Summa Th. III EN Qu.16 a.6

Whether this is true: "God was made man"?



Objection: 1. It would seem that this is false: "God was made man." For since man signifies a substance, to be made man is to be made simply. But this is false: "God was made simply." Therefore this is false: "God was made man."
2. Further, to be made man is to be changed. But God cannot be the subject of change, according to Ml 3,6: "I am the Lord, and I change not." Hence this is false: "God was made man."
3. Further, man as predicated of Christ stands for the Person of the Son of God. But this is false: "God was made the Person of the Son of God." Therefore this is false: "God was made man."

On the contrary It is written (Jn 1,14): "The Word was made flesh": and as Athanasius says (Ep ad Epictetum), "when he said, 'The Word was made flesh,' it is as if it were said that God was made man."
I answer that A thing is said to be made that which begins to be predicated of it for the first time. Now to be man is truly predicated of God, as stated above (Article [1]), yet in such sort that it pertains to God to be man, not from eternity, but from the time of His assuming human nature. Hence, this is true, "God was made man"; though it is understood differently by some: even as this, "God is man," as we said above (Article [1]).

Reply to Objection: 1. To be made man is to be made simply, in all those in whom human nature begins to be in a newly created suppositum. But God is said to have been made man, inasmuch as the human nature began to be in an eternally pre-existing suppositum of the Divine Nature. And hence for God to be made man does not mean that God was made simply.
2. As stated above, to be made implies that something. is newly predicated of another. Hence, whenever anything is predicated of another, and there is a change in that of which it is predicated, then to be made is to be changed; and this takes place in whatever is predicated absolutely, for whiteness or greatness cannot newly affect anything, unless it be newly changed to whiteness or greatness. But whatever is predicated relatively can be newly predicated of anything without its change, as a man may be made to be on the right side without being changed and merely by the change of him on whose left side he was. Hence in such cases, not all that is said to be made is changed, since it may happen by the change of something else. And it is thus we say of God: "Lord, Thou art made [Douay: 'hast been'] our refuge" (Ps 89,1). Now to be man belongs to God by reason of the union, which is a relation. And hence to be man is newly predicated of God without any change in Him, by a change in the human nature, which is assumed to a Divine Person. And hence, when it is said, "God was made man," we understand no change on the part of God, but only on the part of the human nature.
3. Man stands not for the bare Person of the Son of God, but inasmuch as it subsists in human nature. Hence, although this is false, "God was made the Person of the Son of God," yet this is true: "God was made man" by being united to human nature.



Whether this is true: "Man was made God"?



Objection: 1. It would seem that this is true: "Man was made God." For it is written (Rm 1,2-3): "Which He had promised before by His prophets in the holy Scriptures, concerning His Son Who was made to Him of the seed of David according to the flesh." Now Christ, as man, is of the seed of David according to the flesh. Therefore man was made the Son of God.
2. Further, Augustine says (De Trin. i, 13) that "such was this assumption, which made God man, and man God." But by reason of this assumption this is true: "God was made man." Therefore, in like manner, this is true: "Man was made God."
3. Further, Gregory Nazianzen says (Ep ad Chelid. ci): "God was humanized and man was deified, or whatever else one may like to call it." Now God is said to be humanized by being made man. Therefore with equal reason man is said to be deified by being made God; and thus it is true that "Man was made God."
4. Further, when it is said that "God was made man," the subject of the making or uniting is not God, but human nature, which the word "man" signifies. Now that seems to be the subject of the making, to which the making is attributed. Hence "Man was made God" is truer than "God was made man."

