Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the union of the Word Incarnate did not take place in the suppositum or hypostasis. For Augustine says (Enchiridion xxxv, xxxviii): "Both the Divine and human substance are one Son of God, but they are one thing by reason of the Word and another thing by reason of the man." And Pope Leo says in his letter to Flavian (Ep. xxviii): "One of these is glorious with miracles, the other succumbs under injuries." But "one" and "the other" differ in suppositum. Therefore the union of the Word Incarnate did not take place in the suppositum.

Objection 2: Further, hypostasis is nothing more than a "particular substance," as Boethius says (De Duab. Nat.). But it is plain that in Christ there is another particular substance beyond the hypostasis of the Word, viz. the body and the soul and the resultant of these. Therefore there is another hypostasis in Him besides the hypostasis of the Word.

Objection 3: Further, the hypostasis of the Word is not included in any genus or species, as is plain from 1, Question 3, Article 5. But Christ, inasmuch as He is made man, is contained under the species of man; for Dionysius says (Div. Nom. 1): "Within the limits of our nature He came, Who far surpasses the whole order of nature supersubstantially." Now nothing is contained under the human species unless it be a hypostasis of the human species. Therefore in Christ there is another hypostasis besides the hypostasis of the Word of God; and hence the same conclusion follows as above.

On the contrary, Damascene says (De Fide Orth. iii, 3,4,5): "In our Lord Jesus Christ we acknowledge two natures and one hypostasis."

I answer that, Some who did not know the relation of hypostasis to person, although granting that there is but one person in Christ, held, nevertheless, that there is one hypostasis of God and another of man, and hence that the union took place in the person and not in the hypostasis. Now this, for three reasons, is clearly erroneous. First, because person only adds to hypostasis a determinate nature, viz. rational, according to what Boethius says (De Duab. Nat.), "a person is an individual substance of rational nature"; and hence it is the same to attribute to the human nature in Christ a proper hypostasis and a proper person. And the holy Fathers, seeing this, condemned both in the Fifth Council held at Constantinople, saying: "If anyone seeks to introduce into the mystery of the Incarnation two subsistences or two persons, let him be anathema. For by the incarnation of one of the Holy Trinity, God the Word, the Holy Trinity received no augment of person or subsistence." Now "subsistence" is the same as the subsisting thing, which is proper to hypostasis, as is plain from Boethius (De Duab. Nat.). Secondly, because if it is granted that person adds to hypostasis something in which the union can take place, this something is nothing else than a property pertaining to dignity; according as it is said by some that a person is a "hypostasis distinguished by a property pertaining to dignity." If, therefore, the union took place in the person and not in the hypostasis, it follows that the union only took place in regard to some dignity. And this is what Cyril, with the approval of the Council of Ephesus (part iii, can. 3), condemned in these terms: "If anyone after the uniting divides the subsistences in the one Christ, only joining them in a union of dignity or authority or power, and not rather in a concourse of natural union, let him be anathema." Thirdly, because to the hypostasis alone are attributed the operations and the natural properties, and whatever belongs to the nature in the concrete; for we say that this man reasons, and is risible, and is a rational animal. So likewise this man is said to be a suppositum, because he underlies whatever belongs to man and receives its predication. Therefore, if there is any hypostasis in Christ besides the hypostasis of the Word, it follows that whatever pertains to man is verified of some other than the Word, e.g. that He was born of a Virgin, suffered, was crucified, was buried. And this, too, was condemned with the approval of the Council of Ephesus (part iii, can. 4) in these words: "If anyone ascribes to two persons or subsistences such words as are in the evangelical and apostolic Scriptures, or have been said of Christ by the saints, or by Himself of Himself, and, moreover, applies some of them to the man, taken as distinct from the Word of God, and some of them (as if they could be used of God alone) only to the Word of God the Father, let him be anathema." Therefore it is plainly a heresy condemned long since by the Church to say that in Christ there are two hypostases, or two supposita, or that the union did not take place in the hypostasis or suppositum. Hence in the same Synod (can. 2) it is said: "If anyone does not confess that the Word was united to flesh in subsistence, and that Christ with His flesh is both---to wit, God and man---let him be anathema."

