Caput 39 Chapter 39 Quid Catholica fides sentiat de incarnatione Christi The teaching of the Catholic Church on the Incarnation of Christ Ex supra dictis igitur manifestum est quod, secundum Catholicae fidei traditionem, oportet dicere quod in Christo sit natura divina perfecta et humana natura perfecta, ex anima scilicet rationali et humana carne constituta; et quod hae duae naturae unitae sunt in Christo non per solam inhabitationem; neque accidentali modo, ut homo unitur vestimento; neque in sola personali habitudine et proprietate; sed secundum unam hypostasim et suppositum unum. Hoc enim solum modo salvari possunt ea quae in Scripturis circa incarnationem traduntur. Cum enim Scriptura sacra indistincte quae sunt Dei homini illi attribuat, et quae sunt illius hominis Deo, ut ex praemissis patet; oportet unum et eundem esse de quo utraque dicantur. From the foregoing chapters it is plain that according to the tradition of Catholic faith we must confess that in Christ there is one perfect divine nature, and a perfect human nature composed of a rational soul and human flesh. Also, that these two natures are united in Christ not by mere indwelling, nor accidentally as a man to his clothes, nor by mere personal habitude and property, but in one hypostasis and one suppositum. In this way alone can we safeguard the teaching of the Scriptures about the Incarnation. We have already observed that sacred Scripture, without making any distinction, ascribes divine things to the man; and things pertaining to the man to God. Therefore, in both cases it is the same one to whom reference is made. Sed quia opposita de eodem secundum idem dici vere non possunt; divina autem et humana quae de Christo dicuntur, oppositionem habent, utpote passum et impassibile, mortuum et immortale, et cetera huiusmodi; necesse est quod secundum aliud et aliud divina et humana praedicentur de Christo. Sic igitur quantum ad id de quo utraque praedicantur, non est distinctio facienda, sed invenitur unitas. Quantum autem ad id secundum quod praedicantur, distinctio est facienda. Naturales autem proprietates praedicantur de unoquoque secundum eius naturam: sicut de hoc lapide ferri deorsum secundum naturam gravitatis. Cum igitur aliud et aliud sit secundum quod divina et humana praedicantur de Christo, necesse est dicere in Christo esse duas naturas inconfusas et impermixtas. Id autem de quo praedicantur proprietates naturales secundum naturam propriam ad genus substantiae pertinentem, est hypostasis et suppositum illius naturae. Quia igitur indistinctum est et unum id de quo humana et divina praedicantur circa Christum, necesse est dicere Christum esse unam hypostasim et unum suppositum humanae et divinae naturae. Sic enim vere et proprie de homine illo praedicabuntur divina, secundum hoc quod homo ille importat suppositum non solum humanae naturae, sed divinae: et e converso de verbo Dei praedicantur humana inquantum est suppositum humanae naturae. But, seeing that opposite statements cannot be true about the same subject in the same respect, and that the divine and human things that are said about Christ are opposed to one another—for instance, that he suffered and was impassible, that he died and was immortal, and so on—it follows that divine and human things must be said of Christ in different respects. Accordingly, as regards the subject of which these things are predicated, we must make no distinction, and hold to unity; but as regards the things in respect of which these predications are made, a distinction is to be observed. Natural properties are attributed to a thing in respect of its nature: thus a stone falls down in respect of its nature as a heavy body. Accordingly, since divine and human things are attributed to Christ in different respects, it follows that in Christ there are two distinct unmixed natures. Now natural properties are attributed to something that belongs by its own nature to the genus of substance, and this is a hypostasis or suppositum of that nature. And since human and divine things predicated of Christ are attributed to one undivided subject, it follows that Christ is one hypostasis and one suppositum subsisting in the human and divine natures. In this way, divine things are truly and properly attributed to that man inasmuch as that man indicates a suppositum of both natures, human and divine. Vice versa, human things are attributed to the Word inasmuch as he is a suppositum of human nature. Ex quo etiam patet quod, licet filius sit incarnatus, non tamen oportet neque patrem neque spiritum sanctum esse incarnatum: cum