In philosophy of mind, mentalism is the view that the mind and mental states exist as causally efficacious inner states of persons. The view should be distinguished from substance dualism, which is the view that the mind and the body (or brain) are two distinct kinds of things which nevertheless interact with one another. Although this dualistic view of the mind-body connection entails mentalism, mentalism does not entail dualism. Jerry Fodor and Noam Chomsky have been two of mentalism's most ardent recent defenders.
In linguistic terms, Mentalism represents rationalistic philosophy (as opposed to Behaviouristic).