Abstract

The purpose of this dissertation is to examine how Aquinas's conception of the soul influences his moral psychology. Aquinas adheres to the Aristotelian principle that the human soul is the form of the body. Seen this way, human beings are hylomorphic beings--composites of matter and form. The powers characteristic of the human soul I consider include intellect, will, and emotion. These powers are the means by which human beings engage in practical thought and action. Because Aquinas thinks that the soul is essentially an enmattered form, these powers will not be predicated of the soul alone, but of the whole composite. Although these powers are not essentially powers of physical beings, it is the case that for composite beings such as ourselves, acts of intellect, will, and emotion are acts of something embodied. ;The outline of this dissertation is roughly as follows: first, I will present an account of Aquinas's view of the soul as form . I will then show how the soul's powers are jointly at work in practical reason . I then address a problem that is particularly germane to the topic under discussion, namely, the problem of incontinence . Aquinas sometimes suggests that the passions undermine the agent's adherence to right reason. Just how passion corrupts one's moral understanding without removing culpability for incontinent acts is the subject of this chapter. In the last chapter, I argue that perfected human action requires the virtue of temperateness, the purpose of which is to amend the vehemence of passion and make it consonant with right reason . According to this account, temperateness produces a harmony between the intellective and sensitive parts of the soul by modifying the inclinations characteristic of embodied human beings