Abstract
In his metaphysics and natural philosophy, Aristotle uses the concept of a material cause,i.e., that from which something can be made or generated. This paper argues that Aristotle also has a concept of matter in the sense of physical stuff. Aristotle develops this concept of matter in the course of investigating the material causes of perceptible substances. Because of the requirements for change, locomotion, and the physical interaction of material objects, Aristotle holds that all perceptible substances must be extended in three dimensions, movable, and corporeal due to their material causes. Thus, perceptible substances are physical substances because they are made out of something physical.