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Most people who believe in temporal parts believe that the referents of our ordinary referring terms, like Bill Clinton, or that table, are fusions of temporal parts from past, present and future times. Call these fusions worms, and the theory that the referents of ordinary referring terms (ordinary objects) the worm theory. Buying the metaphysical theory of temporal parts does not immediately imply that we must buy the worm theory. Theodore Sider (1996, 2000), for example, has suggested that these ordinary referring terms just pick out a single, instantaneous, temporal part. Sider’s theory, called the stage theory, solves some pressing philosophical problems, including the problem of temporary intrinsics. But the stage theory has several difficulties of its own, especially what I will call the problem of long-term intrinsics. I argue for a rival theory, the growing individuals theory. On this theory, the referents of our ordinary referring terms have past and present temporal parts, but not future temporal parts. This theory best accounts for our intuitions about which intrinsic properties ordinary objects have.

“The truth,” Quine says, “is that you can bathe in the same river twice, but not in the same river stage. You can bathe in two river stages which are stages of the same river, and this is what constitutes bathing in the same river twice. A river is a process through time, and the river stages are its momentary parts.” (Quine 1953, p. 65) Quine’s view is four-dimensionalism, and that is what Theodore Sider’s book is about. In Sider’s usage, four-dimensionalism is the view that, necessarily, anything in space and time has a distinct temporal part, or stage, corresponding to each time at which it exists (p. 59).

On stage theory, ordinary continuants are instantaneous stages which persist by exduring—by bearing temporal counterpart relations to other such stages. Exduring objects lack temporal extension and there is a sense in which they are wholly present at multiple instants. How then is exdurance different from endurance? I offer a definition of ‚exdurance’ that clearly sets it apart from other modes of persistence.

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.

The nature of persistence of physical objects over time has been intensely debated in contemporary metaphysics. The two opposite views are widely known as "endurantism" (or "three-dimensionalism") and "perdurantism" ("four-dimensionalism"). According to the former, objects are extended in three spatial dimensions and persist through time by being wholly present at any moment at which they exist. On the rival account, objects are extended both in space and time and persist by having "temporal parts," no part being present at more than one time. Relativistic considerations seem highly relevant to this debate. But they have played little role in it so far. This paper seeks to remedy that situation. I argue that considerations based on the special theory of relativity and the notion of coexistence favor perdurantism over endurantism.

How do the familiar concrete objects of common-sense – houses, trees, people, cars and the like – persist through time? According to the position known as ‘four-dimensionalism’ or ‘the doctrine of temporal parts’, ordinary concrete objects persist through time by perduring, i.e., by having temporal parts at all those times at which they exist, in addition to their ordinary spatial parts.1 The contrasting position, known as ‘three-dimensionalism’, holds that ordinary concrete objects lack such an additional temporal dimension; rather, they persist through time by enduring, i.e., by being ‘wholly present’ (whatever exactly that comes to) at each of those times at which they exist.2,3 In his excellent recent book, Four-Dimensionalism: An Ontology of Persistence and Time (Sider, 2001), Theodore Sider defends a version of four-dimensionalism which he calls the ‘stage-theory’: according to this view, ordinary persisting objects are analyzed as being identical to momentary stages; they persist by having temporal counterparts at other times. (The ‘stage-theory’ contrasts with the more familiar ‘worm-theory’, according to which ordinary persisting objects are analyzed as extended space-time worms, rather than momentary stages.) Sider’s claim on behalf of the stagetheory is that it is the position which, on the whole, provides the best analysis of the persistence of ordinary concrete objects: when compared with competing views, the stage-theory yields the best unified solution to a wide range of classical metaphysical puzzles and has “on balance, the most important advantages and the least serious drawbacks” (Sider, 2001, p. 140). Despite all of its many significant virtues, however, Sider’s case for four-dimensionalism is troubling in certain crucial respects, both philosophically and meta-philosophically. My purpose in this paper Philosophical Studies 114: 107–134, 2003. © 2003 Kluwer Academic Publishers. Printed in the Netherlands. 108..

