Article 2 — Whether there is only one hypostasis or suppositum in Christ or two

Second, it is asked whether there is only one hypostasis or suppositum in Christ or two. (Parallel texts: ST III.1.3; In III Sent., d. 6, q. 1, a. 1, qa. 1–2; d. 7, q. 1, a. 1; SCG IV.38–39; On the Catholic Faith of the Greek Fathers (Contra errores Graecorum), part 1, ch. 20; Compendium theologiae, cc. 210–11; Quodlibet IX, q. 2, a. 1; Commentary on John, ch. 1, lect. 7.) It seems that there is not only one.

Obj. 1: Augustine says in the book Against Felicianus, in the mediator of God and of man, the Son of God was one thing and the son of man another. (Rather: Vigilius of Thapsus, Contra Felicianus, ch. 11 (PL 42:1166).) But nothing that is one in suppositum or according to hypostasis differs from one another. Therefore, in Christ there is not only one suppositum or hypostasis.

Obj. 2: Further, Augustine says in the book On the Trinity (Augustine, On the Trinity, bk. 1, ch. 7, para. 14 (PL 42:829; Corpus Christiana Series Latina [CCSL] 50).) that each of the natures in Christ is God on account of God who receives, and each is man on account of the man received. But nothing that is one in suppositum or according to the hypostasis is two in such a way that it may be called both. Therefore, there is not only one hypostasis or suppositum in Christ.

Obj. 3: Further, the human nature in Christ is a certain substance. But it was not a universal substance, because a universal substance does not exist beyond the mind. Therefore, it was a particular substance. But a particular substance is a hypostasis. Therefore, the human nature in Christ was a hypostasis. But the human nature in Christ is something beyond the hypostasis of the Word of God, and thus there are many hypostases in Christ.

Obj. 4: Further, this name “man” is said univocally of Christ and of Peter. When it is said of Peter, it entails nothing other than something composed of a rational soul and a body. Therefore, it also entails this when it is said of Christ. But beyond the soul and the body, there is in Christ the hypostasis or the suppositum of the Word of God. Therefore, in Christ, the hypostasis or suppositum of the human nature is one thing, and that of the divine nature is another. Thus, there is not only one hypostasis or suppositum in Christ.

Obj. 5: Further, nothing infinite can be contained under a finite nature. But the suppositum or hypostasis of the Word of God possesses infinity. Therefore, it cannot be contained under a human nature which is finite. But every suppositum is contained under that nature whose suppositum it is. Therefore, the suppositum which is the Word of God cannot be the suppositum of a human nature, but there must be some other suppositum. Therefore, there is some other suppositum in Christ beyond the suppositum which is the Word of God. Therefore, there are two supposita or hypostases in Christ.

Obj. 6: Further, just as a genus is related to the species, so the species is related to an individual. But the same species cannot be in different genera. Therefore, one individual cannot be in diverse species. But the hypostasis is an individual substance, as is the suppositum. Therefore, there cannot be one hypostasis or suppositum of the human and divine natures, as these do not belong to one species.

Obj. 7: Further, just as there is one nature in three persons in the Trinity, so there are two natures in one person in Christ. But the three persons are one on account of a unity of nature, according to John 10:30, I and the Father are one. Therefore, Christ is two on account of the duality of natures. But nothing which is one in its suppositum or according to its hypostasis, can be called two. Therefore, Christ is not one in his suppositum or according to his hypostasis.

Obj. 8: Further, Christ has something in common with the Father insofar as he is the Son of God; and insofar as he is the son of man, he has nothing in common with the Father. Therefore, in Christ the Son of God is one thing and the son of man is another, so he is not one in suppositum or according to the hypostasis.

Obj. 9: Further, what is incommunicable of itself does not seem to be able to become communicable by itself. So too, what is impossible of itself cannot become possible, as the Commentator says in Metaphysics 10. (Averroes (Ibn Rushd, 1126–1196 AD), Commentary on the Metaphysics, bk. 10, ch. 9, comm. 26.) But insofar as the human nature is in Christ, it is incommunicable of itself, since it is something particular. Therefore, it cannot be communicated to the suppositum of the divine nature, so the suppositum of the human and divine nature cannot be the same.

Obj. 10: Each thing is resolved into those things out of which it consists. Therefore, if it were granted, through some impossibility, that the Word of God set aside the human nature, then the human nature would have its own hypostasis and suppositum. Therefore, in the united state, it has its own hypostasis or suppositum united. Therefore, there is not only one hypostasis or one suppositum here.

