Capítulo XXXIV da Summa Contra Gentiles, de São Tomás de Aquino:
Of the Error of Theodore of Mopsuestia concerning the Union of the Word with Man
BY the foregoing chapters it appears that neither was the divine nature wanting to Christ, as Photinus said; nor a true human body, according to the error of the Manicheans; nor again a human soul, as Arius and Apollinaris supposed. These three substances then meet in Christ, the Divinity, a human soul, and a true human body. It remains to enquire, according to the evidence of Scripture, what is to be thought of the union of the three. Theodore of Mopsuestia, then, and Nestorius, his follower, brought out the following theory of this union.
 They said that a human soul and a human body were naturally united in Christ to constitute one man of the same species and nature with other men; and that in this man God dwelt as in His temple by grace, as He does in other holy men. Hence He said Himself: Dissolve this temple, and in three days I will raise it up: which the Evangelist explains: He spoke of the temple of his body (John ii, 19). Hereupon there followed a union of affections between the Man Christ and God, the Man adhering with hearty good will to God, and God willingly accepting Him, as He says Himself: He that sent me is with me; and he hath not left me alone, because I do always the things that are pleasing to him (John viii, 29): giving us to understand that the union of that Man with God is as the union of which the Apostle speaks: He that adhereth to God, is one spirit (1 Cor. vi, 17). And as by this union the names that properly apply to God are transferred to men, so that they are called gods, and sons of God, and lords, and holy ones, and christs, as appears by divers passages of Scripture (e.g., Pss. lxxxi, civ); so are divine names duly applied to the Man Christ, and by reason of the indwelling of God and the union of affections with Him He is called God, and Son of God, and Lord, and Holy One, and Christ. Moreover, because in that Man there was greater fulness of grace than in other holy men, He was above others the temple of God, and more closely united with God in affection, and shared the divine names by a peculiar privilege of His own; and for this excellence of grace He was put in participation of divine honour and dignity, and has come to be adored along with God. And thus one is the person of the Word of God, and another the person of that Man who is adored along with God. Or if there is said to be one person of them both, that will be by reason of the aforesaid union of affections, on the strength of which that Man and the Word of God will be one person, in the same way in which it is said of husband and wife that they are no more two, but one flesh (Matt. xix, 6). And because such a union does not authorise us to predicate of the one whatever can be predicated of the other – for not whatever is true of the husband is true of the wife, or vice versa, — therefore in the case of the union of the Word with that Man this Nestorian doctrine has it we should not fail to notice how the properties of that Man, belonging to His human nature, cannot fitly be predicated of the Word of God, or God. Thus it is proper to that Man to have been born of a Virgin, to have suffered, died, and been buried: all of which things, Nestorians say, are impossible to predicate of God, or of the Word of God. But because there are some names which, while applying to God in the first place, are communicated to man in a sense, as Christ, Lord, Holy One, or even Son of God, they see no difficulty in terms expressive of the above incidents of humanity being united as predicates with these names. So they think 625 it proper to say that `Christ,’ `the Lord of glory,’ `the Saint of saints,’ or even `the Son of God,’ was `born of a virgin,’ ‘suffered,’ `died,’ and `was buried.’ Therefore they say that the Blessed Virgin should not be called `mother of God,’ or `of the Word of God,’ but `mother of Christ.’
1. Any thoughtful person may see that this theory cannot stand with the truth of the Incarnation. The theory holds that the Word of God was united with the Man Christ only by the indwelling of grace and consequent union of wills. But the indwelling of the Word of God in man does not mean the Word of God being Incarnate: for the Word of God and God Himself dwelt in all the saints from the beginning of the world, according to the text: Ye are the temple of the living God, as God says: I will dwell in them (2 Cor vi, 16: Levit. xxvi, 12). But this indwelling cannot be called an incarnation: otherwise God must have become incarnate frequently from the beginning of the world. Nor is it enough to constitute an incarnation, if the Word of God and God dwelt in the Man Christ with more abundant grace: for greater and less do not make a difference of species in point of union.
