Objection 4: Further, what is born by two nativities is born twice. But this proposition is false; "Christ was born twice": because the nativity whereby He was born of the Father suffers no interruption; since it is eternal. Whereas interruption is required to warrant the use of the adverb "twice": for a man is said to run twice whose running is interrupted. Therefore it seems that we should not admit a double nativity in Christ.
On the contrary, Damascene says (De Fide Orth. iii): "We confess two nativities in Christ: one of the Father---eternal; and one which occurred in these latter times for our sake."
I answer that, As stated above (A[1]), nature is compared to nativity, as the terminus to movement or change. Now, movement is diversified according to the diversity of its termini, as the Philosopher shows (Phys. v). But, in Christ there is a twofold nature: one which He received of the Father from eternity, the other which He received from His Mother in time. Therefore we must needs attribute to Christ a twofold nativity: one by which He was born of the Father from all eternity; one by which He was born of His Mother in time.
Reply to Objection 1: This was the argument of a certain heretic, Felician, and is solved thus by Augustine (Contra Felic. xii). "Let us suppose," says he, "as many maintain, that in the world there is a universal soul, which, by its ineffable movement, so gives life to all seed, that it is not compounded with things begotten, but bestows life that they may be begotten. Without doubt, when this soul reaches the womb, being intent on fashioning the passible matter to its own purpose, it unites itself to the personality thereof, though manifestly it is not of the same substance; and thus of the active soul and passive matter, one man is made out of two substances. And so we confess that the soul is born from out the womb; but not as though, before birth, it was nothing at all in itself. Thus, then, but in a way much more sublime, the Son of God was born as man, just as the soul is held to be born together with the body: not as though they both made one substance, but that from both, one person results. Yet we do not say that the Son of God began thus to exist: lest it be thought that His Divinity is temporal. Nor do we acknowledge the flesh of the Son of God to have been from eternity: lest it be thought that He took, not a true human body, but some resemblance thereof."
Reply to Objection 2: This was an argument of Nestorius, and it is thus solved by Cyril in an epistle [*Cf. Acta Concil. Ephes., p. 1, cap. viii]: "We do not say that the Son of God had need, for His own sake, of a second nativity, after that which is from the Father: for it is foolish and a mark of ignorance to say that He who is from all eternity, and co-eternal with the Father, needs to begin again to exist. But because for us and for our salvation, uniting the human nature to His Person, He became the child of a woman, for this reason do we say that He was born in the flesh."
Reply to Objection 3: Nativity regards the person as its subject, the nature as its terminus. Now, it is possible for several transformations to be in the same subject: yet must they be diversified in respect of their termini. But we do not say this as though the eternal nativity were a transformation or a movement, but because it is designated by way of a transformation or movement.
Reply to Objection 4: Christ can be said to have been born twice in respect of His two nativities. For just as he is said to run twice who runs at two different times, so can He be said to be born twice who is born once from eternity and once in time: because eternity and time differ much more than two different times, although each signifies a measure of duration.
Whether the Blessed Virgin can be called Christ's Mother in respect of His temporal nativity?
Objection 1: It would seem that the Blessed Virgin cannot be called Christ's Mother in respect of His temporal nativity. For, as stated above (Q[32], A[4]), the Blessed Virgin Mary did not cooperate actively in begetting Christ, but merely supplied the matter. But this does not seem sufficient to make her His Mother: otherwise wood might be called the mother of the bed or bench. Therefore it seems that the Blessed Virgin cannot be called the Mother of Christ.
Objection 2: Further, Christ was born miraculously of the Blessed Virgin. But a miraculous begetting does not suffice for motherhood or sonship: for we do not speak of Eve as being the daughter of Adam. Therefore neither should Christ be called the Son of the Blessed Virgin.
Objection 3: Further, motherhood seems to imply partial separation of the semen. But, as Damascene says (De Fide Orth. iii), "Christ's body was formed, not by a seminal process, but by the operation of the Holy Ghost." Therefore it seems that the Blessed Virgin should not be called the Mother of Christ.
On the contrary, It is written ( Mat. 1:18 ): "The generation of Christ was in this wise. When His Mother Mary was espoused to Joseph," etc.
I answer that, The Blessed Virgin Mary is in truth and by nature the Mother of Christ. For, as we have said above (Q[5], A[2]; Q[31], A[5]), Christ's body was not brought down from heaven, as the heretic Valentine maintained, but was taken from the Virgin Mother, and formed from her purest blood. And this is all that is required for motherhood, as has been made clear above (Q[31], A[5]; Q[32], A[4]). Therefore the Blessed Virgin is truly Christ's Mother.