Obj. 11: Further, nature is not more dependent upon the suppositum than the suppositum is upon the nature. But the suppositum of the human nature could not be assumed by the Word of God without the human nature itself being assumed. Therefore, neither could the Word of God assume human nature without also assuming the suppositum of the human nature. But the thing assuming is not the assumed. (Cf. Aquinas, Quodlibet IX, q. 2, a. 1.) Therefore, the suppositum of the human nature is not the suppositum of the Word of God; therefore, there are two supposita in Christ.

Obj. 12: The soul and the body were not less powerful or dignified in Christ than in us. But in us a hypostasis or suppositum is constituted from the composition of the soul and the body. Therefore, this also happens in Christ. But the suppositum or hypostasis of the Word of God, which is eternal, cannot be so constituted since the aforesaid union is temporal. Therefore, there are two supposita or hypostases in Christ.

Obj. 13: Further, there are three substances in Christ: body, soul, and God. But the soul is not the suppositum of the body. Therefore, God is not the suppositum of the human nature.

Obj. 14: Further, according to Porphyry, an aggregation of properties which cannot be found in another thing produces individuation. (Porphyry, Isagogue, ch. 2.) But in Christ there was an aggregation of properties pertaining to the human nature, which cannot be found in another. Therefore, they would have produced individuation, but not the individuation of the Word of God, which does not receive accidents. Therefore, there is another individual or suppositum in Christ than the Word of God. Therefore, there are two supposita in Christ.

Obj. 15: Further, those things without some proportional relationship are not able to be one. But there is no proportion between the divine nature, which is infinite, and the human, which is finite. Therefore, one hypostasis or one suppositum cannot be brought about from two natures.

Obj. 16: Further, generation is terminated in the suppositum, for a particular is what is generated. But there is a two-fold nativity in Christ, namely, a temporal and an eternal one. Therefore, there is a two-fold suppositum in Christ and not merely one.

Obj. 17: Further, the Word of God assumed a body and a soul not, indeed, as separated but as united. But the suppositum of the human nature is nothing other than the soul and the body as united. Therefore, in Christ there is another suppositum beyond the suppositum of the Word of God.

Obj. 18: The same thing cannot be both simple and composite. But the suppositum of the human nature is composite, since the human nature is composed. For the suppositum cannot be more simple than the nature whose suppositum it is. Therefore, since the suppositum of the divine nature is simple, there will be a suppositum in Christ besides the suppositum of the divine nature.

On the contrary (1), there is what Damascene says in book 3 of On the Orthodox Faith, we know that there is one hypostasis in the Lord Jesus Christ. (John Damascene, On the Orthodox Faith, bk. 3, ch. 4 (PG 94:997–98).)

Furthermore (2), in those things which differ in suppositum, one is not predicated of another. Therefore, if the suppositum of man and of God were different in Christ, it could not be said that man is God or that God is man, which is an error. Therefore, the suppositum of man and God do not differ in Christ.

I answer that certain men, wanting to avoid the heresy of Nestorius, that is, the heresy of positing two persons in Christ, posited one person in Christ but two hypostases or supposita. They said that this man, pointing to Christ, is a suppositum and a hypostasis of the human nature, but not of the divine nature. Because of the fact that he is called “this man,” nothing else is entailed than a certain particular substance composed from a soul and flesh. Yet they say that a human hypostasis or suppositum pertains to the person of the Word, because it was assumed by the Word. This is the opinion which is posited first in Sentences III, distinction 7. (Peter Lombard, Sentences, bk. 3, d. 5–7 (PL 192:767–73).)

But in the first place, those who posited this were ignorant of the proper word. For a hypostasis is nothing other than an individual substance, which is also signified by the name “suppositum.” Now Boethius says, in the book On the Two Natures, that a person is an individual substance of a rational nature. (Boethius, On the Person and the Two Natures: A Treatise Against Eutyches and Nestorius, ch. 3 (PL 64:1343).) So, therefore, it is obvious that there cannot be a hypostasis of a rational nature unless it is a person. Now, it is clear that the human nature is a rational nature; hence, if there is a proper hypostasis or proper suppositum of the human nature in Christ beyond the hypostasis or suppositum of the Word of God, it follows that there is a proper person of the human nature in Christ beyond the hypostasis of the Word. Thus, this position would not differ from the position of Nestorius.

