Abstract

Scholars often assume that Aristotle uses the terms morphē and eidos interchangeably. Translators of Aristotle's works rarely feel the need to carry the distinctionbetween these two Greek terms over into English. This article challenges the orthodox view that morphē and eidos are synonymous. Careful analysis of texts fromthe Categories, Physics, and Metaphysics in which these terms appear in close proximity reveals a fundamental tension of Aristotle's thinking concerning the being of natural beings. Morphē designates the form as inseparable from the matter in which it inheres, while eidos, because it is more easily separated from matter, is the vocabulary used to determine form as the ontological principle of the composite individual. The tension between morphē and eidos—between form as irreducibly immanent and yet somehow separate—is then shown to animate Aristotle's phenomenological approach to the being of natural beings. This approach is most clearly enacted in Aristotle's biology, a consideration of which concludes the essay.