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.

An intrinsic property, as David Lewis puts it, is a property "which things have in virtue of the way they themselves are", as opposed to an extrinsic property, which things have "in virtue of their relations or lack of relations to other things".1 Having long hair is an intrinsic property; having a long-haired brother is not. Intuitive as this notion is (and valuable in doing philosophy, I might add), it seems to resist analysis. Analysis, that is, to “quasi-logical” notions such (...) as necessity, spatiotemporal location: using stronger tools, Lewis has given an analysis of intrinsicality that I take to be roughly correct. Lewis initially described intrinsic properties in his 1983 paper "Extrinsic Properties" as follows. (shrink)

This book, one of the first full-length studies of the modalities to emerge from the debate to which Saul Kripke, David Lewis, Ruth Marcus, and others are contributing, is an exploration and defense of the notion of modality de re, the idea that objects have both essential and accidental properties. Plantinga develops his argument by means of the notion of possible worlds and ranges over such key problems as the nature of essence, transworld identity, negative existential propositions, and the existence (...) of unactual objects in other possible worlds. He also applies his logical theories to the elucidation of two problems in the philosophy of religion: the problem of evil and the ontological argument. (shrink)

Several alleged counterexamples to the definition of ‘intrinsic’ proposed in Rae Langton and David Lewis, ‘Defining “Intrinsic”’, are unconvincing. Yet there are reasons for dissatisfaction, and room for improvement. One desirable change is to raise the standard of non-disjunctiveness, thereby putting less burden on contentious judgements of comparative naturalness. A second is to deal with spurious independence by throwing out just the disjunctive troublemakers, instead of throwing out disjunctive properties wholesale, and afterward reinstating those impeccably intrinsic disjunctive properties that are (...) not troublemakers. A third, suggested by Brian Weatherson, would be to invoke the general principle that the intrinsic and the extrinsic characters of things are independent, rather than relying just on one special case of this principle; but it is none too obvious how to do this. (shrink)

Several alleged counterexamples to the definition of ‘intrinsic’ proposed in Rae Langton and David Lewis,‘Defining “Intrinsic”’, are unconvincing. Yet there are reasons for dissatisfaction, and room for improvement. One desirable change is to raise the standard of non‐disjunctiveness, thereby putting less burden on contentious judgements of comparative naturalness. A second is to deal with spurious independence by throwing out just the disjunctive troublemakers, instead of throwing out disjunctive properties wholesale, and afterward reinstating those impeccably intrinsic disjunctive properties that are not (...) troublemakers. (The second of these changes makes the first more affordable.) A third, suggested by Brian Weatherson, would be to invoke the general principle that the intrinsic and the extrinsic characters of things are independent, rather than relying just on one special case of this principle; but it is none too obvious how to do this. (shrink)

Something could be round even if it were the only thing in the universe, unaccompanied by anything distinct from itself. Jaegwon Kim once suggested that we define an intrinsic property as one that can belong to something unaccompanied. Wrong: unaccompaniment itself is not intrinsic, yet it can belong to something unaccompanied. But there is a better Kim-style definition. Say that P is independent of accompaniment iff four different cases are possible: something accompanied may have P or lack P, something unaccompanied (...) may have P or lack P. P is basic intrinsic iff (1) P and not-P are nondisjunctive and contingent, and (2) P is independent of accompaniment. Two things (actual or possible) are duplicates iff they have exactly the same basic intrinsic properties. P is intrinsic iff no two duplicates differ with respect to P. (shrink)

Dan Marshall and Josh Parsons note, correctly. that the property of being either a cube or accompanied by a cube is incorrectly classified as intrinsic under the definition we have given unless it turns out to be disjunctive. Whether it is disjunctive, under the definition we gave, turns on certain judgements of the relative naturalness of properties. They doubt the judgements of relative naturalness that would classify their property as disjunctive. We disagree. They also suggest that the whole idea of (...) judging relative naturalness is a dubious business. We reply that, like them or not, such judgements cannot easily be avoided. (shrink)

This is a collection of twenty-five papers and reviews by the leading analytic philosopher of our time. It adds to the papers on metaphysics and epistemology to be found in his previous two-volume collection published by Oxford University Press. One previously unpublished paper—“Why Conditionalize?”—is included. Australasian philosophers may note with some pride that eleven of the pieces were first published in the Australasian Journal of Philosophy.

This volume is devoted to Lewis's work in metaphysics and epistemology. Topics covered include properties, ontology, possibility, truthmaking, probability, the mind-body problem, vision, belief, and knowledge. The purpose of this collection, and the volumes that precede and follow it, is to disseminate more widely the work of an eminent and influential contemporary philosopher. The volume will serve as a useful work of reference for teachers and students of philosophy.