David Lewis (1941-2001) was Class of 1943 University Professor of Philosophy at Princeton University. His contributions spanned philosophical logic, philosophy of language, philosophy of mind, philosophy of science, metaphysics, and epistemology. In On the Plurality of Worlds, he defended his challenging metaphysical position, "modal realism." He was also the author of the books Convention, Counterfactuals, Parts of Classes, and several volumes of collected papers.

The mathematical theory of communication.

This paper presents a partial analysis of perceptual knowledge, an analysis that will, I hope, lay a foundation for a general theory of knowing. Like an earlier theory I proposed, the envisaged theory would seek to explicate the concept of knowledge by reference to the causal processes that produce (or sustain) belief. Unlike the earlier theory, however, it would abandon the requirement that a knower's belief that p be causally connected with the fact, or state of affairs, that p.

Since Edmund L. Gettier reminded us recently of a certain important inadequacy of the traditional analysis of "S knows that p," several attempts have been made to correct that analysis. In this paper I shall offer still another analysis (or a sketch of an analysis) of "S knows that p," one which will avert Gettier's problem. My concern will be with knowledge of empirical propositions only, since I think that the traditional analysis is adequate for knowledge of nonempirical truths.

In the good old days, a large part of the debate about skepticism focused on the quality of the reasons we have for believing propositions of various types. Skeptics about knowledge in a given domain argued that our reasons for believing propositions in that domain were not good enough to give us knowledge; opponents of skepticism argued that they were. The different conclusions drawn by skeptics and non-skeptics could come either from differences in their views about the standards or conditions (...) we had to satisfy in order to have knowledge or from differences in their assessments of the quality or character of the reasons we have. In recent years, discussions of skepticism have often focused on three anti-skeptical responses that don't directly address the questions about reasons or evidence that used to be considered fundamental. These anti-skeptical responses are: 1) content externalism, as proposed by Hilary Putnam1; 2) the denial of closure, as proposed by Robert Nozick2; and 3) contextualism about knowledge attributions, as proposed by Stewart Cohen, Keith DeRose, and David Lewis3. I believe that these recent responses to skepticism characteristically avoid the central epistemological issues raised by skepticism and often concede to skeptics far more than is warranted. In this paper I will examine some contextualist responses to skepticism. In Section I I describe the general idea of contextualism and its application to skepticism. In Section II I describe and briefly discuss some particular versions of contextualism. In Section III I argue that even if it is true that sentences attributing knowledge have contextually variable truth conditions, this fact does not provide the basis for a satisfactory response to skepticism. This is because the central issue raised by skepticism is whether we satisfy the standards for knowledge in place in ordinary contexts, not whether we satisfy some allegedly higher standards which, according to contextualists, are in place in some epistemological contexts. In effect, this paper is part of an argument for a return to the good old days. (shrink)

This book presents an attempt to develop a theory of knowledge and a philosophy of mind using ideas derived from the mathematical theory of communication developed by Claude Shannon. Information is seen as an objective commodity defined by the dependency relations between distinct events. Knowledge is then analyzed as information caused belief. Perception is the delivery of information in analog form for conceptual utilization by cognitive mechanisms. The final chapters attempt to develop a theory of meaning by viewing meaning as (...) a certain kind of information-carrying role. (shrink)

Nozick analyzes fundamental issues, such as the identity of the self, knowledge and skepticism, free will, the foundations of ethics, and the meaning of life.