SECTION 5. -- The Divisions of the Divine Knowledge.

172. Though the Divine knowledge is one undivided act, not really distinct from the Divine Essence, we may nevertheless divide it according to the diversity of the objects to which it extends. Such a division is useful, inasmuch as it is based upon the different relations of the objects of Divine knowledge to God Himself, and thus recalls to us in few words what we have explained fully in the preceding section.

First, then, if we take the whole body of truths which God knows concerning Himself and concerning finite things, His knowledge may be said to be partly necessary, partly free. It is necessary, inasmuch as on no supposition could it have been in any other relation to its objects than it is now; it is free, inasmuch as things are now known as actual, which might not have been known as actual under a different use of the freedom of the Creator and of His creatures. Therefore God has a necessary knowledge of Himself, and of all finite things and actions in so far as they are purely possible. And by a free knowledge He knows His own decrees, and whatever in consequence of the exercise of His own freedom or that of His rational creatures has been actual, is actual, will be actual, or would be actual under certain circumstances, considered precisely in its past, present, future, absolute, or conditional actuality.

At first sight it might seem that such a division is inconsistent with God's immutability. Yet it is not so. In saying that the knowledge which God has of His own decrees and of existences outside Himself might have stood otherwise towards its objects than it does stand, we do not say that His act of knowledge could have changed internally, or that the range of His knowledge could have extended further or less far: we state only that He now sees things as actual which He might have seen as merely possible. If God had created neither matter nor spirit, He would nevertheless have distinctly seen material bodies with all their vicissitudes and all finite spiritual beings with all their actions and states; yet all these things He would have seen as purely possible, whereas He sees now as actual at one time or another the things which He has decreed from eternity to bring into existence, together with their necessary and free actions and the results of both. Yet in no case is His knowledge determined from without: He has it in virtue of His unchangeable essence. Nor would His knowledge of the exercise of created freedom be less, strictly speaking, than it now is, even though He had created no rational creature. The only difference would be that the actions, which now His Intellect represents as really future free actions, would in that case have been represented as conditionally future. And the reason of this difference would be the absence of the free decree to create rational creatures and to provide the circumstances under which they use their freedom as they use it in the present order of things.

173. There is another division of Divine knowledge which has regard only to things distinct from God. These are said to be known by God partly through the scientia visionis (knowledge of vision), partly through the scientia simplicis intelligentiae (knowledge of simple intelligence). The nature of this distinction is clearly explained in the following words of St. Thomas: "A difference must be marked as regards things which are not now actually existing. Some of them, although they are not existing now, yet have existed or will exist, and all these are said to be known by God through the knowledge of vision. For since God's understanding which is His being, is measured by eternity, and eternity is something which, unchangeable in itself, embraces all time, it follows that the intuitive vision of God, as it is at the present moment, takes in all time and all things that are at any time whatever, and He sees all this as distinctly as if it were really present. But there are other things which are in the power of God or of creatures, but which never exist, nor will exist, nor have existed, and of these we do not say that God has a knowledge of vision, but only that He knows them through the knowledge of simple intelligence."^{11}

From this passage of the Angelic Doctor it appears that, according to his terminology, the knowledge of vision comprises whatever is actual outside God at whatever time, whereas to the knowledge of simple intelligence everything is relegated which, though never actual, is in the power either of God alone or of creatures under God. Of conditionally future free actions, St. Thomas did not treat ex professo. These actions cannot be said to be merely possible, and yet they are never actual, if the circumstances under which they will happen are never realized. Hence the question arises: Are they seen by the knowledge of vision or by the knowledge of simple intelligence? We might refer them to the knowledge of simple intelligence, by saying that to it belongs whatever is seen as possible, and yet not actual, whether not actual simply (purely possible), or not actual except under certain conditions (conditionally future). We might also refer conditionally future free actions to the knowledge of vision by saying that to it belongs whatever is at any time either really or conditionally actual. Those Catholic philosophers who reject the notion of physical predetermination, say commonly that conditionally future free actions are seen by what they call scientia media (middle knowledge), as having for its object something neither purely possible nor really actual, but between the two. We ourselves hold strongly to what is meant by the term scientia media, without insisting upon the necessity of retaining this term as such. We conclude then by defining the scientia media as the knowledge that God has of the conditionally future existence of the free actions of His rational creatures, without having decreed physically to predetermine the said creatures to the said actions.

{11} "Horum quae actu non sunt est attendenda quaedam diversitas. Quaedam enim licet non sint nunc in actu, tamen vel fuerunt, vel erunt, et omnia ista dicitur Deus scire scientia visionis. Quia cum intelligere Dei, quod est ejus esse, aeternitate mensuretur, quae sine successione existens totum tempus comprehendit, praesens intuitus Dei fertur in totum tempus, et in omnia quae sunt in quocumque tempore, sicut in subjecta sibi praesentialiter. Quaedam vera sunt, quae sunt in potentia Dei vel creaturae, quae tamen nec sunt, nec erunt, neque fuerunt, et respectu horum non dicitur habere scientiam visionis, sed simplicis intelligentiae." (St. Thomas, Sum. Theol. i. 14.)