Some theories of personal identity allow some variation in what it takes for a person to survive from context to context; and sometimes this is determined by the desires of person-stages or the practices of communities. This leads to problems for decision making in contexts where what is chosen will affect personal identity. `Temporal Phase Pluralism' solves such problems by allowing that there can be a plurality of persons constituted by a sequence of person stages. This illuminates difficult decision making (...) problems when persons have to choose between different life-altering choices. (shrink)

The Argument from Temporary Intrinsics is one of the canonical arguments against endurantism. I show that the two standard ways of presenting the argument have limited force. I then present a new version of the argument, which provides a more promising articulation of the underlying objection to endurantism. However, the premises of this argument conflict with the gauge theories of particle physics, and so this version of the argument is no more successful than its predecessors. I conclude that no version (...) of the Argument from Temporary Intrinsics gives us a compelling reason to favor one theory of persistence over another. (shrink)

When a tree is chopped to bits, or a sweater unravelled, its matter still exists. Since antiquity, it has sometimes been inferred that nothing really has been destroyed: what has happened is just that this matter has assumed new form. Contemporary versions hold that apparent destruction of a familiar object is just rearrangement of microparticles or of 'physical simples' or 'world stuff'. But if destruction of a familiar object is genuinely to be reduced to mere alteration of something else, we (...) must identify an alteration proper to the career, the course of existence, of this something else; relatedly, the alteration must be characterizable without asserting the existence of the familiar object. All contemporary views fail one of these requirements. (shrink)

This paper is an informal presentation of the ideas presented formally in (”Relative-Sameness Counterpart Theory”. Relative-sameness relations -- such as being the same person as -- are like David Lewis’s “counterpart” relations in the following respects: (i) they may hold over time or across worlds between objects that aren’t cross-time or cross-world identical (I propose), and (ii) there are a multiplicity of them, different ones of which may be variously invoked in different contexts. They differ from his counterpart relations, however, (...) in that they are weak equivalence relations (transitive, symmetric and weakly reflexive). The likenesses to counterpart relations make them suitable for an analysis of de-re temporal and modal predications. The difference renders the resulting counterpart theory immune to standard criticisms of Lewis’s Counterpart Theory (e.g., in Hazen 1979, and Fara and Williamson 2005). The use of sameness as opposed to similarity relations in the analysis of de-re temporal and modal predication renders the resulting truth conditions as statable in terms that proponents of Kripke’s identity-based analysis can accept. (shrink)

In the philosophy of science, identity over time emerges as a central concern both as an ontological category in the interpretation of physical theories, and as an epistemological problem concerning the conditions of possibility of knowledge. In Reichenbach and subsequent writers on the problem of indistinguishable quantum particles we see the return of a contrast between Leibniz and Aquinas on the subject of individuation. The possibility of rejecting the principle of the identity of indiscernibles has certain logical difficulties, leading us (...) inexorably from ontology into epistemology. For the epistemological problem we attend to the differences that emerged between the (neo-)Kantian and logical empiricist traditions, also saliently displayed in Reichenbach's writings. After examining the contrast between Kant's and Leibniz's conceptions of empirical knowledge, specifically with respect to the irreducibility of spatiotemporal determinations, we explore an application of a neo-Kantian view to the same problem of indistinguishable quantum particles. (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)

In this paper, we argue for a novel three-dimensionalist (3D'ist) solution to the problem of persistence, i.e. cross-temporal identity. We restrict the discussion of persistence to simple substances, which do not have other substances as their parts. The account of simple substances employed in the paper is a trope-nominalist strong nuclear theory (SNT), which develops Peter Simons' trope nominalism. Regarding the distinction between three dimensionalism (3D) and four dimensionalism (4D), we follow Michael Della Rocca's formulation, in which 3D explains persistence (...) in virtue of same entities and 4D in virtue of distinct entities (temporal parts). SNT is a 3D'ist position because it accounts for the persistence of simple substances in virtue of diachronically identical ‘nuclear’ tropes. The nuclear tropes of a simple substance are necessary for it and mutually rigidly dependent but distinct. SNT explains qualitative change by tropes that are contingent to a simple substance. We show that it avoids the standard problems of 3D: temporal relativization of ontic predication, Bradley's regress and coincidence, fission and fusion cases. The temporal relativization is avoided because of the analysis of temporary parts that SNT gives in terms of temporal sub-location, which is atemporal part–whole relation. (shrink)

Lowe argues in this fascinating new study that metaphysics should be restored to centrality in philosophy, as the most fundamental form of inquiry, whose findings underpin those of all other disciplines. He portrays metaphysics as charting the possibilities of existence, by identifying the categories of being and the relations between them. He then sets out his own metaphysical system, with which he seeks to answer many of the most vexed questions in philosophy.

