One of the Truths about Actuality Author(s): Allen Hazen Source: Analysis, Vol. 39, No. 1 (Jan., 1979), pp. 1-3 Published by: Blackwell Publishing on behalf of The Analysis Committee Stable URL: http://www.jstor.org/stable/3327296 Accessed: 16/10/2008 10:26 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=black. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact
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JANUARY 1979
ANALYSIS 39.1
ONE OF THE TRUTHS ABOUT ACTUALITY By ALLEN HAZEN
T HERE are two questions about the nature of actuality. Many
writers have treated both. Some have confused them. Separated, one turns out to have a clearcut and undoubtedly correct answer. Stating it may make it easier to concentrate on the harder question. There is the metaphysical question. Positions include extreme realism about possible worlds, with the attendant claim that there is nothing special about the actual world (Locus classicus: the chapter on foundations in David Lewis's Counterfactuals),as well as various kinds of actualism: positions according to which the actual world is the only fully concrete world, non-actual possible worlds being construed as states of affairs (Locus classicus: Alvin Plantinga's The Nature of Necessity) or propositions (Locus classicus: Robert Stalnaker, 'Possible Worlds, Nous, I976) or mathematical constructs (Locus Classicus: Quine's 'Propositional Objects' in his OntologicalRelativity and Other Essays) or otherwise explained away. The other question is semantical, or logical. How shall we categorize, within the framework of some semantic theory, and characterize the specific content of, words like 'actual' and its cognates? Assuming that at least some members of the family may be thought of as logical constants, what formal logic best embodies their function in our language? Here we may distinguish the realization theory (Plantinga, op. cit.),
according to which actualityis a property of worlds possessed by each possible world at itself aridat no other, the indexicaltheory (Lewis, op. cit.), according to which the (English speaking) inhabitants of each possible world call that world and no other actual, just as each (English speaking) person calls himself and no one else 'I', and the name theory (nobody I know; proposed as a foil to the indexical theory), according
to which the function of 'the actualworld' is that of a proper name for the actual world. Given the obvious relations between the various adjectives, nouns, and adverbs of the family, each of these theories provides a semantic account of the whole family, including the adjective expressing a property of possible worlds, the adjective expressing a property of possible objects, and an adverb that can be construed as a monadic propositional connective. An object is actual if it exists in the actual world, a proposition actually true if it is true at the actual world. These different semantic answers are each compatible with any of a range of answers to the metaphysical question, but a choice between them I
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ANALYSIS
can be made on non-metaphysicalgrounds. 'Actual'and its cognates are at home in what can be broadly described as modal language. They function in sentences containing counterfactuallocutions, epistemic ones, and constructionsthat the logician would formalizewith a modal operator.Their role is to distinguish those parts of the sentence which are descriptiveof the real world from those describingwhat might have been, what would have been if, and what is only thought to be: 'It could have turnedout worse than it actuallydid,' 'If you had come the partywould have been more boring thanit actuallywas,' 'I thought that your yacht was longer than it actuallyis.' Sometimestheirfunction is merelycontrastive.Sometimes,however, they have real logical, as well as stylistic, importance: they insulate some part of a sentencefrom its surroundings,allowing it to escape the influence of a modal, etc., locution that would ordinarilygovern a part of the sentence in its position. Thus in the sentence, 'There could have been objects other than those there actually are,' the inner existential quantifier('there are') would, on the basis of its location, ordinarilybe governed by possibility operator('could'), and so would range over the domain of the same possible world as the other existential quantifier.'Actually,' which here may be formalized as a connective (with a good deal less distortion of the syntax than is involved in construing 'could' as one), protects this quantifier against the 'could', allowing it to range over the domain of the actualworld. Or again, in the sentence 'It is logically possible for P to be the case with all actual individualsexisting,' the 'all' occurs within the scope of the possibility operator, but which individuals are subsumed under it? Not those existing in some arbitraryworld where P is the case, but those existingin the real world. The 'actual' allows us to quantify over actualiain a position where an unadorned 'all' would quantify over the possibilia in some, perhapsquite peculiar,possible world. This is enough to refute the realization theory. The actuality operatorit would provide would be unable to insulate subformulasof a modal sentence against the influence of modal operators.According to that theory actuallyP must be true at a world if and only if P is true at just those possible worlds which, at the given world, have the property of actuality.But on the realizationtheory, each world has actuality at itself alone, so this reducesto: actuallyP is true at a world just in case P is true at it. But then a sentence like Possibly(P andactuallyQ) will have the same truth conditions as Possibly(P and Q) ratherthan those we have argued it does have: those of Q andpossiblyP. The realizationtheory of actualityis a mistake. It completely fails to capture,and rendersinexplicable,the logical function of 'Actually'. It was, I suspect, inspired by an understandablebut unfortunateway of talking currentamong modal logicians. Ordinarilyto say of a state of
ONE OF THE TRUTHS ABOUT ACTUALITY
3
affairsthat it is actualis the same as to say that it is realized, or that it obtains: ordinarilywe are describing the actual world, and an actual state of affairsis simply one that is realizedin the actualworld. Because of this it was very easy for modal logicians, when they were talking about possible worlds and the states of affairsobtaining in them, to fall into the habit of saying a state of affairswas actualizedin the worlds in which it obtained. But this is a special usage, and an artificialone. That leaves us with the indexical and name theories. Each has the correct consequence that actuallyP is true at any world just in case P is true at our world. The decision between these theories must be made on other grounds. There are possible but non-actualworlds some of whose inhabitants, speaking a language in other respects resembling English, use 'actual' and its cognates to referto their own world. Perhapstherearealso possible worlds some of whose inhabitants,speaking a language otherwise like English, use the same words to refer, not to their own world, but to ours. (I ratherdoubt it, but that would get us into complicatedissues about the conditions under which thought or intention or verbal behaviourcan single out a single entity as the referentof a term.) If the first kind of otherworldlyusage amounts to using the words with the same meaning we use them with, then they are indexical.What, after all, is an indexicalword but one which can be used with the same meaning but differentreferencein differentcircumstances,the circumstances of its use determiningits reference?If, on the other hand, it is the second kind of otherworld speakerwho would be using the words with our meanings,then they are semanticallymore like a propername. There is no question in my mind about where the truth lies. Words like 'actual'are partof the fabricof the language,unlike propernamesof specific individuals. One cannot be said to know their meaning if one does not use them in certainway, understandthem as having a certain function. I have describedthis function above. One consequenceof the English speaker'stacit knowledge of his language is that the inference from the negation of an instanceof the BarcanFormulato 'There could have been objects other than those there actually are' is a valid one. No one using 'actually'in such a way as not to validate this inference can be said to be using it with the sense we use with it. So the inhabitants of other worlds who use 'actually'with our meaningmust use it to refer to their own worlds, and the indexical ratherthan the name theory is correct. Semantically,logically, the indexical theory is the truth. This does not answerthe metaphysicalquestionaboutthe natureof possible worlds: it is a metaphysicalquestion. Synthesisis needed, not just analysis. TrinityCollegeDublin
? ALLEN HAZEN I979
