Commentaria in Summam contra Gentiles, Liber IV

Having rejected the opinion of Photinus, St. Thomas proceeds to the refutation of the opinion of Sabellius¹. And first, he sets forth the opinion itself; secondly, he refutes it²; thirdly, he responds in general to the objections³.

I. As to the first point, he says first that, because all who think rightly about God hold that there can naturally be only one God, certain persons, conceiving from the Scriptures that Christ is truly and naturally God and the Son of God, confessed that Christ the Son of God and God the Father are one God; but that God is not called Son according to his nature or from eternity, but only from the time he was born of the Virgin Mary; and thus they attributed to God the Father all the things that Christ endured according to the flesh. This was the opinion of the Sabellians: who were also called Patripassians, because they said that the Father suffered, asserting that the Father himself is Christ. Moreover, they confirm their position by the authority of Deut.⁴ 6, Hear, O Israel, etc.; and Deut. 32, See, etc.; likewise John 5, The Father in me, etc.; and 14, He that seeth me, etc.

He says secondly that this opinion differs from the aforesaid one regarding the divinity of Christ, but is in agreement with it regarding generation and sonship: because both confess that the sonship and generation by which Christ is called the Son of God did not exist before Mary, referring these only to the human nature. — This position also has this peculiar feature, that when he is called the Son of God, what is designated is not a subsisting person, but a certain property supervening upon the person, inasmuch as the Father himself, according as he took flesh from the Virgin, received the name of Son.

2. It should be noted that one who posits that the Son is not a person distinct from the Father, but that the Father himself is called Son according as he assumed flesh, does not posit between him who is called Father and him who is called Son any real distinction, but only a distinction of reason, just as Socrates standing is said to be distinguished from Socrates sitting. Hence just as, when Socrates is called sitting, a person other than the person of Socrates standing is not designated, but only an extrinsic disposition supervening upon him; so, when according to this position the Son of God is spoken of, a person other than that which is called God the Father is not designated, but a certain disposition or relation of reason supervening upon him; which relation St. Thomas in this place calls a property.

II. As to the second point, St. Thomas argues against this position⁵.

First, thus. Christ is called the Son of God. Therefore God the Father is not the Son himself. — The consequence is proved. Because the same cannot be the Son of himself: otherwise, since the generator gives being to the generated, the same would be the giver and the receiver of being.

Secondly. The Lord says, John 6, I came down from heaven, etc.; and 17, Father, glorify me, etc. From which it is shown that the Son is other than the Father. Therefore etc.

If it should be said that God according to his divinity is called the father of himself according to his humanity, inasmuch as he created and sanctified the human nature which he assumed: — on the contrary it is argued, because it would follow that Christ is called the Son of God just as other men are: namely, either by reason of creation or by reason of sanctification. But it is clear from the preceding that Christ is called the Son of God for a different reason than other saints are.

Thirdly. Christ speaks of himself and the Father plurally, saying: I and the Father are one. Which does not happen where there is only one supposit. Therefore etc.

Fourthly. It is found from Sacred Scripture that the Son was distinct from the Father before the Incarnation: as in John 1, where it is said, In the beginning, etc.; and Prov. 8, I was with him, etc.; likewise Hosea 1, I will have mercy on the house of Jacob, etc.; likewise Gen. 1, Let us make man, etc.; from which the distinction of the Father and the Son before the Incarnation is shown. Therefore it is false that the Son is distinguished from the Father solely through the mystery of the Incarnation.

For the understanding of this reason⁶, it must be considered, from the teaching of St. Thomas on John, in the exposition of that which is said, And the Word was with God⁷, that this preposition with (apud), according as it is properly taken, implies subsistence in that which is said to be with another: for we do not say that whiteness is with a body; but rather, that a man is with a man, and a stone with a stone. It also implies distinction: because one is not properly said to be with oneself. From which it is clear that when the Son of God is said to be with God, it is signified that the Son of God is a certain supposit distinct from God the Father, but having some union with him. Therefore it is well said here that the Word, which was with God, had a certain distinction from him: because the custom of speech has this, that one thing is said to be with another.

Sixthly. Christ is truly the Son of God, as is clear from 1 John the last chapter, That we may be, etc. Therefore he must be distinguished from the Father in supposit. — The consequence is proved. Because, since sonship belongs to the supposit itself, and the names of paternity and sonship require distinction in those of whom they are said (namely, truly and properly): if someone is truly called a son, he must be distinguished in supposit from the father.

Seventhly. Even after the mystery of the Incarnation, the Father testifies concerning the Son, This is my beloved Son, etc. Which demonstration refers to the supposit. Therefore Christ is according to his supposit other than the Father.

III. As to the third point⁸, responding to all the foundations of the Sabellians at once—for below he will respond in detail—St. Thomas says that they do not show their intent. For from the fact that God is one, or that the Father is in the Son and conversely, it does not follow that the Father and the Son are one in supposit: since between two distinct in supposit there can be a certain unity.