Worlds, Lewis says this: Let us say that something persists iff, somehow or other, it exists at various times; this is the neutral word. Something perdures iff it persists by having different temporal parts, or stages, at different times, though no one part of it is wholly present at more than one time; whereas it endures iff it persists by being wholly present at more than one time. Perdurance corresponds to the way a road persists through space; part of it (...) is here, and part of it is there, and no part is wholly present at two different places. Endurance corresponds to the way a universal, if there are such things, would be wholly present wherever and whenever it is instantiated. Endurance involves overlap: the content of two different times has the enduring thing as a common part. Perdurance does not.1 Lewis's remarks suggest the following formulations of the two views in the 3D/4D controversy.2.. (shrink)

Comparative overall similarity lies at the basis of a lot of recent metaphysics and epistemology. It is a poor foundation. Overall similarity is supposed to be an aggregate of similarities and differences in various respects. But there is no good way of combining them all.

A view of individuals as constituted of quantities of matter, both understood as continuants enduring over time, is elaborated in some detail. Constitution is a three-place relation which can't be collapsed to identity because of the place-holder for a time and because individuals and quantities of matter have such a radically different character. Individuals are transient entities with limited lifetimes, whereas quantities are permanent existents undergoing change in physical and chemical properties from time to time. Coincidence, considered as a matter (...) of occupying the same place, is developed, alongside sameness of constitutive matter, as a criterion of identity for individuals. Quantities satisfy the mereological criterion of identity, applicable to entities subject to mereological relations and operations such as regions of space and intervals of time. A time-dependent analogue of mereological parthood is defined for individuals, in terms of which analogues of the other mereological relations can be defined. But it is argued that there is no analogue of the mereological operation of summation for individuals. (shrink)

What is a temporal part? Most accounts explain it in terms of timeless parthood: a thing's having a part without temporal qualification. Some find this hard to understand, and thus find the view that persisting things have temporal parts—four-dimensionalism—unintelligible. T. Sider offers to help by defining temporal parthood in terms of a thing's having a part at a time. I argue that no such account can capture the notion of a temporal part that figures in orthodox four-dimensionalism: temporal parts must (...) be timeless parts. This enables us to state four-dimensionalism more clearly. (shrink)

Philosophers often talk as if what it takes for a person to persist through time were up to us, as individuals or as a linguistic community, to decide. In most ordinary situations it might be fully determinate whether someone has survived or perished: barring some unforeseen catastrophe, it is clear enough that you will still exist ten minutes from now, for example. But there is no shortage of actual and imaginary situations where it is not so clear whether one survives. (...) Here reasonable people may disagree. There are "fission" cases where each of one's cerebral hemispheres is transplanted into a different head; Star-Trek-style "teletransportation" stories; actual cases of brain damage so severe that one can never again regain consciousness, even though one's circulation, breathing, digestion, and other "animal" functions continue; and stories where one's brain cells are gradually removed and replaced by cells from someone else, to name only a few favorites. (shrink)

David Lewis suggests and dismisses two ways, and endorses one further way, of visually representing persisting objects as changing over time. He argues that reflecting on these artistic observations should lead us to endorse a temporal parts theory of objects. This paper argues that Lewis's objections on these grounds to alternative theories of persistence and intrinsic change can be resisted, and that his argument in favour of his preferred method of drawing changing persisting objects fails to show that objects perdure.

