Nigel Thomas

Philosopher's zombies are hypothetical beings behaviorally, functionally, and perhaps even physically indistinguishable from normal humans, but who lack our consciousness. Many people seem to be convinced that such zombies are a real conceptual possibility, and that this bare possibility entails that understanding human consciousness must remain forever beyond the reach of science. However, the conceptual entailments of zombiehood have not been sufficiently examined. This brief article shows that any way of understanding the behavior of zombies that does in fact support the suggested entailment, leads to contradictions and absurdities. Zombies are _not_ conceptually possible

Commentary on "On Specification and the Senses," by Thomas A. Stoffregen and Benoît G. Bardy: Behavioral and Brain Sciences, 24, 195-261 (2001).
The target article's value lies not in its defence of specification, or the "global array" concept, but in its challenge to the paradigm of 5+ senses, and its examples of multiple receptor types cooperatively participating in specific information pick-up tasks. Rather than analysing our perceptual endowment into 5+ senses, it is more revealing to type perceptual systems according to task.

The concepts of imagination and consciousness have, very arguably, been inextricably intertwined at least since Aristotle initiated the systematic study of human cognition (Thomas, 1998). To imagine something is ipso facto to be conscious of it (even if the wellsprings of imaginative creativity are in the unconscious), and many have held that our conscious thinking consists largely or entirely in a succession of mental images, the products of imagination (see, e.g., Damasio, 1994 -- or, come to that, see Aristotle, or Hume, or almost any pre-twentieth century cognitive theorist). A venerable tradition also regards perceptual experiences, the main focus of most recent work on consciousness, as products of the imagination, whose primary function is to integrate sensory inputs and render them meaningful (Thomas, 1998, 1999). As Coleridge (1817) famously put it, primary imagination is "the living power and prime agent of all human perception." A better understanding of imagination is likely to deepen our insight into the nature of consciousness (and, probably, vice-versa)

Stich & Ravenscroft (1994) have argued that (contrary to most people's initial assumptions) a simulation account of folk psychology may be consistent with eliminative materialism, but they fail to bring out the full complexity or the potential significance of the relationship. Contemporary eliminativism (particularly in the Churchland version) makes two major claims: the first is a rejection of the orthodox assumption that realistically construed propositional attitudes are fundamental to human cognition; the second is the suggestion that with the advancement of scientific understanding of the mind it will be possible to entirely eliminate the mentalistic and intentional from our ontology, thus dissolving the mind-body problem. The first claim (which has been argued in detail) supplies the principal grounds for accepting the second, much more ambitious and significant, claim. Robert Gordon's (1995, 1996, 2000) radical simulation theory of "folk psychology", proposed initially (Gordon, 1986) as an alternative to "theory theory" accounts of self and interpersonal understanding, but subsequently developing into a quite general challenge to symbolic computational accounts of mind, is not merely consistent with, but actually provides considerable additional support for, the first eliminativist claim. However, although radical simulationism has no use for reified propositional attitudes, it relies on another family of mentalistic and intentional notions, including perspective taking, "seeing as", pretending, imagery, and, most centrally, imagination. It is thus inconsistent with eliminativist metaphysical ambitions. Nevertheless, from this perspective the mind-body problem is transformed. Its solution no longer depends on accounting directly for the intentionality of the attitudes, but rather on accounting for the intentionality of imagination. Although standard accounts of imagination derive its intentionality from that of the attitudes, the recently proposed "perceptual activity" theory of imagery and imagination (Thomas, 1999) can provide a direct account of the intentionality of imagination that is consistent with physicalism..