The thesis that there can be vague objects is the thesis that there can be identity statements which are indeterminate in truth-value (i.e., neither true nor false) as a result of vagueness (as opposed, e.g., to reference-failure), "the singular terms of which do not have their references fixed by vague descriptive means". (if this is "not" what is meant by the thesis that there can be vague objects, it is not clear what "is" meant by it.) the possibility of vague (...) objects should not be taken, in itself, to imply the more radical thesis that the identity relation can be one of "degree". one can hold that the concept of degrees of identity is absurd (how can one thing be more or less identical to another?) "and" that indeterminacy in identity is possible; hence, any incoherence in the idea of degrees of identity does not thereby undermine the idea of indeterminate identity. (shrink)

This provocative book attempts to resolve traditional problems of identity over time. It seeks to answer such questions as 'How is it that an object can survive change?' and 'How much change can an object undergo without being destroyed'? To answer these questions Professor Heller presents a theory about the nature of physical objects and about the relationship between our language and the physical world. According to his theory, the only actually existing physical entities are what the author calls 'hunks', (...) four-dimensional objects extending across time and space. This is a major contribution to ontological debate and will be essential reading for all philosophers concerned with metaphysics. (shrink)

When one considers one's own persistence over time from the first-person perspective, it seems as if facts about one's persistence are "further facts," over and above facts about physical and psychological continuity. But the idea that facts about one's persistence are further facts is objectionable on independent theoretical grounds: it conflicts with physicalism and requires us to posit hidden facts about our persistence. This essay shows how to resolve this conflict using the idea that imagining from the first-person point of (...) view is a guide to centered possibility, a type of possibility analyzed in terms of centered worlds. (shrink)

_Identity and Discrimination_, originally published in 1990 and the first book by respected philosopher Timothy Williamson, is now reissued and updated with the inclusion of significant new material. Williamson here proposes an original and rigorous theory linking identity, a relation central to metaphysics, and indiscriminability, a relation central to epistemology.__ Updated and reissued edition of Williamson’s first publication, with the inclusion of significant new material Argues for an original cognitive account of the relation between identity and discrimination that has been (...) influential in the philosophy of perception Pioneers the use of epistemic logic to solve puzzles about indiscriminability Develops the application of techniques from mathematical logic to understand issues about identity over time and across possible worlds. (shrink)

_Personal Identity and Self-Consciousness_ is about persons and personal identity. What are we? And why does personal identity matter? Brian Garrett, using jargon-free language, addresses questions in the metaphysics of personal identity, questions in value theory, and discusses questions about the first person singular. Brian Garrett makes an important contribution to the philosophy of personal identity and mind, and to epistemology.

Derek Parfit claims that we are not human beings. Rather, each of us is the part of a human being that thinks in the strictest sense. This is said to solve a number of difficult metaphysical problems. I argue that the view has metaphysical problems of its own, and is inconsistent with any psychological-continuity account of personal identity over time, including Parfit's own.

In this paper I consider an objection that friends of the Metaphysic of Temporal Parts (MTP) press against other solutions to the problem of temporary intrinsics and turn it against the MTP itself. I do not argue that the MTP must be false, nor do I argue that there are no arguments in favor of the MTP. Rather, the conclusion I draw is conditional: if the MTP provides an adequate response to the problem of temporary intrinsics, then the MTP provides (...) no reason to reject our commonsense view of the nature of material objects. (shrink)

Abstract: Presentism is the view that whatever exists presently exists. Without defending Presentism, I argue first that Presentists should be Time-Free Presentists – Presentists whose views do not imply that there exist irreducible times. Second, I argue that Presentists should accept Limited Thick Presentism, the view that 'the present' has some extension and is thereby neither durationlessly thin nor unlimitedly 'thick'. Third, before addressing several objections to Limited Time-Free Thick Presentism [LTFTP], I argue that defenders of LTFTP should accept that (...) 'temporal becoming' involves an overlapping succession of present entities, not a 'skipping' from one set of present entities to the next discrete set. (shrink)

The only anthology available on material constitution, this book collects important recent work on well known puzzles in metaphysics and philosophy of mind. The extensive, clearly written introduction helps to make the essays accessible to a wide audience.

