ABSTRACT
When considering the formal cause in the context of living things from an Aristotelian perspective, two philosophical theses are fundamental: the identification of form and activity (energeia) in Metaphysics VIII–IX, and the related, yet distinct, identification of soul as form and first fulfilment (protê entelecheia) in De anima II. In recent work, the author has puzzled over how these two theses inform Aristotle’s systematic and richly empirical investigations of animals, by asking how this abstract notion of form relates to two concepts central both to the way he organizes information about animals in the Historia animalium and to the way he explains that information in the Parts of Animals and Generation of Animals—action (praxis) and way of life (bios). This chapter focuses on formal causation, and thus on how soul (psychê) as formal cause is related to praxis and bios in their explanatory roles in biology. This chapter is not, however, a merely historical exploration: it connects with two contemporary philosophical projects which are grappling with questions about the phenomena of life and their explanation that are akin to Aristotle’s, namely, the project of Michael Thompson in Life and Action and Denis Walsh in Organism, Agency, and Evolution.