Reply to Objection 1: As accidental difference makes a thing "other" , so essential difference makes "another thing" . Now it is plain that the "otherness" which springs from accidental difference may pertain to the same hypostasis or suppositum in created things, since the same thing numerically can underlie different accidents. But it does not happen in created things that the same numerically can subsist in divers essences or natures. Hence just as when we speak of "otherness" in regard to creatures we do not signify diversity of suppositum, but only diversity of accidental forms, so likewise when Christ is said to be one thing or another thing, we do not imply diversity of suppositum or hypostasis, but diversity of nature. Hence Gregory Nazianzen says in a letter to Chelidonius (Ep. ci): "In the Saviour we may find one thing and another, yet He is not one person and another. And I say 'one thing and another'; whereas, on the contrary, in the Trinity we say one Person and another (so as not to confuse the subsistences), but not one thing and another."

Reply to Objection 2: Hypostasis signifies a particular substance, not in every way, but as it is in its complement. Yet as it is in union with something more complete, it is not said to be a hypostasis, as a hand or a foot. So likewise the human nature in Christ, although it is a particular substance, nevertheless cannot be called a hypostasis or suppositum, seeing that it is in union with a completed thing, viz. the whole Christ, as He is God and man. But the complete being with which it concurs is said to be a hypostasis or suppositum.

Reply to Objection 3: In created things a singular thing is placed in a genus or species, not on account of what belongs to its individuation, but on account of its nature, which springs from its form, and in composite things individuation is taken more from matter. Hence we say that Christ is in the human species by reason of the nature assumed, and not by reason of the hypostasis.

Articulus 3

Argumentum 1

Ad tertium sic proceditur. Videtur quod unio verbi incarnati non sit facta in supposito, sive in hypostasi.

Dicit enim Augustinus, in enchirid., divina substantia et humana utrumque est unus dei filius, sed aliud propter verbum, et aliud propter hominem.

Leo Papa etiam dicit, in epistola ad flavianum, unum horum coruscat miraculis, et aliud succumbit iniuriis.

Sed omne quod est aliud et aliud, differt supposito.

Ergo unio verbi incarnati non est facta in supposito.

Argumentum 2

Praeterea, hypostasis nihil est aliud quam substantia particularis, ut boetius dicit, in libro de duabus naturis.

Manifestum est autem quod in christo est quaedam alia substantia particularis praeter hypostasim verbi, scilicet corpus et anima et compositum ex eis. Ergo in christo est alia hypostasis praeter hypostasim verbi dei.

Argumentum 3

Praeterea, hypostasis verbi non continetur in aliquo genere, neque sub specie, ut patet ex his quae in prima parte dicta sunt.

Sed christus, secundum quod est factus homo, continetur sub specie humana, dicit enim dionysius, I cap. De div. Nom., intra nostram factus est naturam qui omnem ordinem secundum omnem naturam supersubstantialiter excedit.

Non autem continetur sub specie humana nisi sit hypostasis quaedam humanae speciei. Ergo in christo est alia hypostasis praeter hypostasim verbi dei. Et sic idem quod prius.

Sed Contra

Sed contra est quod Damascenus dicit, in III libro, in domino nostro iesu christo duas naturas cognoscimus, unam autem hypostasim.

Corpus

Respondeo dicendum quod quidam, ignorantes habitudinem hypostasis ad personam, licet concederent in christo unam solam personam, posuerunt tamen aliam hypostasim dei et aliam hominis, ac si unio sit facta in persona, non in hypostasi.

Quod quidem apparet erroneum tripliciter. Primo, ex hoc quod persona supra hypostasim non addit nisi determinatam naturam, scilicet rationalem; secundum quod boetius dicit, in libro de duabus naturis, quod persona est rationalis naturae individua substantia.

Et ideo idem est attribuere propriam hypostasim humanae naturae in christo, et propriam personam.

Quod intelligentes sancti patres, utrumque in Concilio quinto, apud constantinopolim celebrato, damnaverunt, dicentes, si quis introducere conetur in mysterio christi duas subsistentias seu duas personas, talis anathema sit, nec enim adiectionem personae vel subsistentiae suscepit sancta trinitas, incarnato uno de sancta trinitate, deo verbo.

