 The argument is complicated in virtue of its manner of presentation. First, it is a narrative in which Aristotle gradually develops his own views by exposing the errors of those who investigated nature before him; it is structured as presenting an alternative to views expressed by Empedocles and Democritus, and as in the spirit of Socrates (642a24–31). Second, as is so typical of him, what initially may appear to be three separate narratives turn out to be a single, complex case for emphasizing the study of form, teleological explanation, and conditional necessity when studying living things. Form, in the case of living things, turns out to be the capacity to perform living functions such as nutrition, perception, or locomotion, i.e. soul; and thus the form of a living thing is causally prior to the matter, because it is the goal for the sake of which the parts of the animal—its matter—come to be and exist. This, in turn, provides us with the appropriate way to understand ‘conditional necessity’—parts and the processes that produce them do not necessitate the outcome; on the contrary, the outcome necessitates that the developmental processes bring about the parts that are necessary for the organism to live its life, and do so in a temporally and spatially coordinated manner (cf. GA II 4, 740b19–34; II 6, 743a16–36).