The aim of this paper is to think through the philosophical problems of René Descartes’s (1596-1650) metaphysical dualism, an issue he presents in both Meditations on First Philosophy (1641) and Discourse on Method (1637). Firstly, the issue of what constitutes a thinking substance will be discussed. Since Descartes posits a pluralistic ontology, it is important to clarify the distinction he makes between thinking and extended substances, and why he considers such a dualism to be philosophically useful. Secondly, the issue of what makes Descartes’ position satisfactory will be examined, as well as outlining central flaws in his argument. Continue reading...