This volume begins with excerpts from Aquinas' commentary on De Anima, excerpts that proceed from a general consideration of soul as common to all living things to a consideration of the animal soul and, finally, to what is peculiar to the human soul. These are followed by the Treatise on Man, Aquinas' most famous discussion of human nature, but one whose organization is dictated by theological concerns and whose philosophical importance is thus best appreciated when seen as presented here: within the historical philosophical framework of which it constitutes a development. Aquinas' discussions of the will and the passions follow, providing fruitful points of comparison with other philosophers.