The most central capacities of the self are its capacities for perception, action, thought and self-knowledge, and the remaining chapters of this book deal with each of these in turn. In each case, I present an account of the capacity in question in terms which assign a fundamental role to the conscious states of the subject and their causal relations both with one another and with physical states of the self's body and environment. In this chapter, I make a start with perception – in some ways the most primitive of the self's capacities (being shared with many of the lower animals), but in others the most remarkable and puzzling. It is my belief that, provided certain logical and conceptual distinctions are properly observed and due cognizance is taken of relevant empirical evidence, it is possible to defend a theory of perception which is at once a causal theory, a representative theory and a direct realist theory (direct realist inasmuch as it does not postulate mental entities as the immediate objects of perception). The theory that I shall be defending in this chapter possesses all three of these features. The three features are not irreconcilable, as may commonly be supposed, and indeed I believe that only by combining them can an account of perception be given which is at once naturalistic and philosophically tenable.

1. PERCEPTION AND PERCEPTUAL EXPERIENCE

I consider it vital, in the philosophy of perception, to recognize the conceptual distinction between perceiving and having perceptual experiences. One may – for instance, when undergoing a hallucination – have a perceptual experience and yet not be perceiving; or so I would claim.