Online research in philosophy

Four-Dimensionalism is a thorough, lively and forceful defence of the claim that “necessarily, every spatiotemporal object has a temporal part at every moment at which it exists” (59). The standard four-dimensionalist view is perdurance theory, according to which everyday things like boats are temporally extended. But Sider rejects perdurance theory, nicely disparaging it as the “worm view”, and he argues for the “stage view” version of fourdimensionalism instead. According to the stage view, everyday things like boats are instantaneous, and claims about the history of the Anstruther lifeboat are made true or false by the boat’s past counterparts. Sider reserves the term “four-dimensionalism” for these two views of persistence; he also defends a tenseless B-theory of time. The book develops, extends and systematises work which Sider has published over the last few years, and it makes a compelling and readable whole. I am sympathetic with many of the conclusions, but I will take issue with some of the arguments.

Minimally, causal realism (as understood here) is the view that accounts of causation in terms of mere, regular or probabilistic conjunction are unsatisfactory, and that causal phenomena are correctly associated with some form of de re necessity. Classic arguments, however, some of which date back to Sextus Empiricus and have appeared many times since, including famously in Russell, suggest that the very notion of causal realism is incoherent. In this paper I argue that if such objections seem compelling, it is only because everyday expressions concerning causal phenomena are misleading with respect to certain metaphysical details. These expressions generally make reference to the relations of events or states of affairs, but ignore or obscure the role played by causal properties. I argue that on a proposed alternative, an analysis in terms of causal processes, more refined descriptions of causal phenomena escape the charge of incoherence. Causal necessity is here located in the relations of causal properties. I distinguish this view from the recent process theories of Salmon and Dowe, which are disinterested in causal realism.

The ‘friends of temporal parts’ and their opponents disagree about how things persist through time. The former, who hold what is sometimes called a ‘4D’ theory of persistence, typically claim that all objects that last for any period of time are spread out through time in the same way that spatially extended objects are spread out through space — a different part for each region that the object fills. David Lewis calls this manner of persisting ‘perdurance’. The opposing, ‘3D’ theory has it that at least some objects do not persist in this manner; they ‘endure’ through time by ‘being wholly present at more than one time’.1 A related dispute pits ‘presentists’ against ‘non-presentists’. Presentists hold that the only things that really exist are those that exist now, at the present moment; and nonpresentists believe in something like a ‘block-universe’ in which non-simultaneous objects and events nevertheless co-exist (in a tenseless or non-temporal sense). Of late, the relations between these four positions have come under considerable scrutiny.2 As Ned Markosian has pointed out, it would be surprising if commitment to a perdurance or endurance theory of persistence automatically foreclosed one’s options in the presentism—non-presentism debate. But, says Markosian, that is just what the standard formulations of the perdurance and endurance theories imply.3 David Lewis has set the terms of the debate; in his usage, someone who thinks that all persisting objects endure would be said to hold the following.

Recently, Cody Gilmore has deployed an ingenious case involving backwards time travel to highlight an apparent conflict between the theory that objects persist by perduring, and the thesis that wholly coincident objects are impossible. However, careful attention to the concepts of location and parthood that Gilmore’s cases involve shows that the perdurantist faces no genuine objection from these cases, and that the perdurantist has a number of plausible and dialectically appropriate ways to avoid the supposed conflict.

Putnam originally developed his causal theory of meaning in order to support scientific realism and reject the notion of incommensurability. Later he gave up this position and adopted instead what he called ‘internal realism’, but apparently without changing his mind on topics related to his former philosophy of language. The question must arise whether internal realism, which actually is a species of antirealism, is compatible with the causal theory of meaning. In giving an answer I begin with an analysis of the content and metaphysical background of scientific realism. I show that it presupposes metaphysical realism and that Putnam's philosophical conversion is due to his becoming aware of the latter's incoherence. After giving a brief sketch of internal realism I conclude by arguing that within this new theoretical framework the causal theory of meaning loses its force as a weapon against incommensurability.

In this paper, I argue that both perdurance theory and the ‘relations-to-times’ endurantist view rely on an atemporal notion of property instantiation and relation bearing. I distinguish two possible meanings of ‘atemporal’ which result in two different understandings of what it is for an object to have a property or to bear a relation atemporally. I show that standard presentations of the theories considered are indeterminate as to which of these two understandings is the intended one. I claim that even if both understandings are admissible, one of them is more attractive and has more to recommend than the other.

The terms ‘endurance’ and ‘perdurance’ are commonly thought to denote distinct ways for an object to persist, but it is surprisingly hard to say what these are. The common approach, defining them in terms of temporal parts, is mistaken, because it does not lead to two coherent philosophical alternatives: endurance so understood becomes conceptually incoherent, while perdurance becomes not just true but a conceptual truth. Instead, we propose a different way to articulate the distinction, in terms of identity rather than temporal parts: an object endures if its identity is determined at every moment at which it exists. We make precise what it means for the identity of an object to be determined at a moment. We also discuss what role the endurance/perdurance distinction, so understood, should play in the debates about time, material objects and personal identity.

The terms ‘endurance’ and ‘perdurance’ are commonly thought to denote distinct ways for an object to persist, but it is surprisingly hard to say what these are. The common approach, defining them in terms of temporal parts, is mistaken, because it does not lead to two coherent philosophical alternatives: endurance so understood becomes conceptually incoherent, while perdurance becomes not just true but a conceptual truth. Instead, we propose a different way to articulate the distinction, in terms of identity rather than temporal parts: an object endures if its identity is determined at every moment at which it exists. We make precise what it means for the identity of an object to be determined at a moment. We also discuss what role the endurance/perdurance distinction, so understood, should play in the debates about time, material objects and personal identity.

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).