the truth of realistically interpreted M- and P-statements should be a posteriori knowledge and that resistance to skepticism should therefore assume an empirical form. But the question of realism with respect to a class of statements is not whether and how we might justify our claim to know the statements to be true (though to establish it would presumably be to show that we do know they have verification-transcendent meaning); and, given this conception of the enterprise, it is also not very surprising that it should be capable of a priori demonstration. (I do not mean to deny that there might be an a posteriori defense of metaphysical realism; I am only insisting upon a careful separation of questions.) Moreover, I think one's strong conviction is that the falsity of phenomenalism and behaviorism, as theories about the meaning of M- and P-statements, is of a much deeper and more conceptual character than the standard talk of simplicity and the like would seem to suggest. I t does not appear to have the status of a mere empirical fact, albeit a highly general one, that M-statements are not true in virtue of E-statements and that P-statements are not true in virtue of B-statements. If that is right, it seems preferable to have a way of establishing it which adequately reflects its intuitive status in our general conception of the world. VI
Dummett has advanced a perfectly general argument, based upon what is involved in understanding a language, designed to under16 See, for example, Putnam's discussion in "Other Minds," ,op. cit., and J . L. Madtie in "What's Really 127rongwith Phenomenalism?," Brztzsh Academy Lecture, 1969. T h e view is well expounded (though not endorsed) in R.I. Williams, Groundless Belief (Oxford: Basil Blackwell, 1977), chap. 4.
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mine realism about the meaning possessed by certain sentences of natural language.17 T h e purported upshot of the argument, which will not be repeated here, is that truth cannot, as realism requires, transcend the recognition of truth. Dummett suggests instead that we might do better to adopt a verificationist or assertibility-conditions theory of meaning, thus relinquishing (as he thinks) realism about the subject matter of the relevant statements. We already saw in section 11 that there must be some limit on such a general argument, since the anti-realisms to which it leads are jointly incompatible. But if the thesis of the present paper is correct, then, at least in respect of M- and P-statements, a realist interpretation of their subject matter is obligatory, and so a verificationist theory of meaning according to which the content of these statements reduces to the content of some suitable set of E- and B-statements cannot be acceptable. So I think that the considerations here adduced constitute a direct demonstration, not predicated on any particular theory of language mastery, that some sort of truth-conditions theory, as opposed to a Dummettian verification-conditions theory, has to be right. Our considerations also bear upon another theme of Dummett's. He insists that the semantic theorist produce some account of how his favored meaning assignments to sentences are manifested in the use a speaker makes of his sentences. This translates in the present case into a demand to specify in what way the phenomenalist or behaviorist differs from the realist in his employment of M- and P-sentences. What we have already said about what makes a person a realist suggests the outlines of an answer. Aside from commitment to bivalence for M- and P-sentences, which is plausibly necessary but not (I have suggested) sufficient for realism, the realist may be said to differ from the anti-realist precisely in his acknowledging the logical independence I have made so much of-he will assent to E- and B-statements without automatically assenting to the corresponding M- and P-statements, and vice versa-and he will employ the latter types of statement in a practice of explaining the former, as well as accept causal statements of the kinds I identified earlier. Given knowledge of such linguistic dispositions, the radical interpreter will be empirically warranted in construing his speaker as a realist about M- and P-statements. Taken together, these two points-the direct metaphysical argument for realism and the pro17 See especially "What Is a Theory of Meaning? (II)," o p . cit. I have criticized the argument in "Truth and Use," forthcoming in the collection cited in footnote 1; that paper and the present one may be read in tandem.
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posed manifestation conditions for a realist semantics-seem to me to add u p to a way of confronting and deflecting Dummett's general line of argument. VII
A discursive argument unbacked by an intuitive picture seldom convinces. I hasten in conclusion, then, to place the argument of this paper in some sort of over-all perspective; what follow are some more or less impressionistic gestures in that direction. Our comprehensive realist conception of empirical reality is of an objective spatiotemporal world whose intrinsic nature is independent of the local and relative peculiarities of the conscious beings that form a part of it.10 We think of objective reality as causing changes in the course of experience undergone by these beings, notably in perception; and of changes in objective reality as being occasionally wrought by the actions and movements of these beings, as a causal result of mental states and events within them. Neither sector of reality-external or internal-is a closed system; they interact in various ways. Our picture of the world is in this way fundamentally dualistic (which is not to say Cartesian). This dualism exhibits a certain categorial difference which may be characterized as follows. T h e external world of material bodies and events has the characteristic of objectivity; i.e., it is to be conceived in an absolute way, as not owing its intrinsic nature to the relative and subjective sensory modalities and conscious experience of the sentient beings that inhabit it. T o conceive it aright, therefore, one needs somehow to prescind from one's subjective and local standpoint and aspire to what might be called an "absolute" conception of the objective. By contrast, the internal mental world is distinctively subjective, and so, to grasp how it is for a conscious being, one needs to project oneself imaginatively into his subjective position, to ask what it is like for that being.19 Rather than attempt to prescind from the subjective, one needs precisely to recognize the relativity of mental facts to a particular standpoint. T h e two kinds of fact-corresponding to M- and P-statements-are thus categorially different: one sort of fact is essentially observer-independent, the other essentially observer-dependent. T o put it yet another way, a proper compre1 0 Cf. Bernard Williams' discussion of the "absolute conception" of the world in Descartes: T h e Project of Pure Enquiry (New York: Penguin Books, 1978), and Dummett on "absolute and relative forms of description" in 'Common Sense and Physics', op. cit. 1 9 1 rely here upon Thomas Nagel's "What Is I t Like to Be a Bat?," Philosophical Review, LXXXIII,4 (October 1974): 435-450.
