Online research in philosophy

Puzzles about persistence and change through time, i.e., about identity across time, have foundered on confusion about what it is for ‘two things’ to be have ‘the same thing’ at a time. This is most directly seen in the dispute over whether material objects can occupy exactly the same place at the same time. This paper defends the possibility of such coincidence against several arguments to the contrary. Distinguishing a temporally relative from an absolute sense of ‘the same’, we see that the intuition, ‘this is only one thing’, and the dictum, ‘two things cannot occupy the same place at the same time’, are individuating things at a time rather than absolutely and are therefore compatible with coincidence. Several other objections philosophers have raised ride on this same ambiguity. Burke, originating what has become the most popular objection to coincidence, argues that if coincidence is possible there would be no explanation of how objects that are qualitatively the same at a time could belong to different sorts. But we can explain an object’s sort by appealing to its properties at other times. Burke’s argument to the contrary equivocates on different notions of ‘cross-time identity’ and ‘the statue’. From a largely negative series of arguments emerges a positive picture of what it means to say multiple things coincide and of why an object’s historical properties explain its sort rather than vice versa – in short, of how coincidence is possible.

It seems to be a platitude of common sense that distinct ordinary things cannot coincide, that they cannot fit into the same place nor be composed of the same parts at the same time. The paradoxes of coincidence are instances of a breakdown of this platitude in light of counter-examples that are licensed by innocuous assumptions about particular sorts of ordinary thing. Since both the anti-coincidence principle and the assumptions driving the counterexamples flow from the folk conception of ordinary things, the paradoxes threaten this conception with inconsistency.

ln "Possibilities and the Arguments for Origin Essentialism" Teresa Robertson (1998) contends that the best-known arguments in favour of origin essentialism can succeed only at the cost of violating modal common sense—by denying that any variation in constitution or process of assembly is possible. Focusing on the (Kripke-style) arguments of Nathan Salmon and Graeme Forbes, Robertson shows that both founder in the face of sophisticated Ship of Theseus style considerations. While Robertson is right that neither of the arguments is compelling as formulated, each can be modified to fend off her particular counterexamples; these modifications do not differ in kind from those already needed to deal with ordinary Theseus cases, requiring only a further narrowing of the sufficiency clause from which the necessity of origins is derived.

In his recent book, Aquinas and the Ship of Theseus, Christopher Brown has argued that the metaphysics of St. Thomas is preferable to contemporary analyticviews because it can solve the “problem of material constitution” (PMC) without requiring us to relinquish any of the common-sense beliefs that generate that problem. In this critical study, I show that in the case of both substances and aggregates, Brown’s Aquinas endorses views that are extremely implausible. Consequently, even if it is granted that the solutions to the PMC fall right out of his views, it is still not clear that this gives us reason to prefer his ontology to its competitors. I also consider Brown’s take on the status of the human being after death.

One familiar form of argument for rejecting entities of a certain kind is that, by rejecting them, we avoid certain difficult problems associated with them. Such problem-avoidance arguments backfire if the problems cited survive the elimination of the rejected entities. In particular, we examine one way problems can survive: a question for the realist about which of a set of inconsistent statements is false may give way to an equally difficult question for the eliminativist about which of a set of inconsistent statements fail to be 'factual'. Much of the first half of the paper is devoted to explaining a notion of factuality that does not imply truth but still consists in 'getting the world right'. The second half of the paper is a case study. Some 'compositional nihilists' have argued that, by rejecting composite objects (and so by denying the composition ever takes place), we avoid the notorious puzzles of coincidence, for example, the statue/lump and the ship of Theseus puzzles. Using the apparatus developed in the first half of the paper, we explore the question of whether these puzzles survive the elimination of composite objects.

The aim of this paper is to derive a perfectly general criterion of identity through time from Locke’s Principle, which says that two things of the same kind cannot occupy the same space at the same time. In this way, the paper pursues a suggestion made by Peter F. Strawson almost thirty years ago in an article called ‘Entity and Identity’. The reason why the potential of this suggestion has so far remained unrealized is twofold: firstly, the suggestion was never properly developed by Strawson, and secondly, it seemed vulnerable to an objection that he himself raised against it. Consequently, the paper’s aim is to further develop Strawson’s suggestion, and to show that the result is not vulnerable to the objection that seemed fatal to its underdeveloped predecessor. In addition, the paper aims to defend Locke’s Principle against alleged counterexamples such as those produced by Leibniz, Fine and Hughes.