Abstract

Aristotle outlines two methods in De Anima that one can employ when one investigates the soul. The first focuses on the exercises of a living organism’s vital capacities and the proper objects upon which these activities are directed. The second focuses on a living organism’s nature, its internal principle of movement and rest, and the single end for the sake of which this principle is exercised. I argue that these two methods yield importantly different, and prima facie incompatible, views about what souls are. According to the first, the soul is a set of independently specifiable capacities that are related to one another in a manner that effects a unity of soul over and above the multiplicity. According to the second, the soul is a single, unitary nature that has a living organism’s form as its end. I bring the differences between these two conceptions of soul into relief and then attempt to reconcile the opposing views in a way privileges the conception according to which the soul is a unitary nature. In doing so, I discuss the following interrelated topics: (a) what makes a capacity a part of soul, (b) the relationship between the parts of soul within a given organism, (c) how a soul can be a unity while comprising various parts, (d) whether it is possible to give an adequate definition of life or soul, (e) what unity obtains among the various ways life is said that would allow for a proper, scientific investigation of life, and (f) the principle that grounds the hierarchy of souls—the nutritive, the perceptual, and the rational.