On the contrary Damascene says (De Fide Orth. iii, 2): "We do not say that man was deified, but that God was humanized." Now to be made God is the same as to be deified. Hence this is false: "Man was made God."
I answer that This proposition, Man was made God, may be understood in three ways. First, so that the participle "made" absolutely determines either the subject or the predicate; and in this sense it is false, since neither the Man of Whom it is predicated was made, nor is God made, as will be said (Articles [8],9). And in the same sense this is false: "God was made man." But it is not of this sense that we are now speaking. Secondly, it may be so understood that the word "made" determines the composition, with this meaning: "Man was made God, i.e. it was brought about that Man is God." And in this sense both are true, viz. that "Man was made God" and that "God was made Man." But this is not the proper sense of these phrases; unless, indeed, we are to understand that "man" has not a personal but a simple supposition. For although "this man" was not made God, because this suppositum, viz. the Person of the Son of God, was eternally God, yet man, speaking commonly, was not always God. Thirdly, properly understood, this participle "made" attaches making to man with relation to God, as the term of the making. And in this sense, granted that the Person or hypostasis in Christ are the same as the suppositum of God and Man, as was shown (Question [2], Articles [2],3), this proposition is false, because, when it is said, "Man was made God," "man" has a personal suppositum: because, to be God is not verified of the Man in His human nature, but in His suppositum. Now the suppositum of human nature, of Whom "to be God" is verified, is the same as the hypostasis or Person of the Son of God, Who was always God. Hence it cannot be said that this Man began to be God, or is made God, or that He was made God.But if there were a different hypostasis of God and man, so that "to be God" was predicated of the man, and, conversely, by reason of a certain conjunction of supposita, or of personal dignity, or of affection or indwelling, as the Nestorians said, then with equal reason might it be said that Man was made God, i.e. joined to God, and that God was made Man, i.e. joined to man.

Reply to Objection: 1. In these words of the Apostle the relative "Who" which refers to the Person of the Son of God ought not to be considered as affecting the predicate, as if someone already existing of the "seed of David according to the flesh" was made the Son of God---and it is in this sense that the objection takes it. But it ought to be taken as affecting the subject, with this meaning---that the "Son of God was made to Him ('namely to the honor of the Father,' as a gloss expounds it), being of the seed of David according to the flesh," as if to say "the Son of God having flesh of the seed of David to the honor of God."
2. This saying of Augustine is to be taken in the sense that by the assumption that took place in the Incarnation it was brought about that Man is God and God is Man; and in this sense both sayings are true as stated above.The same is to be said in reply to the third, since to be deified is the same as to be made God.
3. A term placed in the subject is taken materially, i.e. for the suppositum; placed in the predicate it is taken formally, i.e. for the nature signified. Hence when it is said that "Man was made God," the being made is not attributed to the human nature but to the suppositum of the human nature, Which is God from eternity, and hence it does not befit Him to be made God. But when it is said that "God was made Man," the making is taken to be terminated in the human nature. Hence, properly speaking, this is true: "God was made Man," and this is false: "Man was made God"; even as if Socrates, who was already a man, were made white, and were pointed out, this would be true: "This man was made white today," and this would be false; "This white thing was made man today." Nevertheless, if on the part of the subject there is added some word signifying human nature in the abstract, it might be taken in this way for the subject of the making, e.g. if it were said that "human nature was made the Son of God's."



Whether this is true: "Christ is a creature"?



Objection: 1. It would seem that this is true: "Christ is a creature." For Pope Leo says [*Cf. Append. Opp. August., Serm. xii de Nativ.]: "A new and unheard of covenant: God Who is and was, is made a creature." Now we may predicate of Christ whatever the Son of God became by the Incarnation. Therefore this is true; Christ is a creature.
2. Further, the properties of both natures may be predicated of the common hypostasis of both natures, no matter by what word they are signified, as stated above (Article [5]). But it is the property of human nature to be created, as it is the property of the Divine Nature to be Creator. Hence both may be said of Christ, viz. that He is a creature and that he is uncreated and Creator.
3. Further, the principal part of a man is the soul rather than the body. But Christ, by reason of the body which He took from the Virgin, is said simply to be born of the Virgin. Therefore by reason of the soul which is created by God, it ought simply to be said that He is a creature.