The ‘paradoxes of coincidence’ are generally taken as an important factor for deciding between rival views on persistence through time. In particular, the ability to deal with apparent cases of temporary coincidence is usually regarded as a good reason for favouring perdurantism (or ‘four-dimensionalism’) over endurantism (or ‘three-dimensionalism’). However, the recent work of Gilmore ( 2007 ) and McGrath ( 2007 ) challenges this standard view. For different reasons, both Gilmore and McGrath conclude that perdurantism does not really obtain support (...) from the puzzles of temporary coincidence. In this paper, I will evaluate their arguments and defend the opposite view: that the paradoxes of coincidence do give some support to perdurantism. However, the way in which they do so is rather unexpected. As we will see, there are different ways in which coincidence scenarios may be thought to support perdurantism, some of which have not yet been sufficiently explored. Thus, my immediate goal is to explore one of those directions, bringing into focus a new argument from coincidence to perdurantism. And although I motivate my discussion by examining the arguments in the work of Gilmore and McGrath, the merits of this argument can be independently assessed. More generally, my overall purpose is to contribute to our general understanding of how the topics of coincidence and persistence bear on each other. (shrink)

What happens to a person in a case of fission? Does it survive? Does it go out of existence? Or is the outcome indeterminate? Since each description of fission based on the persistence conditions associated with our ordinary concept of a person seems to clash with one or more platitudes of common sense about the spatiotemporal profile of macroscopic objects, fission threatens the common-sense conception of persons with inconsistency. Standard responses to this paradox agree that the common-sense conception of persons (...) is unstable, differing over which part of the conception requires revision. I will show that this entrenched view of fission is not compulsory. I will develop a solution to the paradox that maintains the consistency of the common-sense conception of persons on the basis of an ontology of persons and other ordinary objects as double-layered compounds. Each of various descriptions of the outcome of personal fission is compatible with principles about the spatiotemporal profile of persons, because the descriptions and the principles manifest different perspectives on persons and are made true or false by different ontological components of the latter. What holds for the fission of persons, holds for the fission of other kinds of objects. (shrink)

Taking ontological realism about social groups as the thesis that groups are composite material objects constituted by their members, this paper considers a challenge to the very possibility that groups be regarded as material entities. Ordinarily we believe that two groups can have synchronic co-extensive memberships—for example, the choir and the rugby team—while preserving their distinctive identity conditions. We also doubt that two objects of the same kind can be in the same place at the same time, which would appear (...) to be the case when groups have identical memberships. I explain that the principle denying the synchronic co-location of objects of the same kind need not apply universally to material objects and that it is a mistake to take resistance to penetrability as a necessary feature of materiality. Therefore, initial appearances notwithstanding, groups can be in the same place at the same time. Key Words: identity • materiality • location • social group. (shrink)

The existence and importance of supervenience principles for identity across times and worlds have been noted, but insufficient attention has been paid to their precise nature. Such attention is repaid with philosophical dividends. The issues in the formulation of the supervenience principles are two. The first involves the relevant variety of supervenience: that variety is global, but there are in fact two versions of global supervenience that must be distinguished. The second involves the subject matter: the names “identity over time” (...) and “identity across worlds” are misnomers, for in neither case is identity at issue. The philosophical dividends then follow. Nathan Salmon’s argument that identity over time needs no “grounds” in matters of qualitative fact can be answered, as can an argument offered by many, that coincident objects (such as statues and lumps of clay) would require objectionably ungrounded differences in identities across times and worlds. (shrink)

This paper brings together two theories that I have propounded separately elsewhere. The first is the view that concrete individuals are constituted completely by tropes, that they are trope bundles. The second and more recently developed theory is that of the two major categories of concrete individuals, continuants and occurrents, the latter are ontologically more basic than the former and that continuants are to be viewed as invariants among occurrents under equivalence relations. The latter theory embodies on its own an (...) account of the nature of identity through time of things that are in time but not extended in time. The question is whether this view is compatible with the trope bundle account of concrete particulars, and, assuming it is (both theories being separately attractive) whether bringing them together entails any modifications (other than complexity) to either theory. After examining likely metaphysical difficulties the tentative conclusion is that the attractiveness of the trope bundle theory persists despite the marriage, but that the mental picture of what tropes and trope bundles are must be overhauled. (shrink)

