[202] Of the rational soul

The faculties of the human rational soul can also be divided into a practical faculty and a theoretical faculty. Each of these faculties is called by the homonymous term “intellect.” The practical faculty is a principle that moves the human body to the particular actions that are specific to it, by deliberation, in accordance with common opinions that are specific to it. It is related to the animal faculty of appetite, to the animal faculty of imagination and estimation, and to itself. It is related to the animal faculty of appetite in that dispositions originate there that are specific to humans, which dispose it to quick actions and affections, such as timidity, shame, laughter, crying, and similar things. It is related to the animal faculty of imagination and estimation insofar as it uses it to discover measures pertaining to the realm of generation and corruption, and to discover the human arts. It is related to itself in that, along with the theoretical intellect, it generates the [203] commonly held opinions, for example that lying is repugnant, injustice is repugnant, and similar premises, which are clearly distinguished from the pure intellectual [premises] in the books of logic.

This faculty [i.e. the practical faculty] should be the one to dominate all the other bodily faculties, in accordance with what is necessitated by the judgments of the other faculty mentioned [i.e. the theoretical faculty], so that the practical faculty is not affected by the bodily faculties at all.