Summa contra Gentiles3.53 Chapter LIII. That the created intellect needs a ray) of) the divine light in order to see God in his essence

To so sublime a vision the created intellect needs to be raised by some kind of outpouring of the divine goodness. For it is impossible that the proper form of anything become the form of another, unless this other bear some resemblance to the thing to which that form properly belongs: thus light does not actuate a body which has nothing in common with the diaphanous. Now the divine essence is the proper intelligible form of the divine intellect, and is proportionate thereto: for these three, understanding, medium of understanding, and object understood, are one in God. Therefore that same essence cannot become the intelligible form of a created intellect, except through the created intellect participating in some divine likeness. Therefore this participation in a divine likeness is necessary in order that the divine substance be seen.

Again. Nothing can receive a higher form unless it be disposed thereto through its capacity being raised: because every act is in its proper power. Now the divine essence is a higher form than any created intellect. Wherefore in order that the divine essence become the intelligible species to a created intellect, which is requisite in order that the divine substance be seen, the created intellect needs to be raised for that purpose by some sublime disposition.

Besides. If two things from not being united become united, this must be either through both being changed, or one only. Now if we suppose that some created intellect begin to see the divine essence, it follows from what we have said,! that the divine essence is united to that intellect as an intelligible species. But it is impossible that the divine ' essence be changed, as we have proved. Therefore this union must begin through a change in the created intellect. And this change can only consist in the created intellect acquiring some new disposition—The same conclusion follows if we suppose some created intellect to be endowed from the outset of its creation with such a vision. For if, as we have proved,’ this vision exceeds the faculty of nature, it is possible to conceive any created intellect as complete in its natural species without its seeing God’s substance. Consequently, whether it see God from the beginning, or be- ‘gin to see Him afterwards, its nature needs something to be added to it. Further. Nothing can be raised to a higher operation except through its power being strengthened. Now a power iY [may be increased in two ways. First, by a mere intensifying of the power: thus the active power of a hot subject 1s increased by the intensity of the heat, so that it is capable of a more vehement action in the same species. Secondly, by the addition of a new form: thus the power of a diaphanous body is increased so that it can give light, through its being made actually lightsome by receiving the form of light anew.) This increase of power is necessary in order that there result an operation of another species. Now the natural power of the created intellect is not sufficient for the vision of the divine substance, as we have shown. Therefore its power needs to be increased, in order that it attain to that vision. But increase through intensification of the natural power is insufficient: because that vision is not of the same kind as ‘the natural vision of the created intellect: which is clear from the distance of the things seen. Therefore there must be an increase of the intellective power through its receiving anew disposition. Now owing to the fact that we derive our knowledge of intelligible beings from sensible things, we transfer the terms employed in sensual knowledge to our intellectual knowledge; especially those that appertain to the sight, which of all the senses is the highest and most spiritual, Sebi. 1., ch. xu, 2 Ch. lii. §.Ch. li.

and therefore most akin to the intellect: and for this réason intellectual knowledge is called sight. And because bodily sight is not effected without light, those things which serve for the perfection of intellectual vision are called light: wherefore Aristotle (3 De Anima, v.) compares the active intellect to light, because the active intellect makes things actually intelligible, even as light somewhat makes things to be actually visible. Accordingly the disposition whereby the created intellect is raised to the intellectual vision of the divine substance, is rightly called the light of glory: not that it makes the object actually intelligible, as the light of the active intellect does; but because it makes the intellect able actually to understand.

This is the light of which it is said (Ps. xxxv. 10): In Thy light we shall see light, i.e. the light of the divine substance. Again it is said (Apoc. xxii. 5): The city, namely of the Blessed, hath no need of the sun, nor of the moon... for the glory of God hath enlightened it. Again it is said (Is. lx. 19): Thou shalt no more have the sun for thy light by day, neither shall the brightness of the moon enlighten thee: but the Lord shall be unto thee for an everlasting light, and thy God for thy glory.—For this reason too, since in God to be is the same as to understand, and because He is to all the cause of their understanding, He is said to be the light (Jo. i. 9): That was the true light which enlighteneth every man that cometh into this world: and (1 Jo. i. 5): God is light: and (Ps. ciii. 2): Thou... art clothed with light as with a garment.—For this reason too, both God and the angels are described in Holy Writ in figures of fire, on account of the brilliancy of fire.”