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hension of the objective external world requires a distinction between appearance and reality; but to understand the region of subjective reality-how it is consciously for a being-appearance is all; we are here interested precisely in how things seem. If these rough and intuitive remarks have verisimilitude, it is not hard to explain why it is that phenomenalism and behaviorism should seem to the realist so rebarbative to reason: for phenomenalism represents a refusal to register the objectivity of the material world, since the materials it allows itself-viz. experiences-have the effect of assimilating its essential character to the subjective; whereas behaviorism for its part tries to assimilate subjectivity to objective and publicly accessible behavioral facts, and so fails to do justice to what the realist takes to be distinctive of the mental realm.20 Phenomenalism is objectionably anthropocentric; behaviorism is objectionably nonanthropocentric. These reflections help us appreciate better, I think, why realism about one area ineluctably brings realism about the other: it stems partly from the fact that our conception of the objective world is founded upon a contrast with how things subjectively seem to us or to other creatures-independence and this notion of objectivity are thus two sides of the same coin, which is why the behaviorist reduction of E-statements was inadequate to capture the realist conception of M-statements; whereas, symmetrically, our notion of the subjective world is defined by a contrast with the objectiveindependence from behavior and this notion of subjectivity are thus intimately related, which is (in part) why the phenomenalist reduction of B-statements was inadequate to capture the content of a realist view of P-statements. It is interesting also to observe that the assertibility conditions for M- and P-statements invert the categories that define their truth conditions: I mean that subjective experiences comprise the assertibility conditions for objective Mstatements, while (at least for other-ascriptions) objective items of 20 4 large question raised by this sort of objection to behaviorism concerns whether physicalism is equally cast into doubt by it. Though I cannot discuss this issue here, I think that we should take a different view of the two cases. My reason, roughly stated, is that if an organism is in the same internal physical state as another for which there is something it is subjectively like to be that organism, then there is something i t is like-the very same thing-to be that first organism; but it is not true that the subjective is similarly supervenient on the behavioral. T o put it another way, corresponding physical makeup gives organisms the same range of accessible subjective viewpoints, but corresponding behavior does not. Not all versions of physicalism need to deny the subjective; reductive behaviorism, it would seem, is another matter. But clearly the question requires further investigation.
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behavior comprise the assertibility conditions for subjective P-statements. I t is no surprise, therefore, to find that affirming realism about one area in terms of independence from assertibility conditions should place us squarely in the other area, and that the respective assertibility conditions should resist reduction to facts of the opposite category.21What is more, it seems to me hardly to be doubted that E- and B-statements play a unique role in our assertion of M- and P-statements, a role which may be characterized by saying that it is an a priori truth that E- and B-statements constitute assertibility conditions for M- and P-statements: i.e., that these classes of statements are related in this way is not something we know merely empirically, but is such that it is part of the sense of M- and P-statements that E- and B-statements comprise assertibility classes for those statements. These assertibility conditions may be contrasted in this respect with (say) statements about the micro-structural properties of material bodies and statements about conditions in a person's nervous system. We can readily conceive of coming to learn empirically that such statements can function as assertibility conditions for ordinary material-object statements and mental attributions, but plainly knowing this to be so is not built into understanding the sense of M- and P-statements; it could not be, since we understood those sentences before we knew of molecules and neurons. Clearly such empirically discovered assertibility conditions cannot play the same role in shaping our understanding of M- and P-sentences as does a grasp of their semantic relation to E- and B-statements.22 It is this fact, perhaps, that captures the element of truth in phenomenalism and behaviorism; but this alone. COLIN MCGINN
University College London 21 Recall
the discussion of reductively reformulated independence in section 11. This difference seems to correspond to one aspect of Wittgenstein's distinction between symptoms and criteria; see T h e Blue and Brown Books (New York: Harper 6. Row, 1965), pp. 24/5. Notice that I claim @ace Wittgenstein) an a priori evidential relation only between the classes of statements, not between individual statements in those classes. A closely allied point about behavior and the mental occurs in my "hlental States, Natural Kinds and Psychophysical Laws," Proceedings of the Aristotelian Society, supp. vol. 1978: 195-220, 95. 22
