Commentaria in Summam contra Gentiles, Liber IV

The fifth point that St. Thomas premises ¹ is that it was necessary for the man Christ to be born of a virgin mother, without natural seed.

Concerning this, however, he does three things: first, he proves that Christ's generation was without natural seed; second, that Christ's mother was a virgin ²; third, he removes certain doubts ³.

I. As to the first, it is argued first thus. The seed of the man is required in human generation as an active principle, on account of the active power which is in it. But the active power in the generation of Christ's body could not be natural: because natural power does not complete the whole formation of the body instantaneously, as was the case in a conception of this kind. Therefore etc.

Second. In the human generation of Christ, the ultimate terminus of the generation was the union to the divine person, not, however, the constituting of some human hypostasis or person. Therefore etc. — The consequence is proved. Because the seed of the male, in the generation of an animal, draws to itself and to its own substance the matter which the mother supplies, as though its power intends its own completion as the end of the generation. Hence also, the generation being completed, the seed itself, transformed and completed, is the offspring that is born.

2. For the evidence of this reason, it must be considered that, although the opinion of Aristotle in XV and XVI de Animalibus ⁴ was that the seed of the male does not enter materially into the constitution of the conceived offspring, but is only an active principle; there were nevertheless others, as St. Thomas relates in the Third Book, d. III, q. V, a. 1, saying that the human body is formed from the mixture of the seeds, namely of the mother and of the father, with the menstrual blood, and that the seed of the male is the matter of the human body, at least as to some part of it, as was shown in the second book ⁵. But because it is more difficult in the generation of Christ to preserve the mother's virginity if the seed of the male is held to concur materially in the constitution of the conceived offspring, than if the seed is held to concur only actively; therefore here, in order to show that even according to that opinion which makes the greater difficulty, the virginity of the Mother of God can be preserved, he follows that very opinion, although in other places he follows the opinion of Aristotle, as more conformable to the faith. Wherefore here he says that the seed of the man draws into its own substance the matter supplied by the mother; and that, the generation being completed, the seed itself, transformed and completed, is the offspring that is born.

II. In the second place, he proves that it was fitting that this generation be from a virgin ⁶. Here it must be noted that the preceding reasons prove that it was necessary that Christ's generation be without human seed; and they were reasons, certain things being supposed, concluding necessarily. The following reasons, however, show the fittingness of this, and they are probable.

He argues first thus. The word, insofar as it proceeds from the speaker, whether conceived inwardly or uttered outwardly, brings no corruption to the speaker, but rather the fullness of perfection is regarded in the speaker through the word. Therefore etc. – The consequence is proved. Because it was fitting that in the human generation itself of the Word of God some spiritual property of the word should shine forth.

Second. By the Word of God all things were established, and are preserved in their integrity. Therefore etc.

III. As to the third, three objections are removed ⁷. For someone could, first, urge in this way. Christ was generated otherwise than other men. Therefore in Christ there was not true and natural humanity.

St. Thomas answers that, just as the power which is in the seed produces a true man, having the human species and nature; so too the divine power, which gave such a power to the seed, can, without a power of this kind, produce the effects of that power: because, since it is infinite, and through it all causes obtain the power of producing their effect, whatever effect is produced through whatever cause can, through God, be produced without the aid of that cause, of the same species and nature.

IV. Second ⁸, someone could argue: – A man naturally generated has a body naturally constituted from the seed of the male and from that which the female supplies. This, however, is not fitting to the body of Christ, if it was not generated from the seed of the male. Therefore etc.

St. Thomas answers, and says first, that according to Aristotle's position, the assumption is false. For the seed of the male does not enter materially into the constitution of the conceived offspring, but is only an active principle.

2. He says second that, even if it is contrary to Aristotle's position, the consequence is none. Because the similarity or dissimilarity of things in matter is not considered according to the state of the matter at the beginning of the generation, but according to its condition already prepared at the terminus of the generation: as is clear in the fire generated from earth and from water. Hence, because the matter which is taken from the woman alone can, by divine power, be reduced, at the end of the generation, to the same disposition which the matter has if it be taken from male and female together, therefore there will be no dissimilarity on account of the diversity of matter between the body of Christ and our bodies. This is also shown in the first man, who was a true man and in all things like us, and yet the clay of the earth, from which he was formed by God, is farther from the matter which is taken from man and woman together than the matter taken from the woman alone, from which the body of Christ was formed.

