Commentaria in Primam Partem Summae Theologiae

The title is clear. – In the body, a single conclusion, answering the question affirmatively: God understands Himself through Himself. – It is proved. God is, without any potentiality, pure act: therefore intellect and what is understood are in every way the same: therefore He understands Himself through Himself.

The antecedent is clear. The first consequence, however, rests upon two propositions. One is: the object of the intellect must be in act in the one understanding, in order that he may understand. The other is: every diversity of intellect from its object arises from a nature of potency mixed in. The first is proved from the difference between a transitive and an immanent operation: because the latter has its term within. The second, from book de Anima, as follows. Sense in act is identical with the sensible in act, and likewise intellect in act with the intelligible in act; but they are not ¹ identical in potency: therefore the identity of these follows from the actuality of their state, while diversity follows from potentiality. For from these it is manifestly clear how the first sequel follows, thus: the intelligible must be in the one understanding, and is distinct from him in no way except through potency: therefore the intelligible of that being in which there is no potency is in no way distinct from it: if, then, God is without potency etc., therefore etc. – Next, in the text the consequent is explained as to the phrase omnibus modis, by excluding two modes of diversity, namely between act and potency, and between substance and accident. – The second consequence is clear.

II. Concerning the words of the text in the second proposition grounding the consequence ², note that what is said, namely, on this account alone the sense or intellect is other than the sensible or intelligible, because each is in potency, can be expounded in two ways. First, so that the term each refers to the power and the object. Second, so that it refers to both powers which he had named, namely, the sensitive and the intellective. And if this second sense is held, no difficulty arises, and the plain sense of the text is preserved. But if the first sense is intended, it needs polishing. For from it would be expressly obtained that for the distinction between the knower and the known there is required potentiality not only in the knower but also in the known: which is not true in every case. For this can be understood in two ways. First, that potentiality is required in both, such that each is in itself a being in potency, and this twofold potency is the root of the distinction. And this is false, as is clear when God is seen by some created intellect: for then the object is pure act, and yet there is a distinction between the intellect and the object. Second, that the potentiality of each is required with respect to this; that is, that the object be intelligible in potency by the intellect itself, and that the intellect be in some potency with respect to understanding it. And this is true: but, in my judgment, it is not what is intended here. First, because one potentiality, namely that of the power, suffices. Second, because this potentiality of the object, not in itself but with respect to this, is not a potentiality of imperfection, of which we are speaking. Third, because both of these potencies are ultimately resolved, with respect to this effect which is the distinction between object and power, into the potentiality of the cognitive power itself. Fourth, because the plain sense of the text embraces the first exposition very well, and it satisfies the proposal. And therefore let us follow the first.

III. On the exposition of the consequent ³, where the phrase identical in every respect is explained by the exclusion of two things, namely, the state of potentiality and the diversity of the intellect from the intelligible species, a doubt arises: for the exclusion of these does not sufficiently explain the complete identity of intellect and intelligible. And this is proved in the case of an angel understanding itself. For it is clear that it is neither in potency, nor is the species by which it understands itself other than its own substance; and yet intellect and intelligible are not identical in every respect, even when it understands itself: both because this is proper to God, and because the concept it forms of itself, whatever that may be, is not its own substance.

IV. In this respect it is said in two ways. First, that the phrase namely, so as neither to lack the species, nor for the species to be something else, etc. is taken restrictively; that is, what he had said—namely the same in every way—is limited by these two words, as if he had said: they are the same in every way with respect to these two. And on this reading the doubt raised has no place.

And although this sense of the letter is consonant, insofar as in article 4 it remains to be asked whether God's understanding is the same as God himself; yet considering that this is a discourse on the identity of the understood and the understanding, and that the remaining doubt concerns understanding itself, insofar as there are certain difficulties arising from understanding itself, as distinguished against the intellect, it seems it can be said otherwise, by taking the word "thus," namely "so that it not lack the species, etc.," expositively. V. And to the doubt raised⁴ the answer is given that the exclusion of these two fully establishes every kind of identity of the understanding and the understood. But by the name "species" is to be understood not only the impressed species, but universally both the impressed and the expressed. For where the understanding and the species are not distinguished universally, there the understanding and the understood are entirely one and the same. And this in the doctrine of St. Thomas is undoubtedly true: since the concept itself is the expressed species, which in God alone is substance; and thus in no other being is the complete exclusion of these two preserved. Whether, however, this suffices according to the doctrines of other philosophers is not the present business, but is treated in III De Anima or in XII Metaphysics. That the species is here taken so universally in the present text, the text itself indicates through those words, "when it is actually understanding." If he intended only the impressed species, he would not have needed to say "when it is actually understanding"; since that is also present when our intellect is not actually understanding, but asleep. Hence, by explaining the intelligible species through the state of the intellect in second act, he indicated that he was speaking universally of the species concurring in the second act, which is understanding. Now both species concur in that act. The discourse on the species, therefore, must be interpreted universally, so that the sense may be more universal.