Book Four — Salvation, Chapter 7 — Summa Contra Gentiles
[1] That this opinion is manifestly repugnant to divine Scripture anyone can see who considers diligently what sacred Scripture says.
[2] For, when divine Scripture names Christ the Son of God and angels the sons of God it does so for different reasons. Hence, the Apostle says: “To which of the angels has He said at any time, ‘You are My Son, today have I begotten You” (Heb. 1:5). And it was to Christ that this was said, he asserts. But, according to the aforesaid position, angels are called sons for the same reason as Christ, for the name of sonship is fitting to each according to a kind of sublimity of nature in which they were created by God.
[3] Neither is this objection met if Christ is of a nature more excellent than other angels. For, even among the angels diverse orders are discovered, which became clear above, and for all that, to all of them the same notion of sonship is suitable. Therefore, Christ is not called the Son of God in the way the position described maintains.
[4] Again, since by reason of creation the name of divine sonship is suitable to many-for it belongs to all the angels and saints—if Christ also were called Son on the same ground, He would not be “only-begotten; although by reason of the excellence of His nature over all others He could be called “firstborn.” However, Scripture asserts that He is only-begotten: “We saw His glory, the glory as it were of the only-begotten of the Father” (John 1:14). It is not, therefore, by reason of creation that He is called the Son of God.
[5] Moreover, the name of sonship properly and truly follows on the generation of living things in which the begotten proceeds from the substance of the one begetting; otherwise, the name of sonship is taken not in truth but in similitude, as when we call either students or others who are in our charge our sons. If, then, Christ were not called Son except by reason of creation, since that which is created by God is not derived from the substance of God, Christ could not be called Son truly. But He is called the true Son in 1 John (5:20): “that we may be; he says, “in His true Son, Jesus Christ.” Therefore, He is not called the Son of God as created by God in an excellence of nature, however great, but as one begotten of God’s substance.
[6] What is more, if Christ is called Son by reason of creation, He will not be truly God. For nothing created can be called God unless by some similitude to God. But this same Jesus Christ is true God, for, when John had said: “that we may be in His true Son,” he added: “This is the true God and life eternal.” Therefore, Christ is not called the Son of God by reason of creation.
[7] Furthermore, the Apostle says: “Of whom is Christ, according to the flesh, who is over all things, God blessed forever. Amen” (Rom. 9:5); and in Titus (2:13): “Looking for the blessed hope and coming of the glory of the great God and our Savior Jesus Christ.” And Jeremiah (23:5-6) says: “I will raise up to David a just branch”; and adds below: “and this is the name that they shall call Him: The Lord our just one.” There in Hebrew the name is the tetragrammaton, which certainly is said of God alone. From these sayings it is clear that the Son of God is true God.
[8] Moreover, if Christ be the true Son, of necessity it follows that He is true God. For, that cannot truly be called son which is begotten of another, even if the thing be born of the substance of the one begetting unless it comes forth in species like the one begetting; the son of a man must be a man. If, therefore, Christ be the true Son of God, He must be true God. Therefore, He is not anything created.
[9] Again, no creature receives the complete fullness of divine goodness, because, as was made clear above, perfections proceed from God to creatures in a kind of descent. But Christ has in Himself the complete fullness of the divine goodness, for the Apostle says: “In Him dwells all the fulness of the Godhead” (Col. 2:9). Therefore, Christ is not a creature.
[10] Grant, furthermore, that the intellect of an angel has a more perfect knowledge than the intellect of man; it is still in great want from the divine intellect. But the intellect of Christ is not in want of knowledge from the divine intellect, for the Apostle says that in Christ “are hidden all the treasures of wisdom and knowledge” (Col. 2:3). Therefore, Christ the Son of God is not a creature.
[11] Furthermore, whatever God has in Himself is His essence, as was shown in Book I. But, all things the Father has are the Son’s. For the Son Himself says: “All things whatsoever the Father has are Mine” (John 16:15); and in John (17:10), speaking to the Father, he says: “All My things are Yours, and Yours are Mine.” The essence and nature, then, of the Father and Son is the very same. Therefore, the Son is not. a creature.
[12] What is more, the Apostle says that the Son, before He emptied himself taking the form of a servant, was “in the form of God” (Phil. 2:6-7). By the form of God, however, nothing is understood but the divine nature, just as by the form of the servant human nature is understood. The Son, then, is in the divine nature. Therefore, He is not a creature.