The purpose of this article is to reconstruct Aristotle’s distinction between primary substances and their homonyms. It is shown that the Stagirite regards both body parts and artefacts as mere homonyms of primary substances when they are no longer capable of performing their function (ergon) and actualizing their end (telos). In the course of the present discussion, Aristotle’s approach is confronted with his famous doctrine of the four causes, whilst an analysis of the examples given by the Stagirite serves the (...) purpose of determining the ontic status of homonyms. Subsequently, this paper argues that Aristotle’s hylomorphism not only defies the functionalist assumption of the irrelevance of matter but also precludes the possibility of equating artefacts with living organisms. The discussion concludes with an observation that primary substances which are truly (alēthōs) and things which are only homonymously (plēn homōnymōs) require different definitions. (shrink)