incarnatio non sit facta secundum unionem in natura, in qua tres personae divinae conveniunt, sed secundum hypostasim et suppositum, prout tres personae distinguuntur. Et sic, sicut in Trinitate sunt plures personae subsistentes in una natura, ita in mysterio incarnationis est una persona subsistens in pluribus naturis. Hence also it is clear that although the Son took flesh, it does not follow that either Father or Holy Spirit became incarnate, since the Incarnation was effected by union not in the nature common to the three persons, but in the hypostasis or person, in which the three persons are distinct. And thus, even as in the Trinity there are several persons subsisting in one nature, so in the mystery of the Incarnation is there one person subsisting in two natures. Caput 40 Chapter 40 Obiectiones contra fidem incarnationis Objections against faith in the Incarnation Sed contra hanc Catholicae fidei sententiam, plures difficultates concurrunt, propter quas adversarii fidei incarnationem impugnant. This view of the Incarnation, as laid down by the Catholic faith, is beset with a number of difficulties which have led the enemies of the faith to impugn this mystery. Ostensum est enim in primo libro quod Deus neque corpus est, neque virtus in corpore. Si autem carnem assumpsit, sequitur quod vel sit mutatus in corpus, vel quod sit virtus in corpore, post incarnationem. Impossibile igitur videtur Deum fuisse incarnatum. It has been proved that God is neither a body nor a force in a body. But, if he took flesh, it follows that either he was transformed into a body or that he became a force in a body after the Incarnation. Therefore, it would seem impossible for God to be incarnate. Item. Omne quod acquirit novam naturam, est substantiali mutationi subiectum: secundum hoc enim aliquid generatur, quod naturam aliquam acquirit. Si igitur hypostasis filii Dei fiat de novo subsistens in natura humana, videtur quod esset substantialiter mutata. Again. Whatsoever acquires a new nature is subject to substantial change, because when a thing is generated, it acquires a nature. Hence, if the person of the Son of God became subsistent in human nature, it would seem that he was substantially changed. Adhuc. Nulla hypostasis alicuius naturae extenditur extra naturam illam: quin potius natura invenitur extra hypostasim, utpote multas hypostases sub se habens. Si igitur hypostasis filii Dei sit per incarnationem facta hypostasis humanae naturae, sequitur quod filius Dei non sit ubique post incarnationem: cum humana natura ubique non sit. Further. No hypostasis extends beyond the nature in which it subsists; rather does nature extend beyond the hypostasis, seeing that it includes many hypostases. And thus, if by the Incarnation the hypostasis of the Son of God became a hypostasis of human nature, it would follow that, after the Incarnation, the Son of God was not everywhere, since human nature is not everywhere. Amplius. Rei unius et eiusdem non est nisi unum quod quid est: hoc enim significat substantiam rei, quae unius una est. Sed natura cuiuslibet rei est quod quid est eius: natura enim rei est quam significat definitio. Impossibile est igitur, ut videtur, quod una hypostasis in duabus naturis subsistat. Moreover. One and the same thing has only one quiddity, for this is its essence, which is one in each one thing. Now the quiddity of a thing is its nature, because its nature is indicated by its definition. Therefore, it seems that one hypostasis cannot subsist in two natures. Praeterea. In his quae sunt sine materia, non potest esse aliud quidditas rei et res, ut supra ostensum est. Et hoc praecipue est in Deo, qui est non solum sua quidditas, sed etiam suum esse. Sed humana natura non potest esse idem quod divina hypostasis. Ergo impossibile esse videtur quod divina hypostasis subsistat in humana natura. Again. In things devoid of matter, the quiddity is not distinct from the thing, as we proved above. This is especially true of God, who is not only his own quiddity, but also his own being. Now human nature cannot be the same as a divine hypostasis. Therefore, it seems that a divine person cannot subsist in human nature. Item. Natura est simplicior et formalior hypostasi quae in ea subsistit: nam per additionem alicuius materialis natura communis individuatur ad hanc hypostasim. Si igitur divina hypostasis subsistat in humana natura, videtur sequi quod humana natura sit simplicior et formalior quam divina hypostasis. Quod est omnino impossibile. Again. Nature is more simple and more formal than the hypostasis that subsists