Reply Obj. 4: The Scriptures are wont to designate as the first-born, not only a child who is followed by others, but also the one that is born first. "Otherwise, if a child were not first-born unless followed by others, the first-fruits would not be due as long as there was no further produce" [*Jerome, Adversus Helvid. x]: which is clearly false, since according to the law the first-fruits had to be redeemed within a month (Num. 18:16).
Reply Obj. 5: Some, as Jerome says on Matt. 12:49, 50, "suppose that the brethren of the Lord were Joseph's sons by another wife. But we understand the brethren of the Lord to be not sons of Joseph, but cousins of the Saviour, the sons of Mary, His Mother's sister." For "Scripture speaks of brethren in four senses; namely, those who are united by being of the same parents, of the same nation, of the same family, by common affection." Wherefore the brethren of the Lord are so called, not by birth, as being born of the same mother; but by relationship, as being blood-relations of His. But Joseph, as Jerome says (Contra Helvid. ix), is rather to be believed to have remained a virgin, "since he is not said to have had another wife," and "a holy man does not live otherwise than chastely."
Reply Obj. 6: Mary who is called "the mother of James and Joseph" is not to be taken for the Mother of our Lord, who is not wont to be named in the Gospels save under this designation of her dignity—"the Mother of Jesus." This Mary is to be taken for the wife of Alphaeus, whose son was James the less, known as the "brother of the Lord" (Gal. 1:19). _______________________
FOURTH ARTICLE [III, Q. 28, Art. 4]
Whether the Mother of God Took a Vow of Virginity?
Objection 1: It would seem that the Mother of God did not take a vow of virginity. For it is written (Deut. 7:14): "No one shall be barren among you of either sex." But sterility is a consequence of virginity. Therefore the keeping of virginity was contrary to the commandment of the Old Law. But before Christ was born the old law was still in force. Therefore at that time the Blessed Virgin could not lawfully take a vow of virginity.
Obj. 2: Further, the Apostle says (1 Cor. 7:25): "Concerning virgins I have no commandment of the Lord; but I give counsel." But the perfection of the counsels was to take its beginning from Christ, who is the "end of the Law," as the Apostle says (Rom. 10:4). It was not therefore becoming that the Virgin should take a vow of virginity.
Obj. 3: Further, the gloss of Jerome says on 1 Tim. 5:12, that "for those who are vowed to virginity, it is reprehensible not only to marry, but also to desire to be married." But the Mother of Christ committed no sin for which she could be reprehended, as stated above (Q. 27, A. 4). Since therefore she was "espoused," as related by Luke 1:27 it seems that she did not take a vow of virginity.
On the contrary, Augustine says (De Sanct. Virg. iv): "Mary answered the announcing angel: 'How shall this be done, because I know not man?' She would not have said this unless she had already vowed her virginity to God."
I answer that, As we have stated in the Second Part (II-II, Q. 88, A. 6), works of perfection are more praiseworthy when performed in fulfilment of a vow. Now it is clear that for reasons already given (AA. 1, 2, 3) virginity had a special place in the Mother of God. It was therefore fitting that her virginity should be consecrated to God by vow. Nevertheless because, while the Law was in force both men and women were bound to attend to the duty of begetting, since the worship of God was spread according to carnal origin, until Christ was born of that people; the Mother of God is not believed to have taken an absolute vow of virginity, before being espoused to Joseph, although she desired to do so, yet yielding her own will to God's judgment. Afterwards, however, having taken a husband, according as the custom of the time required, together with him she took a vow of virginity.