Commentaria in Summam contra Gentiles, Liber IV

After St. Thomas excluded the errors concerning the soul and body of Christ, he wishes further to exclude the errors concerning the union of the divine Word with man ¹. Concerning this, however, he does two things: first, he excludes the errors themselves; second, he concludes what must be held according to the truth of the faith, in chapter xxxix.

Concerning the first, he does five things, according as he excludes five errors. For first he excludes the error of Theodore of Mopsuestia and Nestorius; second, the error of Eutyches, in the following chapter; third, the error of the Antiochene, in chapter xxxvi; fourth, the error of certain unnamed persons, in chapter xxxvii; fifth, the error of others, also unnamed, in chapter xxxviii.

I. As to the first, he does three things: first, he sets forth the error itself; second, he disproves it ²; third, he compares it to the opinion of Photinus ³.

He says therefore first: Since in Christ there are the divinity, a human soul, and a true human body, Theodore of Mopsuestia and Nestorius his follower said, first, that the human soul and the human body came together in Christ by a natural union to constitute one man, of the same species and nature with other men; and that God dwelt in this man as in His temple, namely through grace, as in other saints. Hence He Himself said, John II, Destroy etc.; and the Evangelist, as if explaining, adds, But He etc.; and in Coloss. I, it is said that in Him it pleased etc.

They said secondly, that from this there followed a kind of affective union between that man and God, while that man by his good will cleaved to God, and God by His will accepted him: according to that of John VIII, He who sent me etc. Hence such a union is understood as that about which the Apostle speaks, 1 Cor. VI, He who cleaves etc.

They said thirdly, that on account of the indwelling of God and the union of affection, divine names belong to that man: namely, so that he is called God, and Son of God, and Lord, and holy, and Christ.

They said fourthly that, because there was in that man a greater fullness of grace than in other holy men, he was above all others the temple of God, and more closely united to God according to affection. And therefore he was established in a participation of divine dignity and honor, namely, so as to be co-adored with God.

From these things it follows that the person of the Word is one, and the person of that man another. And if there is said to be one person of both, this will be on account of the aforesaid affective union: just as of a woman and a man it is said that they are no longer two, but one flesh.

They said fifthly that, because such a union does not bring it about that whatever is said of the one can be said of the other—for not whatever belongs to the husband is true of the wife, or conversely—they think this must be observed, that the proper attributes of that man, pertaining to the human nature, cannot fittingly be said of the Word of God or of God, such as that He was born of the Virgin, that He suffered, died, and was buried, and other things of this kind: but they can well be predicated of certain divine names which are communicated to men in a certain manner, such as Christ, Lord, holy, Son of God. For it is fittingly said, according to them, that Christ the Lord of glory, or the Holy of holies, or the Son of God, was born of the Virgin, suffered, and the like. Hence they say that the Blessed Virgin is to be named not the Mother of God, or of the Word of God, but the Mother of Christ.

II. In the second place, St. Thomas argues against this position ⁴.

First. This position excludes the truth of the Incarnation, and consequently takes away the foundation of the Christian religion. Therefore etc. — The assumption is proved. Because the indwelling of the divine Word in man through grace is not for the Word of God to be incarnate: otherwise, since from the constitution of the world there was such an indwelling in holy men, according to that of the Apostle, 2 Cor. VI, You are the temple etc., God would have been incarnate frequently from the beginning of the world. Nor is it sufficient for this that a more abundant grace dwelt in that man: because more and less do not diversify the species of a union.

Second. Sacred Scripture was accustomed to signify the indwelling of the Word of God in holy men in these ways: The Lord spoke to Moses; The word of the Lord came to Jeremiah, and modes of this kind; but it is never read that the word of the Lord was made Moses, or Jeremiah, or any other of them. But the Evangelist designates the union of the Word of God with the flesh, saying, The Word was made flesh. Therefore etc.