3. He says third that, although natural power requires determinate matter for producing a determinate effect from it, divine power, nevertheless, is not confined to determinate matter.

Note that St. Thomas adds this last statement because someone could say that, although the dissimilarity or similarity of things in matter is considered according to the condition of the matter prepared at the end of the generation, different things nevertheless require different matters to be prepared at the beginning of the generation; and things of the same species require the same matter from which they are generated; for a horse is not generated from the blood of a woman, but only from the blood of a mare. And so, if the matter of the body of Christ at the beginning of the generation was only the blood of the Blessed Virgin; but the matter of other men is the blood of the woman together with the seed of the man: it seems that Christ is not of the same nature as other men. – But this is excluded by that which St. Thomas says. For that proposition, Things of the same nature require the same matter from which they are generated, and different things require different matters, has truth only when they are produced by a natural agent, and especially a univocal one: not, however, when one is produced by a natural agent, the other indeed by a supernatural agent, as is the case in the present matter.

V. Third ⁹, someone could object that it seems at least to detract from the dignity of the Mother of Christ, if a virgin conceived and gave birth: because she will not be called the true and natural mother of the Son of God.

St. Thomas answers that this is no obstacle to her being called the true and natural mother of the Son of God. Because, the divine power acting, that is, holding the place of the agent, she supplied the natural matter for the generation of the body of Christ, which alone is required on the part of the mother. Those things, however, which in other mothers bring about the corruption of virginity, are ordered only to that which belongs to the father, namely that the seed of the male should reach the place of generation.

2. For the evidence of this last statement, it must be considered that it is verified on one foundation that the Blessed Virgin is the Mother of Christ the man; on another that she is the Mother of the Son of God; and on another that she is the Mother of God; although these same propositions have a certain connection among themselves. For the proximate foundation of the first is that the Blessed Virgin did in the conception of the body of Christ whatever other mothers do in the conception of other men. – The foundation of the second, however, is that the Son of God united to himself, in the unity of person, the human nature, on account of which this is true, The Son of God is a man. For from this it follows, since the man was conceived and born temporally from the Blessed Virgin, that the Son of God also was temporally conceived and born from the Blessed Virgin. From which it follows that the Blessed Virgin is the Mother of the Son of God. – The foundation of the third, moreover, is that the same supposit subsists in the human nature and in the divine, on account of which it is true to say that he is man and God. From which it follows that this is true, God is man. And further it follows that, just as it is true to say that the Blessed Virgin is the mother of the man, so it is true to say that she is the Mother of God.

3. It must be considered, second, from the doctrine of St. Thomas in the Third Book, d. III, q. II, a. 1, as we also brought forward above ¹⁰, that, since a threefold action concurs in conception, namely the preparation and disposition of the woman's blood so that it may be apt for generation; the formation and organization of the body; and a certain strengthening of the conceived offspring: toward the first and the third the mother conducts herself actively; toward the second, however, she conducts herself merely passively, insofar as, namely, from the blood prepared by her the body is formed and organized by the power of the paternal seed. What therefore St. Thomas says, that on the part of the mother it is required only that she supply the natural matter for the generation of the body, is understood as to the formation and organization itself of the body, in which the ratio of conception consists, as was said above ¹¹ concerning the mind of St. Thomas: for the first of the said actions precedes the conception, the third, however, follows it.

VI. But against the aforesaid it is argued that, I say, this is not proper, The Blessed Virgin is the Mother of God. For this one, God is man, is not altogether proper, nor per se in the first mode of speaking ¹². Therefore neither is this one, The Blessed Virgin is the Mother of God.

The consequence is clear. Because it is not true that the Blessed Virgin is the mother of God, unless it is true that God is man, and conversely that man is God.

2. The assumption, however, is proved, as to the first part indeed, by Durandus ¹³, first, because this one, Peter is a man, is more proper: for there is a greater identity of subject and predicate, in that it is a per se identity. – Again. Peter, remaining Peter, cannot not be a man. Which does not belong to the aforesaid proposition. – Again. The supposit of Peter is constituted through that nature which is imported by the name man. The supposit of God, however, is not constituted formally through the nature imported by the name man.

Second ¹⁴, because of whatever man is predicated altogether properly, it is predicated in quid. Of God, however, it is not predicated in quid: since, when the question is asked concerning God, Through what? there is not properly returned an answer.

