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.

Reply Obj. 2: Transition imports a certain succession of parts; and

hence it is that the infinite cannot be traversed by the finite, nor

by the infinite. But equality suffices for comprehension, because

that is said to be comprehended which has nothing outside the

comprehender. Hence it is not against the idea of the infinite to be

comprehended by the infinite. And so, what is infinite in itself can

be called finite to the knowledge of God as comprehended; but not as

if it were traversable.

Reply Obj. 3: The knowledge of God is the measure of things, not

quantitatively, for the infinite is not subject to this kind of

measure; but it is the measure of the essence and truth of things.

For everything has truth of nature according to the degree in which

it imitates the knowledge of God, as the thing made by art agrees

with the art. Granted, however, an actually infinite number of

things, for instance, an infinitude of men, or an infinitude in

continuous quantity, as an infinitude of air, as some of the ancients

held; yet it is manifest that these would have a determinate and

finite being, because their being would be limited to some

determinate nature. Hence they would be measurable as regards the

knowledge of God.

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