The question arises, both within the teleological analysis of UP, and much more broadly throughout the Galenic corpus, of the relationship between the different causes. Some scholars have seen a tension between teleology and material causation in Galen (and some, such as Moraux 1984, even believed that they could identify a chronological development, from the “early” position of UP, with its clear Aristotelian “instrumentalism”, to the apparent physicalism or materialism of the “late” QAM—on which see §7 below). For further exploration of these issues see Singer 1997b; Havrda 2017; van der Eijk 2017; Singer and van der Eijk ad loc. on the passages from Temp. cited below.