The Concept of Mind is the best known and the most important work of Gilbert Ryle. Ryle is thought to have accomplished two major tasks. First, he was seen to have put the final nail in the coffin of Carteisan dualism. Ryle rejects Descartes’ dualistic theory of the relation between mind and body. This doctrine of separation between mind and body is referred by Ryle as “the dogma of the ghost in the machine.” Second, he himself anticipated and suggested dualism’s replacement, the doctrine known as philosophical (sometimes analytical) behaviourism. This is an attempt of this paper is to draw outlines of his criticism of Dualism his dispositional theory of mind and how it is relevant in today’s philosophy of mind.