Earlier today I was thumbing through Aquinas’ commentary on Aristotle’s De Anima, specifically book III. There’s a passage in chapter 4 of that book that grabbed my attention, where Aquinas critically engages Avicenna. The passage in question is a gloss on the following stretch of text from Aristotle, wherein he says something about how a knower of x comes to actively think x:
 But when [intellect] becomes the individual things in this way, as a knower, [it] is said to be that which [it is] in actuality. But this happens as soon as [a person] can operate by himself. Even then, therefore, it is in potentiality in a way, but not like it was before learning or discovering […]. (De Anima, III.4, 429b5-9, tr. Pasnau, 1999)*
Initially, I thought Aquinas’ critique was interesting; but then on reflection, I thought it was rather implausible and unfair.
Aristotle seems to be making (at least) two points in : first, there’s a certain way in which our intellects can come to be actual. Call this way the knower way (KW), which can be defined as follows: we think/know x in the knower way when we can think x on our own initiative, i.e., by ourselves, simply whenever we will or want to. (Presumably, KW is supposed to contrast with some other way in which we come to think/know x. And judging by the last clause in , that way is presumably one in which we come to think/know x without having previously learned or discovered x. Obviously, there’s a difference between the two: take Zayd and ‘Amr. Zayd previously learned x but is not actively thinking x; ‘Amr too is not actively thinking x but hasn’t even learned x to begin with. Zayd can think x whenever he wants – which is to say he can come to know x qua KW. ‘Amr can’t do that, which is to say he comes to know/think x (whenever he in fact does so) in some other way.) The second point Aristotle seems to make in  is that even in the case of knowing qua KW, the knower (=Zayd) is in a state of potentiality, i.e., with respect to x. (But, importantly, not in the same sort of potential state in which, say, ‘Amr is with respect to x).
In commenting on 429b5-9, Aquinas more or less says the same thing. But then, in the immediately succeeding set of remarks, he criticizes Avicenna, stating that: given what  says, Avicenna’s view of the intelligibles is both (1) false and (2) contrary to Aristotle’s view. (The view in question is Avicenna’s doctrine the intelligibles which we’ve acquired are not preserved in our intellect but are stored in an immaterial being external to us). In support of (1), Aquinas offers no reasons that are independent of the textual, interpretive points he makes in support of (2); basically, he implies that Avicenna’s view is false, on the basis of a mere interpretation of what Aristotle’s view is, without justifying that view. That’s just unfair to his opponent.
As for justifying (2), Aquinas thinks Avicenna’s view conflicts with Aristotle’s in  because he thinks  entails that:
 […] when the intellect cognizes actually, the intelligible[s] are in it in respect of a completed act; but when it has the disposition of knowledge [i.e., qua KW], there are [intelligibles] in the intellect in a way that is between pure potentiality and pure actuality. (pp. 352-3, emphasis mine)
The implication is that for Aristotle, on the basis of what  says, acquired but not actively thought intelligibles still somehow exist in the human potential intellect. Aquinas’ critique in  presupposes that Aristotle in  is making a point about the ontic status of intelligibles that we’ve acquired (but are not actively thinking).
But as an account of , that seems like a stretch, no? Clearly,  is making a point about the faculty (that is our potential intellect), not about its objects per se. If so, then there’s no conflict between Aristotle’s and Avicenna’s views. For as we’ve already seen, all  is saying is that: the intellectual power can come to think x whenever we will to and that, even as such, it, i.e., the intellect, the faculty, is still in a way in potency to x. Text  says nothing about the place of x when x is not being thought of by our intellect. That’s a separate issue. Yet, Aquinas makes it about just that, and then goes on to critique Avicenna, urging in text  that Avicenna’s account is false because even when the intellect has acquired x but is not currently thinking x (i.e., when it’s ‘disposed’ to x), x is still in the intellect, i.e., in a state between pure potentiality and pure actuality.
But let my reservation about the man’s interpretation of  slide. Apart from interpretive concerns, there’s a more pressing, philosophical worry about the Thomist position: what is supposed to be the nature of an intelligible that is in between pure potency and pure act? Given my mashsha’i commitments, I’d flesh out the worry like so: in that in between state, the acquired (but not actively thought) intelligible is either actually intelligible or potentially intelligible. If the former, it is actually being thought, which is a state of pure act. But on the present assumption it isn’t – this is a contradiction. Hence, it must be potentially intelligible. As potentially intelligible, its potency is either a feature of it itself, i.e., the object, or a feature of the power that comes to know it (i.e., our intellect). If of itself, then it is, in itself, not an object of the intellect but rather of one of the sub-rational internal senses. This is because, insofar as it itself is bound up with potency somehow, it is not fully intelligible. The Peripatetics all are agreed on this. Hence, qua potentially intelligible in that sense, it must be a phantasm of some sort. And phantasms are not objects of the intellectual faculty, whether their potency is pure or not (whatever that means). And so Aquinas’ claim in  is false. But if the potency is a feature of the power that comes to know it, Aquinas interpretation of  is off the mark (not merely a stretch): as I said,  is making a point about the faculty (that is our potential intellect), not about its objects per se. Either way, it seems there’s no conflict, contra what Aquinas claims, between Aristotle and Avicenna on this issue (to say nothing about the latter’s view being false).
*The Oxford translation of the passage reads:
When thought has become each thing in the way in which a man who actually knows is said to do so (this happens when he is now able to exercise the power on his own initiative), its condition is still one of potentiality, but in a different sense from the potentiality which preceded the acquisition of knowledge by learning or discovery […].