Suppose that we repair a wooden ship by replacing its planks one by one with new ones while at the same time reconstructing it using the discarded planks. Some defenders of vague or indeterminate identity claim that: (1) although the reconstructed ship is distinct from the repaired ship, it is indeterminate whether the original ship is the reconstructed ship and indeterminate whether it is the repaired ship, and (2) the indeterminacy is due to the world and not just an imprecision (...) in the language used to describe the situation. I argue that such a description is incoherent. The argument has two features. First, it differs in spirit from Gareth Evans's more general famous proof against the possibility of indeterminate identity. This is because I rely on facts regarding counting and sets. Second, I focus on Terence Parsons's recent defence of indeterminate identity. I argue that his attempts at making sense of counting objects involving indeterminate identities fail on technical and philosophical grounds. (shrink)

Four- Dimensionalism defends the thesis that the material world is composed of temporal as well as spatial parts. This defense includes a novel account of persistence over time, new arguments in favour of the four-dimensional ontology, and responses to the challenges four- dimensionalism faces." "Theodore Sider pays particular attention to the philosophy of time, including a strong series of arguments against presentism, the thesis that only the present is real. Arguments offered in favour of four- dimensionalism include novel arguments based (...) on time travel, the debate between spacetime substantivalists and relationalists, and vagueness. Also included is a comprehensive discussion of the paradoxes of coinciding material objects, and a novel resolution of those paradoxes based on temporal counterpart theory. In conclusion Sider replies to prominent objections to four- dimensionalism, including discussion of the problem of the rotating homogenous disk. (shrink)

Absolute identity seems at first sight to be presupposed in the branch of formal logic called identity theory. Classical identity theory may be obtained by adjoining a single schema to ordinary quantification theory.

ONE KIND OF PHILOSOPHICAL PUZZLEMENT arises when we have an apparent conflict of intuitions. If we are philosophers, we then try to show that the apparent conflict of intuitions is only an apparent conflict and not a real one. If we fail, we may have to say that what we took to be an apparent conflict of intuitions was in fact a conflict of apparent intuitions, and then we must decide which of the conflicting apparent intuitions is only an apparent (...) intuition. But if we succeed, then both of the intuitions will be preserved. Since there was an apparent conflict, we will have to conclude that the formulation of at least one of the intuitions was defective. And though the formulation may be imbedded in our ordinary language, we will have to say that, strictly and philosophically, a different formulation is to be preferred. But to make it clear that we are not rejecting the intuition we are reformulating, we must show systematically how to interpret the ordinary formulation into the philosophical one. The extent to which we can show this will be one mark of our success in dealing with the philosophical puzzle. Another will be the extent to which our proposed solution contributes to the solution of still other philosophical puzzles. (shrink)

In 'Vague Identity: Evans Misunderstood' David Lewis defends Gareth Evans against a widespread misunderstanding of an argument that appeared in his article 'Can There be Vague Objects?'. Lewis takes himself to be 'defending Evans' and not just correcting a mistake; witness his remark that, 'As misunderstood, Evans is a pitiful figure: a "technical philosopher" out of control of his technicalities, taken in by a fallacious proof of an absurd conclusion'. Let me say at the outset that I take Lewis to (...) be exactly right in regarding as a misunderstanding the interpretation of Evans which he exposes as such. On Lewis's account, everything Evans says 'falls into place', and he quotes from a letter that 'settles the matter'. (shrink)

On the most popular account of material constitution, it is common for a material object to coincide precisely with one or more other material objects, ones that are composed of just the same matter but differ from it in sort. I argue that there is nothing that could ground the alleged difference in sort and that the account must be rejected.

The paper defends Gareth Evan's argument against vague identity "de re" from a criticism that quantum mechanics provides actual counter-examples to its validity. A more general version of Evans's argument is stated in which identity involving properties are not essential and it is claimed that the scientific facts as so far known are consistent with the Evansian thesis that indeterminacy in truth-value must always be due to semantic indecision.

It is tempting to think that in the case of complete spatio-temporal coincidence, the statue is identical with the constituent lump of clay. However, some philosophers have thought that accepting constitution as identity in this type of case forces one to reject the necessity of identity. I show that there is no conflict here. By distinguishing between an object's being necessarily an F and an object's being necessity identical with an F, we can see that accepting the necessity of identity (...) does not, and should not, compel one to reject constitution as identity. (shrink)

The following quotation, from Frank Jackson, is the beginning of a typical exposition of the debate between those metaphysicians who believe in temporal parts, and those who do not: The dispute between three-dimensionalism and four-dimensionalism, or more precisely, that part of the dispute we will be concerned with, concerns what persistence, and correllatively, what change, comes to. Three-dimensionalism holds that an object exists at a time by being wholly present at that time, and, accordingly, that it persists if it is (...) wholly present at more than one time. For short, it persists by enduring. Four-dimensionalism holds that an object exists at a time by having a temporal part at that time, and it persists if it has distinct temporal parts at more than one time. For short, it persists by perduring. In the light of these comments, some readers will perhaps find the question that forms the title of this paper a little puzzling. They may have learned to use the terms ‘fourdimensionalism’ ‘perdurantism’ and ‘belief in temporal parts’ interchangeably; or perhaps even to define one in terms of the other. Such a usage, however, is inapposite. We might imagine a Flatland-like world of two spatial dimensions and one temporal, whose philosophers are divided between a theory of persistence on which they persist by having temporal parts, and a theory on which they persist by being wholly located in each of several times. This is just the same issue we face, but at least the label ‘four-dimensionalism’ seems inapposite: the four-dimensionalist Flatlanders believe in only three dimensions! (shrink)

