Knowledge argument

Abstract: J n “Naming and Necessity”1 and “Identity and Necessity,”2 Kripke presents a version of the Cartesian argument against mate­ rialism. His argument involves two central claims: first, that all identity state­ ments using rigid designators on both sides of the identity sign are, if true at all, true in all possible worlds where the terms refer; second, that psycho-physical identity statements are conceivably false, and therefore, by the first claim, actually false. My purpose in this paper is to transform Kripke’s argument from a metaphysical one into an epistemological one. My general point is this. Kripke relies upon a particular intuition regarding conscious experience to support his second claim. I find this intuition important, not least because of its stubborn resistance to philosophical dissolution. But I don’t believe this intuition supports the meta­ physical thesis Kripke defends—namely, that pyscho-physical identity statements must be false. Rather, I think it supports a closely related epistemological thesis— namely, that psycho-physical identity statements leave a significant explanatory gap, and, as a corollary, that we don’t have any way of determining exactly which psycho-physical identity statements are true.3 One cannot conclude from my version of the argument that materialism is false, which makes my version a weaker attack than Kripke’s. Nevertheless, it does, if correct, constitute a problem for materialism, and one that I think better captures the uneasiness many philos­ ophers feel regarding that doctrine. I will present this epistemological argument by starting with Kripke’s own argument and extracting the underlying intuition. For brevity’s sake, I am going to assume knowledge of Kripke’s general position concerning necessity and the theory of reference, and concentrate only on the argument against materialism. To begin with, let us assume that we are dealing with a physicalist type-identity theory. That is, our materialist is committed to statements like: (1) Pain is the firing of C-fibers. On Kripke’s general theory, if (1) is true at all it is necessarily true. The same of course, is the case with the following statement: (2) Heat is the motion of molecules. That is, if (2) is true at all it is necessarily true. So far so good.

Abstract: Experiences and feelings are inherently conscious states. There is something it is like to feel pain, to have an itch, to experience bright red. Philosophers call this sort of consciousness "phenomenal consciousness." Even though phenomenal consciousness seems to be a relatively primitive matter, something more widespread in nature than higher-order or reflective consciousness, it is deeply puzzling. In 1995 Michael Tye proposed a theory of phenomenal consciousness now known as representationalism. This book is, in part, devoted to a further development of that theory along with replies to common objections. Tye's focus is broader than representationalism, however. Two prominent challenges for any reductive theory of consciousness are the explanatory gap and the knowledge argument. In part I of this book, Tye suggests that these challenges are intimately related. The best strategy for dealing with the explanatory gap, he claims, is to consider it a kind of cognitive illusion. Part II of the book is devoted to representationalism. Part III connects representationalism with two more general issues. The first is the nature of color. Tye defends a commonsense, objectivist view of color and argues that such a view is compatible with modern color science. In the final chapter, Tye addresses the question of where on the phylogenetic scale phenomenal consciousness ceases, arguing that consciousness extends beyond the realm of vertebrates to such relatively simple creatures as the honeybee.

Abstract: Many philosophers are impressed by the progress achieved by physical sciences. This has had an especially deep effect on their ontological views: it has made many of them physicalists. Physicalists believe that everything is physical: more precisely, that all entities, properties, relations, and facts are those which are studied by physics or other physical sciences. They may not all agree with the spirit of Rutherford's quoted remark that 'there is physics; and there is stamp-collecting',' but they all grant physical science a unique ontological authority: the authority to tell us what there is. Physicalism is now almost orthodox in much philosophy, notably in much recent philosophy of mind. But although often invoked, it is rarely explicitly defined. It should be. The claim that everything is physical is not as clear as it seems. In this paper, we examine a number of proposed definitions of physicalism and reasons for being a physicalist. We will argue both that physicalism lacks a clear and credible definition, and that in no non-vacuous interpretation is it true. We are concerned here only with physicalism as a doctrine about the empirical world. In particular, it should not be confused with nominalism, the doctrine that there are no universals.2 Nominalism and physicalism are quite independent doctrines. Believers in universals may as consistently assert as deny that the only properties and relations are those studied by physical science. And nominalists may with equal consistency assert or deny that physical science could provide enough predicates to describe the world. That is the question which concerns physicalists, not whether physical predicates name real universals. (We will for brevity write as if they do, but we do not need that assumption.) As we will understand it, then, physicalism is not a doctrine about universals or other abstract objects, but about the empirical world, and specifically about minds. It says that mental entities, properties, relations and facts are all really physical. The mental is physicalism's chief target; but one we think it does not hit. Physicalism is a kind of monism, opposing the dualist's distinction between two kinds of substance: matter and mind. As such, it is descended