3. Everything that is made anything is that which it is made, as what is made man is man, and what is made white is white. But the Word of God has been made man (John i, 14). Therefore the Word of God is man. But, of two things differing in person, or suppositum,  the one cannot possibly be predicated of the other. When it is said `Man is an animal,’ that self-same being which is an animal is man. When it is said, `Man is white,’ some particular man himself is pointed at as being white, although whiteness is beyond the essential notion of humanity. But in no way can it be said that Socrates is Plato, or any other of the individuals either of the same or of a different species. If then the Word has been made flesh, that is, man, it is impossible for there to be two persons, one of the Word, the other of the Man.
4. No one would say, `I am running,’ when some one else was running, except perhaps figuratively, meaning that another was running in his place. But that man who is called Jesus (John ix, 11) says of Himself, Before Abraham was, I am (John viii, 58); I and the Father are one (John x, 30); and sundry other phrases, manifestly proper to the divinity of the Word. Therefore the person of that Man speaking is the person of the Son of God. 6. To ascend into heaven is clearly an attribute of Christ as man, who in their sight was taken up (Acts i, 9). And to descend from heaven is an attribute of the Word of God.
But he who descended, the same is he that hath ascended (Eph. iv, 10). 11. Though a man be called `Lord’ by participation in the divine dominion, still no man, nor any creature whatever, can be called `the Lord of glory’: because the glory of happiness to come is something which God alone by nature possesses, others only by the gift of grace: hence it is said: The Lord of mighty deeds, he is the king of glory (Ps. xxiii, 10). But, had they known, never could they have crucified the Lord of glory (1 Cor. ii, 8). It is true then to say that God was crucified.
12. Scripture attributes suffering and death to the only-begotten Son of God: He spared not his own Son, but gave him up for us all (Rom. viii, 32): God so loved the world as to give his only begotten Son (John iii, 16: cf. verse 1 and Rom. v, 8).
17. The word was made flesh (John i, 14). But the Word was not flesh except of a woman. The Word then was made of a woman (Gal. iv, 4), — of a Virgin Mother, for a Virgin is the Mother of the Word of God.  19. Phil. ii, 5-11. If with Nestorius we divide Christ into two — into the Man, who is the Son of God by adoption, and the Son of God by nature, who is the Word of God, — this passage cannot be understood of the Man. That Man, if he be mere man, was not, to begin with, in the form of God so as afterwards to come to be in the likeness of men, but rather the other way about, being man, He became partaker of the Deity, in which participation He was not emptied, but exalted. It must then be understood of the Word of God, that He was, to begin with, from eternity in the form of God, that is, in the nature of God, and afterwards emptied himself by being made in the likeness of men. That emptying cannot be understood to mean the mere in dwelling of the Word of God in the man Christ Jesus. For from the beginning of the world the Word of God has dwelt by grace in all holy men, yet not for that is it said to be emptied: for God’s communication of His goodness to creatures is no derogation from Himself but rather an exaltation, inasmuch as His pre-eminence appears by the goodness of creatures, and all the more the better the creatures are. Hence if the Word of God dwelt more fully in the Man Christ than in other saints, there was less emptying of the Word in His case than in the case of others. Evidently then the union of the Word with human nature is not to be understood to mean the mere indwelling of the Word of God in that Man, but the Word of God truly being made man. Thus only can that emptying be said to take place; the Word of God being said to be emptied, that is made small, not by any loss of His own greatness, but by the assumption of human littleness. 
24. The man Christ, speaking of Himself, says many divine and supernatural things, as, I will raise him up at the last day (John vi, 40): I give them life everlasting (John x, 28). Such language would be the height of pride, if the speaker were not Himself God, but only had God dwelling in him. And still Christ says of Himself: Learn of me, because I am meek and humble of heart (Matt. xi, 29). 
