Abstract

These days it is common to see matter as a type of substance, that is, as an entity that possesses features such as shape or mass, as a sort of thing distinct in kind from mind or soul or spirit. This way of understanding matter is now common even among philosophers who deny that immaterial substances exist, and is inherited from Descartes and Locke. Locke, for instance, defined material substances as substances that are “extended, figured [i.e., have shape], and capable of motion,” ¹ while spiritual substances as capable of thought, will, and action. In teaching that matter is a kind of substance, Descartes and Locke were themselves resurrecting a doctrine held by many pre-Socratic philosophers, and opposing Aristotle.