(13) Whether He knows future contingent things?
(14) Whether He knows enunciable things?
(15) Whether the knowledge of God is variable?
(16) Whether God has speculative or practical knowledge of things?
Whether there is knowledge [*Scientia]?
Objection 1: It seems that in God there is not knowledge. For knowledge is a habit; and habit does not belong to God, since it is the mean between potentiality and act. Therefore knowledge is not in God.
Objection 2: Further, since science is about conclusions, it is a kind of knowledge caused by something else which is the knowledge of principles. But nothing is caused in God; therefore science is not in God.
Objection 3: Further, all knowledge is universal, or particular. But in God there is no universal or particular ( Question [3], Article [5]). Therefore in God there is not knowledge.
On the contrary, The Apostle says, "O the depth of the riches of the wisdom and of the knowledge of God" (Rm. 11:33).
I answer that, In God there exists the most perfect knowledge. To prove this, we must note that intelligent beings are distinguished from non-intelligent beings in that the latter possess only their own form; whereas the intelligent being is naturally adapted to have also the form of some other thing; for the idea of the thing known is in the knower. Hence it is manifest that the nature of a non-intelligent being is more contracted and limited; whereas the nature of intelligent beings has a greater amplitude and extension; therefore the Philosopher says (De Anima iii) that "the soul is in a sense all things." Now the contraction of the form comes from the matter. Hence, as we have said above ( Question [7], Article [1]) forms according as they are the more immaterial, approach more nearly to a kind of infinity. Therefore it is clear that the immateriality of a thing is the reason why it is cognitive; and according to the mode of immateriality is the mode of knowledge. Hence it is said in De Anima ii that plants do not know, because they are wholly material. But sense is cognitive because it can receive images free from matter, and the intellect is still further cognitive, because it is more separated from matter and unmixed, as said in De Anima iii. Since therefore God is in the highest degree of immateriality as stated above ( Question [7], Article [1]), it follows that He occupies the highest place in knowledge.
Reply to Objection 1: Because perfections flowing from God to creatures exist in a higher state in God Himself ( Question [4], Article [2]), whenever a name taken from any created perfection is attributed to God, it must be separated in its signification from anything that belongs to that imperfect mode proper to creatures. Hence knowledge is not a quality of God, nor a habit; but substance and pure act.
Reply to Objection 2: Whatever is divided and multiplied in creatures exists in God simply and unitedly ( Question [13], Article [4]). Now man has different kinds of knowledge, according to the different objects of His knowledge. He has "intelligence" as regards the knowledge of principles; he has "science" as regards knowledge of conclusions; he has "wisdom," according as he knows the highest cause; he has "counsel" or "prudence," according as he knows what is to be done. But God knows all these by one simple act of knowledge, as will be shown ( Article [7]). Hence the simple knowledge of God can be named by all these names; in such a way, however, that there must be removed from each of them, so far as they enter into divine predication, everything that savors of imperfection; and everything that expresses perfection is to be retained in them. Hence it is said, "With Him is wisdom and strength, He hath counsel and understanding" (Job 12:13).
Reply to Objection 3: Knowledge is according to the mode of the one who knows; for the thing known is in the knower according to the mode of the knower. Now since the mode of the divine essence is higher than that of creatures, divine knowledge does not exist in God after the mode of created knowledge, so as to be universal or particular, or habitual, or potential, or existing according to any such mode.
Whether God understands Himself?
Objection 1: It seems that God does not understand Himself. For it is said by the Philosopher (De Causis), "Every knower who knows his own essence, returns completely to his own essence." But God does not go out from His own essence, nor is He moved at all; thus He cannot return to His own essence. Therefore He does not know His own essence.
Objection 2: Further, to understand is a kind of passion and movement, as the Philosopher says (De Anima iii); and knowledge also is a kind of assimilation to the object known; and the thing known is the perfection of the knower. But nothing is moved, or suffers, or is made perfect by itself, "nor," as Hilary says (De Trin. iii), "is a thing its own likeness." Therefore God does not understand Himself.
Objection 3: Further, we are like to God chiefly in our intellect, because we are the image of God in our mind, as Augustine says (Gen. ad lit. vi). But our intellect understands itself, only as it understands other things, as is said in De Anima iii. Therefore God understands Himself only so far perchance as He understands other things.
On the contrary, It is written: "The things that are of God no man knoweth, but the Spirit of God" (1 Cor. 2:11).
I answer that, God understands Himself through Himself. In proof whereof it must be known that although in operations which pass to an external effect, the object of the operation, which is taken as the term, exists outside the operator; nevertheless in operations that remain in the operator, the object signified as the term of operation, resides in the operator; and accordingly as it is in the operator, the operation is actual. Hence the Philosopher says (De Anima iii) that "the sensible in act is sense in act, and the intelligible in act is intellect in act." For the reason why we actually feel or know a thing is because our intellect or sense is actually informed by the sensible or intelligible species. And because of this only, it follows that sense or intellect is distinct from the sensible or intelligible object, since both are in potentiality.
Since therefore God has nothing in Him of potentiality, but is pure act, His intellect and its object are altogether the same; so that He neither is without the intelligible species, as is the case with our intellect when it understands potentially; nor does the intelligible species differ from the substance of the divine intellect, as it differs in our intellect when it understands actually; but the intelligible species itself is the divine intellect itself, and thus God understands