in it, since the common nature is confined to a particular hypostasis by the addition of something material. If, then, a divine hypostasis subsists in human nature, it would appear to follow that human nature is more simple and more formal than the divine hypostasis: and this is altogether impossible. Adhuc. In his solum quae sunt ex materia et forma composita, differre invenitur singulare et quidditas eius: ex eo quod singulare est individuatum per materiam designatam, quae in quidditate et natura speciei non includitur; in signatione enim Socratis includitur haec materia, non autem in ratione humanae naturae. Omnis igitur hypostasis in natura humana subsistens est constituta per materiam signatam. Quod de divina hypostasi dici non potest. Non est igitur possibile, ut videtur, quod hypostasis verbi Dei subsistat in humana natura. Further. It is only in things composed of matter and form that the singular differs from its quiddity, in that the singular is individualized by signate matter, which is not included in the quiddity and specific nature: for this or that matter is included in the designation of Socrates, but not in the definition of human nature. Consequently, every hypostasis that subsists in human nature is constituted by signate matter, and this cannot be said of a divine hypostasis. Therefore, it would seem impossible for the hypostasis of the Word of God to subsist in human nature. Amplius. Anima et corpus in Christo non fuerunt minoris virtutis quam in aliis hominibus. Sed in aliis hominibus ex sua unione constituunt suppositum, hypostasim et personam. Igitur in Christo ex unione animae et corporis constituitur suppositum, hypostasis et persona. Non autem suppositum, hypostasis et persona Dei verbi, quae est aeterna. Igitur in Christo est aliud suppositum, hypostasis et persona, praeter suppositum, hypostasim et personam Dei verbi, ut videtur. Moreover. In Christ the soul and body were not less effective than in other men. Now in other men, they constitute suppositum, hypostasis, or person by their union. Hence, in Christ, a suppositum, hypostasis, or person likewise results from the union of soul and body. But this is not the suppositum, hypostasis, or person of the Word of God, because this is eternal. Therefore, in Christ there seems to be another suppositum, hypostasis, or person besides the suppositum, hypostasis, or person of the Word of God. Praeterea. Sicut ex anima et corpore constituitur humana natura in communi, ita ex hac anima et ex hoc corpore constituitur hic homo, quod est hypostasis hominis. Sed in Christo fuit haec anima et hoc corpus. Igitur ex eorum unione constituta est hypostasis, ut videtur. Et sic idem quod prius. Further. As human nature in general consists of a soul and body, so do this soul and this body make this man, or a human hypostasis. Now in Christ there were this soul and this body. Therefore, from their union there seemed to result a hypostasis, and so the same conclusion follows as above. Item. Hic homo qui est Christus, prout consideratur ex anima solum et carne consistens, est quaedam substantia. Non autem universalis. Ergo particularis. Ergo est hypostasis. Again. This man Christ, considered as formed merely of soul and body, is a substance. But he is not a substance in general. Therefore, he is a particular substance; and consequently a hypostasis. Adhuc. Si idem est suppositum humanae et divinae naturae in Christo, oportet quod de intellectu hominis qui est Christus, sit hypostasis divina. Non autem est de intellectu aliorum hominum. Homo igitur aequivoce de Christo dicetur et aliis. Et sic non erit eiusdem speciei nobiscum. Moreover. If in Christ there is but one suppositum of both human and divine natures, it follows that the divine hypostasis is included in the definition of this man Christ. But it is not included in the definition of other men. Therefore, ‘man’ is predicated equivocally of Christ and of other men, so that he would not be of the same species as we are. Amplius. In Christo tria inveniuntur, ut ex dictis patet: scilicet corpus, anima et divinitas. Anima autem, cum sit nobilior corpore, non est suppositum corporis, sed magis forma eius. Neque igitur id quod est divinum, est suppositum humanae naturae, sed magis formaliter se habet ad ipsam. Further. We have proved that in Christ are these three: body, soul, and divinity. Now the soul, being a more noble thing than the body, is not the body’s suppositum, but its form. Neither, therefore, is something divine a suppositum of human nature. Rather, we ought to say that it informs human