Abstract

I develop an approach to the interpretation and evaluation of Cartesian dualism which stresses the central role that Descartes's mechanistic science plays in its development. Descartes's contention that mind and body are distinct, I argue, is analogous to the contention in Aristotelian psychology that nous is distinct from other parts of soul, such as those governing nutrition and growth. The innovation of Cartesian psychology lies both in its commitment to the separability of pure intellect, and in its commitment to mechanistic physiology as a legitimate mode of psychological explanation. Descartes's defense of dualism is grounded in the attempt to demonstrate that because the pure intellect can function independently of other forms of cognition, such as those involved in sense and imagination, it is separable from body. The demonstration of the separability of pure intellect, however, is closely linked to the argument that humans exhibit capacities, such as the ability to use language, which are not and cannot be explained by reference to any possible machine which is identical with its body. Descartes offers both empirical and metaphysical reasons for asserting that the potential for supplying mechanistic explanations of human activity is limited in this way. His empirical reasons, though now outdated, reflect a deep commitment to the hypothetico-deductive method of scientific inquiry. His metaphysical reasons reflect his underlying beliefs regarding the role of the meditating ego in the construction of mechanistic science and his belief in the possibility of a priori knowledge of the nature of extended substance and the laws governing its motion