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 these He is said to have knowledge, not of vision, but of simple intelligence. This is so called because the things we see around us have distinct being outside the seer.
Reply to Objection 1: Those things that are not actual are true in so far as they are in potentiality; for it is true that they are in potentiality; and as such they are known by God.
Reply to Objection 2: Since God is very being everything is, in so far as it participates in the likeness of God; as everything is hot in so far as it participates in heat. So, things in potentiality are known by God, although they are not in act.
Reply to Objection 3: The knowledge of God, joined to His will is the cause of things. Hence it is not necessary that what ever God knows, is, or was, or will be; but only is this necessary as regards what He wills to be, or permits to be. Further, it is in the knowledge of God not that they be, but that they be possible.
Whether God knows evil things?
Objection 1: It seems that God does not know evil things. For the Philosopher (De Anima iii) says that the intellect which is not in potentiality does not know privation. But "evil is the privation of good," as Augustine says (Confess. iii, 7). Therefore, as the intellect of God is never in potentiality, but is always in act, as is clear from the foregoing ( Article [2]), it seems that God does not know
