I offer an argument in defense of four-dimensionalism, the view that objects are temporally, as well as spatially extended. The argument is of the inference-to-the-best-explanation variety and is based on relativistic considerations. It deals with the situation in which one and the same object has different three-dimensional shapes at the same time and proceeds by asking what sort of thing it must be in order to present itself in such different ways in various “perspectives” (associated with moving reference frames) without (...) being different from itself. I argue that the best answer is that the object must be four-dimensional. It will then have differing 3D shapes in different perspectives because such shapes are intrinsic properties of its 3D parts. (shrink)

In an earlier work I developed an argument favoring one view of persistence (viz., perdurance) over its rivals, based on considerations of the relativity of three-dimensional spatial shapes of physical objects in Minkowski spacetime. The argument has since come under criticism (in the works of Theodore Sider, Kristie Miller, Ian Gibson, Oliver Pooley, and Thomas Sattig). Two related topics, explanatory virtues and explanatory relevance, are central to these critical discussions. In this paper I deal with these topics directly and respond (...) to my critics by offering a new perspective on the issue. (shrink)

How do ordinary objects persist through time and across possible worlds ? How do they manage to have their temporal and modal properties ? These are the questions adressed in this book which is a "guided tour of theories of persistence". The book is divided in two parts. In the first, the two traditional accounts of persistence through time (endurantism and perdurantism) are combined with presentism and eternalism to yield four different views, and their variants. The resulting views are then (...) examined in turn, in order to see which combinations are appealing and which are not. It is argued that the 'worm view' variant of eternalist perdurantism is superior to the other alternatives. In the second part of the book, the same strategy is applied to the combinations of views about persistence across possible worlds (trans-world identity, counterpart theory, modal perdurants) and views about the nature of worlds, mainly modal realism and abstractionism. Not only all the traditional and well-known views, but also some more original ones, are examined and their pros and cons are carefully weighted. Here again, it is argued that perdurance seems to be the best strategy available. (shrink)

In his article 'The Evil of Death' (henceforth: ED) Harry Silverstein argues that a proper refutation of the Epicurean view that death is not an evil requires the adoption of a particular revisionary ontology, which Silverstein, following Quine, calls 'four-dimensionalism'.1 In 'The Evil of Death Revisited' (henceforth: EDR) Silverstein reaffirms his earlier position and responds to several criticisms, including some targeted at his ontology. There remain, however, serious problems with Silverstein's argument, and I shall highlight five major ones below. I (...) conclude that Silverstein has not shown that an appeal to four-dimensionalism facilitates a refutation of Epicurus, although a consideration of some of Silverstein's points helps to indicate the limited scope of the Epicurean thesis. (shrink)

In this paper, I focus on three issues intertwined in current debates between endurantists and perdurantists—(i) the dimension of persisting objects, (ii) whether persisting objects have timeless, or only time-relative, parts, and (iii) whether persisting objects have proper temporal parts. I argue that one standard endurantist position on the first issue is compatible with standard perdurantist positions on parthood and temporal parts. I further argue that different accounts of persistence depend on the claims about objects’ dimensions and not on the (...) auxiliary claims about parthood and temporal parts. (shrink)

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.

In ‘Location and Perdurance’ (2010), I argued that there are no compelling mereological or sortal grounds requiring the perdurantist to distinguish the molecule Abel from the atom Abel in Gilmore’s original case (2007). The remaining issue Gilmore originally raised concerned the ‘mass history’ of Adam and Abel, the distribution of ‘their’ mass over spacetime. My response to this issue was to admit that mass histories needed to be relativised to a way of partitioning the location of Adam/Abel, but that did (...) not amount to relativising any fundamental natural intrinsic properties—the latter are all had unrelativised, and (so most perdurantists would say). (shrink)

Recently, Jim Stone has argued that counterpart theory is incompatible with the existence of temporal parts. I demonstrate that there is no such incompatibility.

In 'Does Four-Dimensionalism Explain Coincidence?' Mark Moyer argues that there is no reason to prefer the four-dimensionalist (or perdurantist) explanation of coincidence to the three-dimensionalist (or endurantist) explanation. I argue that Moyer's formulations of perdurantism and endurantism lead him to overlook the perdurantist's advantage. A more satisfactory formulation of these views reveals a puzzle of coincidence that Moyer does not consider, and the perdurantist's treatment of this puzzle is clearly preferable.