26. In him all things were made (Col. i, 16) is said of the Word of God; and first-born of the dead (ib. 18) is said of Christ; in such context as to show that the Word of God and Christ are one and the same person. 27. The same conclusion appears in 1 Cor. viii, 6: And one Lord Jesus Christ, by whom are all things. The opinion of Nestorius on the mystery of the Incarnation differs little from the opinion of Photinus. Both asserted that the man Christ was God only through the indwelling of grace. Photinus said that Christ merited the name and glory of Godhead by His passion and good works. Nestorius avowed that He had this name and glory from the first 627 instant of His conception on account of the full and ample indwelling of God in Him. But concerning the eternal generation of the Word they differ considerably; Nestorius confessing it, Photinus denying it entirely.
 The great feature in the theology of the fourth and fifth centuries was the opposition between the school of Alexandria, allegorical, mystical, Oriental, and the school of Antioch, matter-of-fact, literal, accurate, Western-minded. There were Saints and Doctors of both schools, and heretics in both, the latter carrying the tendencies of their respective schools to excess. From Alexandria came Origen, Athanasius, Cyril, Arius, Apollinaris, Dioscorus. From Antioch, John Chrysostom, Theodoret, Theodore of Mopsuestia, Nestorius. Theodore in his early career was a friend of St John Chrysostom, who addressed to him the still extant treatise, Ad Theodorum lapsum, against the forsaking of monastic life. He was a priest with Chrysostom at Antioch, then in 392 bishop of Mopsuestia (Mopsou hestia) in Cilicia, and died in his bishopric in 428, three years before the Council of Ephesus. Theodore was a voluminous writer and biblical commentator, fond of the literal sense, hating allegories. He was a vigorous opponent of Arius, and especially of Apollinaris. On the other hand, he countenanced the Pelagians, and wrote against St Jerome and St Augustine. Theodore, like Bishop Jansenius of Ypres, enjoyed the reputation of orthodoxy all his life, and died in the peace of the Church. As the Jansenists took up the book of Jansenius, drew their heresy from it, and involved themselves and it in a final condemnation; so the Nestorians fell back upon Theodore, the protagonist of the Antiochene school. Thus Theodore and his works came to be condemned in the fifth General Council, the second of Constantinople in 553.
Since their condemnation, the greater part of them have perished. Nestorius, a Syrian, educated at Antioch, became bishop of Constantinople in 428, the year of Theodore’s death. He was condemned and deposed in the Council of Ephesus in 431. Nestorianism is the most rationalistic, and in that way the acutest, of all heretical perversions of the Incarnation. At this day, east and west, beyond the visible pale of the Catholic Church, thousands of professing Christians are, consciously or unconsciously, Nestorians.
 Persona is a rational nature complete by itself Suppositum is any nature so complete, whether rational or irrational.
 “Enough,” says St Thomas, “that the body is of the mother, though the soul is not. Suitably therefore is the Blessed Virgin said to be the mother of the Word of God, and even of God, though the divinity of the Word is not borrowed from a mother. There is no need of a son borrowing all his substance from his mother, but only his body” (above, n. 13) — Mary is the mother of Him who is God. She is not mother of the Godhead, or divine nature. Neither is any man’s mother mother of his soul.
 In note on page 361] a somewhat different interpretation is offered according to more modern views of this important passage. St Thomas and the older school take the emptying (exinanitio, kenosis) to consist in the Incarnation itself. The more modern view represents it as consisting, not in the Incarnation itself, but in the manner of life chosen 628 by the Word Incarnate, a life fraught with the miseries, needs and liabilities of ordinary humanity, whereas the glory and impassibility, which He assumed only at His resurrection, was His by right from His mother’s womb. This is the meaning of that term, so celebrated in modern theology, kenosis. If we regard the divine nature, the Incarnation itself was, as St Thomas says, “no loss of God’s own greatness,” which nothing can possibly diminish. Again, if we regard the human nature assumed at the Incarnation, that humanity, again to employ St Thomas’s words, “was not emptied, but exalted,” — and that much more by the hypostatic union than by any Nestorian inhabitatio divinitatis. Either way explained, the passage tells against Nestorius.
 This is the thesis, Christus si non Deus, non bonus, urged in Liddon’s Bampton Lectures on the Divinity of Christ, where also many of these texts are handled.