Third. The Word of God is man: because what is made something, is that thing. But of two things differing in person or supposit or hypostasis, one cannot be predicated of the other: just as it cannot be said that Socrates is Plato, or any other of singulars. Therefore it is impossible that there be two persons or two supposits of the Word of God and of that man.

It must be noted, from the doctrine of St. Thomas, Prima, q. XIII, a. 12, that in every proposition in which something is affirmed of another, there must be identity between the predicate and the subject, although sometimes the formal signified of the subject is one thing, and the formal signified of the predicate another: for it is implied that the form of the subject and the form of the predicate are in the same thing, and thus an identity of supposit is implied. For when it is said, Man is an animal, it is signified that it is the same supposit to which belongs the rational nature, from which he is called man, and the sensible nature, from which he is called animal. Likewise when it is said, The man is white, it is signified that it is the same supposit to which both humanity and whiteness belong. And therefore it was fittingly said that those things which are distinguished according to supposits cannot be predicated of one another.

III. Fourth. That man who was called Jesus says of Himself, John VIII, Before Abraham was made, I am; and John X, I and the Father are one; and many other things which pertain to the divinity of the Word. Therefore the person of that man speaking is the very person of the Son of God. — The consequence is proved. Because demonstrative pronouns refer to the person, hypostasis, or supposit.

It must be noted that the foundation of this response is that that man who was called Jesus attributed to His own proper supposit those things which belong to the divinity, such as to be before Abraham, and to be one with the Father. Now this is signified by the pronoun I, which is a demonstrative sign of the supposit. And therefore it is necessary that the supposit of that man be the divine supposit, to which it belongs to be eternally, and to be the same with the Father as to essence.

Fifth. That man, speaking from His own person, says that He descended from heaven, John VI. Therefore His person is the person of the Word of God. — The consequence is proved. Because, since neither the body of Christ nor His soul descended from heaven, as has been shown, it remains that this belongs to the Word of God, not by local motion, but by union with an inferior nature.

Sixth. To ascend into heaven belongs to the man Christ, as is said in Acts I: but to descend, to the Word of God. Now He that descended is the same also that ascended, Ephes. IV. Therefore etc.

Seventh. What belongs to the Word of God is truly said of that man. Therefore there is one person of both. — The assumption is proved. To come into the world belongs to the Word of God, as is clear in John I: but not to the man Christ according to His humanity, since according to the flesh He has His origin from the world, and according to the soul He did not exist before He was in the world. But that man says that He came into the world, John XVI. Therefore etc.

It must be noted that for someone to come into the world presupposes that he is: for just as every local motion presupposes the being of the thing, so also everything which is signified to belong to someone after the manner of local motion presupposes that he is. For although of someone newly born it is said that he has now come into the world, this is nonetheless said improperly, and is rather given to be understood that he was newly born in the world; unless it be understood that, existing previously in the maternal womb, he afterwards came forth into the light. Therefore St. Thomas well says that to that which has its origin from the world, and which never was before it was in the world, it does not belong to come into the world.

IV. Eighth. The Word of God is entering into the world. Therefore a body is fitted to Him, namely, so that it may be His proper body: according to that which is said in Heb. X, When he cometh into the world etc. But this could not be unless the hypostasis of the Word of God and of that man were the same. Therefore etc.

Ninth. The body of that man was the body of the Word of God, as has been shown. Therefore every passion wrought in that body can be attributed to the Word, so that it can be said that God suffered, was crucified, etc. Which is against the last assertion of that position ⁵. — The consequence is proved. Because every passion belonging to the body of someone can be attributed to him whose body it is.

Tenth. He on account of whom are all things; through whom are all things; who brought men into glory; and who is the author of human salvation, suffered and died, as is clear in Heb. II. But these things belong singularly to God, and are attributed to no other: for it is said in Prov. XVI, The Lord hath made all things etc.; and John I, All things were made by him; and in the Psalm, Grace and glory etc.; and again, The salvation of the just etc. Therefore etc.