In this paper I present a new definition of endurance. I argue that the three-dimensionalist ought to adopt a different understanding from the four-dimensionalist, of what it is to have a part simpliciter. With this new understanding it becomes possible to define endurance in a manner that both preserves the central endurantist intuitions, whilst avoiding commitment to any controversial metaphysical theses. Furthermore, since this endurantist definition is a mereological one, there is an elegant symmetry between the definitions of endurance and (...) perdurance in that the theories of three- and four-dimensionalism are both expressed in the language of mereology. Nevertheless, though both definitions are expressed within the same broad language, some of the terms of that language have subtly different meanings within the context of each theory. It is in understanding on the one hand that each theory is essentially a mereological theory and that therefore each shares some underlying theoretical similarities, and yet also that there are some subtle differences in the way each theory understands some of the terms of mereology, that allows us to see clearly what lies at the heart of the debate between these two accounts of persistence. (shrink)

Two things become one thing, something having parts, and something becoming something else, are cases of many things being identical with one thing. This apparent contradiction introduces others concerning transitivity of identity, discernibility of identicals, existence, and vague existence. I resolve the contradictions with a theory that identity, number, and existence are relative to standards for counting. What are many on some standard are one and the same on another. The theory gives an account of the discernibility of identicals using (...) phrases like “insofar as”. And it holds that standards for counting remain or shift depending on our purposes. (shrink)

It may be that all that matters for the modalities, possibility and necessity, is the object named by the proper name, not which proper name names it. An influential defender of this view is Saul Kripke. Kripke’s defense is criticized in the paper.

Attacks on ?closest continuer? and ?best candidate? theories of identity have something correct in them while still failing to discredit the theories they oppose. What follows from Noonan's and Wiggins's objections to such theories is that they need to be so formulated as not to deny the necessity of identity. The best metaphysics for best?candidate theories to adopt is one in which everyday objects are taken to transcend, in a certain sense, their life histories in given worlds. This metaphysics also (...) has the potential for solving problems about contingent identity, transworld identity, and the issue of haecceitism or individual essence. To develop the metaphysics, it is only necessary to follow through the analogy between worlds and times suggested by writers like Plantinga and Schlesinger. (shrink)

Williams (1970) argues that our intuitions about personal identity vary depending on how a given thought experiment is framed. Some frames lead us to think that persistence of self requires persistence of one's psychological characteristics; other frames lead us to think that the self persists even after the loss of one's distinctive psychological characteristics. The current paper takes an empirical approach to these issues. We find that framing does affect whether or not people judge that persistence of psychological characteristics is (...) required for persistence of self. Open-ended, abstract questions about what is required for survival tend to elicit responses that appeal to the importance of psychological characteristics. This emphasis on psychological characteristics is largely preserved even when participants are exposed to a concrete case that yields conflicting intuitions over whether memory must be preserved in order for a person to persist. Insofar as our philosophical theory of personal identity should be based on our intuitions, the results provide some support for the view that psychological characteristics really are critical for persistence of self. (shrink)

Vagueness is currently the subject of vigorous debate in the philosophy of logic and language. Vague terms -- such as 'tall', 'red', 'bald', and 'tadpole' -- have borderline cases ; and they lack well-defined extensions. The phenomenon of vagueness poses a fundamental challenge to classical logic and semantics, which assumes that propositions are either true or false and that extensions are determinate.This anthology collects for the first time the most important papers in the field. After a substantial introduction that surveys (...) the field, the essays form four groups, starting with some historically notable pieces. The 1970s saw an explosion of interest in vagueness, and the second group of essays reprints classic papers from this period. The following group of papers represent the best recent work on the logic and semantics of vagueness. The essays in the final group are contributions to the continuing debate about vague objects and vague identity. (shrink)

Bishop Butler objected to Locke's theory of personal identity on the grounds that memory presupposes personal identity. Most of those sympathetic with Locke's account have accepted Butler's criticism, and have sought to devise a theory of personal identity in the spirit of Locke's that avoids Butler's circularity objection. John McDowell has argued that even the more recent accounts of personal identity are vulnerable to the kind of objection Butler raised against Locke's own account. I criticize McDowell's stance, drawing on a (...) distinction introduced by Annalisa Coliva between two types of immunity to error through misidentification. (shrink)

