—namely the “where,” the “how,” and every other accident that constantly arises for things in motion because of their motion.

The Intellect in act, with respect to what it knows, never acquires any new knowledge of a thing it did not already know; it is eternally actual, remaining in a single unchanging state toward the objects it apprehends. By contrast, the soul passes through varied conditions owing to the knowledge it gains and elicits from bodies, within them and through the motions it imparts to them. Hence the soul is an intellect in potency, whereas the Intellect is an intellect in act: the Intellect comprehends all intelligibles, while the soul grasps only some of them. If the soul is stripped of bodies, its ties to them severed, and it is counted both among the intelligibles and among those that apprehend, it too becomes an intellect in act. Its rank will then be determined by its species among existing beings and by the measure of knowledge it has acquired.

They say that the first of the intellects is the one that has emanated from the First Cause. The earliest thing they ever called “intellect” received that designation in reference to the human soul, for they held that the soul is an intellect in potential that becomes an intellect in act. What exists only in potential cannot bring itself into actuality; something already actual must actualize it—just as actual fire turns naphtha, which is fire in potential, into fire in actuality, for the naphtha does not ignite itself. In the same way, the being that is an intellect in act and makes the human soul an intellect in act is termed the Active Intellect; they liken it, in relation to our souls, to a tutor and teacher.