 The remainder of the chapter, therefore, recommends approaching the activities associated with animals and their parts in a manner exactly analogous to the approach to the study of parts recommended in chapter 4 (645b1–14); and it concludes with a schematic discussion of the variety of teleological relationships that hold among parts, between parts and their activities, and among activities. Aristotle encourages us to conceive of these relationships in a yet more unified way, as a single complex relationship between a single complex activity (living, I suppose) and a single complex instrument, the animal’s body. (645b15–36)