This is the first systematic analysis of Aristotles concept of lexis. Ana Kotarcic argues that it should be approached on three interconnected levels: the first dealing with language as a system the second with actual language usage into which sociolinguistic factors come into play and the third with prescriptions for the kind of language to be used in poetic and rhetorical compositions. She introduces ideas and concepts from classics and modern linguistics into the analysis alongside the philosophical approaches which have prevailed until now. The results reveal that Aristotles ideas on lexis are complex well-developed and intimately connected to many other fundamental concepts in his works such as aretē energeia ēthos logos mimēsis pathos phantasia and technē. A major component of his thought is therefore illuminated comprehensively for the first time.