An elementary mathematical proof is offered that mental states cannot be either intensionally or extensionally identical with brain states. the proof consists in taking a subset of mental states, namely, possible thoughts of integers and showing that this set has the cardinal number aleph null; then taking the largest physically possible set of brain states k and the number of subsets of k which is 2 to the power k, and which, no matter how large, is necessarily finite. it follows (...) that these two sets cannot correspond one to one from which it then follows that they cannot have identical elements. i conclude with answers to likely objections and with a denial that my argument supports traditional dualism. (shrink)

A transcript of three lectures, given at Princeton University in 1970, which deals with (inter alia) debates concerning proper names in the philosophy of language.

In a previous article, Professor abelson contended that the mind-Body identity theory was 'mathematically impossible' inasmuch as the number of possible mental states of a finite thinking organism are infinite, While the number of possible bodily states of such an organism are necessarily finite. I argue that this refutation does not succeed because although it is true that a finite brain can have only a finite number of brain states, Abelson had not demonstrated that there was a limitation on what (...) type of brain state could be generated by a finite brain. Thus, For instance, Although the number of natural numbers that such a brain could think of was necessarily finite, This in itself did not militate against the possibility of the brain producing a brain state corresponding to any natural number, Out of a possible infinite set, That can be thought of. (shrink)

The principle of charity (“Charity”), in one form or other, is held by many and for various reasons. After cataloging discernible kinds of Charity, I focus on the most familiar versions as found in Davidson, Dennett, Devitt, Lewis, Putnam, Quine, Stich, and others. To begin with, I argue that such versions of Charity are untenable because beliefs cannot be counted, and even if they could be counted there is reason to believe that true beliefs need not outnumber false beliefs. Next (...) I rebut one of the arguments behind Charity, the intelligibility argument. If indeed beliefs are postulated simply as a way to make some system intelligible (predictable and explicable) then a number of theses ensue. First, it would be perfectly intelligible to ascribe mostly false beliefs to an intentional system, or even entirely false beliefs. Second, lower animals would have beliefs. Third, it would sometimes make sense to ascribe beliefs even to inanimate beings. And fourth, the resulting indeterminacy of belief-ascription would suggest a kind of irrealism about belief which may in turn be expressed by the slogan that rejects the container metaphor of the mind. (shrink)

Plena are large-scale macro-totalities appropriate to the realms of all facts, all truths, and all things. Our attempt here is to take some first technical steps toward an adequate conception of plena.

This is the second volume of philosophical essays by one of the most innovative and influential philosophers now writing in English. Containing thirteen papers in all, the book includes both new essays and previously published papers, some of them with extensive new postscripts reflecting Lewis's current thinking. The papers in Volume II focus on causation and several other closely related topics, including counterfactual and indicative conditionals, the direction of time, subjective and objective probability, causation, explanation, perception, free will, and rational (...) decision. Throughout, Lewis analyzes global features of the world in such a way as to show that they might turn out to supervene on the spatiotemporal arrangement of local qualities. (shrink)

Tn this paper I explore and to an extent defend HS. The main philosophical challenges to HS come from philosophical views that say that nomic concepts-laws, chance, and causation-denote features of the world that fail to supervene on non-nomic features. Lewis rejects these views and has labored mightily to construct HS accounts of nomic concepts. His account of laws is fundamental to his program, since his accounts of the other nomic notions rely on it. Recently, a number of philosophers have (...) criticized Lewis's account, and Humean accounts of laws generally, for delivering, at best, a pale imitation ofthe genuine item. These philosophers think that the notion of law needed by science requires laws-if there are any-to be fundamental features of our world that are completely distinct from and not supervenient on the particular facts that they explain. I side with Lewis against these philosophers. Here I will argue that although Lewis-laws don't fulfill all our philosophical expectations, they do play the roles that science needs laws to play. The metaphysics and epistemology of Humean laws, and more specifically, Lewis-laws, are in much better shape than the metaphysics and epistemology of the main anti-Humean alternatives. However, I do have inisgivings about Lewis's account. Both he and his critics assume that the basic properties are so individuated so that the laws are not metaphysically necessary. If this assumption is rejected, then the question of Humean supervenience lapses. I conclude with a brief discussion of this position. (shrink)

It is shown that Lewis’ ontological doctrine of Humean supervenience incorporates at its foundation the so-called separability principle of classical physics. In view of the systematic violation of the latter within quantum mechanics, the claim that contemporary physical science may posit non-supervenient relations beyond the spatiotemporal ones is reinforced on a foundational basis concerning constraints on the state representation of physical systems. Depending on the mode of assignment of states to quantum systems — unit state vectors versus statistical density operators (...) — we distinguish between strongly and weakly non-Humean, non-supervenient relations. It is demonstrated that in either case, the relations of quantum entanglement constitute prototypical examples of irreducible physical relations that do not supervene upon a spatiotemporal arrangement of Humean qualities, weakening, thereby, the thesis of Humean supervenience. In this respect, the status of Lewis’ recombination principle is examined, whereas his conception of lawhood is critically investigated. It is concluded that the assumption of ontological reductionism, as expressed in Lewis’ Humean doctrine, cannot be regarded as a reliable code of the nature of the physical world and its contents. It is proposed instead that due to the undeniable existence of non-supervenient relations, a metaphysic of relations of a moderate kind ought to be acknowledged as an indispensable part of our understanding of the natural world at a fundamental level. (shrink)

The book is an extended study of the problem of consciousness. After setting up the problem, I argue that reductive explanation of consciousness is impossible , and that if one takes consciousness seriously, one has to go beyond a strict materialist framework. In the second half of the book, I move toward a positive theory of consciousness with fundamental laws linking the physical and the experiential in a systematic way. Finally, I use the ideas and arguments developed earlier to defend (...) a form of strong artificial intelligence and to analyze some problems in the foundations of quantum mechanics. (shrink)