Commentaria in Summam contra Gentiles, Liber IV

The second error was that of Eutyches ¹.

I. For since, as has been shown, the person of the Word of God and of the man must be one and the same; and this seems to have a difficulty, since it seems necessary that its own personality follow both the divine nature and similarly the human nature: to remove this difficulty, diverse thinkers brought forward diverse positions. Among whom Eutyches, in order to preserve one person in Christ against Nestorius, said that there is also one nature in Christ. For although before the union there were two distinct natures, divine and human, nevertheless in the union they came together into one nature, as he says. And thus he used to say that the person of Christ is from two natures, but does not subsist in two natures. On account of which he was condemned in the Synod of Chalcedon.

It must be noted that it is one thing for a person to be from two natures, and another for a person to subsist in two natures. For, for the first it suffices that the person be the hypostasis of a nature constituted from two natures: and thus it is not necessary that in him there be two distinct natures. For the second, however, it is required that there be two distinct natures, and that one person have being as subsisting per se in both of these at once. Therefore, because Eutyches posited only one nature in Christ constituted from the human and the divine, he therefore said that the person of Christ is from two natures, but does not subsist in two natures.

II. But St. Thomas argues against this position. First. After the union, the human nature in Christ was other than the divinity of the Word, which is His nature. Therefore even after the union there were two natures in Christ. — The assumption is proved. The body of Christ, even after the union, was not the divinity itself: since it was passible, and visible to bodily eyes, and distinct by the lineaments of its members, all of which are alien to divinity. Similarly, the soul was other than the divinity: since it was affected by the passions of sadness, pain, and anger, which cannot belong to divinity. But the human soul and body constitute human nature. Therefore etc.

III. Second. In Christ there are two forms, even after the union. Therefore two natures. — The consequence is proved. Because the form of a natural thing is its nature: since a natural thing is so called from the fact that it has a form, just as an artificial thing also is. — But the antecedent is proved by the authority of the Apostle saying, to the Philippians II, concerning Christ, that, although He was in the form of God, He took the form of a servant. For it cannot be said that the form of God and the form of a servant are the same: because, since He already had the form of God, He would not have taken the form of a servant; for nothing takes what it already has. Nor can it be said that the form of God was corrupted through the union: because Christ would not be God. Nor similarly the form of a servant: because thus He would not have taken the form of a servant. Nor can it be said that the form of a servant was commingled with the form of God: because, since things which are commingled do not remain intact, but both are partly corrupted, the Apostle would not say that He took the form of a servant, but something of it. And thus, according to the intention of the Apostle, one must say that after the union there were two forms in Christ.

2. It must be noted, regarding that proposition, A natural thing is so called from the fact that it has a form, that the term natural thing is not taken as the predicate, but as the subject. For the sense is not that some thing is called natural from the fact that it has a form: but that a natural thing is said to be of such a nature from the fact that it has such a form, and not before it has the form; just as an artificial thing also is said to be of such a species from the fact that it has such a form; for nothing is called a horse before it has the form of the nature of a horse, but when it has the form itself; and nothing is called a house before it has the form of a house, but after it has it. And thus it is clear that the form of a natural thing is fittingly called a nature, since from it the natural thing has it that it is of such a nature.

3. It must also be noted, regarding that proposition, Things which are commingled do not remain intact, but both are partly corrupted, that it is not so understood as if one integral part of the commingled thing were corrupted and another part of the same species remained: but that it is totally corrupted as to its proper species, and remains virtually, inasmuch as in the form that results from the mixture, there remains something of the power of the things that are mixed; or even their qualities remain in the same species, but in a remiss degree, according to the opinion of some. For in this way both of the mixed things are said to be partly corrupted and not to remain intact, because it does not altogether cease to be, since it remains in its power; nor does it remain altogether, because it does not remain in the proper form and proper species of the substance.

IV. Third. It is presupposed that, although the name of nature is said of the generation of things that are born; of the principle of such generation; and of the intrinsic principle of motion; and consequently of the form and matter of a natural thing; as well as of the essence of any thing existing in nature, which the definition signifies; in this place nature is taken in the last way; and thus we say that there is a human and a divine nature in Christ.

Then as follows. If there is only one nature in Christ after the union, either this is understood in such a way that one nature was constituted from the divine and human; or in such a way that only one of them remained after the union. If the first, either one thing was made from them according to order alone, as a city from many houses; or according to order and composition, as a house from its parts; or according to commixture, as a mixture from the four elements. Not the first or the second. Because these modes are not suitable for the constitution of one nature from several: since those things whose form is order or composition are not natural things, so that their unity could thus be called a unity of nature. — Nor also the third. Both because mixture is only of those things that share in matter, and that are naturally apt to act and be acted upon reciprocally: which cannot be the case here. And because the divine nature infinitely exceeds the human: but from those things of which one greatly exceeds the other, a mixture cannot be made; as is clear concerning a drop of wine put into a thousand jars of water; on account of which we also do not say that wood put into a furnace of fire is mixed with the fire, but consumed by the fire, on account of the fire's surpassing power. And because, even granted that a mixture were made, neither would remain preserved: because in a true mixture the things to be mixed are not preserved. And thus Christ would be neither God nor man. Therefore etc.

