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)

Three-dimensionalists , sometimes referred to as endurantists, think that objects persist through time by being “wholly present” at every time they exist. But what is it for something to be wholly present at a time? It is surprisingly difficult to say. The threedimensionalist is free, of course, to take ‘is wholly present at’ as one of her theory’s primitives, but this is problematic for at least one reason: some philosophers claim not to understand her primitive. Clearly the three-dimensionalist would be (...) better off if she could state her theory in terms accessible to all. We think she can. What is needed is a definition of ‘is wholly present at’ that all can understand. in this paper, we offer one. (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)

How can an object remain the same, numerically identical, while undergoing change? This is a worry for endurantists, who hold that for any stages, x and y, of a persisting object, x is numerically identical with y. Endurantists might try to avoid the problem of change by insisting that all properties are temporally anchored. It is argued here that while this strategy helps in many cases, it does not help in all. A type of case is presented in which a (...) property is time-indexed but the property is one that an object exemplifies at only one time in its career. The choice between the A theory and the B theory of time (in particular, presentism versus eternalism), and how that bears on the problem presented here, is also considered. It is argued that regardless of our views about the nature of time, so long as objects persist through time while undergoing change, the risk of violating the Indiscernibility of Identicals remains a serious threat to endurantism. (shrink)

Three arguments for the conclusion that objects cannot endure in B-time even if they remain intrinsically unchanged are examined: Carter and Hestevolds enduring-objects-as-universals argument (American Philosophical Quarterly 31(4):269-283, 1994) and Barker and Dowe's paradox 1 and paradox 2 (Analysis 63(2):106-114, 2003, Analysis 65(1):69-74, 2005). All three are shown to fail.

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)

Judith Thomson, David Lewis, and Ted Sider have each formulated different arguments that apparently pose problems for our ordinary claims of diachronic sameness, i.e., claims in which we assert that familiar, concrete objects survive (or persist) through time by enduring as numerically the same entity despite minor changes in their intrinsic or relational properties. In this paper, I show that all three arguments fail in a rather obvious way--they beg the question--and so even though there may be arguments that provide (...) grounds to fuss about whether our ordinary claims of diachronic sameness are defective, Thomson, Lewis, and Sider's arguments are not among them. (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.

The following is a transcript of what might very well have been five telephone conversations between Michael Jordan and former Chicago Bulls coach Phil Jackson. The conversations took place in early March 1995, just before the announcement of MJ’s comeback after a year spent pursuing baseball.

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. (shrink)

In this paper I explore how the tenseless copula is to be interpreted in sentences of the form “ a is F at t ”, where “ a ” denotes a persisting, changeable object, “ F ” stands for a prima facie intrinsic property and “ t ” for a B-time. I argue that the interpretation of the copula depends on the logical role assigned to the time clause. Having rejected the idea that the time clause is to be treated (...) as a sentence operator, I argue: (1) that if “at t ” is thought of as being associated with “ a ” or “ F ”, then the tenseless copula is most plausibly read as an “is” simpliciter ; and (2) that if “at t ” is treated as being associated with the copula, then the tenseless copula is most plausibly understood as expressing a disjunction of tensed copulas. I end the paper by explaining the importance of the issue. I indicate the ramifications interpretation of the tenseless copula has for the so-called problem of temporary intrinsics. (shrink)