The stage theory is a four-dimensional account of persistence motivatedby the worm theory's inability to account for our intuitions in thecases involving coinciding objects. Like the worm theory, it claimsthat there are objects spread out in time, but unlike the worm theory,it argues that these spacetime worms are not familiar particulars liketables and chairs. Rather, familiar particulars are the instantaneoustemporal slices of worms. In order to explain our intuitions that particulars persist for more than an instant, the stage theory drawson the counterpart theory of modal possibilism, which it is supposedto parallel. In this paper I show how the stage theory presupposes thattime can be divided into instants, which I call the atomistic view oftime. I do this by laying out an alternative theory of the nature oftime, the gunky view, and show that if time is gunky the stage theorycollapses into the worm theory. The deeper problem is that the merepossibility of gunky time would cause the stage theory's parallels topossibilism to break down. I therefore conclude that the stage theoryis committed to the view that time is necessarily atomistic. Finally,in the last section I argue that the fact that the stage theory rulesout a priori the possibility of time being gunky gives us reason toreject it as an account of persistence.

Four-dimensionalism, as I’ll use the term, is the doctrine that reality is spread out in time as well as space.1 Just as objects that are located at multiple regions of space contain parts con ned to those regions of space, so objects that are located at multiple regions of time contain parts — temporal parts — that are con ned to those regions of time. (Or better: an object that occupies an extended spatiotemporal region R has parts con ned to the various subregions of R; but I’ll ignore this complication henceforth.) Most who accept this ontology of perduring objects, as they are often called, identify the continuants of our everyday ontology with “space-time worms” — mereological sums of stages from different times. Elsewhere ( ) I have proposed a different version of four-dimensionalism, which identi es continuants with the stages themselves, and which analyses de re temporal predication with a temporal version of modal counterpart theory (Lewis, , ). On this view, a current assertion of ‘Clinton was indiscreet’ is true iff the (current) referent of ‘Clinton’ — a stage — has an indiscreet temporal counterpart in the past. The temporal counterpart relation is the same “genidentity” or “unity” relation used by the worm theorist to unify the successive stages of continuing space-time worms. In my I supported this view by appeal to its ability to resolve various philosophical puzzles, including the paradoxes of material constitution and Derek Par t’s ( ) puzzle about identity and what matters; the purpose of the present note is to mention one other line of argument. A widely discussed contemporary argument for temporal parts is David Lewis’s argument from temporary intrinsics, according to which only the fourdimensionalist can explain the phenomenon of intrinsic change.2 I am now straight-shaped, but will fail to be straight-shaped in the future. There is an..

Four-dimensionalism, as I’ll use the term, is the doctrine that reality is spread out in time as well as space.1 Just as objects that are located at multiple regions of space contain parts confined to those regions of space, so objects that are located at multiple regions of time contain parts — temporal parts — that are confined to those regions of time. (Or better: an object that occupies an extended spatiotemporal region R has parts confined to the various subregions of R; but I’ll ignore this complication henceforth.) Most who accept this ontology of perduring objects, as they are often called, identify the continuants of our everyday ontology with “space-time worms” — mereological sums of stages from different times. Elsewhere (1996) I have proposed a different version of four-dimensionalism, which identifies continuants with the stages themselves, and which analyses de re temporal predication with a temporal version of modal counterpart theory (Lewis, 1968, 1971). On this view, a current assertion of ‘Clinton was indiscreet’ is true iff the (current) referent of ‘Clinton’ — a stage — has an indiscreet temporal counterpart in the past. The temporal counterpart relation is the same “genidentity” or “unity” relation used by the worm theorist to unify the successive stages of continuing space-time worms. In my 1996 I supported this view by appeal to its ability to resolve various philosophical puzzles, including the paradoxes of material constitution and Derek Parfit’s (1971) puzzle about identity and what matters; the purpose of the present note is to mention one other line of argument. A widely discussed contemporary argument for temporal parts is David Lewis’s argument from temporary intrinsics, according to which only the fourdimensionalist can explain the phenomenon of intrinsic change.2 I am now straight-shaped, but will fail to be straight-shaped in the future. There is an..

Some philosophers believe that everyday objects are 4-dimensional spacetime worms, that a person (for example) persists through time by having temporal parts, or stages, at each moment of her existence. None of these stages is identical to the person herself; rather, she is the aggregate of all her temporal parts.1 Others accept “three dimensionalism”, rejecting stages in favor of the notion that persons “endure”, or are “wholly present” throughout their lives.2 I aim to defend an apparently radical third view: not only do I accept person stages; I claim that we are stages.3 Likewise for other objects of our everyday ontology: statues are statue-stages, coins are coin-stages, etc. At one level, I accept the ontology of the worm view. I believe in spacetime worms, since I believe in temporal parts and aggregates of things I believe in. I..