On the contrary Ambrose says (De Trin. i): "Was Christ made by a word? Was Christ created by a command?" as if to say: "No!" Hence he adds: "How can there be a creature in God? For God has a simple not a composite Nature." Therefore it must not be granted that "Christ is a creature."
I answer that As Jerome [*Gloss, Ord. in Os 2,16] says, "words spoken amiss lead to heresy"; hence with us and heretics the very words ought not to be in common, lest we seem to countenance their error. Now the Arian heretics said that Christ was a creature and less than the Father, not only in His human nature, but even in His Divine Person. And hence we must not say absolutely that Christ is a "creature" or "less than the Father"; but with a qualification, viz. "in His human nature." But such things as could not be considered to belong to the Divine Person in Itself may be predicated simply of Christ by reason of His human nature; thus we say simply that Christ suffered, died and was buried: even as in corporeal and human beings, things of which we may doubt whether they belong to the whole or the part, if they are observed to exist in a part, are not predicated of the whole simply, i.e. without qualification, for we do not say that the Ethiopian is white but that he is white as regards his teeth; but we say without qualification that he is curly, since this can only belong to him as regards his hair.

Reply to Objection: 1. Sometimes, for the sake of brevity, the holy doctors use the word "creature" of Christ, without any qualifying term; we should however take as understood the qualification, "as man."
2. All the properties of the human, just as of the Divine Nature, may be predicated equally of Christ. Hence Damascene says (De Fide Orth. iii, 4) that "Christ Who God and Man, is called created and uncreated, passible and impassible." Nevertheless things of which we may doubt to what nature they belong, are not to be predicated without a qualification. Hence he afterwards adds (De Fide Orth. iv, 5) that "the one hypostasis," i.e. of Christ, "is uncreated in its Godhead and created in its manhood": even so conversely, we may not say without qualification, "Christ is incorporeal" or "impassible"; in order to avoid the error of Manes, who held that Christ had not a true body, nor truly suffered, but we must say, with a qualification, that Christ was incorporeal and impassible "in His Godhead."
3. There can be no doubt how the birth from the Virgin applies to the Person of the Son of God, as there can be in the case of creation; and hence there is no parity.



Whether this Man, i.e. Christ, began to be?



Objection: 1. It would seem that this Man, i.e. Christ, began to be. For Augustine says (Tract. cv in Joan.) that "before the world was, neither were we, nor the Mediator of God and men---the Man Jesus Christ." But what was not always, has begun to be. Therefore this Man, i.e. Christ, began to be.
2. Further, Christ began to be Man. But to be man is to be simply. Therefore this man began to be, simply.
3. Further, "man" implies a suppositum of human nature. But Christ was not always a suppositum of human nature. Therefore this Man began to be.

On the contrary It is written (He 13,8): "Jesus Christ yesterday and today: and the same for ever."
I answer that We must not say that "this Man"---pointing to Christ---"began to be," unless we add something. And this for a twofold reason. First, for this proposition is simply false, in the judgment of the Catholic Faith, which affirms that in Christ there is one suppositum and one hypostasis, as also one Person. For according to this, when we say "this Man," pointing to Christ, the eternal suppositum is necessarily meant, with Whose eternity a beginning in time is incompatible. Hence this is false: "This Man began to be." Nor does it matter that to begin to be refers to the human nature, which is signified by this word "man"; because the term placed in the subject is not taken formally so as to signify the nature, but is taken materially so as to signify the suppositum, as was said (Article [1], ad 4). Secondly, because even if this proposition were true, it ought not to be made use of without qualification; in order to avoid the heresy of Arius, who, since he pretended that the Person of the Son of God is a creature, and less than the Father, so he maintained that He began to be, saying "there was a time when He was not."

