Summa contra Gentiles3.51 Chapter LI. How God may be seen in his essence

Since then it is impossible for a natural desire to be void;—and it would be were it impossible to arrive at understanding the divine substance; for all minds desire this naturally:—we must conclude that it is possible for the divine substance to be seen by means of the intellect; both by separate intellectual substances, and by our souls.

It is sufficiently clear from what has been said, what manner of vision this is. For we have proved that the divine substance cannot be seen by the intellect in any created species. Wherefore if God’s essence be seen at all, it must be that the intellect sees it in the divine essence itself: so that in that vision the divine essence is both the object and the medium of vision.

Since, however, the intellect is unable to understand any particular substance, unless it be actuated by some species informing it, that is the image of the thing understood; someone might deem it impossible for a created intellect to see the very substance of God in the divine essence as an intelligible species, inasmuch as the divine essence is self-subsistent, and we have proved in the First Book? that God cannot be the form of anything.

In order to understand this truth, we must note that a self-subsisting substance is either a form alone, or is composed of matter and form. Accordingly, that which is composed of matter and form cannot be the form of something else: because the form therein is already confined to that matter, so that it cannot be the form of another thing. But that which subsists so as nevertheless to be a form alone, can be the form of something else, provided its being be such proved concerning the human soul in the Second Book. If, however, its being cannot be participated in by another, it cannot be the form of anything; because by its very being it is determined in itself, as material things are by their regards intelligible being. For, since truth is the perfection be a pure form in the genus of intelligible things. This applies solely to God: for, since truth is consequent upon being, that alone is its own truth, which is its own being; and this belongs to God alone, as we proved in the Second Book.? Consequently other subsistent intelligibles are not to the created intellect as an intelligible species by which separate substance. And yet it cannot be the form of another thing as to its natural being: for it would follow that being united to this other, it would constitute one nature; which is impossible, since the divine essence is perfect in This immediate vision of God is promised to us in Holy the Godhead: since we have proved that God has no body. Nor is.it possible for us to see God with a bodily face since the eyes of the body, which are situate in the face, can only see bodily things. Thus then shall we see God face to face, because we shall see Him immediately, even as a man whom we see face to face.

It is according to this vision that we become most like unto God, and participators of His bliss: since God understands His substance by His essence, and this is His bliss. Wherefore it is said (1 Jo. iii. 2): When He shall appear, we shall be like to Him; because we shall see Him as He is. And (Luke xxii. 29, 30) our Lord said: I dispose to you, as My Father hath disposed to Me, a banquet,' that you may eat and drink at My table in My kingdom. Now these words cannot be understood as referring to the food and drink of the body, but to that which is taken from the table of Wisdom, of which Wisdom says (Prov. ix. 5): Eat my bread and drink the wine which I have mingled for you. Accordingly, to eat and drink at God’s table is to enjoy the same bliss as that which makes God happy, and to see God as He sees Himself.