Reply to Objection 1: As stated above (Q[32], A[3]), not every generation implies fatherhood or motherhood and sonship, but only the generation of living things. Consequently when inanimate things are made from some matter, the relationship of motherhood and sonship does not follow from this, but only in the generation of living things, which is properly called nativity.
Reply to Objection 2: As Damascene says (De Fide Orth. iii): "The temporal nativity by which Christ was born for our salvation is, in a way, natural, since a Man was born of a woman, and after the due lapse of time from His conception: but it is also supernatural, because He was begotten, not of seed, but of the Holy Ghost and the Blessed Virgin, above the law of conception." Thus, then, on the part of the mother, this nativity was natural, but on the part of the operation of the Holy Ghost it was supernatural. Therefore the Blessed Virgin is the true and natural Mother of Christ.
Reply to Objection 3: As stated above (Q[31], A[5], ad 3; Q[32], A[4]), the resolution of the woman's semen is not necessary for conception; neither, therefore, is it required for motherhood.
Whether the Blessed Virgin should be called the Mother of God?
Objection 1: It would seem that the Blessed Virgin should not be called the Mother of God. For in the Divine mysteries we should not make any assertion that is not taken from Holy Scripture. But we read nowhere in Holy Scripture that she is the mother or parent of God, but that she is the "mother of Christ" or of "the Child," as may be seen from Mat. 1:18. Therefore we should not say that the Blessed Virgin is the Mother of God.
Objection 2: Further, Christ is called God in respect of His Divine Nature. But the Divine Nature did not first originate from the Virgin. Therefore the Blessed Virgin should not be called the Mother of God.
Objection 3: Further, the word "God" is predicated in common of Father, Son, and Holy Ghost. If, therefore, the Blessed Virgin is Mother of God it seems to follow that she was the Mother of Father, Son, and Holy Ghost, which cannot be allowed. Therefore the Blessed Virgin should not be called Mother of God.
On the contrary, In the chapters of Cyril, approved in the Council of Ephesus (P. 1, Cap. xxvi), we read: "If anyone confess not that the Emmanuel is truly God, and that for this reason the Holy Virgin is the Mother of God, since she begot of her flesh the Word of God made flesh, let him be anathema."
I answer that, As stated above (Q[16], A[1]), every word that signifies a nature in the concrete can stand for any hypostasis of that nature. Now, since the union of the Incarnation took place in the hypostasis, as above stated (Q[2], A[3]), it is manifest that this word "God" can stand for the hypostasis, having a human and a Divine nature. Therefore whatever belongs to the Divine and to the human nature can be attributed to that Person: both when a word is employed to stand for it, signifying the Divine Nature, and when a word is used signifying the human nature. Now, conception and birth are attributed to the person and hypostasis in respect of that nature in which it is conceived and born. Since, therefore, the human nature was taken by the Divine Person in the very beginning of the conception, as stated above (Q[33], A[3]), it follows that it can be truly said that God was conceived and born of the Virgin. Now from this is a woman called a man's mother, that she conceived him and gave birth to him. Therefore the Blessed Virgin is truly called the Mother of God. For the only way in which it could be denied that the Blessed Virgin is the Mother of God would be either if the humanity were first subject to conception and birth, before this man were the Son of God, as Photinus said; or if the humanity were not assumed unto unity of the Person or hypostasis of the Word of God, as Nestorius maintained. But both of these are erroneous. Therefore it is heretical to deny that the Blessed Virgin is the Mother of God.
Reply to Objection 1: This was an argument of Nestorius, and it is solved by saying that, although we do not find it said expressly in Scripture that the Blessed Virgin is the Mother of God, yet we do find it expressly said in Scripture that "Jesus Christ is true God," as may be seen 1 Jn. 5:20, and that the Blessed Virgin is the "Mother of Jesus Christ," which is clearly expressed Mat. 1:18. Therefore, from the words of Scripture it follows of necessity that she is the Mother of God.
Again, it is written ( Rom. 9:5 ) that Christ is of the Jews "according to the flesh, who is over all things, God blessed for ever." But He is not of the Jews except through the Blessed Virgin. Therefore He who is "above all things, God blessed for ever," is truly born of the Blessed Virgin as of His Mother.
Reply to Objection 2: This was an argument of Nestorius. But Cyril, in a letter against Nestorius [*Cf. Acta Conc. Ephes., p. 1, cap. ii], answers it thus: "Just as when a man's soul is born with its body, they are considered as one being: and if anyone wish to say that the mother of the flesh is not the mother of the soul, he says too much. Something like this may be perceived in the generation of Christ. For the Word of God was born of the substance of God the Father: but because He took flesh, we must of necessity confess that in the flesh He was born of a woman." Consequently we must say that the Blessed Virgin is called the Mother of God, not as though she were the Mother of the Godhead, but because she is the mother, according to His human nature, of the Person who has both the divine and the human nature.