Biologising Consciousness I. Evolutionary Theories

Abstract

In this chapter and the next, I want to examine the belief that consciousness is, in Paul Churchland’s words ‘a wholly natural phenomenon’¹ and that ‘conscious intelligence is the activity of suitably organised matter’. These beliefs seem to relate to two others. The first is that consciousness can be explained within the framework of evolutionary theory: as Churchland puts it, ‘the sophisticated organisation responsible for [conscious] intelligence is, on this planet at least, the outcome of billions of years of chemical, biological, and neurophysiological evolution’. The second is that consciousness is explained by, or even identical with, processes occurring in a particular biological structure — the brain — and that these processes are the result of a causal chain of events originating in the perceived object. Both beliefs assume, or are imbued with the assumption, that consciousness can be understood in terms of the purposes it serves. The idea that consciousness exists because it serves a purpose is explicit in the evolutionary account of it (which I shall examine in this chapter); but it is also implicitly present in impingement or causal theories of consciousness (which I shall examine in the next).