Thomas Aquinas, Disputed Questions on Truth (De Veritate)

This inquiry is occasioned by the position of Avicenna mentioned above. We wish to inquire whether God knows propositions, especially about singulars.

Difficulties:

It seems that He does not, for

1. The divine intellect always remains in the same state; but a singular, inasmuch as now it exists and now it does not exist, has different states. Consequently, the divine intellect does not know whether or not a singular now exists.

2. Those powers of the soul which are indifferent to a thing's presence or absence--as, for example, the imagination--do not know whether or not a thing exists; this is known only by those powers, such as sense, which do not know absent things as though they were present. Now, the divine intellect is disposed in the same way to things present or absent. Consequently, it does not know whether things exist now or not; it knows merely their natures.

3. According to the Philosopher, the composition signified when a thing is said to be or not to be is not in things but only in the intellect. Now, there can be no composition in the divine intellect. Therefore, God does not know whether or not a thing exists.

4. In the Gospel according to St. John (1:3-4) we read: "What was made, in Him was life." Now, in his explanation of this passage, Augustine says that created things are in God in the way in which a trunk is in the mind of the one who makes it. By means of the mental likeness of the trunk, however, a carpenter does not know whether the trunk exists or not. Consequently, neither does God know whether or not a singular now exists.

5. The more noble knowledge is, the more it resembles God's knowledge. But the knowledge of an intellect comprehending the definitions of things is more noble than sense knowledge; for, when the intellect defines, it penetrates to the interior of a thing, but sense deals with externals. When the intellect defines, however, it does not know whether a thing exists or not, but simply the nature of the thing. Sense, however, does have such knowledge. It seems, therefore, that that type of knowledge by which only the nature of a thing is known, but not whether a thing exists or not, should be attributed to God.

6. God knows each and every thing by means of the idea He has of it. Now, that idea is indifferent to the existence or the non-existence of the thing. Otherwise, God could not know the future by means of it. God, therefore, does not know whether or not a thing exists.

To the Contrary:

1'. The more perfect knowledge is, the more conditions it grasps in its object. Now, divine knowledge is most perfect; consequently, it knows a thing according to all its conditions. Therefore, God knows whether or not a thing exists.

2'. As we have said above, God has a proper and distinct knowledge of things. Now, He would not know things distinctly unless He could distinguish an existing thing from one which does not exist. Therefore, He knows if a thing does or does not exist.

REPLY:

The relation of the universal essence of any species to the essential properties of that species is the same as that of a singular essence to all the proper accidents of that singular, that is, all the accidents found in the singular; for, in so far as they are individuated by the singular, they are made proper to it. Now, by knowing the essence of a species, the intellect comprehends all the essential properties of that species; for, as the Philosopher says, the definition is the principle of any demonstration that concludes to the proper accidents of a subject. Therefore, once the proper essence of any singular were known, all the accidents of that singular would also be known. Our intellect, however, cannot know the essence of a singular, because it abstracts from designated matter, which pertains to the essence of a singular and would be placed in its definition if the singular had one. The divine intellect, however, can comprehend not only the universal essence of a species, but, since it can apprehend matter, it can also comprehend the singular essence of each and every thing. Therefore, it knows all accidents, those common to the entire species or genus, as well as those proper to each individual. Among these latter is time, in which every concrete reality is found and according to which a thing is said to exist now or not. Consequently, God knows whether or not each and every thing exists; and He knows all other propositions that can be formed about universals or individuals.

In this respect, however, the divine intellect differs from ours. In order to know a subject and an accident and to know different accidents, our intellect forms separate concepts, and, consequently, passes from knowledge of a substance to knowledge of one of its accidents. Again, in order to know the inherence of one of its accidents, it joins one species with the other, and, in a certain manner, unites them. In this way, the intellect forms propositions in itself. But by one reality, namely, its own essence, the divine intellect knows all substances and all accidents. Consequently, it neither passes from substance to accident nor joins one with the other; but instead of the joining of species which takes place in our intellect, there is, in the divine intellect, complete unity; because of this, God, without complexity, knows what is complex, just as He knows many things simply and with unity, and material things immaterially.

Answers to Difficulties:

1. By means of one and the same reality, the divine intellect knows all the conditions in a thing that are subject to change; so, while remaining in one and the same state, it knows all the states of things, no matter how they change.

2. The likeness in the imagination is a likeness merely of the thing; it is not a likeness by which one can know the time in which a thing exists. This limitation is not found in the divine intellect, so the cases are not parallel.

3. In place of the composition found in our intellect, there is, instead, a unity in the divine intellect. This composition, however, is a kind of imitation of unity, and for this reason it is said to be a union. Thus, it is clear that God knows enunciable truths by not composing more truly than an intellect that does compose and divide.

4. The trunk in the mind of its maker is not a likeness of everything which can belong to it. Consequently, a craftsman's knowledge and God's are not similar.

5. He who knows a definition knows potentially the truths demonstrable by the definition. But in the divine intellect, actually to be does not differ from to be able to be. Consequently, from the fact that it knows the essences of things, it immediately comprehends all the accidents that follow upon them.

6. That idea in the divine mind is related to a thing in the same way, no matter what its condition is, for it is a likeness of the thing according to all its states. Consequently, through it the divine mind knows that thing in any condition whatever.