If time travel is possible, presumably so is my shooting my younger self ; then apparently I can kill him – I can commit retrosuicide. But if I were to kill him I would not exist to shoot him, so how can I kill him? The standard solution to this paradox understands ability as compossibility with the relevant facts and points to an equivocation about which facts are relevant: my killing YS is compossible with his proximity but not with his (...) survival, so I can kill him if facts like his survival are irrelevant but I cannot if they are relevant. I identify a lacuna in this solution, namely its reliance without argument on the hidden assumption that my killing YS is possible: if it is impossible, it is not compossible with anything. I argue that this lacuna is important, and I sketch a different solution to the paradox. (shrink)

The so-called "argument from vagueness", the clearest formulation of which is to be found in Ted Sider’s book Four-dimensionalism, is arguably the most powerful and innovative argument recently offered in support of the view that objects are four-dimensional perdurants. The argument is defective--I submit--and in a number of ways that is worth looking into. But each "defect" corresponds to a model of change that is independently problematic and that can hardly be built into the common-sense picture of the world. So (...) once all the gaps of the argument are filled in, the three-dimensionalist is left with the burden of a response that cannot rely on a passive plea for common sense. The argument is not a threat to common sense as such; it is a threat to the three-dimensionalist faithfulness to common sense. (shrink)

According to three-dimensionalism, objects persist in time by being wholly present at each time they exist; on the contrary, four-dimensionalism asserts that objects persist by having different temporal parts at different times or that they are instantaneous temporal parts of four-dimensional aggregates. Le Poidevin has argued that four-dimensionalism better accommodates two common assumptions concerning persistence and continuity; namely, that time itself is continuous and that objects persist in time in a continuous way. To this purpose, he has offered two independent (...) arguments, each of which moves from a different understanding of continuity. In this paper, both of Le Poidevin’s arguments will be discussed and rejected. (shrink)

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, I discuss two recent attempts to show that the transition in question does serious damage to endurantism.

The notion of multiple location plays an important role in the characterization of endurantism. Several authors have recently offered cases intended to demonstrate the incoherence of multiple location. I argue that these cases do not succeed in making multiple location problematic. Along the way, several crucial issues about multiple location and its use by endurantists are clarified.

There are certain metaphysically interesting arguments ‘from vagueness’, for unrestricted mereological composition and for four-dimensionalism, which involve a claim to the effect that idioms for unrestricted quantification are precise. An elaboration of Lewis’ argument for this claim, which assumes the view of vagueness as semantic indecision, is presented. It is argued that the argument also works according to other views on the nature of vagueness, which also require for an expression to be vague that there are different admissible alternatives of (...) the relevant sort, such as epistemicism, as defended by Williamson. Recent attempts to resist the argument are discussed and rejected. (shrink)

David Lewis (1986) criticizes moderate views of composition on the grounds that a restriction on composition must be vague, and vague composition leads, via a precisificational theory of vagueness, to an absurd vagueness of existence. I show how to resist this argument. Unlike the usual resistance, however, I do not jettison precisificational views of vagueness. Instead, I blur the connection between composition and existence that Lewis assumes. On the resulting view, in troublesome cases of vague composition, there is an object, (...) which definitely exists, about which it is vague whether the relevant borderline parts compose it. (shrink)

Ted Sider aptly and concisely states the self-visitation paradox thus: 'Suppose I travel back in time and stand in a room with my sitting 10-year-old self. I seem to be both sitting and standing, but how can that be?' (2001, 101). I will explore a relativist resolution of this paradox offered by, or on behalf of, endurantists.1 It maintains that the sitting and the standing are relative to the personal time or proper time of the time traveler and is intended (...) to yield the result that Ted is sitting at a certain initial personal/proper time but is not standing relative to that time. Similarly, it is also supposed to yield that Ted is standing relative to a later personal/proper time, but not sitting relative to that .. (shrink)

I offer a new criticism of the argument from vagueness to four-dimensionalism [Sider 2001. The argument is modelled after an older argument for mereological universalism [Lewis 1986 and may be looked upon as a tightened-up and extended version of the latter. While I agree with other critics [Koslicki 2003; Markosian 2004 that the argument from vagueness fails precisely because of this affinity, my recipe for dealing with it is different. I reject the assumption, shared by Sider with his opponents, that (...) synchronic composition and ‘minimal diachronic fusion’ are sufficiently similar to use considerations inspired by the analysis of the former to bear on the latter. My objection to a crucial premise of the argument from vagueness turns on the relevant aspect of dissimilarity between these two cases. (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. 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 would give rise to a new type of puzzle. (...) The new puzzles confront perdurantists and can be solved just by shifting to endurantism. (shrink)