Chapter 51 — Reasons for inquiring how there is a multitude of things understood in the divine intellect

Lest, however, from the fact that God understands many things, we be led to conclude that there is composition in the divine intellect, we must examine in what way the things he understands are many.

Now, they cannot be understood to be many as though the many things God understands had a distinct being in him. For these understood things would either be the same as the divine essence, and thus we should have multitude in the essence of God, which has been disproved above (Cc. 18, 20, 42.) in many ways, or else they would be added to the divine essence, and thus there would be something accidental in God, and this again we have proved above to be impossible. (Ch. 23.)

Nor again can it be admitted that these intelligible forms exist in themselves, as Plato, in order to avoid the above impossibilities, seems to have maintained by holding the existence of Ideas. (Plato, Phaedo 48, 49; Timaeus.) For the forms of natural things cannot exist apart from matter, since neither are they understood without matter.

And even if the above supposition were admissible, it would not suffice to explain how God understands many things. For, since the aforesaid forms are outside the essence of God, if God were unable without them to understand the multitude of things (as is requisite for the perfection of his intellect), it would follow that the perfection of his understanding depends on something else. Consequently also the perfection of his being, since his being is his act of intelligence, the contrary of which has been shown above. (Ch. 13.)

Again. Since all that is beside his essence is caused by him, as we shall prove further on, (Bk. 2, ch. 15.) it must be that if the aforesaid forms are outside God, they are caused by him. Now he is the cause of things by his intellect, as we shall show further on. (Bk. 2, cc. 23–24.) Therefore, in order that these intelligible forms may exist, it is required that previously in the order of nature God should understand them. And consequently, God does not understand multitude through the fact that many intelligible things exist outside him in themselves.

Again. The intelligible in act is the intellect in act, even as the sensible in act is the sense in act. (Aristotle, On the Soul 3.2; 3.4, 429b14–22; 3.5.) But so far as the intelligible is distinct from the intellect, both are in potency, as appears in the senses: for neither is the sight actually seeing, nor the visible actually seen, except when the sight is informed by the species of the visible object, so that one thing results from sight and visible. Accordingly, if the intelligible objects of God are outside his intellect, it will follow that his intellect is in potency, and likewise his intelligible objects: and thus he will need something to reduce him to act. But this is impossible, since this thing would be prior to him.

Further. The object understood must be in the intellect. Therefore, in order to explain how God understands the multitude of things, it is not enough to suppose that the forms of things exist in themselves outside the divine intellect, but they must be in the divine intellect itself.