Thomas Aquinas - Summa Theologica, Part I (Prima Pars)

Obj. 2: Further, in us those faculties alone know the singular, which

receive the species not abstracted from material conditions. But in

God things are in the highest degree abstracted from all materiality.

Therefore God does not know singular things.

Obj. 3: Further, all knowledge comes about through the medium of some likeness. But the likeness of singular things in so far as they are singular, does not seem to be in God; for the principle of singularity is matter, which, since it is in potentiality only, is altogether unlike God, Who is pure act. Therefore God cannot know singular things.

On the contrary, It is written (Prov. 16:2), "All the ways of a man are open to His eyes."

I answer that, God knows singular things. For all perfections found in creatures pre-exist in God in a higher way, as is clear from the foregoing (Q. 4, A. 2). Now to know singular things is part of our perfection. Hence God must know singular things. Even the Philosopher considers it incongruous that anything known by us should be unknown to God; and thus against Empedocles he argues (De Anima i and Metaph. iii) that God would be most ignorant if He did not know discord. Now the perfections which are divided among inferior beings, exist simply and unitedly in God; hence, although by one faculty we know the universal and immaterial, and by another we know singular and material things, nevertheless God knows both by His simple intellect.

Now some, wishing to show how this can be, said that God knows singular things by universal causes. For nothing exists in any singular thing, that does not arise from some universal cause. They give the example of an astrologer who knows all the universal movements of the heavens, and can thence foretell all eclipses that are to come. This, however, is not enough; for singular things from universal causes attain to certain forms and powers which, however they may be joined together, are not individualized except by individual matter. Hence he who knows Socrates because he is white, or because he is the son of Sophroniscus, or because of something of that kind, would not know him in so far as he is this particular man. Hence according to the aforesaid mode, God would not know singular things in their singularity.

On the other hand, others have said that God knows singular things by the application of universal causes to particular effects. But this will not hold; forasmuch as no one can apply a thing to another unless he first knows that thing; hence the said application cannot be the reason of knowing the particular, for it presupposes the knowledge of singular things.

Therefore it must be said otherwise, that, since God is the cause of things by His knowledge, as stated above (A. 8), His knowledge extends as far as His causality extends. Hence as the active power of God extends not only to forms, which are the source of universality, but also to matter, as we shall prove further on (Q. 44, A. 2), the knowledge of God must extend to singular things, which are individualized by matter. For since He knows things other than Himself by His essence, as being the likeness of things, or as their active principle, His essence must be the sufficing principle of knowing all things made by Him, not only in the universal, but also in the singular. The same would apply to the knowledge of the artificer, if it were productive of the whole thing, and not only of the form.

Reply Obj. 1: Our intellect abstracts the intelligible species from the individualizing principles; hence the intelligible species in our intellect cannot be the likeness of the individual principles; and on that account our intellect does not know the singular. But the intelligible species in the divine intellect, which is the essence of God, is immaterial not by abstraction, but of itself, being the principle of all the principles which enter into the composition of things, whether principles of the species or principles of the individual; hence by it God knows not only universal, but also singular things.

Reply Obj. 2: Although as regards the species in the divine intellect its being has no material conditions like the images received in the imagination and sense, yet its power extends to both immaterial and material things.

Reply Obj. 3: Although matter as regards its potentiality recedes from likeness to God, yet, even in so far as it has being in this wise, it retains a certain likeness to the divine being. _______________________

TWELFTH ARTICLE [I, Q. 14, Art. 12]

Whether God Can Know Infinite Things?

Objection 1: It seems that God cannot know infinite things. For the infinite, as such, is unknown; since the infinite is that which, "to those who measure it, leaves always something more to be measured," as the Philosopher says (Phys. iii). Moreover, Augustine says (De Civ. Dei xii) that "whatever is comprehended by knowledge, is bounded by the comprehension of the knower." Now infinite things have no boundary. Therefore they cannot be comprehended by the knowledge of God.

Obj. 2: Further, if we say that things infinite in themselves are finite in God's knowledge, against this it may be urged that the essence of the infinite is that it is untraversable, and the finite that it is traversable, as said in Phys. iii. But the infinite is not traversable either by the finite or by the infinite, as is proved in Phys. vi. Therefore the infinite cannot be bounded by the finite, nor even by the infinite; and so the infinite cannot be finite in God's knowledge, which is infinite.

Obj. 3: Further, the knowledge of God is the measure of what is known. But it is contrary to the essence of the infinite that it be measured. Therefore infinite things cannot be known by God.

On the contrary, Augustine says (De Civ. Dei xii), "Although we cannot number the infinite, nevertheless it can be comprehended by Him whose knowledge has no bounds."

I answer that, Since God knows not only things actual but also things possible to Himself or to created things, as shown above (A. 9), and as these must be infinite, it must be held that He knows infinite things. Although the knowledge of vision which has relation only to things that are, or will be, or were, is not of infinite things, as some say, for we do not say that the world is eternal, nor that generation and movement will go on for ever, so that individuals be infinitely multiplied; yet, if we consider more attentively, we must hold that God knows infinite things even by the knowledge of vision. For God knows even the thoughts and affections of hearts, which will be multiplied to infinity as rational creatures go on for ever.

The reason of this is to be found in the fact that the knowledge of every knower is measured by the mode of the form which is the principle of knowledge. For the sensible image in sense is the likeness of only one individual thing, and can give the knowledge of only one individual. But the intelligible species of our intellect is the likeness of the thing as regards its specific nature, which is participable by infinite particulars; hence our intellect by the intelligible species of man in a certain way knows infinite men; not however as distinguished from each other, but as communicating in the nature of the species; and the reason is because the intelligible species of our intellect is the likeness of man not as to the individual principles, but as to the principles of the species. On the other hand, the divine essence, whereby the divine intellect understands, is a sufficing likeness of all things that are, or can be, not only as regards the universal principles, but also as regards the principles proper to each one, as shown above. Hence it follows that the knowledge of God extends to infinite things, even as distinct from each other.

Reply Obj. 1: The idea of the infinite pertains to quantity, as the Philosopher says (Phys. i). But the idea of quantity implies the order of parts. Therefore to know the infinite according to the mode of the infinite is to know part after part; and in this way the infinite cannot be known; for whatever quantity of parts be taken, there will always remain something else outside. But God does not know the infinite or infinite things, as if He enumerated part after part; since He knows all things simultaneously, and not successively, as said above (A. 7). Hence there is nothing to prevent Him from knowing infinite things.