Reply to Objection: 1. The words quoted must be qualified, i.e. we must say that the Man Jesus Christ was not, before the world was, "in His humanity."
2. With this word "begin" we cannot argue from the lower species to the higher. For it does not follow if "this began to be white," that therefore "it began to be colored." And this because "to begin" implies being now and not heretofore: for it does not follow if "this was not white hitherto" that "therefore it was not colored hitherto." Now, to be simply is higher than to be man. Hence this does not follow: "Christ began to be Man---therefore He began to be."
3. This word "Man," as it is taken for Christ, although it signifies the human nature, which began to be, nevertheless signifies the eternal suppositum which did not begin to be. Hence, since it signifies the suppositum when placed in the subject, and refers to the nature when placed in the predicate, therefore this is false: "The Man Christ began to be": but this is true: "Christ began to be Man."



Whether this is true: "Christ as Man is a creature"?



Objection: 1. It would seem that this is false: "Christ as Man is a creature," or "began to be." For nothing in Christ is created except the human nature. But this is false: "Christ as Man is the human nature." Therefore this is also false; Christ as Man is a creature.
2. Further, the predicate is predicated of the term placed in reduplication, rather than of the subject of the proposition; as when I say: "A body as colored is visible," it follows that the colored is visible. But as stated (Articles [8],9) we must not absolutely grant that "the Man Christ is a creature"; nor consequently that "Christ as Man is a creature."
3. Further, whatever is predicated of a man as man is predicated of him "per se" and simply, for "per se" is the same as "inasmuch as itself," as is said Metaph. v, text. 23. But this is false: "Christ as Man is per se and simply a creature." Hence this, too, is false; "Christ as Man is a creature."

On the contrary Whatever is, is either Creator or creature. But this is false: "Christ as Man is Creator." Therefore this is true: "Christ as Man is a creature."
I answer that When we say "Christ as Man" this word "man" may be added in the reduplication, either by reason of the suppositum or by reason of the nature. If it be added by reason of the suppositum, since the suppositum of the human nature in Christ is eternal and uncreated, this will be false: "Christ as Man is a creature." But if it be added by reason of the human nature, it is true, since by reason of the human nature or in the human nature, it belongs to Him to be a creature, as was said (Article [8]).It must however be borne in mind that the term covered by the reduplication signifies the nature rather than the suppositum, since it is added as a predicate, which is taken formally, for it is the same to say "Christ as Man" and to say "Christ as He is a Man." Hence this is to be granted rather than denied: "Christ as Man is a creature." But if something further be added whereby [the term covered by the reduplication] is attracted to the suppositum, this proposition is to be denied rather than granted, for instance were one to say: "Christ as 'this' Man is a creature."

Reply to Objection: 1. Although Christ is not the human nature, He has human nature. Now the word "creature" is naturally predicated not only of abstract, but also of concrete things; since we say that "manhood is a creature" and that "man is a creature."
2. Man as placed in the subject refers to the suppositum---and as placed in the reduplication refers to the nature, as was stated above. And because the nature is created and the suppositum uncreated, therefore, although it is not granted that "this man is a creature," yet it is granted that "Christ as Man is a creature."
3. It belongs to every man who is a suppositum of human nature alone to have his being only in human nature. Hence of every such suppositum it follows that if it is a creature as man, it is a creature simply. But Christ is a suppositum not merely of human nature, but also of the Divine Nature, in which He has an uncreated being. Hence it does not follow that, if He is a creature as Man, He is a creature simply.



Whether this is true: "Christ as Man is God"?



Objection: 1. It would seem that Christ, as Man, is God. For Christ is God by the grace of union. But Christ, as Man, has the grace of union. Therefore Christ as Man is God.
2. Further, to forgive sins is proper to God, according to Is 43,25: "I am He that blot out thy iniquities for My own sake." But Christ as Man forgives sin, according to Mt 9,6: "But that you may know that the Son of Man hath power on earth to forgive sins," etc. Therefore Christ as Man is God.
3. Further, Christ is not Man in common, but is this particular Man. Now Christ, as this Man, is God, since by "this Man" we signify the eternal suppositum which is God naturally. Therefore Christ as Man is God.

