This chapter addresses an interpretive question about why Aristotle identifies generation, growth, and nourishment as the three distinct functions or activities of nutritive soul. Scholars typically try to explain this by appealing to the shared goal of these activities, though there is no consensus about what that goal is: Does Aristotle think that generation is a way of keeping oneself alive (and thus that the shared goal is self-maintenance), or is nourishment really a quasi-generative activity (and thus that the shared goal is “form (re)production”)? Rather than taking that approach, Gelber offers a different but complementary way of accounting for the unity of these activities, by focusing on the continuity of their shared physiological basis. As it is argued here, the fact that these biological processes form a continuous cycle stems from Aristotle’s adherence, in his biological theory, to principles from his hylomorphic metaphysics. Attending to the details in works such as Generation of Animals that focus on the mechanisms underlying generation, growth, and nourishment, it is shown how we can construct a coherent account of the unity of the three nutritive soul activities.

The activities undergone by living things are paradigmatically end-directed, and so this chapter examines Aristotle’s invocation of teleological notions (as well as their contrast with non-teleological notions) in his scientific investigation of life. In particular, the chapter looks at how Aristotle explains why various processes occur, why some kinds of organisms have (or lack) certain parts or features, and why those parts or features vary in their sizes and shapes. Aristotle’s biological explanations are complex and rich in detail, thus providing valuable resources for making headway into some of the interpretive challenges facing our understanding of his distinctive form of natural teleology – one that countenances purposes in the absence of intentions and volitions, and one that finds the occurrence of necessity compatible with goal-directedness.

Gelber focuses on passages in GA where Aristotle treats heat and cold as agents which are said to be making (poiei), fabricating (dêmiourgei), solidifying (pêgnutai), putting together (sunistatai), or working (ergazetai) to accomplish something, and thereby playing a role in the formation of a living organism. Gelber s aim is to explain how heat and cold do this, and the significance, for Aristotle, of calling heat and cold the tools of soul in his explanation of animal reproduction.