Logical behaviourism first began as an offshoot of Logical Positivism and the philosophy of the Vienna Circle (see TOK Unit 4 and Philosophy of Religion Unit 7). It was taken up by the American philosopher Carl Hempel (b. 1905) and is apparent in the later philosophy of the Cambridge-based Austrian philosopher Ludwig Wittgenstein (1889 – 1951). At the same time in Oxford, the British philosopher Gilbert Ryle (1900 - 1976) became influenced by Wittgenstein and the new linguistic philosophy and used a largely behaviourist approach to refute the Cartesian model of the mind in his most famous work, The Concept of Mind (1945), where he called Cartesian dualism the “dogma of the ghost in the machine”.