On the contrary Whatever belongs to Christ as Man belongs to every man. Now, if Christ as Man is God, it follows that every man is God---which is clearly false.
I answer that This term "man" when placed in the reduplication may be taken in two ways. First as referring to the nature; and in this way it is not true that Christ as Man is God, because the human nature is distinct from the Divine by a difference of nature. Secondly it may be taken as referring to the suppositum; and in this way, since the suppositum of the human nature in Christ is the Person of the Son of God, to Whom it essentially belongs to be God, it is true that Christ, as Man, is God. Nevertheless because the term placed in the reduplication signifies the nature rather than the suppositum, as stated above (Article [10]), hence this is to be denied rather than granted: "Christ as Man is God."

Reply to Objection: 1. It is not with regard to the same, that a thing moves towards, and that it is, something; for to move belongs to a thing because of its matter or subject---and to be in act belongs to it because of its form. So too it is not with regard to the same, that it belongs to Christ to be ordained to be God by the grace of union, and to be God. For the first belongs to Him in His human nature, and the second, in His Divine Nature. Hence this is true: "Christ as Man has the grace of union"; yet not this: "Christ as Man is God."
2. The Son of Man has on earth the power of forgiving sins, not by virtue of the human nature, but by virtue of the Divine Nature, in which Divine Nature resides the power of forgiving sins authoritatively; whereas in the human nature it resides instrumentally and ministerially. Hence Chrysostom expounding this passage says [*Implicitly. Hom. xxx in Matth; cf. St. Thomas, Catena Aurea on Mc 2,10]: "He said pointedly 'on earth to forgive sins,' in order to show that by an indivisible union He united human nature to the power of the Godhead, since although He was made Man, yet He remained the Word of God."
3. When we say "this man," the demonstrative pronoun "this" attracts "man" to the suppositum; and hence "Christ as this Man, is God, is a truer proposition than Christ as Man is God."



Whether this is true: "Christ as Man is a hypostasis or person"?



Objection: 1. It would seem that Christ as Man is a hypostasis or person. For what belongs to every man belongs to Christ as Man, since He is like other men according to Ph 2,7: "Being made in the likeness of men." But every man is a person. Therefore Christ as Man is a person.
2. Further, Christ as Man is a substance of rational nature. But He is not a universal substance: therefore He is an individual substance. Now a person is nothing else than an individual substance of rational nature; as Boethius says (De Duab. Nat.). Therefore Christ as Man is a person.
3. Further, Christ as Man is a being of human nature, and a suppositum and a hypostasis of the same nature. But every hypostasis and suppositum and being of human nature is a person. Therefore Christ as Man is a person.

On the contrary Christ as Man is not an eternal person. Therefore if Christ as Man is a person it would follow that in Christ there are two persons---one temporal and the other eternal, which is erroneous, as was said above (Question [2], Article [6]; Question [4], Article [2]).
I answer that As was said (Articles [10],11), the term "Man" placed in the reduplication may refer either to the suppositum or to the nature. Hence when it is said: "Christ as Man is a person," if it is taken as referring to the suppositum, it is clear that Christ as Man is a person, since the suppositum of human nature is nothing else than the Person of the Son of God. But if it be taken as referring to the nature, it may be understood in two ways. First, we may so understand it as if it belonged to human nature to be in a person, and in this way it is true, for whatever subsists in human nature is a person. Secondly it may be taken that in Christ a proper personality, caused by the principles of the human nature, is due to the human nature; and in this way Christ as Man is not a person, since the human nature does not exist of itself apart from the Divine Nature, and yet the notion of person requires this.

Reply to Objection: 1. It belongs to every man to be a person, inasmuch as everything subsisting in human nature is a person. Now this is proper to the Man Christ that the Person subsisting in His human nature is not caused by the principles of the human nature, but is eternal. Hence in one way He is a person, as Man; and in another way He is not, as stated above.
2. The "individual substance," which is included in the definition of a person, implies a complete substance subsisting of itself and separate from all else; otherwise, a man's hand might be called a person, since it is an individual substance; nevertheless, because it is an individual substance existing in something else, it cannot be called a person; nor, for the same reason, can the human nature in Christ, although it may be called something individual and singular.
3. As a person signifies something complete and self-subsisting in rational nature, so a hypostasis, suppositum, and being of nature in the genus of substance, signify something that subsists of itself. Hence, as human nature is not of itself a person apart from the Person of the Son of God, so likewise it is not of itself a hypostasis or suppositum or a being of nature. Hence in the sense in which we deny that "Christ as Man is a person" we must deny all the other propositions.






