Abstract

A fundamental and familiar feature of Aristotle’s natural philosophy is his use of the concept of physis as an explanatory principle of the development and growth of certain kinds of things. Natural things are those that possess within them an original principle of continuous movement towards some completion. Nature is thus said to belong among the causes which are for the sake of something or are purposeful. The concept is crucial, Aristotle argues, if one is to be able to explain the motion and phenomena that constitute life and development in the world. Lacking this concept, as the earlier philosophers did, natural science is seriously incomplete and inadequate.