The Commonitory of Vincent of Lérins, For the Antiquity and Universality of the Catholic Faith Against the Profane Novelties of All Heresies 13
13 Chapter XIII. The Catholic Doctrine of the Trinity and the Incarnation explained PL 50, 655
[36.] In these ways then do these rabid dogs, Nestorius, Apollinaris, and Photinus, bark against the Catholic faith: Photinus, by denying the Trinity; Apollinaris, by teaching that the nature of the Word is mutable, and refusing to acknowledge that there are two substances in Christ, denying moreover either that Christ had a soul at all, or, at all events, that he had a rational soul, and asserting that the Word of God supplied the place of the rational soul; Nestorius, by affirming that there were always or at any rate that once there were two Christs. But the Catholic Church, holding the right faith both concerning God and concerning our Saviour, is guilty of blasphemy neither in the mystery of the Trinity, nor in that of the Incarnation of Christ. For she worships both one Godhead in the plenitude of the Trinity, and the equality of the Trinity in one and the same majesty, and she confesses one Christ Jesus, not two; the same both God and man, the one as truly as the other. One Person indeed she believes in Him, but two substances; two substances but one Person: Two substances, because the Word of God is not mutable, so as to be convertible into flesh; one Person, lest by acknowledging two sons she should seem to worship not a Trinity, but a Quaternity.
[37.] But it will be well to unfold this same doctrine more distinctly and explicitly again and again.
In God there is one substance, but three Persons; in Christ two substances, but one Person. In the Trinity, another and another Person, not another and another substance (distinct Persons, not distinct substances); in the Saviour another and another substance, not another and another Person, (distinct substances, not distinct Persons). How in the Trinity another and another Person (distinct Persons) not another and another substance (distinct substances)? Because there is one Person of the Father, another of the Son, another of the Holy Ghost; but yet there is not another and another nature (distinct natures) but one and the same nature. How in the Saviour another and another substance, not another and another Person (two distinct substances, not two distinct Persons)? Because there is one substance of the Godhead, another of the manhood. But yet the Godhead and the manhood are not another and another Person (two distinct Persons), but one and the same Christ, one and the same Son of God, and one and the same Person of one and the same Christ and Son of God, in like manner as in man the flesh is one thing and the soul another, but one and the same man, both soul and flesh. In Peter and Paul the soul is one thing, the flesh another; yet there are not two Peters,—one soul, the other flesh, or two Pauls, one soul, the other flesh,—but one and the same Peter, and one and the same Paul, consisting each of two diverse natures, soul and body. Thus, then, in one and the same Christ there are two substances, one divine, the other human; one of (ex) God the Father, the other of (ex) the Virgin Mother; one co-eternal with and co-equal with the Father, the other temporal and inferior to the Father; one consubstantial with his Father, the other, consubstantial with his Mother, but one and the same Christ in both substances. There is not, therefore, one Christ God, the other man, not one uncreated, the other created; not one impassible, the other passible; not one equal to the Father, the other inferior to the Father; not one of his Father (ex), the other of his Mother (ex), but one and the same Christ, God and man, the same uncreated and created, the same unchangeable and incapable of suffering, the same acquainted by experience with both change and suffering, the same equal to the Father and inferior to the Father, the same begotten of the Father before time, (“before the world”), the same born of his mother in time (“in the world”), perfect God, perfect Man. In God supreme divinity, in man perfect humanity. Perfect humanity, I say, forasmuch as it hath both soul and flesh; the flesh, very flesh; our flesh, his mother’s flesh; the soul, intellectual, endowed with mind and reason. There is then in Christ the Word, the soul, the flesh; but the whole is one Christ, one Son of God, and one our Saviour and Redeemer: One, not by I know not what corruptible confusion of Godhead and manhood, but by a certain entire and singular unity of Person. For the conjunction hath not converted and changed the one nature into the other, (which is the characteristic error of the Arians), but rather hath in such wise compacted both into one, that while there always remains in Christ the singularity of one and the self-same Person, there abides eternally withal the characteristic property of each nature; whence it follows, that neither doth God (i.e., the divine nature) ever begin to be body, nor doth the body ever cease to be body. The which may be illustrated in human nature: for not only in the present life, but in the future also, each individual man will consist of soul and body; nor will his body ever be converted into soul, or his soul into body; but while each individual man will live for ever, the distinction between the two substances will continue in each individual man for ever. So likewise in Christ each substance will for ever retain its own characteristic property, yet without prejudice to the unity of Person.