This thesis is about the conceptualization of persistence of physical, middle-sized objects within the theoretical framework of the revisionary ‘B-theory’ of time. According to the B-theory, time does not flow, but is an extended and inherently directed fourth dimension along which the history of the universe is ‘laid out’ once and for all. It is a widespread view among philosophers that if we accept the B-theory, the commonsensical ‘endurance theory’ of persistence will have to be rejected. The endurance theory says (...) that objects persist through time by being wholly present at distinct times as numerically the same entity. Instead of endurantism, it has been argued, we have to adopt either ‘perdurantism’ or the ‘stage theory’. Perdurantism is the theory that objects are four-dimensional ‘space-time worms’ persisting through time by having distinct temporal parts at distinct times. The stage theory says that objects are instantaneous temporal parts (stages) of space-time worms, persisting by having distinct temporal counterparts at distinct times. In the thesis, it is argued that no good arguments have been provided for the conclusion that we are obliged to drop the endurance theory by acceptance of the B-theory. This conclusion stands even if the endurance theory incorporates the claim that objects endure through intrinsic change. It is also shown that perdurantism and the stage theory come with unwelcome consequences. Paper I demonstrates that the main arguments for the view that objects cannot endure in B-time intrinsically unchanged fail. Papers II and III do the same with respect to the traditional arguments against endurance through intrinsic change in B-time. Paper III also contains a detailed account of the semantics of the tenseless copula, which occurs frequently in the debate. The contention of Paper IV is that four-dimensional space-time worms, as traditionally understood, are not suited to take dispositional predicates. In Paper V, it is shown that the stage theory needs to introduce an overabundance of persistence-concepts, many of which will have to be simultaneously applicable to a single object (qua falling under a single sortal), in order for the theory to be consistent. The final article, Paper VI, investigates the sense in which persistence can, as is sometimes suggested, be a ‘conventional matter’. It also asks whether alleged cases of ‘conventional persistence’ create trouble for the endurance theory. It is argued that conventions can only enter at a trivial semantic level, and that the endurance theory is no more threatened by such conventions than are its rivals. (shrink)

Temporal parts are analogous to spatial parts: just as the conference has one spatial part which occupies the seminar room, and another which occupies the lecture hall, it has one temporal part which ‘occupies’ Friday and another which ‘occupies’ Saturday. These temporal parts of the conference have half-hour coffee-breaks as temporal parts of their own; these coffee-breaks are also temporal parts of the whole conference.

I claim that, if persisting objects have temporal parts, then there are non-supervenient relations between those temporal parts. These are relations which are not determined by intrinsic properties of the temporal parts. I use the Kripke-Armstrong 'rotating homogeneous disc' argument in order to establish this claim, and in doing so I defend and develop that argument. This involves a discussion of instantaneous velocity, and of the causes and effects of rotation. Finally, I compare alternative responses to the rotating disc argument, (...) and consider the implications of my arguments for the doctrines of Humean Supervenience and unrestricted mereology. (shrink)

Despite its first page this paper is not yet another piece on Kant! Rather, the paper is a contribution to the literature on incongruent counterparts. Specifically, it concerns the question of whether we can construct a temporal version of the puzzle of incongruent counterparts--a question which (as far as I can tell) has been thoroughly neglected. I maintain that we can construct such a version of the puzzle, and that this temporal variant on the phenomenon has something to teach us (...) about popular arguments for the possibility (or even actuality) of four-dimensional space. (shrink)

Review: Tobias Hansson Wahlberg, Objects in Time. Studies of Persistence in B-time (2009) Content Type Journal Article DOI 10.1007/s12133-010-0054-2 Authors Ingvar Johansson, Umeå University Umeå Sweden Journal Metaphysica Online ISSN 1874-6373 Print ISSN 1437-2053 Journal Volume Volume 11 Journal Issue Volume 11, Number 1.