Eleventh. The Apostle says that they crucified the Lord of Glory, 1 Cor. II. But no creature can be called the Lord of Glory: since God alone possesses by nature the glory of future beatitude, but others through the gift of grace. Therefore etc.

Twelfth. Scripture attributes passion and death to the proper and only-begotten Son of God: as in Rom. VIII, and John III, and Rom. V, etc. But that man in whom the Word is indwelling, according to the aforesaid position, although he is the son of God through the grace of adoption, cannot be called the proper or only-begotten Son of God: but only the Word of God, which according to the property of nativity is singularly begotten of the Father. Therefore etc.

V. Thirteenth. The body of that man was taken from the Virgin mother; and consequently, according to what was said before, it is the body of the Word of God. Therefore it is fittingly said that the Blessed Virgin is the Mother of God. — The consequence is proved. Because someone is said to be the son of a certain mother from the fact that his body is taken from her, although his soul is not taken from the mother, but is from without, namely from God.

Fourteenth. As is held in Gal. IV, God sent his Son, made of a woman: from which it is understood that the Son of God is said to be sent in that He was made of a woman. But this cannot be understood of the son who, according to Nestorius, is adoptive: because he did not exist before he was born of a woman; now that which is sent is understood to be prior to being in that into which it is sent. Therefore it is understood of the natural Son. But from the fact that someone is made of a woman, he is called the son of the woman. Therefore God, the Word of God, is the Son of the woman.

If it be said that the word of the Apostle is not understood in such a way as if the Son of God were sent to this end, that He might be made of a woman, but that the Son of God, who was made of a woman and under the law, was sent to this end, that he might redeem them who were under the law; and thus it is not necessary to take the Son of God for the natural Son, but for that man who is the son of adoption: — against this is the fact that the Apostle attributes to the Son of God this, namely to rescue from the servitude of the law. But this belongs to God alone, by whom the law was established.

It is confirmed first, because the redemption of the human race is attributed to God Himself in the Psalms, where it is said, Thou hast redeemed us, O Lord etc.

It is confirmed secondly, because the adoption of sons is not caused by man, but by God: since it is brought about through the Holy Spirit, according to that of Rom. VIII, You have received etc.; and the Holy Spirit is not the gift of man, but of God. But it is caused by the Son of God, sent by God and made of a woman: as is clear from what is added, that we might receive the adoption of sons. Therefore the word of the Apostle is understood of the natural Son of God.

Fifteenth. The Word was made flesh. And He has it only from a woman. Therefore He was made of a woman. Therefore the Blessed Virgin is the mother of the Word of God.

Sixteenth. Christ, who is over all things, is of the Fathers according to the flesh, as is said in Rom. IX. But He is not of the Fathers except by means of the Virgin. Therefore He is of the Virgin according to the flesh. Therefore etc.

VI. Seventeenth. The Apostle says of Christ Jesus, Philip. II: Who being in the form of God, emptied himself etc. But this cannot be understood of that man who, according to Nestorius, is the son of adoption: because, if he is a mere man, he was not previously in the form of God, so as afterwards to be made in the likeness of men. Therefore it is understood of the natural Son, which is the Word of God. But this emptying cannot be understood through the indwelling alone of the Word of God in man: because the Word of God from the beginning of the world dwelt in all the saints through grace, and yet is not said to be emptied; since in the communication of the divine goodness nothing is subtracted from God, but rather He is in a certain way exalted, according as His sublimity appears from the goodness of creatures; and all the more so the better they are. Therefore the union of the Word of God with the human nature is not to be understood according to indwelling through grace alone, but according as the Word of God was truly made man: in which way He is said to be emptied, that is, made small, not by the loss of His own greatness, but by the assumption of human smallness. — This is illustrated by the example of the soul etc.

Eighteenth. It will be necessary to say that the Holy Spirit also was incarnate, if the Incarnation of the Word is understood according to this alone, that the Word of God dwelt most fully in that man. For the Holy Spirit also dwelt in the man Christ, as is clear from Luke IV. But this is completely alien to the faith. Therefore etc.

