Online research in philosophy

I introduce a puzzle about contact and de re temporal predication in relativistic spacetime. In particular, I describe an apparent counterexample to the following principle, roughly stated: if B is never in a position to say ‘I was touching A, I am touching A, and I will be touching A’, then (time travel aside) A is never in a position to say ‘I was touching B, I am touching B, and I will be touching B’. In the case I present, (...) the most that A is ever in a position to say is: ‘I am now touching B, but this is the only instant at which this will ever be so’. B, on the other hand, can say: ‘I was formerly touching A, I am currently touching A, and I will in the future be touching A’. (And neither object is a time traveler.). (shrink)

Russellianism, roughly put, is the view that a sentence of the form ‘Ra1, . . ., an’ expresses a proposition that is composed of the universal expressed by the predicate in that sentence and the objects referred to by the names in the sentence. If ‘composed of’ is defined in terms of a parthood relation (rather than in terms of a constituency relation that is said not to be a parthood relation), the resulting version of Russellianism gives rise to a (...) pair of mereological puzzles. (1) As Frege suggested, it generates counterexamples to the view that any parthood relation will be governed by a transitivity principle (or by some ‘adicity-appropriate analogue’ of such a principle, in case the parthood relation in question is not two-place). (2) It generates counterexamples to the view that any parthood relation will be governed by a certain ‘supplementation’ principle (or by an adicity-appropriate analogue of that principle). Elsewhere I have suggested on independent grounds that parthood might be a four-place relation (expressed by ‘x, at its location y, is a part of z, at its location w’). Here I argue that, on one natural way of spelling out Russellianism in terms of such a relation, it avoids both puzzles. (shrink)

I defend coincidentalism (the view that some pluralities have more than one mereological fusion) and restricted composition (the view that some pluralities lack mereological fusions) against recent arguments due to Theodore Sider.

How is the debate between endurantism and perdurantism affected by the transition from pre-relativistic spacetimes to relativistic ones? After suggesting that the endurance vs. perdurance distinction may run together a pair of cross-cutting distinctions (mereological endurance vs. mereological perdurance and locational endurance vs. locational perdurance), I discuss two recent attempts to show that the transition in question does serious damage to endurantism (at least of the locational variety).

What is it for a thing to be dead? Fred Feldman holds, correctly in my view, that a definition of ‘dead’ should leave open both (1) the possibility of things that go directly from being dead to being alive, and (2) the possibility of things that go directly from being alive to being neither alive nor dead, but merely in suspended animation. But if this is right, then surely such a definition should also leave open the possibility of things that (...) go directly from being dead to being neither alive nor dead, but merely in suspended animation. I show that Feldman’s own definition of ‘dead’ (in terms of ‘lives’ and ‘dies’) does not leave this possibility open. I propose a new definition that does. (shrink)

Existing puzzles about coinciding objects can be divided into two types, corresponding to the manner in which they bear upon the endurantism v. perdurantism debate. (Endurantism is the view that material objects lack temporal extent and persist through time by being wholly present at each moment of their careers. Perdurantism is the opposing view that material objects persist by being temporally extended and having different temporal parts located at different times.) Puzzles of the first type, which involve temporary (...) spatial co-location, can be solved simply by abandoning endurantism in favor of perdurantism, whereas those of the second type, which involve career-long spatial co-location, remain equally puzzling on both views. I show that the possibility of backward time travel (either via discontinuous jumps or via closed timelike curves) would give rise to a new type of puzzle. The new puzzles confront perdurantists and can be solved just by shifting to endurantism. (shrink)

This is a review of The Metaphysics of Hyperspace (OUP: 2005) by Hud Hudson.

I formulate a theory of persistence in the endurantist family and pose a problem for the conjunction of this theory with orthodox versions of special or general relativity. The problem centers around the question: Where are things?

Immanent universals, being wholly present wherever they are instantiated, are capable of both multi-location and co-location. As a result, they can become involved in some bizarre situations, situations whose contradictory appearance cannot be dispelled by any of the relativizing maneuvers familiar to metaphysicials as solutions to the problem of change. Douglas Ehring takes this to be a fatal problem for immanent universals, but I do not. Although the old relativizing maneuvers don't solve the problem, I propose a new one that (...) does. I spend half the paper defending the proposed solution against objections, and in the course of this task I touch upon such topics as backward time travel and the distinction between universals and particulars. I close by putting forward -- merely as an option -- a new way to draw the distinction in question. (shrink)

According to what Barry Dainton calls the 'Strong Introspectibility thesis', it is a necessary truth that mental states S and S* are co-conscious (experienced together) if and only if they are 'jointly introspectible', i.e., if and only if it is possible for there to be some single state of introspective awareness that represents both S and S*. Dainton offers two arguments for the conclusion that joint introspectibility is unnecessary for co-consciousness. In these comments I attempt to show, first, that Dainton's (...) arguments fail, and, second, that joint introspectibility is actually insufficient for co-consciousness. (As to whether it is also unnecessary, I take no stance.). (shrink)

Yuri Balashov has argued that endurantism isuntenable in the context of Minkowskispacetime. Balashov's argument runs through twomain theses concerning the relation ofcoexistence, or temporal co-location. (1)Coexistence must turn out to be an absolute or objective matter; and inMinkowski spacetime coexistence must begrounded in the relation of spacelikeseparation. (2) If endurantism is true, then(1) leads to absurd conclusions; but ifperdurantism is true, then (1) is harmless. Iobject to both theses. Against (1), I arguethat coexistence is better construed as beingrelative to a (...) hyperplane of simultaneity.Against (2), I argue that the consequences of(1) given endurantism are no worse than theconsequences of (1) given perdurantism. (shrink)