(Though this very early argument it is substantially similar to the way St. Thomas answered this question throughout his career, this particular response is, in many ways, simply astonishing.)
Whether the rational powers are always in act with respect to the object which they are the image of [namely, the soul and God]
It seems not.
2.) Aristotle says that we cannot simultaneously understand many things. But the soul sometimes understands things other [than God and itself] and so it does not then understand itself and God at that time.
3.) According to Augustine, in order for the soul to understand itself, an intention of the one knowing is necessary, by which it has an idea which leads it to know the thing. But sometimes the soul understands itself by such an intention. So since we do not sense ourselves always to understand the soul and God, it seems that our intellect is not always in act with respect to these objects.
Aristotle says that the agent intellect always understands but this most of all seems to happen with respect to things that are always present to it, namely the soul and God. So it seems that the soul is always in act with respect to these things.
Augustine says that whatever is in my memory, that I remember. But the soul and God are always present in memory…
As Augustine says, there is a difference between thinking, discerning, and understanding (intellegere). To discern is to know one in thing by its difference from others. To think is to consider a thing by its its parts and properties, as though “to think ” (cogitare) was like “to shake things up” (coagitare) But to understand (intellegere, or perhaps “to see”) is nothing other than an undivided intuition of the intellect on an intelligible thing present to it. And so I say that the soul does not always think about or discern God or itself, because then anyone would naturally know the whole nature of his soul, which is scarcely attained by a great amount of study; for the mere presence of the thing does not suffice to know it in any way, since it has to be known as an object, and the intention of the one knowing needs to set out towards it. But to understand only requires an intuition, which is just the the intelligible presence of the thing (in some way) to the intellect – and in this way the soul always understands itself and God indeterminately, and, as a result, has an indeterminate love.
That the soul always understands itself can be understood in another way. As Aristotle says, everything that is understood, is only understood by the illumination of the agent intellect received into the possible intellect; and just as every color is seen in light, so every intelligible is seen in the light of the agent intellect, not as an object but as a means of knowing.
to the second:
Aristotle is talking about understanding which is the complete operation of the intellect distinguishing or thinking about something, and not as “understanding” is taken here.