Second, this is because, if it is granted that the person adds to a hypostasis in a rational nature some property pertaining to dignity, just as all wearing a mask are said to be like one having some dignity, (The English translation is unfortunately unable to retain the connection between personatum, “wearing a mask,” and persona, which originally simply meant “mask” and referred to the mask that an actor would wear in order to show the person he was supposed to be on the stage. See Boethius, On the Person and the Two Natures: A Treatise Against Eutyches and Nestorius, ch. 3 (PL 64:1343).) it would follow that the union of the human nature to the Word was not brought about except in something accidental, namely, in some property pertaining to dignity, which is what Nestorius also posited. Hence, it must be known that this heresy was condemned in the fifth Council carried out at Constantinople, where it is read, if anyone tries to introduce two subsistences into the mystery of Christ or to argue that two persons are said to be one person according to dignity and honor and adoration, as Theodorus and Nestorius wrote foolishly, let them be anathema. For the Holy Trinity did not receive a person or subsistence cast away in the one incarnation of the holy Trinity from the Word of God. (The Second Council of Constantinople (fifth ecumenical council, in 553 AD), “Anathemas against the ‘Three Chapters,’” anathema 5.)

Therefore, in order that it may be known what must be conceded and what denied in these matters, it is necessary to consider which of the names pertain to individuation, whether they are names of first imposition, such as “person” and “hypostasis,” which signify things themselves, or whether they are names of second imposition, such as “individual,” “suppositum,” and others of this kind, which signify the intention of individuality. Some of these pertain only to the genus of substance, such as “suppositum” and “hypostasis,” which are not said of accidents, and person in a rational nature, and also a thing of nature according to the understanding of St. Hilary. (Hilary of Poitiers (4th cent. AD), On the Trinity, bk. 8, para. 22 (PL 10:252).) But others pertain to individuation in every genus, such as “individual,” “particular,” and “singular,” which are also said of accidents.

Now, it is proper to a substance that it subsists through itself and in itself, but it is the character of an accident to be in another. Thus, those names which pertain to the individuation of a substance only have a place in those things which subsist through themselves and in themselves. For this reason also, these names are not said of the parts of substances, since they are not in themselves but in a whole, although they are not in a subject. Yet the names pertaining to individuation as much in substances as in accidents can fittingly be said of those things. For it cannot be said that this hand is a person, or a hypostasis, or a suppositum, although it can be said that it is some particular, singular, or individual. For even if a hand pertains to the genus of substance, yet because it is not a completed substance, subsisting in itself, it is not called a hypostasis, or a suppositum, or a person.

Thus, therefore, since the human nature in Christ does not subsist separately through itself but exists in another, that is, in the hypostasis of the Word (indeed, not as an accident in a subject, nor properly as a part in a whole, but through an ineffable assumption), thus the human nature in Christ can indeed be called some individual or particular or singular, yet it cannot be called a hypostasis or suppositum, just as it cannot be called a person. Hence, it remains that in Christ there is only one hypostasis or suppositum, namely, the divine Word.

Reply Obj. 1: Human and divine things are said of Christ, and if it is asked what they are said of, the answer is one and the same thing. But if one considers that according to which they are predicated, this is one thing and another, as Augustine says in On the Trinity 1, since divine things are predicated of Christ according to the divine nature, but human things are predicated of him according to the human nature. (Augustine, On the Trinity, bk. 1, ch. 7, para. 14; ch. 13, para. 28 (PL 42:829; 840).) Therefore, when it is said that in Christ the Son of God is one thing and the son of man another, this otherness must not be referred to what both are predicated of, that is one suppositum of each filiation, but to that according to which predication takes place. Thus, Augustine in the same place adds, I say ‘other’ (aliud) on account of a distinction of substance, that is, of nature, not ‘other’ (alius) on account of the unity of person. (Rather: Vigilius of Thapsus, Contra Felicianus, ch. 11 (PL 42:1166).)

Reply Obj. 2: In fact, the divine nature is predicated of Christ, but the human nature cannot be predicated of him, just as it cannot be predicated of Peter, with whom Christ is univocally a man. (In other words, on account of the real distinction between being and essence, it is false to say, “Peter is his humanity” or “Peter is human nature.”) Hence, it cannot be said that Christ is two or both, although there are two natures. A suppositum of a human nature is indeed predicated of Christ, but it does not combine in number with the suppositum of the divine nature, as was shown. Hence, it remains that when Christ is called both, it is understood materially, just as when it is said that “walls and a roof are a house,” because both coincide in one house. Hence, Augustine also says, in the book Against Felicianus, that one and the same man is called both body and soul. (Rather: Vigilius of Thapsus, Contra Felicianus, ch. 11 (PL 42:1166).) Or it can be said that what is called “both” must be referred to the number of names signifying the two natures. For the man Christ is called both God and man, just as God the Word is called both God and man. And this is why both are called God, on account of receiving God, since, of course, this name “God” is predicated both of God and of man. Also, both are called man on account of receiving man, because this name “man” is predicated of both.

Reply Obj. 3: It does not suffice for the account of a hypostasis or suppositum that something is a particular in the genus of substance; but, further, it is required that it be complete and subsisting in itself as was said. (Above: resp.)

