Correct. However, that means he would not have undergone a “becoming.”
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But by the Incarnation God would be intrinsically otherwise than He is. Therefore the Incarnation is impossible.
Reply. I distinguish the minor. That God would undergo a change, if by reason of passive potency He were to receive some distinct perfection, this I concede; that God only terminates the human nature, and undergoes a change, this I deny.
God in the Incarnation neither loses nor acquires anything, but merely makes creatures partakers in His perfection. Therefore, as St. Thomas says: “When it is said, 'God was made man,’ we understand no change on the part of God, but only on the part of the human nature.”[186] Similarly, if we see the sun, it undergoes no change, but is only the object of our vision.
As St. Thomas says: “To be man belongs to God by reason of the union, which is a relation… But whatever is predicated relatively can be newly predicated of anything without its change, as a man may be made to be on the right side without being changed, and merely by the change of him who was on his left side.”[187] Likewise, anything at first not seen is seen afterward without any change in itself, but inasmuch as it is actually the termination of our vision. It is the visual faculty that is changed, inasmuch as it passes from potentiality to act.
Similarly, as we shall see in the case of the Incarnation, the change is entirely on the part of the nature that is assumed, which is deprived of its own subsistence and acquires the divine. The Word by no means acquires a new and real relation, but the relation is logical; for the real relation is only on the part of the human nature toward the Word, just as the visual faculty is in real relation to the object seen, and not the reverse of this. Hence St. Thomas says: “God is said to be united not by any change in Himself, but in that which is united to Him; similarly, when it is said that He is unitable, this statement does not mean that the union is effected by reason of any passive potency existing in God, but because there is such a potency existing in the creature so as to make this union possible.”[188] So also God is said to be visible and in the next life He is seen by the blessed, not because of any change in Himself, but the change is in the blessed, since He terminates their vision as object seen. Thus a point that already terminates one line, can terminate a second and third line as in the case of the point of a pyramid, and yet the point undergoes no change in itself.