It can seem implausible that a merely bodily existence could be also a personal existence. Two related lines of thought can mitigate this implausibility. The first, developed in the first part of this paper, is the thought that our bodily existence is better described as an organic, animal existence. Organisms, I argue, are essentially temporal; this essential temporality makes sense of the possibility thatsome organisms are persons. The second line of thought, addressed in the second part of the paper, considers (...) the relationship between the notion of a person, and temporal existence. Persons need not exist in time, but some do. Consideration of what the temporal existence of a person must be like makes organic existence seem an appropriate way for temporal persons to exist. (shrink)

What is the relation between time and self? Well, one rather obvious and quite venerable suggestion is that the relation is first and foremost of a negative nature. Consider the claim that experiences never occur in isolation, and that the stream of consciousness is an ensemble of experiences that is unified both at and over time, both synchronically and diachronically. According to a classical view, we need to appeal to a self in order to account for this diachronic and synchronic (...) unity. To think of a simultaneous or temporally dispersed plurality of experiences is to think of myself as being conscious of this plurality, and as the argument goes this requires an undivided, invariable, unchanging me. The self is a principle of identity. It is that which persists and resists temporal change. This is why it has even occasionally been ascribed a certain supratemporal or atemporal character. On such an account, the unity of self is taken to be something with explanatory power rather than something that itself is in need of an explanation. (shrink)

In the debate about the nature and identity of possible worlds, philosophers have neglected the parallel questions about the nature and identity of moments of time. These are not questions about the structure of time in general, but rather about the internal structure of each individual time. Times and worlds share the following structural similarities: both are maximal with respect to propositions (at every world and time, either p or p is true, for every p); both are consistent; both are (...) closed (every modal consequence of a proposition true at a world is also true at that world, and every tense-theoretic consequence of a proposition true at a time is also true at that time); just as there is a unique actual world, there is a unique present moment; and just as a proposition is necessarily true iff true at all worlds, a proposition is eternally true iff true at all times. In this paper, I show that a simple extension of my theory of worlds yields a theory of times in which the above structural similarities between the two are consequences. (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)

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)

This paper establishes that the occasional identity relation and the contingent identity relation are both non-transitive and as such are not properly classified as identity relations. This is achieved by appealing to cases where multiple fissions and fusions occur simultaneously. These cases show that the contingent and occasional identity relations do not even satisfy the time-indexed and world-indexed versions of the transitivity requirement and hence are non-transitive relations.

Here I propose a coherent way of preserving the identity of material objects with the matter that constitutes them. The presentation is formal, and intended for RSL. An informal presentation is in preliminary draft! -/- Relative-sameness relations—such as being the same person as—are like David Lewis's "counterpart" relations in the following respects: (i) they may hold between objects that aren't identical (I propose), and (ii) there are a multiplicity of them, different ones of which may be variously invoked in different (...) contexts. They differ from counterpart relations, however, in that they are weak equivalence relations (transitive, symmetric and weakly reflexive). The likenesses to counterpart relations make them suitable for an analysis of de-re temporal and modal predications. The difference renders the resulting counterpart theory immune to standard criticisms of Lewis's Counterpart Theory (e.g., in Hazen 1979, and Fara and Williamson 2005). (shrink)

An alternative to the standard endurance/perdurance accounts of persistence has recently been developed: the stage theory (Sider, T. Four-Dimensionalism: an Ontology of Persistence and Time. Oxford: Oxford University Press, 2001; Hawley, K. How Things Persist. Oxford: Oxford University Press, 2001). According to this theory, a persisting object is identical with an instantaneous stage (temporal part). On the basis of Leibniz's Law, I argue that stage theorists either have to deny the alleged identity (i.e., give up their central thesis) or hold (...) that stages are both instantaneous and continuants. I subsequently show that, although stage theory is flexible enough to accommodate the latter claim, the cost for accommodating it is an excessive proliferation of persistence concepts. (shrink)

