On the Flesh of Christ 23Simeon's “Sign that Should Be Contradicted,” Applied to the Heretical Gainsaying of the True Birth of Christ. One of the Heretics' Paradoxes Turned in Support of Catholic Truth.

We acknowledge, however, that the prophetic declaration of Simeon is fulfilled, which he spoke over the recently-born Saviour: "Behold, this child is set for the fall and rising again of many in Israel, and for a sign that shall be spoken against." The sign (here meant) is that of the birth of Christ, according to Isaiah: "Therefore the Lord Himself shall give you a sign: behold, a virgin shall conceive and bear a son." We discover, then, what the sign is which is to be spoken against--the conception and the parturition of the Virgin Mary, concerning which these sophists say: "She a virgin and yet not a virgin bare, and yet did not bear;" just as if such language, if indeed it must be uttered, would not be more suitable even for ourselves to use! For "she bare," because she produced offspring of her own flesh and "yet she did not bear," since she produced Him not from a husband's seed; she was "a virgin," so far as (abstinence) from a husband went, and "yet not a virgin," as regards her bearing a child. There is not, however, that parity of reasoning which the heretics affect: in other words it does not follow that for the reason "she did not bear," she who was "not a virgin" was "yet a virgin," even because she became a mother without any fruit of her own womb. But with us there is no equivocation, nothing twisted into a double sense. Light is light; and darkness, darkness; yea is yea; and nay, nay; "whatsoever is more than these cometh of evil." She who bare (really) bare; and although she was a virgin when she conceived, she was a wife when she brought forth her son. Now, as a wife, she was under the very law of "opening the womb," wherein it was quite immaterial whether the birth of the male was by virtue of a husband's co-operation or not; it was the same sex that opened her womb. Indeed, hers is the womb on account of which it is written of others also: "Every male that openeth the womb shall be called holy to the Lord." For who is really holy but the Son of God? Who properly opened the womb but He who opened a closed one? But it is marriage which opens the womb in all cases. The virgin's womb, therefore, was especially opened, because it was especially closed. Indeed she ought rather to be called not a virgin than a virgin, becoming a mother at a leap, as it were, before she was a wife. And what must be said more on this point? Since it was in this sense that the apostle declared that the Son of God was born not of a virgin, but "of a woman," he in that statement recognised the condition of the "opened womb" which ensues in marriage. We read in Ezekiel of "a heifer which brought forth, and still did not bring forth." Now, see whether it was not in view of your own future contentions about the womb of Mary, that even then the Holy Ghost set His mark upon you in this passage; otherwise He would not, contrary to His usual simplicity of style (in this prophet), have uttered a sentence of such doubtful import, especially when Isaiah says, "She shall conceive and bear a son."