If the second is said, either only the divine nature was in Christ; and what seemed human in Him was phantasmal, as Manichaeus said: Or the divine nature was turned into the human, as Apollinaris said. But against these it was disputed above. Therefore etc.

2. Concerning the first and second mode by which one thing is made from several, namely according to order alone, or according to order and composition, it must be noted, from the doctrine of St. Thomas, Tertia Pars, q. II, a. 1, that in such modes of union a composition is made from several remaining intact and perfect, and consequently there is not made one simpliciter, but secundum quid: for from two in act one is not made simpliciter, but from act and potency. Whence composition, order, and figure are not substantial or natural forms, but accidental and artificial. But from an accidental and artificial form there is not made a natural thing and substantial nature, but only an artificial and accidental thing. Therefore St. Thomas exceedingly well says that those things whose form is order or composition are not natural things; and that from these modes one nature is not constituted from several. For a house does not bespeak one nature constituted from many, but many natures bound together by a certain order and composition.

3. It must be noted further that St. Thomas seems to posit these modes in this place differently than he posits them in the Tertia Pars ². For here he posits the first mode to be where something is made one from many according to order alone; but the second where something is made from many according to order and composition. But in the Tertia Pars the first mode is posited when one is made from many brought together by composition alone without order, as a heap is made from many stones; but the second when one is made from many arranged according to some order, as a house from stones and wood. In which there seems to be a certain contradiction. For here he seems to mean that order can be taken without composition: but there that it cannot be taken without composition, but certainly composition without order.

But I think that this difference arises from the fact that composition is taken in one way here, and in another way in the Tertia Pars. For here composition is taken as it implies a certain binding together and indivision. And thus composition includes order, but order does not include composition: for things that are undivided through a certain binding together must necessarily be ordered, namely so that one is prior and the other posterior; but things that have order do not need to be undivided: for in one city there can be many ordered houses, and yet separated from each other and not bound together. And therefore order can be taken both per se, and with composition. — But in the Tertia Pars composition is taken for any bringing together of several things. And thus the order of several things includes composition, but composition does not include order, as is clear. And therefore composition can be taken both per se, and with order.

4. Concerning that proposition, The things to be mixed are not preserved in a mixture, if it is a true mixture, it must be noted that St. Thomas therefore added, if it is a true mixture, because mixture is sometimes taken commonly for all composition, and then the things to be mixed can be preserved in the mixture. But properly a mixture is spoken of when a certain third thing is made from things altered from their nature: according to which the Philosopher, defining it in I De Generatione ³, says that mixture is the union of altered mixable things. And thus it is evident that the things to be mixed do not remain in the mixture except virtually. Therefore, in order to show that he was speaking of mixture properly so called, and not of it commonly taken, St. Thomas added, if it is a true mixture.

V. Fourth. The human nature is a certain complete nature, and similarly the divine. Therefore they cannot concur into one nature unless either both or one is corrupted. But this is impossible: since Christ is true God and true man. Therefore etc. — The first consequence is proved. Because one is never found to be made from two remaining natures: since any nature, as we speak of nature here, is a certain whole; but those things from which something is constituted fall under the ratio of a part.

Fifth. From two remaining things one nature is constituted either as from bodily parts — which cannot be said here, since the divine nature is incorporeal: or as from matter and form. Which also cannot be said here: since God can be neither the matter nor the form of any body. Therefore etc.

Sixth: and it is a confirmation of the preceding reason. If divinity is added to the human nature as a form, it will make another nature: and thus Christ will not be of human nature, but of another. This is false. Therefore etc. — The assumption is proved. Form is an essential principle. But the subtraction or addition of any essential principle varies the species, and consequently changes the nature. This is shown in differences with respect to a definition, and units with respect to number. Therefore etc.

Seventh. Then the nature of Christ will not be in other men. Therefore He will not be similar to us according to species. Which is contrary to the Apostle, Heb. II. — The consequence is proved. Because those things that do not agree in nature are not similar according to species.

VI. Eighth. If the divine nature accrues to the human nature as a form, it will be necessary that from the commixture of both a certain common species result, which is participable by many.

