Abstract

BAristotle introduces his hylomorphism in the De Anima not as a challenge to the immateriality of Platonic souls, but in response to a problem about the causal relationship between soul and body raised by Plato's theory of affections in the Philebus. Plato holds that mental states have a unique structure. They are characterized by what we would call intentionality and are thereby radically different in kind from physiological states . This sharp divide between the affections, however, leaves unexplained how mental and physiological events causally influence one another--how does desire push the body around?--and how we can even talk about interaction between body and soul. Enter hylomorphism. Mental and physiological states, says Aristotle, are related as form to matter. That is, the soul and body enjoy a primitive or metaphysically basic relation which closes the causal gap left by Plato between the mental and the physical level. Our desire for drink causes us to go to the refrigerator in virtue of its being a structure of a bodily state which moves our limbs in a certain way. Thus hylomorphism provides the metaphysical ground for the causal stories we tell about the soul and body, while at the same time preserving the unique and irreducible structure of the mental which Plato had discovered.