André Gallois (1998) attempts to defend the occasional identity thesis (OIT), the thesis that objects which are distinct at one time may nonetheless be identical at another time, in the face of two influential lines of argument against it. One argument involves Kripke’s (1971) notion of rigid designation and the other, Leibniz’s law (affirming the indiscernibility of identicals). It is reasonable for advocates of (OIT) to question the picture of rigid designation and the version of Leibniz’s law that these arguments (...) employ, but, the problem is, some form of rigidity is required for one to affirm the occasional identity of objects, and some (restricted) version of Leibniz’s law must be conceded if identity really is involved. Gallois accordingly recommends an account of rigidity and a version of Leibniz’s law to this end.1 We find Gallois’ proposals entirely inadequate to their task. We aim in this paper is to explicate and defend an alternative approach for occasional identity theorists. We do not seek to defend (OIT) per se; our aim, rather, is simply to show that the arguments from rigid designation and Leibniz’s law are inconclusive. Let’s begin with an outline of these arguments. (shrink)

André Gallois (1998) attempts to defend the occasional identity thesis (OIT), the thesis that objects which are distinct at one time may nonetheless be identical at another time, in the face of two influential lines of argument against it. One argument involves Kripke’s (1971) notion of rigid designation and the other, Leibniz’s law (affirming the indiscernibility of identicals). It is reasonable for advocates of (OIT) to question the picture of rigid designation and the version of Leibniz’s law that these arguments (...) employ, but, the problem is, some form of rigidity is required for one to affirm the occasional identity of objects, and some (restricted) version of Leibniz’s law must be conceded if identity really is involved. Gallois accordingly recommends an account of rigidity and a version of Leibniz’s law to this end.1 We find Gallois’ proposals entirely inadequate to their task. We aim in this paper is to explicate and defend an alternative approach for occasional identity theorists. We do not seek to defend (OIT) per se; our aim, rather, is simply to show that the arguments from rigid designation and Leibniz’s law are inconclusive. Let’s begin with an outline of these arguments. (shrink)

André Gallois’s Occasions of Identity injects a refreshing new perspective into an old debate. Actually, what is new is the advocacy of the perspective: Gallois takes up a view that many consider a non-starter, and shows this reaction to be premature. The debate is over the right way to understand the traditional puzzles involving two things being in the same place at the same time; the perspective is that identity can hold temporarily (and contingently). Suppose an amoeba, name it AMOEBA, (...) divides in two. One of the resultant amoebas, POND, lives in a pond; the other, SLIDE, is examined on a slide in a laboratory. Does AMOEBA survive this process, and if so, does it survive as POND or SLIDE? If we stipulate that POND and SLIDE are symmetrically related to AMOEBA then it seems arbitrary to identify AMOEBA with exactly one of POND and SLIDE. But we cannot identify AMOEBA with each, for then by the transitivity and symmetry of identity we would wrongly identify POND and SLIDE. We are left with the conclusion that AMOEBA is identical to neither. But this seems wrong too; surely fission does not result in death. So just what does happen to AMOEBA? How to respond to this and related cases (involving statues and their constituting hunks of matter, cats and their undetached parts, and so on) has been much discussed.1 There are many proposals, each with distinctive strengths and weaknesses. To these Gallois adds his own, which runs as follows. After division, there are two amoebas, POND and SLIDE, each of which existed before division. But it does not follow that there were two amoebas before division. Though POND and SLIDE are numerically distinct after division, they were numerically identical before division. The identity relation can hold temporarily, or occasionally, as Gallois puts it. My sense is that this sort of claim is regarded by most metaphysicians as downright wacky. And yet there is something very natural about it. Why distinguish POND and SLIDE today because they will differ tomorrow? I suspect the “wackiness” reaction has two sources, one based on Leibniz’s Law.. (shrink)

An alternative to the standard endurance/perdurance accounts of persistence has recently been developed: the stage theory (Sider, T. Four-Dimensionalism: an Ontology of Persistence and Time. Oxford: Oxford University Press, 2001; Hawley, K. How Things Persist. Oxford: Oxford University Press, 2001). According to this theory, a persisting object is identical with an instantaneous stage (temporal part). On the basis of Leibniz's Law, I argue that stage theorists either have to deny the alleged identity (i.e., give up their central thesis) or hold (...) that stages are both instantaneous and continuants. I subsequently show that, although stage theory is flexible enough to accommodate the latter claim, the cost for accommodating it is an excessive proliferation of persistence concepts. (shrink)

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)

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, 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.

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)