(CG 1/043). That God is Infinite (Book 1: Of God As He Is In Himself) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

IN no order of causes is it found that an intelligent cause is the instrument of an unintelligent one. But all causes in the world stand to the prime mover, which is God, as instruments to the principal agent. Since then in the world there are found many intelligent causes, the prime mover cannot possibly cause unintelligently.

5. No perfection is wanting in God that is found in any kind of beings (Chap. XXVIII): nor does any manner of composition result in Him for all that (Chap. XVIII). But among the perfections of creatures the highest is the possession of understanding: for by understanding a thing is in a manner all things, having in itself the perfections of all things.

6. Everything that tends definitely to an end, either fixes its own end, or has its end fixed for it by another: otherwise it would not tend rather to this end than to that. But the operations of nature tend to definite ends: the gains of nature are not made by chance: for if they were, they would not be the rule, but the exception, for chance is of exceptional cases. Since then physical agents do not fix their own end, because they have no idea of an end, they must have an end fixed for them by another, who is the author of nature. But He could not fix an end for nature, had He not Himself understanding.

7. Everything imperfect is derived from something perfect: for perfection is naturally prior to imperfection, as actuality to potentiality. But the forms that exist in particular things are imperfect, for the very reason that they do exist in particular, and not in the universality of their idea, or the fulness of their ideal being. They must therefore be derived from some perfect forms, which are not under particular limitations. Such forms cannot be other than objects of understanding, seeing that no form is found in its universality or ideal fulness, except in the understanding. Consequently such forms must be endowed with understanding, if they are to subsist by themselves: for only by that endowment can they be operative. God therefore, who is the first actuality existing by itself, whence all others are derived, must be endowed with understanding.

This truth also is in the confession of Catholic faith : for it is said: He is wise of heart and mighty of power (Job ix, 4): With him is strength and wisdom (Ibid. xii, 16): Your wisdom is made wonderful to me (Ps. cxxxviii, 6): O depth of riches, of wisdom and of knowledge of God (Rom. vi, 33).