3. As to the second part, indeed, Scotus argues, in the Third Book, d. iv ¹⁵. Both because the predicate is outside the ratio of the subject. And because this one is not properly per se, Christ is a man: since the subject is not per se one.

VII. For the solution of these, it must be considered, first, that the propriety and per se-ness of a proposition were considered by Aristotle and the other logicians according to the exigency of those things which are found in creatures, in which one supposit is not found to subsist in two natures, but diverse natures are found in diverse supposits. And therefore they spoke of them as befits creatures. Through the Incarnation, however, it has come about that one supposit subsists in two natures. Therefore we must speak in a certain particular way of the propriety and per se-ness of those propositions in which the name importing the supposit as it subsists in one nature is predicated of itself as it subsists in another nature: so that, just as it is something particular in Christ, and above that which the philosophers knew, that one supposit subsists in two natures, so a certain particular mode of propriety and per se-ness of propositions may be taken, above the modes handed down by the philosophers and logicians.

2. It must be considered, second, that a proposition is called proper when the predicate is verified of the subject with the terms taken according to their proper significate for which they are born to supposit, and according to their proper mode of signifying. It is called, however, per se in the first mode of per se-ness, when the predicate says the nature and essence of the subject. This, moreover, is found in different ways where, according to the diversity of natures, there is also a diversity of supposits, and one supposit has only one nature: and where one supposit subsists in two natures. This indeed is universally true, that a name signifying a common nature in the concrete can supposit for any of the things contained under the common nature; and that of any supposit of some nature the name signifying that nature in the concrete can be truly and properly predicated. But where one supposit subsists in only one nature, the propriety of the proposition in which the name of the nature is predicated of the name importing the supposit, requires that the predicate be verified of the subject both by reason of the supposit for which it supposits, and by reason of the nature which it formally signifies, because there is no other nature signified by the subject than the nature signified by the predicate: although in material things the individuated nature is in some way distinguished from the nature of the species. Hence this one, Peter is a man, is proper: that one, however, a white thing is a man, is not altogether proper, although man is verified of that which underlies whiteness, which is the supposit of man, because it is not verified of it by reason of the formal significate of this term white. Where, however, one supposit subsists in two natures, the propriety of the expression does not require that the predicate be verified of the subject by reason of the form signified by the subject, but it suffices that it be verified by reason of the supposit imported by the name: since the nature imported by the name of the subject need not be the same as the nature imported by the name of the predicate. And yet the name signifying the nature of some supposit is truly and properly verified of the name importing that supposit. Similarly it is universally true that in a proposition of the first mode of per se-ness, the predicate signifies the nature and essence of the subject. But where one supposit has only one nature, it is necessary that the predicate so signify the essence of the subject that it be of the ratio of the nature imported by it: since one and the same nature is signified in the concrete by the subject and the predicate, as in this one, Peter is a man. Where, however, there is one supposit of two natures, this is not required: because it is not necessary that the same nature be signified by the subject and the predicate in order that the proposition be true, but it suffices that the supposit imported by the name of the subject subsist in the nature imported by the predicate, and have one and the same being with it.

3. If, therefore, we speak of the propriety and per se-ness of the proposition according to the exigency of a created supposit subsisting in only one nature, it is granted indeed that this proposition, God is man, is not altogether proper, nor per se in the first mode of per se-ness; nor is it so proper and per se as this one, Peter is a man; as seems to be the mind of St. Thomas in the Tertia, q. xvi, a. 1, and III Sent., d. vii, q. 1, a. 1. But if we speak of the propriety and per se-ness of the proposition according to the exigency of a supposit subsisting in two natures, so it is altogether proper, and per se in the first mode. Hence ignorance of this distinction made those arguing against St. Thomas err. For they argue as if we said the aforesaid proposition to be proper and per se in the way in which propriety and per se-ness of the proposition is taken according to the exigency of a supposit subsisting in only one nature. From which sense we are far distant: since, according to the Catholic faith, it is held that through the Incarnation of the Son of God one person subsists in two natures, namely in the divine and in the human.