Q17: OF CHRIST'S UNITY OF BEING (TWO ARTICLES)




We must now consider what pertains to Christ's unity in common. For, in their proper place, we must consider what pertains to unity and plurality in detail: thus we concluded (Question [9]) that there is not only one knowledge in Christ, and it will be concluded hereafter (Question [35], Article [2]) that there is not only one nativity in Christ.

Hence we must consider Christ's unity (1) of being; (2) of will; (3) of operation.

Under the first head there are two points of inquiry:

(1) Whether Christ is one or two?

(2) Whether there is only one being in Christ?



Whether Christ is one or two?



Objection: 1. It would seem that Christ is not one, but two. For Augustine says (De Trin. i, 7): "Because the form of God took the form of a servant, both are God by reason of God Who assumed, yet both are Man by reason of the man assumed." Now "both" may only be said when there are two. Therefore Christ is two.
2. Further, where there is one thing and another there are two. Now Christ is one thing and another; for Augustine says (Enchiridion xxxv): "Being in the form of God . . . He took the form of a servant . . . being both in one; but He was one of these as Word, and the other as man." Therefore Christ is two.
3. Further, Christ is not only man; for, if He were a mere man, He would not be God. Therefore He is something else than man, and thus in Christ there is one thing and another. Therefore Christ is two.
4. Further, Christ is something that the Father is, and something that the Father is not. Therefore Christ is one thing and another. Therefore Christ is two.
5. Further, as in the mystery of the Trinity there are three Persons in one Nature, so in the mystery of the Incarnation there are two natures in one Person. But on account of the unity of the Nature, notwithstanding the distinction of Person, the Father and Son are one, according to Jn 10,30: "I and the Father are one." Therefore, notwithstanding the unity of Person, Christ is two on account of the duality of nature.
6. Further, the Philosopher says (Phys. iii, text. 18) that "one" and "two" are predicated denominatively. Now Christ has a duality of nature. Therefore Christ is two.
7. Further, as accidental form makes a thing otherwise [alterum] so does substantial form make another thing [aliud] as Porphyry says (Praedic.). Now in Christ there are two substantial natures, the human and the Divine. Therefore Christ is one thing and another. Therefore Christ is two.

On the contrary Boethius says (De Duab. Nat.): "Whatever is, inasmuch as it is, is one." But we confess that Christ is. Therefore Christ is one.
I answer that Nature, considered in itself, as it is used in the abstract, cannot truly be predicated of the suppositum or person, except in God, in Whom "what it is" and "whereby it is" do not differ, as stated in the FP, Question [29], Article [4], ad 1. But in Christ, since there are two natures, viz. the Divine and the human, one of them, viz. the Divine, may be predicated of Him both in the abstract and in the concrete, for we say that the Son of God, Who is signified by the word Christ, is the Divine Nature and is God. But the human nature cannot be predicated of Christ in the abstract, but only in the concrete, i.e. as it is signified by the suppositum. For we cannot truly say that "Christ is human nature," because human nature is not naturally predicated of its suppositum. But we say that Christ is a man, even as Christ is God. Now God signifies one having the Godhead, and man signifies one having manhood. Yet one having manhood is differently signified by the word "man" and by the word "Jesus" or "Peter." For this word "man" implies one having manhood indistinctly, even as the word "God" implies indistinctly one having the Godhead; but the word "Peter" or "Jesus" implies one having manhood distinctly, i.e. with its determinate individual properties, as "Son of God" implies one having the Godhead under a determinate personal property. Now the dual number is placed in Christ with regard to the natures. Hence, if both the natures were predicated in the abstract of Christ, it would follow that Christ is two. But because the two natures are not predicated of Christ, except as they are signified in the suppositum, it must be by reason of the suppositum that "one" or "two" be predicated of Christ.Now some placed two supposita in Christ, and one Person, which, in their opinion, would seem to be the suppositum completed with its final completion. Hence, since they placed two supposita in Christ, they said that God is two, in the neuter. But because they asserted one Person, they said that Christ is one, in the masculine, for the neuter gender signifies something unformed and imperfect, whereas the masculine signifies something formed and perfect. on the other hand, the Nestorians, who asserted two Persons in Christ, said that Christ is two not only in the neuter, but also in the masculine. But since we maintain one person and one suppositum in Christ, as is clear from Question [2], Articles [2],3, it follows that we say that Christ is one not merely in the masculine, but also in the neuter.

