The distinction between the mental and the physical is central both to commonsense thinking about the world and to many philosophical, scientific, and religious theories. Perhaps it is as important to human thought as the distinction between fact and value, and between the empirical and the a priori. This entry will focus both on the role of the distinction in analytic philosophy and on various proposals about how it is to be understood.

The mental/physical distinction plays a role in two main areas of philosophy. First, in philosophy of mind, many arguments and issues are formulated in terms of it. Philosophers who advance physicalist theories about the mind argue that phenomenal consciousness (for example) is a physical phenomenon similar in kind to electricity or sexual reproduction; dualists deny this, saying that what we have here are two fundamentally different sorts of thing or two different...