nature. Praeterea. Omne quod advenit alicui post esse completum, advenit ei accidentaliter. Sed, cum verbum Dei sit ab aeterno, manifestum est quod caro assumpta advenit ei post esse completum. Igitur advenit ei accidentaliter. Further. Whatsoever accrues to a thing that is already complete in being is accidental to it. Now, since the Word of God is eternal, it is clear that the flesh assumed by him accrued to him when he was already complete in being. Therefore, he came by it accidentally. Caput 41 Chapter 41 Quomodo oporteat intelligere incarnationem filii Dei How we are to understand that the Son of God was incarnate Ad horum igitur solutionem considerandam, paulo altius inchoandum est. Cum enim Eutyches unionem Dei et hominis factam esse posuerit in natura; Nestorius autem nec in natura nec in persona; fides autem Catholica hoc teneat, quod sit facta unio in persona, non in natura: necessarium videtur praecognoscere quid sit uniri in natura, et quid sit uniri in persona. In order to reply to these objections, we must begin by going into the question a little more deeply. While Eutyches maintained that the union of God with man was effected in the nature, whereas Nestorius held that it was effected neither in the nature nor in the person, the Catholic faith teaches that it was effected in the person, and not in the nature. And so it would seem necessary to know first of all what is meant by being united in the nature, and by being united in the person. Natura igitur licet multis modis dicatur—nam et generatio viventium, et principium generationis et motus, et materia et forma natura dicuntur: item et aliquando natura dicitur quod quid est rei, continens ea quae ad speciei pertinent integritatem; sic enim dicimus naturam humanam communem esse omnibus hominibus, et similiter in ceteris: illa ergo uniuntur in natura ex quibus constituitur integritas speciei alicuius: sicut anima et corpus humanum uniuntur ad constituendum speciem animalis, et universaliter quaecumque sunt partes speciei. The word ‘nature’ has various meanings. It may mean either the birth of a living being, or the principle of generation and movement, or matter and form. It is also sometimes used to signify a thing’s essential definition, which contains all that belongs to the species of that thing; thus we say that human nature is common to all men, and so on. Accordingly, those things are united in nature which go to form the complete species of a thing; thus, for instance, the soul and body are united together to form the species of an animal; and, generally speaking, whatsoever things are the parts of a species. Est autem impossibile quod alicui speciei in sua integritate iam constitutae aliquid extraneum uniatur in unitatem naturae, nisi species solvatur. Cum enim species sint sicut numeri, in quibus quaelibet unitas addita vel subtracta variat speciem si quid ad speciem iam perfectam addatur, necesse est iam aliam speciem esse: sicut si substantiae animatae tantum addatur sensibile, erit alia species; nam animal et planta diversae species sunt. Contingit tamen id quod non est de integritate speciei, in aliquo individuo sub illa specie contento reperiri: sicut album et vestitum in Socrate vel Platone, aut digitus sextus, vel aliquid huiusmodi. Unde nihil prohibet aliqua uniri in individuo quae non uniuntur in una integritate speciei: sicut humana natura et albedo et musica in Socrate, et huiusmodi, quae dicuntur esse unum subiecto. Et quia individuum in genere substantiae dicitur hypostasis, in substantiis autem rationalibus dicitur etiam persona, convenienter omnia huiusmodi dicuntur uniri secundum hypostasim, vel etiam secundum personam. Sic igitur patet quod nihil prohibet aliqua non unita esse secundum naturam, uniri autem secundum hypostasim vel personam. Now it is impossible for anything extraneous to be united in unity of nature to a species that is already complete without doing away with the species. For, since species are like numbers, in which either the addition or the subtraction of unity changes the species, if any addition be made to an already complete species, the result must be another species. Thus, if you add sensibility to a substance that is only animate, you have another species, because animal and plant are different species. On the other hand, something not belonging to the integrity of the species may be found in an individual of another species; for instance, ‘white’ or ‘clothed’ in Socrates or Plato, or a sixth finger, and so forth. Consequently, nothing hinders things from being united in an individual that are not united in