In this passage Aristotle seems to postulate the existence of an active intellect which is separable from the passive intellect and which is primarily responsible for the intellectual activities of the human soul.
The second has no basis in reality but is purely a creation of the mind; it arises out of the intellect's activity of comparing, which makes possible its infinite multiplication (DM 39, 2, 23; 1861, 25:517a).
Soul is not the principle of life, for the activity of Intellect is the highest activity of life.
Beliefs play a role in our deliberations over what to do; thus the constraints placed upon beliefs in turn constrain the intellect in its activities.
Similarly, Intellect's internal activity is its contemplation of the Forms, and its external activity is found in every possible representation of the activity of being eternally identical with all that is intelligible (i.e., the Forms).
However, what he did not claim in 75.4 is that the activity of intellect that characterizes the soul is not one of Socrates activities.
So according to Aquinas, while it is true that the activities of intellect and will are not the actualities of any physical organs, they are nonetheless the activities of the living human animal.
Foods they like, favorite activities, sexuality, intellect, family ties, openness, integrity, and a myriad of other qualities are discoverable.
Anything that is understandable is an external activity of Intellect; and any form of cognition of that is also an external activity of it.
The activity of Intellect, or its cognitive identity with all Forms, is the paradigm for all embodied cognitive states of any soul as well as any of its affective states.
