What we think of as the “mind” is little more than an illusion. That’s the provocative thesis of British philosopher Gilbert Ryle’s 1949 work The Concept of Mind.

Seventeenth-century French writer René Descartes, one of the fathers of philosophy, imagined the mind and body as two separate entities that combine to form a human being. This concept came to be called “mind-body dualism.” Ryle set about ridiculing Descartes’s idea of, as he put it, a “ghost in the machine” stating that it was “entirely false, and false not in detail but in principle … not merely an assemblage of particular mistakes. It is one big mistake and a mistake of a special kind.”

Ryle argues that our distinction between concepts pertaining to the mind and others pertaining to matter arise from a problematic use of language (and particularly through what he calls “category mistakes”).

In The Concept of Mind, his best-known and most important book, Ryle establishes a new branch of philosophy, “the philosophy of mind.” The work remains an important statement in mid-twentieth-century philosophy.