one complete species: for instance, human nature, whiteness, and music in Socrates, and whatsoever things may be united together in one subject. And since an individual substance is called a ‘hypostasis,’ and an individual rational substance is called a ‘person,’ it is reasonable to say that all these are united together in the hypostasis, or person. Hence it is possible for things not to be united in the nature, and yet united in the hypostasis or person. Audientes autem haeretici in Christo unionem Dei et hominis esse factam, contrariis viis incesserunt ad hoc exponendum, praetermisso tramite veritatis. Aliqui enim hanc unionem aestimaverunt ad modum eorum quae uniuntur in unam naturam: sicut Arius et Apollinaris, ponentes quod verbum erat corpori Christi pro anima, sive pro mente; et sicut Eutyches, qui posuit ante incarnationem duas naturas Dei et hominis, post incarnationem vero unam. Accordingly, hearing that the union of God and man in Christ is a fact, heretics, disregarding the path of truth, have explained this fact in various ways. Some deemed this union to be like the union of things in one nature. Such were Arius and Apollinaris, who contended that the Word supplied, in Christ’s body, the place of the soul or mind. Such also was Eutyches, who held the existence of the two natures of God and man before the Incarnation, but of only one after the Incarnation. Sed eorum dictum omnino impossibilitatem continet. Manifestum est enim naturam verbi ab aeterno in sua integritate perfectissimam esse, nec omnino corrumpi aut mutari posse. Unde impossibile est aliquid extrinsecum a natura divina, utpote naturam humanam vel aliquam partem eius, in unitatem naturae ei advenire. But their view involves an utter impossibility. For it is evident that the nature of the Word, from all eternity, was most perfectly complete, and wholly incorruptible and unchangeable. Therefore, it is impossible for anything extraneous to the divine nature, such as human nature or a part of it, to be joined to the Word in unity of nature. Alii vero, huius positionis impossibilitatem videntes, in viam contrariam diverterunt. Ea enim quae habenti aliquam naturam adveniunt nec tamen pertinent ad integritatem naturae illius, vel accidentia esse videntur, ut albedo et musica; vel accidentaliter se habere ad ipsum, sicut anulus, vestimentum, domus, et similia. Consideraverunt autem, quod, cum humana natura verbo Dei adveniat nec ad eius naturae integritatem pertineat, necesse est, ut putaverunt, quod humana natura accidentalem unionem haberet ad verbum. Et quidem manifestum est quod non potest inesse verbo ut accidens: tum quia Deus non est susceptivum accidentis, ut supra probatum est; tum quia humana natura, cum sit de genere substantiae, nullius accidens esse potest. Unde reliquum videbatur quod humana natura adveniret verbo, non sicut accidens, sed sicut accidentaliter se habens ad ipsum. Posuit igitur Nestorius quod humana natura Christi se habebat ad verbum sicut templum quoddam: ita quod secundum solam inhabitationem erat intelligenda unio verbi ad humanam naturam. Et quia templum seorsum habet suam individuationem ab eo qui inhabitat templum; individuatio autem conveniens humanae naturae est personalitas: reliquum erat quod alia esset personalitas humanae naturae, et alia verbi. Et sic verbum et ille homo erant duae personae. Others, realizing the impossibility of this view, adopted the contrary position. For when a thing of a certain nature receives the addition of something that does not belong to the integrity of its nature, this would seem either to be an accident, such as whiteness or music, or to bear an accidental relationship to that thing, such as a ring, clothes, a house, and the like. Seeing, then, that human nature is joined to the Word of God, and yet does not belong to the integrity of his nature, they concluded that human nature was united to the Word accidentally. And since it is evident that it cannot be an accident in the Word of God—both because in God there cannot be any accidents, as we have proved, and because human nature, through being in the genus of substance, cannot be the accident of anything—it seemed to follow that human nature was joined to the Word not as an accident, but as bearing an accidental relationship to it. Therefore, Nestorius maintained that Christ’s human nature was the temple of the Word, as it were, so that the union of the Word with human nature would be reduced to a kind of indwelling. And since a temple is individually distinct from one who dwells in it, and since individuality in human nature