Abstract: Descartes argues that no explanation of any phenomenon may assume or merely re-describe what needs to be explained. He cannot, therefore, propose substance dualism as a theory of mind. To explain mental activities such as sensation, memory, or imagination, one must hypothesize how they result from interaction between the environment, the senses, and the processing of the brain. Descartes initiated such a naturalized account. However, given the state of neurology in the seventeenth century, his efforts were doomed. The failure to construct a scientific theory that bridges the theoretical gap between mental events and matter (as understood by Descartes) results, by default, in a property dualism that marks the limits of his scientific efforts.

Keywords: Descartes, dualism, explanation, imagination, matter, memory, sensation, substance, theory of mind