Wednesday, July 16, 2008

On Aristotelian Actualism

Here is an interesting appellation for a philosophical position! The initial question is: how could any philosophical tenet which claimed in any way to be Aristotelian fail to have actualist commitments? Aristotelian Actualism has such commitments in the expected way - this brand of actualism states that there are no de re modal facts about non-actual objects - ala Adams in 'Actualism and Thisness'. I find this claim theoretically sound - if one is an actualist that is. However, interestingly enough, note that even if one is a possibilitist, one still does not grant a modal profile to non-actual objects since, for the counterpart theorist (excepting here Paul perhaps, though I yet find her position to fall back into straight Lewisian counterpart theory), no object in and of itself has any modal features; not just the indexically-picked 'actual' objects of our world - but none simpliciter.

The more important claim of Aristotelian Actualism however, is the following: what is possible might have not been possible - or, put in another way, there are things which are not possible but which might have been possible. This claim stems from the facts that (i)no non-actual object has a modal profile and (ii)which world (and objects therein) is actual is a contingent matter. But if this is the case, how do we secure the modal claims which involve quantification over non-actual objects and their de re character? In his 'In Defense of Aristotelian Actualism', GW Fitch suggests that we use Adams' 'truth-at-a-world' distinction - these objects do not have a modal profile, but if they were actual, they would.

Now, as an actualist, I find the claim of Aristotelian Actualism intuitively plausible. But I do have a certain qualm with it - it must rely on the accessibility relation. I am deeply committed to an S5 system of modal logic wherein what is possible is necessarily possible - and this is something that the Aristotelian Actualist must deny. But must an actualist simpliciter deny it? I think not; Plantinga, to the extent that he is, as he claims, an actualist, accepts an S5 system of logic.

Firstly then, note that the accessibility relation that is said to hold between possible worlds collapses into incoherency when we note that each possible world contains every other in the following sense: what is possible in W is, no matter what world happens to be actual, still possible in W.That is, every possible world, being abstractions from the concrete world, contains facts about every other possible world. So certain facts about some object which exists in W, but not in W2, still are possible 'from' W2, since the object would have existed were W actual - and there are, furthermore, definitive facts about that object's existence in W2. So, the tenet that Aristotelian Actualism holds which rests upon the accessibility relation is incoherent because any object that is a possible existent is a possible existent 'from' any possible world; admittedly, there is a certain sense according to which certain objects are not possible from certain possible worlds, but this is not possibility per se, but rather some attenuated form of physical possibility.

How can one be an actualist and yet claim that there are certain de re facts about non-actual object? Well, firstly, I think that an actualist has a strong commitment to the denial of non-actual objects. But I also think that the actualist ought to have an equally strong commitment to the sufficiency of the concrete world to provide the basis for any and every object which might exist - that the furniture of the concrete world is large enough to seat any and all modal profiles of any possibly existing objects. This being said, I agree with the Aristotelian Actualist that there are no, as Mondadori puts is, distinct possibilities for non-actual (read: non-existing) objects, but I do not agree that when these objects come into existence, something is made possible which was not already so. Non-actual objects do have full modal profiles, but they are simply not 'present' in the concrete world.

This is the intuition behind the claim that, if these objects were actual, they would have such and such modal profiles. In other words, there is a definitive fact about non-actual object's modal characters, but it is a fact which is yet to obtain. There are, as Adams might put the matter, no propositions with them as constituents, but there would be a definitive set of such propositions, should they come into existence.

In short, I agree with Aristotelian Actualism to the extent that it claims that de re modal characters are applicable only to actual objects and that all other possibility claims about non-actual objects are merely 'generic'. But I do not agree that, had some other world been actual, and some other set of objects actual, that there would be things possible that were not previously. Rather, these de re distinct possibilities were always possible, since the objects themselves were always so, but they are now 'attainable' on account of them being present in the concrete world.

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