Online research in philosophy

This is a book about sensory states and their apparent characteristics. It confronts a whole series of metaphysical and epistemological questions and presents an argument for type materialism: the view that sensory states are identical with the neural states with which they are correlated. According to type materialism, sensations are only possessed by human beings and members of related biological species; silicon-based androids cannot have sensations. The author rebuts several other rival theories (dualism, double aspect theory, eliminative materialism, functionalism), and explores a number of important issues: the forms and limits of introspective awareness of sensations, the semantic properties of sensory concepts, knowledge of other minds, and unity of consciousness. The book is a significant contribution to the philosophy of mind, and has much to say to psychologists and cognitive scientists.

Are sensation ascriptions descriptive, even in the first person present tense? Do sensation terms refer to, denote, sensations, so that truth and falsity of sensation ascriptions depend on the properties of the denoted sensations? That is, do sensation terms have a denotational semantics? As I understand it, this is denied by Wittgenstein. Wittgenstein rejects the idea of a denotational semantics for public language sensation terms, such as.

Some materialists argue that we can eliminate mental entities such as sensations because, like electrons, they are theoretical entities postulated as parts of scientific explanations, but, unlike electrons, they are unnecessary for such explanations. As Quine says, any explanatory role of mental entities can be played by "correlative physiological states and events instead." But sensations are not postulated theoretical entities. This is shown by proposing definitions of the related terms, 'observation term,' and 'theoretical term,' and then classifying the term 'sensation.' The result is that although 'sensation' is a theoretical term, it is also a reporting term because it is used to refer to phenomena we are aware of. Consequently sensations are not postulated and cannot be eliminated merely because they are unnecessary for explanation.

The 1960s saw heated discussion of Eliminative Materialism in regard to sensations and their phenomenal features. Thus directed, Eliminative Materialism is materialism or physicalism plus the distinctive and truly radical thesis that there have never occurred any sensations; no one has ever experienced a sensation. This view attracted few adherents(!), though to this day some philosophers are Eliminativists with respect to various alleged phenomenal features of sensations.

My aim in this paper is to defend a version of the brain process theory, or identity thesis, which differs in one important respect from the theory put forward by J.J.C. Smart. I shall argue that although the sensations which a person experiences are, as a matter of contingent fact, brain processes, nonetheless there are facts about sensations which cannot be described or understood in terms of any physical theory. These 'mental' facts cannot be described by physics for the simple reason that physical descriptions are designed specifically to avoid mentioning such facts. Thus in giving a physical explanation of a sensation we necessarily describe and render intelligible that sensation only as a physical process, and not also as a sensation. If we are to describe and render intelligible a person's sensations, or inner experiences, as sensations, and not as physical processes occurring in that person's brain, then we must employ a kind of description that connot be derived from any set of physical statements.

D. M. Armstrong proposes to explain the possibility of unconscious sensations by means of a distinction between the perceptual consciousness, which is essentially involved in sensations, and our introspective consciousness of sensations. He holds that unconscious sensations are instances of perceptual consciousness of which we are not introspectively conscious. I contend that, although Armstrong''s distinction is plausible and significant, it fails to explain his own examples of unconscious sensation. I argue that the puzzle of how unconscious sensations are possible arises at the level of perceptual consciousness and does not concern our introspective awareness of mental states.