Therefore His knowledge is discursive.
Objection 3: Further, God knows each creature more perfectly than we know it. But we know the effects in their created causes; and thus we go discursively from causes to things caused. Therefore it seems that the same applies to God.
On the contrary, Augustine says (De Trin. xv), "God does not see all things in their particularity or separately, as if He saw alternately here and there; but He sees all things together at once."
I answer that, In the divine knowledge there is no discursion; the proof of which is as follows. In our knowledge there is a twofold discursion: one is according to succession only, as when we have actually understood anything, we turn ourselves to understand something else; while the other mode of discursion is according to causality, as when through principles we arrive at the knowledge of conclusions. The first kind of discursion cannot belong to God. For many things, which we understand in succession if each is considered in itself, we understand simultaneously if we see them in some one thing; if, for instance, we understand the parts in the whole, or see different things in a mirror. Now God sees all things in one (thing), which is Himself. Therefore God sees all things together, and not successively. Likewise the second mode of discursion cannot be applied to God. First, because this second mode of discursion presupposes the first mode; for whosoever proceeds from principles to conclusions does not consider both at once; secondly, because to discourse thus is to proceed from the known to the unknown. Hence it is manifest that when the first is known, the second is still unknown; and thus the second is known not in the first, but from the first. Now the term discursive reasoning is attained when the second is seen in the first, by resolving the effects into their causes; and then the discursion ceases. Hence as God sees His effects in Himself as their cause, His knowledge is not discursive.
Reply to Objection 1: Altogether there is only one act of understanding in itself, nevertheless many things may be understood in one (medium), as shown above.
Reply to Objection 2: God does not know by their cause, known, as it were previously, effects unknown; but He knows the effects in the cause; and hence His knowledge is not discursive, as was shown above.
Reply to Objection 3: God sees the effects of created causes in the causes themselves, much better than we can; but still not in such a manner that the knowledge of the effects is caused in Him by the knowledge of the created causes, as is the case with us; and hence His knowledge is not discursive.
Whether the knowledge of God is the cause of things?
Objection 1: It seems that the knowledge of God is not the cause of things. For Origen says, on Rm. 8:30, "Whom He called, them He also justified," etc.: "A thing will happen not because God knows it as future; but because it is future, it is on that account known by God, before it exists."
Objection 2: Further, given the cause, the effect follows. But the knowledge of God is eternal. Therefore if the knowledge of God is the cause of things created, it seems that creatures are eternal.
Objection 3: Further, "The thing known is prior to knowledge, and is its measure," as the Philosopher says (Metaph. x). But what is posterior and measured cannot be a cause. Therefore the knowledge of God is not the cause of things.
On the contrary, Augustine says (De Trin. xv), "Not because they are, does God know all creatures spiritual and temporal, but because He knows them, therefore they are."
I answer that, The knowledge of God is the cause of things. For the knowledge of God is to all creatures what the knowledge of the artificer is to things made by his art. Now the knowledge of the artificer is the cause of the things made by his art from the fact that the artificer works by his intellect. Hence the form of the intellect must be the principle of action; as heat is the principle of heating. Nevertheless, we must observe that a natural form, being a form that remains in that to which it gives existence, denotes a principle of action according only as it has an inclination to an effect; and likewise, the intelligible form does not denote a principle of action in so far as it resides in the one who understands unless there is added to it the inclination to an effect, which inclination is through the will. For since the intelligible form has a relation to opposite things (inasmuch as the same knowledge relates to opposites), it would not produce a determinate effect unless it were determined to one thing by the appetite, as the Philosopher says (Metaph. ix). Now it is manifest that God causes things by His intellect, since His being is His act of understanding; and hence His knowledge must be the cause of things, in so far as His will is joined to it. Hence the knowledge of God as the cause of things is usually called the "knowledge of approbation."
Reply to Objection 1: Origen spoke in reference to that aspect of knowledge to which the idea of causality does not belong unless the will is joined to it, as is said above.
But when he says the reason why God foreknows some things is because they are future, this must be understood according to the cause of consequence, and not according to the cause of essence. For if things are in the future, it follows that God knows them; but not that the futurity of things is the cause why God knows them.
Reply to Objection 2: The knowledge of God is the cause of things according as things are in His knowledge. Now that things should be eternal was not in the knowledge of God; hence although the knowledge of God is eternal, it does not follow that creatures are eternal.
Reply to Objection 3: Natural things are midway between the knowledge of God and our knowledge: for we receive knowledge from natural things, of which God is the cause by His knowledge. Hence, as the natural objects of knowledge are prior to our knowledge, and are its measure, so, the knowledge of God is prior to natural things, and is the measure of them; as, for instance, a house is midway between the knowledge of the builder who made it, and the knowledge of the one who gathers his knowledge of the house from the house already built.
Whether God has knowledge of things that are not?
Objection 1: It seems that God has not knowledge of things that are not. For the knowledge of God is of true things. But "truth" and "being" are convertible terms. Therefore the knowledge of God is not of things that are not.
Objection 2: Further, knowledge requires likeness between the knower and the thing known. But those things that are not cannot have any likeness to God, Who is very being. Therefore what is not, cannot be known by God.
Objection 3: Further, the knowledge of God is the cause of what is known by Him. But it is not the cause of things that are not, because a thing that is not, has no cause. Therefore God has no knowledge of things that are not.
On the contrary, The Apostle says: "Who . . . calleth those things that are not as those that are" (Rm. 4:17).
I answer that, God knows all things whatsoever that in any way are. Now it is possible that things that are not absolutely, should be in a certain sense. For things absolutely are which are actual; whereas things which are not actual, are in the power either of God Himself or of a creature, whether in active power, or passive; whether in power of thought or of imagination, or of any other manner of meaning whatsoever. Whatever therefore can be made, or thought, or said by the creature, as also whatever He Himself can do, all are known to God, although they are not actual. And in so far it can be said that He has knowledge even of things that are not.
Now a certain difference is to be noted in the consideration of those things that are not actual. For though some of them may not be in act now, still they were, or they will be; and God is said to know all these with the knowledge of vision: for since God's act of understanding, which is His being, is measured by eternity; and since eternity is without succession, comprehending all time, the present glance of God extends over all time, and to all things which exist in any time, as to objects present to Him. But there are other things in God's power, or the creature's, which nevertheless are not, nor will be, nor were; and as regards