Rory Hanlon

abstract: I provide a novel interpretation of Aristotle's account of the unity of soul, treating it as resolving the apparent incompatibility of the existence of psychic parts and the soul's status as a unifying form. This incompatibility, I contend, rests on a problematic assumption: mereological actualism, or the claim that parts are actually distinct and prior to the whole. Aristotle successfully undermines actualism and formulates an alternative conception of parthood within De Anima 's figure-soul analogy. As triangles are only potentially present within quadrilaterals, so lower psychic parts are potential parts of higher souls. This picture treats a soul not as a mere aggregate of capacities, but as essentially unified and prior to its parts. Finally, I argue that this picture can be illuminated and must be read against the background of his hylomorphic account of the unity of form given in Metaphysics H.6.