(Ep. ad Volus. cxxxvii): "This same power of
God brought forth the infant's limbs out of the virginal womb of His
inviolate Mother, by which in the vigor of manhood He passed through
the closed doors. If we are told why this happened, it will cease to
be wonderful; if another instance be alleged, it will no longer be
unique." But miracles that are wrought in confirmation of the Faith
should be manifest. Since, therefore, by her Espousals this miracle
would be less evident, it seems that it was unfitting that Christ
should be born of an espoused virgin.

Obj. 3: Further, the martyr Ignatius, as Jerome says on Matt. 1:18,
gives as a reason of the espousals of the Mother of God, "that the
manner of His Birth might be hidden from the devil, who would think
Him to be begotten not of a virgin but of a wife." But this seems
to be no reason at all. First, because by his natural cunning he
knows whatever takes place in bodies. Secondly, because later on
the demons, through many evident signs, knew Christ after a
fashion: whence it is written (Mk. 1:23, 24): "A man with an unclean
spirit . . . cried out, saying: What have we to do with Thee, Jesus
of Nazareth? Art Thou come to destroy us? I know . . . Thou art the
Holy one of God." Therefore it does not seem fitting that the Mother
of God should have been espoused.

Obj. 4: Further, Jerome gives as another reason, "lest the Mother of
God should be stoned by the Jews as an adulteress." But this reason
seems to have no weight, for if she were not espoused, she could not
be condemned for adultery. Therefore it does not seem reasonable that
Christ should be born of an espoused virgin.

_On the contrary,_ It is written (Matt. 1:18): "When as His Mother
Mary was espoused to Joseph": and (Luke 1:26, 27): "The angel Gabriel
was sent . . . to a virgin espoused to a man whose name was Joseph."

_I answer that,_ It was fitting that Christ should be born of an
espoused virgin; first, for His own sake; secondly, for His Mother's
sake; thirdly, for our sake. For the sake of Christ Himself, for four
reasons. First, lest He should be rejected by unbelievers as
illegitimate: wherefore Ambrose says on Luke 1:26, 27: "How could we
blame Herod or the Jews if they seem to persecute one who was born of
adultery?"

Secondly, in order that in the customary way His genealogy might be
traced through the male line. Thus Ambrose says on Luke 3:23: "He Who
came into the world, according to the custom