Reply Obj. 4: Equivocation and univocation are found inasmuch as the account of the name is the same or different. For the account of a name is what the definition signifies; (See Aristotle, Metaphysics 4.7, 1012a23. However, Aquinas usually provides the definition of “definition” as follows: ratio quam significat nomen est definitio, “the definition is the account that the name signifies.” For example, see: Aquinas, In I Sent., d. 2, q. 1, a. 3; d. 25, q. 1, a. 2, ad 2; In IV Sent., d. 27, q. 1, a. 1, qa. 2, obj. 2; ST I.13.6; I.85.2, ad 3; and elsewhere throughout his works.) thus, equivocation and univocation are found according to the signification, and not according to the supposita. Thus, this name “man” is said univocally of Christ and of Peter, because it signifies one nature in both, namely, human, composed from a body and a soul; but in Christ, the term “man” stands for an eternal suppositum in Christ, which it does not stand for in Peter.

Reply Obj. 5: Being infinite belongs to the suppositum or hypostasis of the Word of God according to the divine nature; but, according to the human nature, it belongs to it to be under a human nature. Hence, Dionysius says that he was produced within our nature who supersubstantially exceeds every order, according to every nature. (Pseudo-Dionysius, On the Divine Names, ch. 1, para. 4 (PG 3:591–92).)

Reply Obj. 6: The name “species” signifies a nature, just as the name “genus” does; hence, if one species were in different genera, it would follow that one nature was two natures. But “individual” entails something which does not pertain to the nature; thus, it is not contrary to the account of an individual that the same individual is the suppositum of two natures.

Reply Obj. 7: The divine nature is entirely the same as all three of the persons in reality; thus, the three persons can be called one being. But the human nature is not entirely the same as its suppositum in reality, and so it is not predicated of it; thus, Christ cannot be said to be two on account of the two natures. (See above: ad 2.)

Reply Obj. 8: The Son of God has the divine nature in common with the Father, but not the hypostasis or the person. Now, the Son of Man does not have either the hypostasis or the nature in common with God the Father. Hence, it does not follow from this that there is a distinction in person between the Son of God and the Son of Man, but only a distinction of nature.

Reply Obj. 9: The human nature assumed by the Word, inasmuch as it is individual, has the property that it cannot be in many things. In this respect, it is called incommunicable. But from that fact that it is a nature, it has the property of being in some suppositum.

Reply Obj. 10: As long as the human nature is united to the Word of God, it does not have its own suppositum or hypostasis beyond the person of the Word, because it does not exist in itself. But if it were separated from the Word, it would have not only its own hypostasis or suppositum, but also its own person, because it would now exist essentially. So too, a part of a composite body, as long as it is undivided from the whole, exists only in potency, not actually; but this is only brought about by separation.

Reply Obj. 11: Nature is included in the suppositum, but not conversely. Thus, the suppositum could not be assumed without the nature; but it was able to happen conversely.

Reply Obj. 12: The union of the soul and the body in Christ is more worthy than in us because it is not terminated in a created suppositum, but in the eternal suppositum of the Word of God.

Reply Obj. 13: The soul is united to the body as its form for constituting the human nature, but the divinity is not united to the humanity in Christ in this way, because the union was not brought about in the nature, as was said above. (Above: a. 1.) Thus, the account of the two cases is not the same.

Reply Obj. 14: The aggregation of his own accidents sufficiently proves the individuation of the human nature in Christ, but it does not have the account of a suppositum or a hypostasis because it does not exist essentially.

Reply Obj. 15: The union of the human nature to the person or the hypostasis of the Word in Christ is not brought about in this way: that it is made equal to the person of the Word as if including it or as though the person of the Word exceeds it according to some fixed proportion since the person of the Word still exceeds the human nature infinitely. Yet this infinite difference does not exclude the person of God from joining the human nature to itself in the unity of the hypostasis in an ineffable way. Rather, the infinite power of the one assuming works more effectively towards a greater union.

Reply Obj. 16: Generation is indeed terminated in the suppositum as to what is generated, but in the nature as to that which is received through generation. Hence, form is called the terminus of generation. Since generations and motions are distinguished according to their terms, hence it is that there are two nativities of Christ according to the two natures, but one nativity according to the unity of the suppositum.

Reply Obj. 17: The united soul and body constitute a suppositum and a hypostasis, if what is composed from both exists essentially, which does not happen in this case.

Reply Obj. 18: Christ is simple according to the divine nature, but composite according to the human nature, as is evident from Dionysius in the first chapter of On the Divine Names. (Pseudo-Dionysius, On the Divine Names, ch. 1, para. 4 (PG 3:591–92).)