This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

One of the central questions of material-object metaphysics is which highly visible objects there are right before our eyes. Daniel Z. Korman defends a conservative view, according to which our ordinary, natural judgments about which objects there are are more or less correct. He begins with an overview of the arguments that have led people away from the conservative view, into revisionary views according to which there are far more objects than we ordinarily take there to be or far fewer. (...) Korman criticizes a variety of compatibilist strategies, according to which these revisionary views are actually compatible with our ordinary beliefs. He goes on to respond to debunking arguments; objections that the conservative's verdicts about which objects that are and aren't are objectionably arbitrary; the argument from vagueness; the overdetermination argument; the argument from material constitution; and the problem of the many. (shrink)

Rose and Schaffer (forthcoming) argue that teleological thinking has a substantial influence on folk intuitions about composition. They take this to show (i) that we should not rely on folk intuitions about composition and (ii) that we therefore should not reject theories of composition on the basis of intuitions about composition. We cast doubt on the teleological interpretation of folk judgments about composition; we show how their debunking argument can be resisted, even on the assumption that folk intuitions have a (...) teleological source; and we argue that, even if folk intuitions about composition carry no weight, theories of composition can still be rejected on the basis of the intuitions of metaphysicians. (shrink)

Precis of my book by this title, for a symposium.

When do the folk think that mereological composition occurs? Many metaphysicians have wanted a view of composition that fits with folk intuitions, and yet there has been little agreement about what the folk intuit. We aim to put the tools of experimental philosophy to constructive use. Our studies suggest that folk mereology is teleological: people tend to intuit that composition occurs when the result serves a purpose. We thus conclude that metaphysicians should dismiss folk intuitions, as tied into a benighted (...) teleological view of nature. (shrink)

This chapter contains sections titled: 1 A Question about Composition 2 Some Answers 3 How Shall We Decide? 4 Common Sense and Unrestricted Composition 5 Common Sense and Compositional Nihilism 6 Compositional Nihilism and the Self 7 The Appeal to Science 8 Problem or Pseudoproblem? What To Do?

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)

Region R Question: How many objects — entities, things — are contained in R? Ignore the empty space. Our question might better be put, 'How many material objects does R contain?' Let's stipulate that A, B and C are metaphysical atoms: absolutely simple entities with no parts whatsoever besides themselves. So you don't have to worry about counting a particle's top half and bottom half as different objects. Perhaps they are 'point-particles', with no length, width or breadth. Perhaps they are (...) extended in space without possessing spatial parts (if that is possible). Never mind. We stipulate that A, B and C are perfectly simple. We also stipulate that they are connected as follows. A and B are stuck together in such a way that when a force is applied to one of them, they move together 'as a unit'. Moreover, the two of them together exhibit behavior that neither would exhibit on its own — Perhaps they emit a certain sound, or glow in the dark — whereas C is.. (shrink)

Précis for a book symposium, with contributions from Meg Wallace, Louis deRosset, and Chris Tillman and Joshua Spencer.

Region R Question: How many objects — entities, things — are contained in R? Ignore the empty space. Our question might better be put, 'How many material objects does R contain?' Let's stipulate that A, B and C are metaphysical atoms: absolutely simple entities with no parts whatsoever besides themselves. So you don't have to worry about counting a particle's top half and bottom half as different objects. Perhaps they are 'point-particles', with no length, width or breadth. Perhaps they are (...) extended in space without possessing spatial parts (if that is possible). Never mind. We stipulate that A, B and C are perfectly simple. We also stipulate that they are connected as follows. A and B are stuck together in such a way that when a force is applied to one of them, they move together 'as a unit'. Moreover, the two of them together exhibit behavior that neither would exhibit on its own — Perhaps they emit a certain sound, or glow in the dark — whereas C is.. (shrink)