We noticed that the assumption of the closure of the physical – that all physical events are caused physically – is reinforced with every bit of brain research. This assumption rules out Cartesian dualism because it rules out the thought that non-physical events are involved in causing events in the brain or anywhere else. The only varieties of dualism for which it might seem to leave room are epiphenomenalism and parallelism; and we have already noted some difficulties with those positions. Empirical facts about the brain and central nervous system, and about how bodily events are caused, thus provide a powerful motive for adopting some variety of “materialism” or “physicalism”. In this chapter we will examine a range of physicalist approaches to the mind.

What is physicalism?

Philosophy has always been concerned with the question, “How do we fit into the rest of the world?” Obviously we have a lot in common with apes, some things in common with cats and dogs, less with insects, even less with flowers and trees. As for stones, rivers, clouds, planets and other inanimate things, we appear to share only the fact that we are more or less solid and take up space and time. But as early as the fifth century BC certain Greek thinkers devised the first version of the atomic theory.

The Greeks were (rightly) perplexed by the phenomena of change such as combustion, digestion and decay.