The phrase 'the ghost in the machine' was coined by Gilbert Ryle in his 1949 book The Concept of Mind, and was intended to point out the absurdity of traditional Cartesian mind-body dualism; presumably there was also an attempt to echo the phrase deus ex machina, or “god from the machine”, i.e. an artificial solution to a complex problem. Koestler, in writing The Ghost in the Machine in 1967, appropriated Ryle's phrase, although he had a pretty low opinion of Ryle himself — he dismissed him as a 'snickering' Oxford don with no knowledge of any of the sciences that would have given his ideas more weight. Ryle nevertheless had the philosopher's gift for analogy, and used a number of metaphors for the mind-body problem, all of which could have supplied titles: they included 'the sealed signal box', 'the two parallel theatres' and 'the horse in the locomotive'.