is personality, he concluded that human nature and the Word had distinct personalities, so that the Word and the man were two persons. Quod quidem inconveniens alii vitare volentes, circa humanam naturam talem dispositionem introduxerunt ut ei personalitas proprie convenire non possit, dicentes animam et corpus, in quibus integritas humanae naturae consistit, a verbo sic esse assumpta ut corpori anima non esset unita ad aliquam substantiam constituendam: ne cogerentur dicere illam substantiam sic constitutam rationem personae habere. Unionem vero verbi ad animam et corpus posuerunt sicut ad ea quae accidentaliter se habent, puta induti ad indumentum, in hoc quodammodo Nestorium imitantes. In order to avoid this difficulty, others imagined that human nature was so assumed that, properly speaking, it could have no personality. They said, in effect, that the soul and body, in which the integrity of human nature consists, were assumed by the Word in such a way that the soul was not united to the body so as to form a substance; they said this lest they should be forced to admit that the substance thus formed was a person. They maintained that the Word is united to the soul and body, as though these were related to it accidentally, even as clothes are related to the one who is clothed, somewhat following in the footsteps of Nestorius. His igitur remotis per supra dicta, necessarium est ponere talem fuisse unionem verbi et hominis ut neque ex duabus una natura conflata sit; neque verbi ad humanam naturam talis fuerit unio sicut est alicuius substantiae, puta hominis, ad exteriora, quae accidentaliter se habent ad ipsum, ut domus et vestimentum; sed verbum in humana natura sicut in sibi propria facta per incarnationem, subsistere ponatur; ut et corpus illud vere sit corpus verbi Dei; et similiter anima; et verbum Dei vere sit homo. Since all this has been refuted above, we must hold that the union of the Word with man is such that neither are the two natures fused into one; nor does the Word stand related accidentally to human nature, as a substance—a man for instance—to something extraneous, as, for instance, his house or his clothes. But we hold that the Word subsists in human nature as made his own nature by the Incarnation, so that the body is truly the body of the Word of God, and the same with the soul; and that the Word of God is truly man. Et quamvis haec unio perfecte ab homine non valeat explicari, tamen, secundum modum et facultatem nostram, conabimur aliquid dicere ad aedificationem fidei, ut circa hoc mysterium fides Catholica ab infidelibus defendatur. And though man cannot perfectly explain this union, we shall nevertheless endeavor as best we can to say something for the building up of faith, so as to defend the Catholic faith from the attacks which unbelievers direct at this mystery. In omnibus autem rebus creatis nihil invenitur huic unioni tam simile sicut unio animae ad corpus: et maior esset similitudo, ut etiam Augustinus dicit, contra Felicianum, si esset unus intellectus in omnibus hominibus, ut quidam posuerunt, secundum quos oporteret dicere quod intellectus praeexistens hoc modo de novo conceptui hominis uniatur ut ex utroque fiat una persona, sicut ponimus verbum praeexistens humanae naturae in personam unam uniri. Unde et propter hanc similitudinem utriusque unionis, Athanasius dicit, in symbolo quod, sicut anima rationalis et caro unus est homo, ita Deus et homo unus est Christus. In all created things nothing bears so great a resemblance to this union as the union of soul and body. Greater still would be the resemblance, as Augustine says, were there but one intellect in all men, as some indeed have maintained. If this were true, we should have to say that the already existing intellect would become united to the human concept in such a way that the two together would form one person, just as we say that the already existing Word was joined to human nature in one person. Hence, on account of this resemblance between the two unions, Athanasius says in his Creed: As a rational soul and flesh are one man, so God and man are one Christ. Sed cum anima rationalis uniatur corpori et sicut materiae et sicut instrumento, non potest esse similitudo quantum ad primum modum unionis: sic enim ex Deo et homine fieret una natura, cum materia et forma proprie naturam constituant speciei. Relinquitur ergo ut attendatur similitudo secundum quod anima unitur corpori ut instrumento. Ad quod etiam dicta antiquorum doctorum concordant, qui humanam naturam in Christo organum quoddam divinitatis posuerunt, sicut