Medieval Philosophy

by Peter S. Adamson

In late antiquity, Plotinus had criticized Aristotle’s definition of soul precisely on the grounds that it would make soul dependent on body.3 Following Plato, he saw the soul as a substance in its own right, which is immaterial and has only a temporary relationship to the body. Christians could find the same attitude in ancient religious authorities like Augustine. On the other hand, Christians had reasons not to go too far in a Platonizing direction. Their religion centered on the incarnation of God, and was committed to the eventual resurrection of the body in paradise. So it was awkward to admit that the body is nothing but an incidental and unwelcome accretion onto the soul. The upshot was that medieval authors had not only an exegetical problem about what to do with Aristotle’s definition of soul, but also a philosophical problem: how to preserve the human soul’s exalted status as an immaterial substance, while still saying that one human person is a union of soul and body? The problems did not end there. For Aristotle, the soul has a whole range of different powers, ranging from the lowly faculty of nutrition, which we share even with plants, to the distinctively human capacity for intellectual thought. How then to show that there is unity, this time not between soul and body, but within the soul itself? If your distinctively human part is your intellect, it might seem that your lower powers would be incidental to you, no part of who or what you really are. One migh...