Our world is a world of change. Children are born and grow into adults. Material possessions rust and decay with age and ultimately perish. Yet scepticism about change is as old as philosophy itself. Heraclitus, for example, argued that nothing could survive the replacement of parts, so that it is impossible to step into the same river twice. Zeno argued that motion is paradoxical, so that nothing can alter its location. Parmenides and his followers went even further, arguing that the (...) very concept of qualitative change is inconsistent. Change in any respect is impossible, they argued, as change requires difference and nothing differs from itself. Few today would accept the Eleatic conclusion that change is impossible. But the topic of change continues to be a source of much debate, as it brings together various issues that are central to metaphysics, language, and logic – including identity, persistence, time, tense, and temporal logic. Author Recommends Wasserman, Ryan. 'The Problem of Change.' Philosophy Compass 1 (2006): 1–10. This article presents the problem of change and provides a brief survey of potential solutions. Haslanger, Sally. 'Persistence Through Time.' The Oxford Handbook of Metaphysics . Eds. M. Loux and D. Zimmerman. Oxford: Oxford University Press, 2003. This article presents the problem of change and provides a detailed survey of potential solutions. Heller, Mark. 'Things Change.' Philosophy and Phenomenological Research 52 (1992): 695–704. This article presents, explains, and defends the temporal parts solution to the problem of change. Hinchliff, Mark. 'The Puzzle of Change.' Philosophical Perspectives 10 (1996): 119–36. This article presents, explains, and defends the presentist solution to the problem of change. Wasserman, Ryan. 'The Argument from Temporary Intrinsics.' Australasian Journal of Philosophy 81 (2003): 413–19. This article presents, explains, and defends the relationist solution to the problem of change. Sider, Theodore. Four-Dimensionalism . Oxford: Oxford University Press, 2001. This book provides an introduction to various issues related to the problem of change, including the nature of time, tense, and persistence. Chapter 5 presents, explains, and defends the stage-view solution to the problem of change. Online Materials Change. URL: http://plato.stanford.edu/entries/change/ The Stanford Encyclopedia of Philosophy entry on change, by Chris Mortensen. Time. URL: http://plato.stanford.edu/entries/time/ The Stanford Encyclopedia of Philosophy entry on time, by Ned Markosian. Temporal Parts. URL: http://plato.stanford.edu/entries/temporal-parts/ The Stanford Encyclopedia of Philosophy entry on temporal parts, by Katherine Hawley. Material Constitution. URL: http://plato.stanford.edu/entries/material-constitution/ The Stanford Encyclopedia of Philosophy entry on material constitution, by Ryan Wasserman. Persistence Bibliography. URL: http://tedsider.org/teaching/pp_bibliography.pdf A bibliography on change and related issues, by Theodore Sider. Sample Syllabus Books on Syllabus Rea, Michael. Material Constitution: A Reader . Lanham: Rowman & Littlefield, 1997. Sider, Theodore. Four-Dimensionalism . Oxford: Oxford University Press, 2001. van Inwagen, P. and Zimmerman, D. 2008. Metaphysics: The Big Questions . 2nd ed. Oxford: Blackwell, 2008. Week 1: Time and Tense Four-Dimensionalism , chapters 1 and 2. Markosian, Ned. 'A Defence of Presentism.' Oxford Studies in Metaphysics, Volume 1. Ed. D. Zimmerman. Oxford: Oxford University Press, 2004: 47–82. In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 116-123. In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 124-129. Week 2: Time and Persistence Four-Dimensionalism , chapter 3. McGrath, Matthew. 'Temporal Parts.' Philosophy Compass 2 (2007): 730–48. In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 265-267. Hawthorne, J, Scala, M., and Wasserman, R. 'Recombination, Humean Supervenience, and Causal Constraints: An Argument for Temporal Parts?' Oxford Studies in Metaphysics , Volume 1. Ed. D. Zimmerman, Oxford: Oxford University Press, 2004: 301-318. Week 3: Change and Presentism In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 141-149. In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 267-269. In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 269-281. Week 4: Change and Temporal Parts Four-Dimensionalism , pp. 92–8. Heller, Mark. 'Things Change.' Philosophy and Phenomenological Research 52 (1992): 695–704. Lombard, Lawrence. 'The Doctrine of Temporal Parts and the "No Change" Objection.' Philosophy and Phenomenological Research 54 (1994): 365–72. Week 5: Change, Relationism, and Adverbialism Hawley, Katherine. 'Why Temporary Properties are not Relations between Physical Objects and Times.' Proceedings of the Aristotelian Society 98 (1998): 211–16. Wasserman, Ryan. 'The Argument from Temporary Intrinsics.' Australasian Journal of Philosophy 81 (2003): 413–19. Lewis, David. 'Tensing the Copula.' Mind 111 (2002): 1–13. Caplan, Ben. 'Why so Tense about the Copula?' Mind 114 (2007): 703–8. Week 6: Change and Tropes Ehring, Douglas. 'Lewis, Temporary Intrinsics and Momentary Tropes.' Analysis 57 (1997): 254–8. MacBride, Fraser. 'Four New Ways to Change Your Shape.' Australasian Journal of Philosophy 79 (2001): 81–9. Simons, Peter. 'On Being Spread Out in Time: Temporal Parts and the Problem of Change.' Existence and Explanation . Eds. W. Spohn, B.C. van Fraassen, and B. Skyrms. Dordrecht: Kluwer, 1991: 131-147. Weeks 7 and 8: Special Topic – Material Change Four-Dimensionalism , chapter 5. Selections from Material Constitution: A Reader. Week 9: Special Topic – Change of Position In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 186-195. In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 195-215. Week 10: Special topic – Changing the Past In van Inwagen, P. and Zimmerman, D. Metaphysics: The Big Questions. 2nd ed. Oxford: Blackwell, 2008: 224-235. van Iwagen, Peter. 'Changing the Past.' Oxford Studies in Metaphysics , Volume 5 . Ed. D. Zimmerman. Oxford: Oxford University Press, 2009: 1-22. Hudson, H. and Wasserman, R. 'Van Inwagen on Time Travel and Changing the Past.' Oxford Studies in Metaphysics , Volume 5. Ed. D. Zimmerman. Oxford: Oxford University Press, 2009: 41-49. (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)