et ponitur corpus organum animae. Now the body is united to the rational soul both as the matter and as the instrument of the soul. But the above resemblance does not regard the former mode of union. For thus there would be one nature made of God and man, since matter and form are the proper constituents of the specific nature. The resemblance, therefore, regards the union of soul with the body as its instrument. In fact, the statements of the early doctors are in agreement with this, who considered the human nature in Christ to be an instrument of the divinity even as the body is the instrument of the soul. Aliter enim est animae organum corpus et eius partes, et aliter exteriora instrumenta. Haec enim dolabra non est proprium instrumentum, sicut haec manus: per dolabram enim multi possunt operari, sed haec manus ad propriam operationem huius animae deputatur. Propter quod manus est organum unitum et proprium: dolabra autem instrumentum exterius et commune. Sic igitur et in unione Dei et hominis considerari potest. Omnes enim homines comparantur ad Deum ut quaedam instrumenta quibus operatur: ipse enim est qui operatur in nobis velle et perficere pro bona voluntate, secundum apostolum, Philipp. 2:13. Sed alii homines comparantur ad Deum quasi instrumenta extrinseca et separata: moventur enim a Deo non ad operationes proprias sibi tantum, sed ad operationes communes omni rationali naturae, ut est intelligere veritatem, diligere bona, et operari iusta. Sed humana natura in Christo assumpta est ut instrumentaliter operetur ea quae sunt operationes propriae solius Dei, sicut est mundare peccata, illuminare mentes per gratiam, et introducere in perfectionem vitae aeternae. Comparatur igitur humana natura Christi ad Deum sicut instrumentum proprium et coniunctum, ut manus ad animam. For the body and its parts are the instruments of the soul otherwise than extraneous instruments. Thus a man’s spade is not so much his own instrument as his hand is, since many can work with that spade, whereas that hand is employed for the special work of that man’s mind. Hence a man’s hand is an instrument united and proper to him, whereas the spade is distinct from him and common to many. Now let us apply this to the union of God with man. All men in comparison with God are instruments of his works: God is at work in you, both to will and to work for his good pleasure (Phil 2:13), as the Apostle says. Now other men are employed by God as extraneous and separate instruments, so to speak, since he moves them not only to their own proper operations, but also to those that are common to all rational creatures, such as understanding the truth, loving what is good, and doing what is right. But human nature was assumed by Christ so that it might be an instrument in works belonging to God alone, such as cleansing from sins, enlightening our minds by grace, and perfecting us unto eternal life. Accordingly, Christ’s human nature is compared to God as a proper and united instrument, as the hand is compared to the soul. Nec discrepat a rerum naturalium consuetudine quod aliquid sit naturaliter proprium instrumentum alicuius quod tamen non est forma ipsius. Nam lingua, prout est instrumentum locutionis, est proprium organum intellectus: qui tamen prout philosophus probat, nullius partis corporis actus est. Similiter etiam invenitur aliquod instrumentum quod ad naturam speciei non pertinet, et tamen ex parte materiae competit huic individuo: ut sextus digitus vel aliquid huiusmodi. Nihil igitur prohibet hoc modo ponere unionem humanae naturae ad verbum quod humana natura sit quasi verbi instrumentum non separatum sed coniunctum, nec tamen humana natura ad naturam verbi pertinet, nec verbum est eius forma; pertinet tamen ad eius personam. Nor is it out of keeping with the usual course of nature that a thing be naturally the proper instrument of that which is not its form. Thus the tongue, as the instrument of speech, is the proper instrument of the understanding, and yet, as the Philosopher proves, the understanding is not the form of any part of the body. In like manner, there may be an instrument that does not belong to the specific nature, and yet belongs to the individual on the part of the matter, as, for instance, a sixth finger, or something of the kind. In this way, therefore, nothing prevents our saying that human nature by its union with the Word became, as it were, the Word’s instrument, not separate but united. Yet human nature does not belong to the nature of the Word, nor is the Word its form; but it does belong to the person of the Word.