4. If, however, the saying of St. Thomas in the Third Book, d. xi, a. 4, ad 6, is brought forward, saying that this proposition is not per se, « God has suffered », because in order that a proposition be per se, it is required that the predicate belong to the subject by reason of the form imported by the subject: - it is answered, as can be established from the determination made in that article, that St. Thomas speaks of propositions in which those things which follow upon the nature in reality are predicated of the name importing the supposit of the nature. In such propositions, indeed, it is necessary that the predicate belong to the subject by reason of the form imported by the subject, if it is to be a per se proposition: because, since the predicate is not the essence and nature of the supposit imported by the name of the subject, it does not appear whence it could be said to be a per se proposition, unless because the predicate belongs to the subject by reason of its form. We, however, have spoken of a proposition in which the nature itself in which the supposit imported by the name of the subject subsists is predicated.

VIII. To the doubt ¹⁶, therefore, the assumption is denied. To the first proof of the first part, it is said, first, that this one, God is man, is proper according to the exigency of one supposit in two natures, just as this one, Peter is a man, is proper according to the exigency of one supposit in only one nature. It is said, second, that the identity of subject and predicate is as great in the one as in the other, in the sense in which each one is true, and according to the exigency of the matter. For when it is said, God is man, the predicate is verified of the subject by reason of the supposit alone for which it supposits, not, however, by reason of the nature imported by the subject. Therefore the predicate and the subject are the same by reason of the supposit alone, insofar as both the subject and the predicate supposit for the same supposit. When, however, it is said, Peter is a man, the predicate is verified of the subject both by reason of the supposit, and by reason of the nature signified: therefore there is also identity between the subject and the predicate by reason of both. It is said, third, that Peter cannot be Peter unless he is a man, but God can be God even if he is not a man; again, the supposit of Peter is constituted through the nature imported by the name man, but not the supposit of God; this does not argue greater per se-ness or propriety of the proposition, but it argues that the mode of propriety and per se-ness is one in the one and another in the other, on account of the different condition of the matter of the propositions. For because Peter cannot be Peter unless he is a man, and is constituted through the human nature, therefore the proposition itself is true and proper, and also per se, not only by reason of the supposit, but also by reason of the form imported by the subject. Because, however, absolutely speaking, God can be God given that he is not a man, and the divine supposit is not constituted through the human nature, but rather draws it to a participation of his own being, therefore the proposition is said to be true and proper and per se by reason of that for which the subject supposits, not, however, by reason of the form imported by the subject.

2. If, however, it is asked whether this proposition, God is man, is necessary, or contingent: - it is said that, absolutely speaking, it is contingent: because God did not unite to himself absolutely necessarily the human nature, but contingently; or, to speak more correctly, freely. Given, however, the Incarnation, it is necessary, nor can it be false: for God, remaining God, cannot not be a man, the Incarnation standing. Hence St. Thomas, in the previously cited places ¹⁷, says that this proposition is in natural matter, not, however, in remote or contingent matter: because neither the human nature nor the divine is united to the supposit subsisting in both natures per accidens, but per se; for the human nature is not united to the Word accidentally, but essentially, as was shown above ¹⁸, insofar as he so united it to himself that he subsisted in it, and it had the being of the divine person; although it has some mode of accidentality.

IX. To the second proof ¹⁹ it is said that the predicate of the said proposition is predicated in quid of God, in the way in which the proposition is true: namely, by reason of the supposit imported by the name of the subject. Nor is it necessary that the same essence be imported by the subject and the predicate, as was shown above ²⁰, but it suffices that the same supposit be imported. For just as this is true, God is man, insofar as this name God supposits for the person of the Son; so of this subject the name man is predicated in quid, because, just as it is truly and per se said that the Son of God is a man, so, if it is asked, What is the Son of God? it is fittingly answered, He is a man, and also fittingly, He is God, in that he subsists in both natures: — the Incarnation, I say, standing.

X. To the first proof of the second part ²¹, which is Scotus's, it is clear from what has been said that for a proposition per se in the first mode in this matter, it is not required that the predicate belong to the ratio of the subject absolutely; rather, it suffices that it express the essence and nature of the supposit signified by the subject, as having subsistent being in it, and that it belong to the ratio of the supposit itself insofar as it is its supposit.

2. To the second proof, it is said first that, even granted that the subject were not per se one, the proposition could still be per se, just as this one is: A white man is an animal, as is said in the Third Book, d. x, q. 1, a. 2 ²².

It is said secondly that Christ signifies something per se one: insofar as the several natures signified by this name Christ are not united per accidens in one supposit, but per se, as having one being, which is the divine being.