This is false: because there is only one Jesus Christ, God and man, namely one in number, and it cannot be truly said of many. Therefore etc. — The consequence is proved. Because from form and matter there is always constituted one species, which is predicable of many in act or in potency, as far as pertains to the ratio of species.

2. Regarding this proof of the consequence, it must be considered first, that by the ratio of species we can understand two things: either, namely, the ratio implied by this name species; or the ratio of that nature which is denominatively called a species, as is the ratio of man or of horse, or of anything of this kind. In the first way, therefore, the ratio of species is not taken here, but in the second way. For it is doubtful to no one that it is not repugnant to a species, according to the ratio of this name species, to be predicated of many: since the ratio of this name is to be predicated of many distinct in number ⁴. But it can well be doubtful how that nature is a species of which only one individual is found. And therefore St. Thomas says that from matter and form is constituted a species that is predicable of many as far as pertains to the ratio of species: that is, no such species is found to which it is repugnant from its proper ratio to be predicated of many; but if it is found in one only, this is from elsewhere, and not from its own proper ratio.

3. It must be considered secondly, that we can interpret the words of St. Thomas in two ways: in one way, so that something common to material and immaterial species is said; in another way, so that something proper to material species, of which mention is made in the proposition itself, is said. In the first way the sense is that every species, as far as is from the ratio of species, whether it is material or immaterial, is predicable of many in act or in potency: taking potency not as saying something positive in the nature of the species, but only non-repugnance. And this is certainly true. For it is not repugnant to the nature and species of the Sun, inasmuch as it is such a nature having such an order in the universe, to be predicated of many: but that it is not predicated of many in act is because the whole matter actuatable by the form of the Sun is contained under one form. Similarly, as is said in Quaestiones de Spiritualibus Creaturis ⁵, a. 8, ad 4, the nature of this separate substance is not prohibited from being in many from the fact that it is a nature in such an order of things, just as this whiteness is not prohibited from having many individuals under itself from the fact that it is whiteness: but it is prohibited from being in many from the fact that it is not naturally apt to be received in something, just as conversely this whiteness is prohibited from having many individuals under itself from the fact that it is in this subject.

In the second way the sense is that every material species is from its ratio predicable of many in act or in potency, insofar as potency says something positive, namely the aptitude of the nature for this, that it be in many and can be predicated of many. And thus it is true, and proper to material species. True indeed, because, as is clear from the doctrine of St. Thomas in De Ente et Essentia ⁶, the essences of composite things, from the fact that they are received in designated matter, are divided according to the division of matter, and thus become several in number in the same species. Whence it belongs to the species itself that it can be in several distinct in number according to matter. If, however, it is not so found, this is because distinction is not found in the matter, but the whole matter, remaining one, is concluded under one form. Whence if God were to make other matter of the Sun besides that which the form of the now existing Sun informs, the nature and species of the Sun would be in many, and would be predicated of many. — But this is proper to material things, because, although it is not repugnant to an immaterial nature from the ratio of its proper species to be in many, nevertheless it does not have the aptitude for this, that it be in many: since it is not receivable in another, nor consequently multiplicable according to the division of matter. — But this second interpretation seems to accord more with the text: although the first interpretation can also be adapted to it.

Lastly ⁷. If there were two natures before the union, it follows that either the soul or the body of Christ, or both, were before the Incarnation of Christ: since human nature is constituted from soul and body. But this is clear to be false through the things said above ⁸. Therefore etc.

VII. But against the aforesaid it can be argued from the statements of Jean de Ripa, recited by Capreolus in III Sent., d. v, q. II ⁹. For he proves that the essence of divinity is united to the soul and body of Christ, communicating esse to both parts and to the whole as an intrinsic form. And he argues thus. According to the Apostle in Coloss. II, in Christ dwells all the fullness of the Godhead bodily. But this cannot be understood through union alone to the hypostasis as it is distinguished against essence: since the hypostasis, as such, is not formally infinite, such that through the fact that it is united to the hypostasis, it is united to divinity. Therefore the divine essence is communicated to it through union according to every essential perfection.

It is confirmed first. By the fullness of the Godhead nothing can be understood except the divine essential esse: as is clear through the Master, III Sent., d. v. But it is necessary that such esse be formal esse. Therefore the divine nature in the esse of nature and of form was communicated to the flesh, according to the Apostle.

It is confirmed second. The flesh of Christ is not united to divinity only in the esse of person, because from such a union a man is not rendered God. Therefore in the esse of divinity. Therefore in the esse of form.

