There seem to be only two well-known theories from the history of the philosophy of mind that have not been attributed to him, namely behaviorism and functionalism. But even here one could make a case. According to Hoffman (1986) and Skirry (2003), Descartes accepted Aristotle’s theory that the soul is the form of the body. According to Kneale (1963, p. 839), the latter theory was “a sort of behaviourism”. According to Putnam (1975), Nussbaum (1978) and Wilkes (1978), it was similar to contemporary functionalism. By transitivity, one might conclude that Descartes was either a sort of behavorist or a functionalist.