This paper begins with a puzzle about certain temporal expressions: phrases like 'Jones as he was ten years ago' and 'the Jones of ten years ago'. There are reasons to take these as substantival, to be interpreted as terms for temporal parts. But it seems that the same reifying strategy would also force us to countenance a host of less attractive posits, among them fictional counterparts of real things (to correspond to such phrases as 'Garrison as he was in the (...) movie JFK') and much more. I argue that there is a better way: we need only the idea of pretense or make-believe to make sense of claims embedding such phrases, leaving us with no reason, so far, to accept an ontology of temporal parts. (shrink)

This paper begins with a puzzle about certain temporal expressions: phrases like 'Jones as he was ten years ago' and 'the Jones of ten years ago'. There are reasons to take these as substantival, to be interpreted as terms for temporal parts. But it seems that the same reifying strategy would also force us to countenance a host of less attractive posits, among them fictional counterparts of real things (to correspond to such phrases as 'Garrison as he was in the (...) movie JFK') and much more. I argue that there is a better way: we need only the idea of pretense or make-believe to make sense of claims embedding such phrases, leaving us with no reason, so far, to accept an ontology of temporal parts. (shrink)

Rebecca Roache has argued that cohabiting individuals cannot enjoy the commonsense desire to survive. This paper argues that they can.

David Lewis's cohabitation theory suffered damaging criticism from Derek Parfit. Though many have defended versions of Lewis's theory Parfit's criticism has not been answered. This paper shows how to defend the cohabitation theory against Parfit's criticism.

If persons endure, personal identity cannot be analyzed in terms of psychological continuity. That is one conclusion defended in my "Endurance, Psychological Continuity, and the Importance of Personal Identity" (PPR, 1999). Rea and Silver (PPR, 2000) claim that my argument for that conclusion is sound only if a parallel argument is sound. The parallel argument concludes that if persons perdure, personal identity cannot be analyzed in terms of psychological continuity. In this paper, I show that Rea and Silver are mistaken. (...) My argument is sound but the parallel argument is not. (shrink)

If persons endure, personal identity cannot be analyzed in terms of psychological continuity. That is one conclusion defended in my "Endurance, Psychological Continuity, and the Importance of Personal Identity" (PPR, 1999). Rea and Silver (PPR, 2000) claim that my argument for that conclusion is sound only if a parallel argument is sound. The parallel argument concludes that if persons perdure, personal identity cannot be analyzed in terms of psychological continuity. In this paper, I show that Rea and Silver are mistaken. (...) My argument is sound but the parallel argument is not. (shrink)

While there has been considerable recent criticism of perdurance theory in connection with a Humean understanding of causality, perdurance theory conjoined with causal realism has received relatively little attention. One might, then, form the impression that perdurance theory under the auspices of causal realism is a relatively safe view. I shall argue, however, to the contrary. My general strategy is to show that there is no plausible way of spelling out the perdurance position (of the non-Humean, causal realist sort). I (...) implement this strategy by revealing several general problems concerning the causally-connected temporal parts scheme. I begin with a short account of perdurance theory. There follows a description of two general views of causality and the two subsequent accounts of the perduring object; then, the criticism. (shrink)

Adopting temporal parts theory is the most popular way of addressing a host of puzzles about diachronic identity. For example, it is not obvious how I am the same person as the baby who shared my name. With the theory, sameness of person, e.g., consists in being comprised by the same temporally extended, four-dimensional object. However, temporal parts theory has unacceptable consequences for notions of freedom and probability. I show that the only acceptable reading of four-dimensionalism entails that the four (...) dimensional object that is me, say, already exists in its entirety. This entails that all of my future properties are already set. This nearly Spinozistic result robs us of familiar notions of choice and possibility. I argue that these notions are more central to our thinking than temporal parts theory, and that on these grounds we must look elsewhere for solutions to our questions about identity across time. (shrink)

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. (shrink)

It is argued that philosophers who adopt the perdurance theory of persistence and who subscribe to the principle of Unrestricted Mereological Composition (UMC) are in a position to regard “Phosphorus is Hesperus” as false.

Disposition ascription has been discussed a good deal over the last few decades, as has the revisionary metaphysical view of ordinary, persisting objects known as 'fourdimensionalism'. However, philosophers have not merged these topics and asked whether four-dimensional objects can be proper subjects of dispositional predicates. This paper seeks to remedy this oversight. It argues that, by and large, four-dimensional objects are not suited to take dispositional predicates.