Cartesian dualism was Descartes's principle of the separation of mind and matter and mind and body. The mind, according to Descartes, was a "thinking thing", and an immaterial substance. This "thing" was the essence of himself, the part that doubts, believes, hopes, and so on. The body is a material substance.

The central claim of Cartesian dualism is that the immaterial mind and the material body causally interact. Mental events cause physical events, and vice versa. This leads to the most substantial claim AGAINST Cartesian dualism. How can an immaterial mind cause anything in a material body, and vice versa? This is called the "problem of interactionism."

For this reason and others, most professional philosophers and scientists have abandoned this view and proffer more competent accounts of the mental. For example, mind-body problem presents competing philosophical positions and cognitive science generally assumes that mind is constructed from matter.

See also: dualism, mind dualism.