Some have concluded that the only appropriate response to the problem of temporary intrinsics is the view that familiar, concrete objects persist through time by perduring, that is, by having temporal parts. Many, including myself, believe this view of persistence is false, and so reject this conclusion. However, the most common attempts to resolve the problem and yet defend the view that familiar, concrete objects endure are self-defeating. This has heretofore gone unnoticed. I consider the most familiar such attempts, based (...) on a strategy called tensing the copula , and present a general argument to demonstrate why this strategy – and any strategy based on relativization – fails. I then show how the considerations raised in this general argument undermine other attempts to resolve the problem while denying perdurance. All these attempts are undermined by an assumption essential to the problem of temporary intrinsics, to wit, that there are many moments of time and all have the same ontological status. As long as this assumption is maintained, the only solution to the problem is that familiar, concrete objects perdure. Thus, in order to defend the view that objects persist through time by enduring, one must adopt a different metaphysics of time (viz., presentism). I conclude that it is neither unreasonable nor impracticable to do so. (shrink)

David Lewis, following in the tradition of Broad, Quine and Goodman, says that change in an object X consists in X's being temporally extended and having qualitatively different temporal parts. Analogously, change in a spatially extended object such as a road consists in its having different spatial parts . The alternative to this view is that ordinary objects undergo temporal change in virtue of having different intrinsic non-relational properties at different times. They endure, remaining the same object throughout change, whereas (...) Lewis's temporally extended 4D objects perdure.It is impossible to come down on one side or the other of the endurance/perdurance debate without a clear and unambiguous understanding of what ‘endurance’ is. ‘Perdurance’ is clear enough. Every 4D object of non-zero temporal thickness perdures simply by having temporal extension, i.e. by having different temporal parts, or stages, at different times. But Lewis muddies the waters by giving a confused and ultimately untenable definition of endurance.His first step is to cover both perduring and enduring by offering the neutral word persist. ‘Let us say that something persists iff, somehow or other, it exists at various times’ . Something then perdures if it persists by having different temporal parts at different times, no one part being wholly present at more than one time. In contrast, a thing endures if it persists by being wholly present at more than one …. (shrink)

In metaphysics, the view that material constitution is transitive is ubiquitous, an assumption expressed by both proponents and critics of constitution views. Likewise, it is typically assumed within the philosophy of mind that physical realization is a transitive relation. In both cases, this assumption of transitivity plays a role in discussion of the broader implications of a metaphysics that invokes either relation. Here I provide reasons for questioning this assumption and the uses to which this appeal to transitivity is put. (...) As my title suggests, I shall focus on the case of material constitution, using a brief discussion of realization at the outset to motivate the discussion of the transitivity of material constitution at the core of the paper. (shrink)