Aristotle’s Compositional Hierarchy in <i>Parts of Animals</i> II 1, 646a12-24

Abstract In Parts of Animals II 1, 646a12-24, Aristotle identifies three compositions, arranged from simple to complex. Although the passage clearly indicates that non-uniform parts are constructed from uniform parts, two ambiguities in the passage call the status of uniform compounds into question. Both ambiguities point toward divergent interpretations of (1) the relationship between uniform parts of living things and their inanimate or inorganic counterparts, and (2) the relationship of uniform compounds to their own material causes. The objective of this paper is to identify and resolve the two ambiguities in PA II 1, 646a12-24, with an eye toward the consequences for uniform materials in Aristotle’s natural philosophy. In doing so, this paper argues that for Aristotle, uniform parts of living things, while they are parts of living bodies, are structurally as well as functionally distinct from inorganic and non-functional compounds.