(CG 1/057). The Knowledge of God is not a Reasoned Knowledge (Book 1: Of God As He Is In Himself) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

THINGS mentally combinable and separable are naturally considered by the mind apart from one another: for there would be no need of their combination and separation, if by the mere apprehension of a thing as being it were at once understood what was in it or not in it. If therefore God understood by a mental process of combination and separation, it would follow that He did not take in all things at one glance, but each thing apart, contrary to what has been shown above (Chap. LV).

3. A mind that combines and separates, forms different judgements by different combinations. For a mental combination does not go beyond the terms of the combination. Hence, in the combination, or affirmative judgement (compositione), whereby the mind judges that man is an animal, it does not judge that a triangle is a figure. Now combination or separation is an operation of the mind. If God therefore views things by mentally combining and separating them, His mental act will not be one only but manifold; and so His essence will not be one only.

Not for this however must we say that He is ignorant of tenable propositions: for His one and simple essence is the pattern of all things manifold and compound; and so by it God knows the whole multitude and complexity as well of actual nature as of the ideal world (tam naturae quam rationis).

This is in consonance with the authority of Holy Scripture: for it is said, For my thoughts are not your thoughts (Isa. lv, 8); and yet, The Lord knows the thoughts of men (Ps. xciii, 11), which certainly proceed by combination and separation of ideas.