mind–body problem

A central problem in philosophy, concerning what mind is and how it relates to the body. Answers range from idealist views that only the mind is real to materialist views that the body alone is real or that mental phenomena are identical with certain physical ones.

The idealist and the materialist views are both monist views – that is, that body and mind are one substance (monism). Other monist views are Aristotelianism (that the mind is to the body as form is to matter), neutral monism (English philosopher Bertrand Russell's theory that physical and mental phenomena can be analysed in terms of a common underlying reality), and the double-aspect theory (that mind and matter as a whole are two aspects of a single substance). The double-aspect theory can refer either to individual minds and their corresponding bodies or to mind and matter as a whole; the latter view was advanced by Baruch Spinoza.

Dualism asserts the distinctness of mind and body. French philosopher René Descartes's Cartesian dualism is a type of interactionism – proposing that mind and body are different substances but still interact. There are several other dualist theories. Epiphenomenalism is the theory that mind has distinctive and irreducible qualities but no power over the body. Psychophysical parallelism is the theory that every mental event has a physical counterpart, and vice versa, but that mind and body do not interact. A version of psychophysical parallelism is occasionalism, the theory put forward by Belgian philosopher Arnold Geulincx that body and mind do not interact but are synchronized by God.