Irenaeus' Opposition To The Perpetual Virginity Of Mary

I want to quote and comment on a few of the relevant passages.

In contrast to the concept of virginity in partu, Irenaeus refers to how Jesus opened Mary's womb:

"the Word should become flesh, and the Son of God the Son of man (the pure One opening purely that pure womb which regenerates men unto God, and which He Himself made pure); and having become this which we also are, He [nevertheless] is the Mighty God, and possesses a generation which cannot be declared." (Against Heresies, 4:33:11)

He refers to Jesus as Mary's "first-begotten". An only child will sometimes be referred to as the firstborn, but the term more often refers to one of multiple children. Both conceptually and in terms of the history of usage, "first-begotten" seems more likely to refer to one within a group rather than an isolated individual. If we had evidence that would override the normal meaning of "first-begotten", then we could interpret Irenaeus accordingly, but we can't go with a less natural reading without overriding evidence. Other terminology could have been used if Irenaeus believed in the perpetual virginity of Mary, especially if he not only believed in it, but also considered it as important as advocates of the concept often suggest it is. For example, Jesus could have been referred to as Mary's "only-begotten" (e.g., as we see with people other than Jesus in Luke 7:12, 8:42, 9:38), which would be consistent with Mary's perpetual virginity and express the fact that Jesus had the advantages associated with being a firstborn. Irenaeus' choice of "first-begotten" instead is evidence that he didn't believe in Mary's perpetual virginity:

"But Simeon also —he who had received an intimation from the Holy Ghost that he should not see death, until first he had beheld Christ Jesus— taking Him, the first-begotten of the Virgin, into his hands, blessed God, and said, 'Lord, now lettest Thou Thy servant depart in peace, according to Thy word: because mine eyes have seen Thy salvation, which Thou hast prepared before the face of all people; a light to lighten the Gentiles, and the glory of Thy people Israel;' confessing thus, that the infant whom he was holding in his hands, Jesus, born of Mary, was Christ Himself, the Son of God, the light of all, the glory of Israel itself, and the peace and refreshing of those who had fallen asleep." (Against Heresies, 3:16:4)

Elsewhere, Irenaeus compares Mary to soil that was initially virgin, then lost its virginity, and he refers to how Mary was "as yet a virgin":

"And as the protoplast himself Adam, had his substance from untilled and as yet virgin soil ('for God had not yet sent rain, and man had not tilled the ground'), and was formed by the hand of God, that is, by the Word of God, for 'all things were made by Him,' and the Lord took dust from the earth and formed man; so did He who is the Word, recapitulating Adam in Himself, rightly receive a birth, enabling Him to gather up Adam [into Himself], from Mary, who was as yet a virgin." (Against Heresies, 3:21:10)

Notice, first, that there was no need to compare Mary to the virgin soil or to go on to comment on how the virginity of the soil eventually ceased. He could have used some other analogy or added a relevant qualifier, for example, if he didn't want people to reach the conclusion that most naturally follows from his comments (that Mary likewise ceased to be a virgin). Secondly, he chose to refer to Mary as "who was as yet a virgin" instead of something like "who would always be a virgin".

Keep in mind that the issue here is how to best explain Irenaeus' comments, not just how he might be interpreted. Not only does he never advocate the perpetual virginity of Mary, despite frequently referring to her virginity in other ways, but he even makes multiple types of comments in multiple contexts that are most naturally taken as inconsistent with perpetual virginity. It's unlikely that Irenaeus believed in the perpetual virginity of Mary. It's even more unlikely that he both believed in it and considered it as important as advocates of the concept often suggest it is.

Sometimes Jerome will be appealed to when Irenaeus is discussed, on the basis that Jerome supposedly gives us reason to think Irenaeus believed in Mary's perpetual virginity. But the appeal to Jerome is dubious, for reasons explained here.