Reply to Objection: 1. This saying of Augustine is not to be taken as if "both" referred to the predicate, so as to mean that Christ is both; but it refers to the subject. And thus "both" does not stand for two supposita, but for two words signifying two natures in the concrete. For I can say that "both, viz. God and Man, are God" on account of God Who assumes; and "both, viz. God and Man," are Man on account of the man assumed.
2. When it is said that "Christ is one thing and another," this saying is to be explained in this sense---"having this nature and another." And it is in this way that Augustine explains it (Contra Felic. xi), where, after saying, "In the mediator of God and man, the Son of God is one thing, and the Son of Man another," he adds: "I say another thing by reason of the difference of substance, and not another thing by reason of the unity of person." Hence Gregory Nazianzen says (Ep ad Chelid. ci): "If we must speak briefly, that of which the Saviour is, is one thing and another; thus the invisible is not the same as the visible; and what is without time is not the same as what is in time. Yet they are not one and another: far from it; for both these are one."
3. This is false, "Christ is only man"; because it does not exclude another suppositum, but another nature, since terms placed in the predicate are taken formally. But if anything is added whereby it is drawn to the suppositum, it would be a true proposition---for instance, "Christ is only that which is man." Nevertheless, it would not follow that He is "any other thing than man," because "another thing," inasmuch as it refers to a diversity of substance, properly refers to the suppositum. even as all relative things bearing a personal relation. But it does follow: "Therefore He has another nature."
4. When it is said, "Christ is something that the Father is"; "something" signifies the Divine Nature, which is predicated even in the abstract of the Father and Son. But when it is said: "Christ is something that is not the Father"; "something" signifies, not the human nature as it is in the abstract, but as it is in the concrete; not, indeed, in a distinct, but in an indistinct suppositum, i.e. inasmuch as it underlies the nature and not the individuating properties. Hence it does not follow that Christ is one thing and another, or that He is two, since the suppositum of the human nature in Christ, which is the Person of the Son of God, does not reckon numerically with the Divine Nature, which is predicated of the Father and Son.
5. In the mystery of the Divine Trinity the Divine Nature is predicated, even in the abstract of the three Persons; hence it may be said simply that the three Persons are one. But in the mystery of the Incarnation both natures are not predicated in the abstract of Christ; hence it cannot be said simply that Christ is two.
6. Two signifies what has duality, not in another, but in the same thing of which "two" is predicated. Now what is predicated is said of the suppositum, which is implied by the word "Christ." Hence, although Christ has duality of nature, yet, because He has not duality of suppositum, it cannot be said that Christ is two.
7. Otherwise implies diversity of accident. Hence diversity of accident suffices for anything to be called "otherwise" simply. But "another thing" implies diversity of substance. Now not merely the nature, but also the suppositum is said to be a substance, as is said Metaph. v, text. 15. Hence diversity of nature does not suffice for anything to be called "another thing" simply, unless there is diversity of suppositum. But diversity of nature makes "another thing" relatively, i.e. in nature, if there is no diversity of suppositum.




Summa Th. III EN Qu.16 a.6