other · 383 · Rome
Helvidius was a Roman layman, otherwise unknown, who argued about 383 that the brothers of the Lord named in the gospels were the sons of Mary and Joseph born after Jesus, and drew from it the conclusion he actually cared about: that marriage is not inferior to virginity, since the mother of the Lord herself lived in one. Jerome answered with Adversus Helvidium, and the answer is the one the western church has kept — that the brothers are cousins or kinsmen, that the Greek and Hebrew usage allows it, and that Mary remained a virgin. The argument is worth having on a page because of what it shows about the period: the ascetic movement was winning and its critics were being answered with a violence that surprised even Jerome's friends. The east had reached the same conclusion about Mary by a different road, holding the brothers to be Joseph's children by an earlier marriage, which this dataset does not have to choose between and does not.
Did Mary have other children?
He said yes, and the reply is the reason the question has a standard answer.