Question:
Answer:
The Church “has always understood” at the level of the Ordinary Magisterium that the “brothers and sisters of the Lord” in Scripture refer to children of a relative of Mary’s who was alive at the time of Christ. The Catechism of the Catholic Church provides:
Against this doctrine the objection is sometimes raised that the Bible mentions brothers and sisters of Jesus. The Church has always understood these passages as not referring to other children of the Virgin Mary. In fact, James and Joseph, “brothers of Jesus”, are the sons of another Mary, a disciple of Christ, whom St. Matthew significantly calls “the other Mary”. They are close relations of Jesus, according to an Old Testament expression (CCC 500).
There is also a later tradition (but very early in Church history, ca. AD 140, in the Protoevangelium of James) that claims Joseph was a widower who married the Virgin Mary later in life (after already having a family with his first wife). This tradition was never embraced by the Church. However, because there is no infallible pronouncement on this matter, Catholics are free to believe either tradition as long as deference is given to the Ordinary Magisterium. In other words, one is not free to contradict the Ordinary Magisterial teaching and teach this later theory as if it is Church teaching.
But having said that, what is perhaps most important is the one thing no one can reasonably deny. The historical record is clear: Mary remained a perpetual virgin. This teaching is infallible in the Catholic Church on two levels. First, this was the unanimous teaching of the Fathers of the Church. That alone would render this teaching infallible. But it is also infallible by virtue of the fact that it represents the teaching of the Universal and Ordinary Magisterium. Moreover, both the teaching of St. Joseph being a virgin spouse of Mary—and the corresponding opinion that he was a widower—are always presented in a context that presupposes Mary’s Perpetual Virginity.