Haec ergo Nestorius, Apollmaris, Photinus adversus Catholicam fidem rabidi canes latrant: Photinus, Trinitatem non confitendo; Apollinaris, convertibilem Verbi dicendo naturam, et duas in Christo substantias non confitendo, et aut totam Christi animam aut certe mentem atque rationem in anima denegando, et adserendo pro sensu mentis fuisse Dei Verbum; Nestorius, duos Christos aut semper esse, aut aliquandiu fuisse adseverando. Ecclesia vero Catholica et de Deo et de Salvatore nostro recta sentiens, nec in Trinitatis mysterio nec in Christi incarnatione blasphemat. Nam et unam divinitatem in Trinitatis plenitudine et Trinitatis aequalitatem in una atque eadem majestate veneratur, et unum Christum Jesum, non duos, eumdemque Deum pariter atque hominem confitetur. Unam quidem in eo personam, sed duas substantias; duas substantias, sed unam credit esse personam: duas substantias, quia mutabile non est Verbum Dei, ut ipsum verteretur in carnem; unam personam, ne duos profitendo filios, quaternitatem videatur colere, non Trinitatem. Sed operae pretium est ut id ipsum etiam atque etiam distinctius et expressius enucleemus. In Deo una substantia, sed tres personae; in Christo duae substantiae, sed una persona. In Trinitate alius atque alius, non aliud atque aliud; in Salvatore aliud atque aliud, non alius atque alius. Quomodo in Trinitate alius atque alius, non aliud atque aliud? Quia scilicet alia et persona Patris, alia Filii, alia Spiritus sancti; sed tamen Patris et Filii et Spiritus sancti non alia et alia, sed una eademque natura. Quomodo in Salvatore aliud atque aliud, non alius atque alius? Quia videlicet altera substantia divinitatis, altera humanitatis; sed tamen deitas et humanitas non alter et alter, sed unus idemque Christus, unus idemque filius Dei, et unius ejusdemque Christi et filii Dei una eademque persona; sicut in homine aliud caro, et aliud anima, sed unus idemque homo anima et caro. In Petro et Paulo aliud anima, aliud caro; nec tamen duo Petri, caro et anima; aut alter Paulus anima, et alter caro; sed unus idemque Petrus, unus idemque Paulus, ex duplici diversaque subsistens animi corporisque natura. Ita igitur in uno eodemque Christo duae substantiae sunt; sed una divina, altera humana; una ex Patre Deo, altera ex matre Virgine; una coaeterna et aequalis Patri, altera ex tempore et minor Patre; una consubstantialis Patri, altera consubstantialis matri; unus tamen idemque Christus in utraque substantia. Non ergo alter Christus Deus, alter homo; non alter increatus, alter creatus; non alter impassibilis, alter passibilis; non alter aequalis Patri, alter minor Patre; non alter ex Patre, alter ex matre; sed unus idemque Christus Deus et homo, idem non creatus et creatus, idem incommutabilis et impassibilis, idem commutatus et passus, idem Patri et aequalis et minor, idem ex Patre ante secula genitus, idem in seculo ex matre generatus, perfectus Deus, perfectus homo. In Deo summa divinitas, in homine plena humanitas. Plena, inquam, humanitas: quippe quae animam simul habeat et carnem, sed carnem veram, nostram, maternam, animam vero intellectu praeditam, mente ac ratione pollentem. Est ergo in Christo verbum, anima, caro; sed hoc totum unus est Christus, unus filius Dei, et unus Salvator ac Redemptor noster. Unus autem, non corruptibili nescio qua divinitatis et humanitatis confusione, sed integra et singulari quadam unitate personae. Neque enim illa conjunctio alterum in alterum convertit atque mutavit (qui est error proprius Arianorum), sed ita in unum potius utrum que compegit, ut manente semper in Christo singularitate unius ejusdemque personae, in aeternum quoque permaneat proprietas uniuscujusque naturae; quo scilicet nec unquàm Deus corpus esse incipiat, nec aliquando corpus, corpus esse desistat. Quod etiam humanae conditionis demonstratur exemplo. Neque enim in praesenti tantum, sed in futuro quoque, unusquisque hominum ex anima constabit et corpore, nec tamen unquam aut corpus in animam aut anima vertetur in corpus; sed unoquoque hominum sine fine victuro, in unoquoque hominum sine fine necessario utriusque substantiae differentia permanebit. Ita in Christo quoque utriusque substantiae sua cuique in aeternum proprietas, salva tamen personae unitate, retinenda est.