Nineteenth. The Word of God also dwells in the holy angels, who are filled with understanding by participation in the Word. But the Apostle says, Heb. II: For nowhere doth he take hold of the angels: but of the seed of Abraham he taketh hold. Therefore etc.

Twentieth. If, according to the position of Nestorius, Christ is separated into two differing according to hypostasis, that is, into the Word of God and that man, it follows that Jesus Himself cannot be called Christ; and thus what the Apostle says in Philip. II will not be true: Let this mind be in you, which was also in Christ Jesus. — The consequence is proved. For neither can the Word of God be called Christ: both because Scripture before the Incarnation never names Him Christ; and because, since Christ is said as it were anointed with the Holy Spirit, as is clear in Acts X, the Holy Spirit would be greater than the Son, as sanctifying the sanctified. Nor also that man: since the Apostle adds, who being in the form of God etc.; because then it would be true to say that that man is in the form, that is, in the nature of God and equal to God; which is false. Therefore etc.

VII. Twenty-first. To the man Christ, of whom it is said in Heb. III that he was made, the Apostle attributes in the same place that he created all things. Therefore the man Christ is God Himself according to hypostasis, and not by reason of indwelling only. — The antecedent is proved. Because the Apostle attributes to the man Christ that he built the house of God, by this reason, because God created all things. Which proof would certainly be of no worth unless Christ were God creating all things. — But the consequence is proved because, although the name of God is transferred to holy men, nevertheless those things which belong to God alone, such as to create heaven and earth, and the like, are never said of any of the saints on account of the indwelling of grace.

Twenty-second. The man Christ says of Himself many divine and supernatural things: as in John VI, I will raise up etc.; and John X, I give eternal life etc. But He would not say this unless the very man speaking were God according to hypostasis: because that would be of the highest pride; but Christ says of Himself, Matt. XI, Learn of me etc. Therefore etc.

Twenty-third. Just as it is said in Acts II that that man is exalted; so in Philip. II it is said that God was emptied. Therefore, just as sublime things can be said of that man by reason of the union, such as that he is God, that he raises the dead, etc.; so lowly things can be said of God, such as that He was born of the Virgin, suffered, etc. Which is indeed contrary to the fifth assertion of Nestorius ⁶.

Twenty-fourth. After the Apostle said, Coloss. I, In him were all things created etc., he adds that he is the firstborn from the dead. But this which is said, in him were all things created, pertains to the Word of God: whereas to be the firstborn from the dead belongs to the man Christ. Therefore the Word of God and the man Christ are one supposit, and consequently one person. Therefore etc. — The consequence is proved. Because relatives, both adverbs ⁷ and pronouns, refer to the same supposit.

It must be noted that person adds nothing above the notion of supposit except that it be of a rational nature: for a person, according to Boethius ⁸, is an individual substance of a rational nature. Therefore St. Thomas rightly infers that if the Word of God and the man Christ are one supposit, they are one person.

Twenty-fifth. As is said in 1 Cor. VIII, There is one Lord Jesus Christ, by whom are all things. Therefore the Word of God and that man are one Lord, not two. Therefore also one person. — The consequence is proved. Because Jesus Christ, namely the name of that man by whom are all things, belongs to the Word of God.

VIII. In the third place, St. Thomas compares the opinion of Nestorius to the opinion of Photinus ⁹. And he says that it differs little from it as to the mystery of the Incarnation, because each asserted that that man was God solely on account of the indwelling of grace: although Photinus said that he merited this very thing through suffering and good works; whereas Nestorius said that from the beginning of his conception he had such a name and glory. But concerning the eternal generation of the Word they differed: for Nestorius confessed it; while Photinus denied it altogether.

It must be noted, according to St. Thomas, Tertia, q. II, a. 3, that this error of Nestorius, positing two persons in Christ, was condemned in the Fifth Council, that of Constantinople, where it is said ¹⁰: If anyone attempts to introduce into the mystery of Christ two subsistences or two persons, let him be anathema.