Aristotle's Physics is a study of nature (phusis) and of natural objects (ta phusei). According to him, these objects—either all of them or at least some of them—are in motion. That is, they are kinoumena, things that are subject to change. The first book of the Physics is largely devoted to this task. The account of substantial change in the Physics is devoid of any commitment to prime matter. Aristotle also takes up the topics of alteration and coming-to-be in De Generatione et Corruptione. He adopts a kind of conservation principle: “the corruption of one thing is the generation of...

Aristotle's Physics is a study of nature (phusis) and of natural objects (ta phusei). According to him, these objects—either all of them or at least some of them—are in motion. That is, they are kinoumena, things that are subject to change. The first book of the Physics is largely devoted to this task. The account of substantial change in the Physics is devoid of any commitment to prime matter. Aristotle also takes up the topics of alteration and coming-to-be in De Generatione et Corruptione. He adopts a kind of conservation principle: “the corruption of one thing is the generation of another, and vice versa.” In addition, Aristotle points out that all changes involve both a subject (hupokeimenon) and an attribute (pathos) of a sort which can be predicated of the subject, and says that either one of these is capable of “change” (metabolê).