Subsistentia autem idem est quod res subsistens, quod est proprium hypostasis, ut patet per boetium, in libro de duabus naturis.

Secundo quia, si detur quod persona aliquid addat supra hypostasim in quo possit fieri unio, hoc nihil est aliud quam proprietas ad dignitatem pertinens, secundum quod a quibusdam dicitur quod persona est hypostasis proprietate distincta ad dignitatem pertinente.

Si ergo facta sit unio in persona et non in hypostasi, consequens erit quod non sit facta unio nisi secundum dignitatem quandam.

Et hoc est, approbante synodo ephesina, damnatum a Cyrillo sub his verbis, si quis in uno christo dividit subsistentias post adunationem, sola copulans eas coniunctione quae secundum dignitatem vel auctoritatem est vel secundum potentiam, et non magis concursu secundum adunationem naturalem, anathema sit.

Tertio, quia tantum hypostasis est cui attribuuntur operationes et proprietates naturae, et ea etiam quae ad naturae rationem pertinent in concreto, dicimus enim quod hic homo ratiocinatur, et est risibilis, et est animal rationale. Et hac ratione hic homo dicitur esse suppositum, quia scilicet supponitur his quae ad hominem pertinent, eorum praedicationem recipiens. Si ergo sit alia hypostasis in christo praeter hypostasim verbi, sequetur quod de aliquo alio quam de verbo verificentur ea quae sunt hominis, puta esse natum de virgine, passum, crucifixum et sepultum.

Et hoc etiam damnatum est, approbante Concilio ephesino, sub his verbis, si quis personis duabus vel subsistentiis eas quae sunt in evangelicis et apostolicis Scripturis impartitur voces, aut de christo a sanctis dictas, aut ab ipso de se; et quasdam quidem velut homini praeter illud ex deo verbum specialiter intellecto applicat, quasdam vero, velut deo decibiles, soli ex deo patre verbo, anathema sit.

Sic igitur patet esse haeresim ab olim damnatam dicere quod in christo sunt duae hypostases vel duo supposita, sive quod unio non sit facta in hypostasi vel supposito.

Unde in eadem synodo legitur, si quis non confitetur carni secundum subsistentiam unitum ex deo patre verbum, unumque esse christum cum sua carne, eundem scilicet deum et hominem, anathema sit.

Ad 1

Ad primum ergo dicendum quod, sicut accidentalis differentia facit alterum, ita differentia essentialis facit aliud. Manifestum est autem quod alteritas, quae provenit ex differentia accidentali, potest ad eandem hypostasim vel suppositum in rebus creatis pertinere, eo quod idem numero potest diversis accidentibus subesse, non autem contingit in rebus creatis quod idem numero subsistere possit diversis essentiis vel naturis. Unde sicut quod dicitur alterum et alterum in creaturis, non significat diversitatem suppositi, sed solum diversitatem formarum accidentalium; ita quod christus dicitur aliud et aliud, non importat diversitatem suppositi sive hypostasis, sed diversitatem naturarum.

Unde Gregorius Nazianzenus dicit, in epistola ad chelidonium, aliud et aliud sunt ea ex quibus salvator est, non alius autem et alius. Dico vero aliud et aliud e contrario quam in trinitate habet. Ibi enim alius et alius dicimus, ut non subsistentias confundamus, non aliud autem et aliud.

Ad 2

Ad secundum dicendum quod hypostasis significat substantiam particularem non quocumque modo, sed prout est in suo complemento.

Secundum vero quod venit in unionem alicuius magis completi, non dicitur hypostasis, sicut manus aut pes. Et similiter humana natura in christo, quamvis sit substantia particularis, quia tamen venit in unionem cuiusdam completi, scilicet totius christi prout est deus et homo, non potest dici hypostasis vel suppositum, sed illud completum ad quod concurrit, dicitur esse hypostasis vel suppositum.

Ad 3

Ad tertium dicendum quod etiam in rebus creatis res aliqua singularis non ponitur in genere vel specie ratione eius quod pertinet ad eius individuationem, sed ratione naturae, quae secundum formam determinatur, cum individuatio magis sit secundum materiam in rebus compositis. Sic igitur dicendum est quod christus est in specie humana ratione naturae assumptae, non ratione ipsius hypostasis.