 In Η.6, Aristotle returns to the problem of the unity of definition  (discussed above in Section 9)  and offers a new solution based on the concepts of potentiality and actuality. He begins by pointing out (recalling the language of Ζ.17) that the things whose unity he is trying to explain are those “that have several parts and where the totality of them is not like a heap, but the whole is something beyond the parts” (1045a8–10). His task is to explain the unity of such complexes.