VIII. For the evidence of this difficulty, it must be considered that, just as we posit the person of the Word to be united to humanity, so also we say that divinity is united to humanity itself: but in one way and in another. For the person is united to humanity as subsisting in it, in that way in which a supposit subsists in its nature. But divinity is united to it as coming together with it in the same supposit: for the same person of the Word subsists at once in both natures, and is the supposit of both natures. And for that reason it is said that through the Incarnation of the Son of God a union was made in person, not in essence: because namely it was brought about that the person of the Word, existing as one, is the person of the human and divine nature; but not that one nature is the other, or that from both some other nature was constituted. But although a union of the divine person and of the divine nature with humanity was made, nevertheless this union was not made through information, by which namely either the divine person or the divine nature would be the form of human nature: for it is not of the ratio of a person that it be the form of the nature of which it is the person, but only that it subsist in it, and be formally and essentially denominated such from it. Similarly it is not of the ratio of those things which are united in one supposit that one be the form of the other: as is clear concerning whiteness and sweetness, which are united in milk. Whence it is conceded indeed that in Christ divinity is united to humanity in the said mode: but it is denied that it is united after the manner of a form giving esse to it.

To the reason, therefore, it is said that certainly all the fullness of the Godhead dwells in Christ according to all its essential perfection: not however in such a way that the divine nature is united to humanity after the manner of form and act to potency; but because they come together in one supposit which subsists in both natures.

2. To the first confirmation it is said that the consequence is null. For although the divine esse, which is formal esse, is united to humanity, it does not however follow that it is united to it after the manner of an intrinsically actuating form: just as, although the soul, which is a form, is united to its accidents, it does not however follow that it is united to them after the manner of a form; rather, it is united to them after the manner of a subject.

3. To the second confirmation it is said first, that in God the esse of person and the esse of divinity are not other in reality, so that the union could be said to have been made in the esse of person, not in the esse of essence, if it is understood of the esse of actual existence.

Secondly, it is said that, if by the esse of the person is understood the person itself, and by the esse of the essence the essence itself, this union was made in the esse of the person only, namely, in the manner in which a nature is united to a person, in so far as it is supposited by it, that is, in so far as the person is the supposit of that nature and subsists in it; but the union was not made in the esse of the divinity, namely, in the manner in which one nature is said to be united to another, either because one passes into the other, or because one is actuated by the other. And when it is argued to the contrary that from such a union in the esse of the person man is not rendered God: I deny it. For man is not said to be God in the sense that the human nature is actuated by divinity and made to be God; but because the same supposit that is the supposit of the human nature and is called man, is also the supposit of the divine nature and is called God. For thus through the union in the person man is rendered God, in so far as through it the divine supposit also becomes a human supposit, from which it follows that it can be said that man is God. Thirdly, it is said that in some way it could be conceded that the union was made in the esse of the divinity: namely, in this sense, that humanity and divinity came together in one person, who subsists in each nature, and formally exists through the esse of the divinity. But then the final intended consequence is denied, namely this: It is united in the esse of divinity and in the esse of a form (that is, an esse which is of a form). Therefore divinity is the form actuating humanity. For although, as has been said¹⁰, divinity is a form, in so far as every act by which something is denominated as such is called a form, and the esse of divinity is the esse of a form, it nevertheless does not follow, if it is united with humanity in one supposit, that it is united to it as a form formally actuating it. IX. But then a doubt remains. For, granted that humanity does not have its own esse, as seems to be the mind of St. Thomas¹¹, but is drawn to the esse of the divine supposit, it does not seem possible to deny that divinity is the form of humanity. For that which exists through the esse of some form is informed by that form, since the esse of a form belongs to nothing except through that form; for the esse of whiteness belongs to nothing except that which is informed by whiteness. If, therefore, the humanity of Christ exists through the esse of the divine supposit, which is the esse of the divinity, it remains that divinity is the form of humanity. He answers that, since to exist properly belongs only to a subsistent thing—namely, one that does not inhere in another either as an accident or as a material form, that is, depending on matter according to esse—while nature does not properly exist, but is that in which the supposit has subsistent esse, the esse of actual existence is not, properly speaking, the act of the nature as actuating it, but is the act of the supposit subsisting in the nature. Hence, when it is said that the human nature is drawn to the esse of the supposit, it is not to be understood as though it were formally actuated by the esse of the supposit, but because the divine supposit subsists in it. For its being drawn to the esse of the divine supposit is nothing other than its being made the nature of the divine supposit subsisting in it through divine esse. It is clear, therefore, that the doubt proceeds from this false supposition: that the human nature in Christ exists through the esse of the supposit as through an act actuating it. For this is false; but it is said to exist, as we have already said, through the esse of the supposit, that is, to be the nature in which the supposit has subsistent esse. Hence St. Thomas says in the Tertia, q. II, a. 6, ad 2, that the human nature is not assumed to the divine esse as it is of the nature, as the body is assumed to the esse of the soul; but as it is of the hypostasis or person.