Particulars, Actuality, and Identity over Time, vol 4
Latest Publications
the (obvious) semantics for modal and temporal adverbs requires relativization neither of the object in the state-type nor of the property. A state-type such as that of a being bent, which might be written , is in a clear sense ‘complete’ by itself; a temporal adverb expresses a temporal mode of obtaining for it, while a modal adverb expresses a way of obtaining for its tokens (in the absence of tense, the modal adverbs can be taken to express ways of obtaining for the types and there is still no problem of accidental intrinsics).4 Ill If the foregoing criticism of Lewis’s argument is correct, then we still lack a reason to require that resolutions of difficulties about identity through time employ the less problematic ontology of thing-stages. So what else might be offered? Lewis’s argument was an attempt to provide new grounds for the ontology of thing-stages. The more traditional grounds have simply been that satisfactory resolution of certain puzzles demands such an ontology. Johnston discusses two of a sort familiar from the literature on identity through time, the Dion/Theon case and the case of the pot, the plasticine and the bust. But in my view, these are not cases to which the advocate of thing-stages should appeal, since they provide little support for his or her way of looking at things. Dion is an as yet unmutilated man and Theon is the parcel of matter consisting of the matter of Dion less the matter of his left foot. Initially, then, Dion/Theon. Next, Dion loses his left foot. So now we have a dilemma. If it is still true that Dion # Theon, distinct things are occupying the same region of space (a ‘worrying co-occupancy’). Alternatively, if Dion = Theon after the mutilation, then distinct things have become identical, which, according to Johnston, is an impossibility. But against the background of an ontology of thing-stages, the difficulty vanishes: there are distinct sums of stages (‘maximal R-inter-related aggregates of stages’, in the terminology of [Lewis 1983, p. 62]), and what happens after the mutilation is that these sums have their constituents in common. Johnston objects to this
intervals. For the computer now on the desk, at the end of this process, is made up of modules yi... yio, while the computer which sat on the desk ten months ago was made up of the entirely distinct modules xi... xio. If these are the same computer, then by OC there are worlds u and v where, respectively, the given computer is made up ofxi... xio as long as it exists and yi... yio as long as it exists. But there is also the world w where, amongst other things, there are two computers, one made of yi... yio as long as it exists and the other of xi... xio as long as it exists, both machines existing simultaneously in different places. We may therefore pose the question: (3) Which, if either, of w’s computers is the one on the desk in the actual world? No answer to (3) is consistent with reasonable views about identity, for whatever answer we the following will be true:
none both, while a defender of endurance will say that the plasticine first constitutes a pot, then a bust. Since constitution is not identity, we may therefore say that the plasticine, pot and bust are pairwise non-identical.5 We cannot argue that since pot and bust have exactly the same parts, they must be the same thing by the mereological principle that if the parts of x are the same as the parts of y, then x = y. First, if the plasticine constitutes the pot, any part of the pot will be constitutedby some part of the plasticine, but will not be identical to that part. Later, the plasticine part in question will constitute a part of the bust. Since constitution is not identity, we may therefore say that no part of the pot is identical to any part of the plasticine, so we cannot identify a part of the pot with a part of the bust via identity with a part of the plasticine. Still, this leaves it open that a pot-part is ‘straight-ofF identical to the bust-part made of the same plasticine, and hence by mereology, that pot and bust are identical. But Wiggins-style strategies again apply. Objects are not mere things, they are things of specific sorts; we can think of the unsubscripted identity symbol in ‘x = y’ as being introduced by existential quantification: ‘x = y’ means that for some sort F, x is the same F as y [Wiggins 1980, pp. 15, 38]. So pot and bust are the same what? If we say they are the same sum of parts, we relativize identity, since they are evidently not the same artifact. What we must do is distinguish sums of parts and artifacts. In the example, there are two sums of parts x and y (the pot parts and the bust parts) and if x and y have the same parts, as was left open by the previous paragraph, x and y are the same sum of parts. But we can deny that x is a pot and y is a bust. In other words, the proper conclusion to draw is that no pot is the same thing as any mereological sum of pot-parts and no bust the same thing as any sum of bust-parts. Some other relation, such as constitution, holds between ordinary things and the mereological sums of their parts. Hence we again avoid the conclusion that the pot and the bust are the same thing. If this discussion is right, the two examples are ineffective as
