The idea that two objects can coincide—by sharing all their proper parts, or matter—yet be non-identical, results in the “Problem of Coincident Objects”: in what relation do objects stand if they are not identical but share all their proper parts? One solution is to introduce material constitution. In this paper, I argue that this is ad hoc since, first, this solution cannot be generalized to solve similar problems, and, second, there are pseudo cases of coincidence that should not trigger the (...) introduction of material constitution and these cannot be distinguished in any principled way from the allegedly real cases of coincidence. (shrink)

This is a copy of my DPhil thesis, the abstract for which is as follows: The first third of this thesis argues for a B-theoretic conception of time according to which all times exist equally and the present is in no way privileged. I distinguish "ontological" A-theories from "non-ontological" ones, arguing that the latter are experientially unmotivated and barely coherent. With regard to the former, I focus mainly on presentism. After some remarks on how to formulate this (and eternalism) non-trivially, (...) I review the non-relativistic case against presentism. I then consider the impact of Special Relativity on the debate, and attempt to deepen this impact by supplying a modal variation on the standard arguments. The middle third of the thesis investigates persistence, contending that both endurance and perdurance are consonant with the eternalism already endorsed. After introducing these theories of persistence, and discussing in particular how best to formulate an eternalist endurance, I proceed to defend the coherence of this combination. The Problem of Change is addressed here. I then respond in some detail to recent allegations of relativistic threats to endurance. The final third of the thesis questions the validity of the endurantist-perdurantist dispute. I criticize two recently proposed translation schemes that aim to show this dispute to be non-substantive. However, the second scheme suggests a doctrine of "Ontological Equivalence" which I develop and consider. I then address the Rotating Discs Argument, using this to launch a discussion of identity, genidentity, and the relationship between them. (shrink)

Mereological essentialists argue that mereological summations cannot change their parts. Mereological inessentialists argue that mereological summations can change some or all of their parts. In this paper I articulate and defend a position called Moderate Mereological Inessentialism, according to which certain mereological summations can change some, but not all, of their parts. Persistent mereological summations occur when the functional parts of mereological summations persist through alterations to its spatial parts.

In recent decades, a view of identity I call Sortalism has gained popularity. According to this view, if a is identical to b, then there is some sortal S such that a is the same S as b. Sortalism has typically been discussed with respect to the identity of objects. I argue that the motivations for Sortalism about object-identity apply equally well to event-identity. But Sortalism about event-identity poses a serious threat to the view that mental events are token identical (...) to physical events: A particular mental event m is identical with a particular physical event p only if there is a sortal S such that m and p are both Ss. If there is no such sortal, the doctrine of token-identity is not true. I argue here that we have no good reason for thinking that there is any such sortal. (shrink)