Were Sts. Simon and Jude the Cousins of Jesus?

Data from the early Church makes the ‘relative’ status of these ‘brothers’ very clear

Ugolino di Nerio, “Saint Simon and Saint Thaddeus (Jude),” 1325
Ugolino di Nerio, “Saint Simon and Saint Thaddeus (Jude),” 1325 (photo: Public Domain)

Matthew 13:55 (RSV) — Is not this the carpenter’s son? Is not his mother called Mary? And are not his brothers James and Joseph and Simon and Judas?

Matthew 27:55-56, 61 — There were also many women there [at the crucifixion], looking on from afar, who had followed Jesus from Galilee, ministering to him; among whom were Mary Magdalene, and Mary the mother of James and Joseph, ... Mary Magdalene and the other Mary were there, sitting opposite the sepulchre.

Matthew 28:1 — Now after the sabbath, toward the dawn of the first day of the week, Mary Magdalene and the other Mary went to see the sepulchre.

Mark 6:3 — “Is not this the carpenter, the son of Mary and brother of James and Joses and Judas and Simon ...?”

Mark 15:40, 47 — There were also women looking on from afar, among whom were Mary Magdalene, and Mary the mother of James the younger and of Joses, and Salome, ... Mary Mag’dalene and Mary the mother of Joses saw where he was laid.

Mark 16:1 — And when the sabbath was past, Mary Magdalene, and Mary the mother of James, and Salome, bought spices, so that they might go and anoint him.

John 19:25 — Standing by the cross of Jesus were his mother, and his mother’s sister, Mary the wife of Clopas, and Mary Magdalene.

By comparing Matthew 27:56, Mark 15:40 and John 19:25, we find that James and Joseph — mentioned in Matthew 13:55 with Simon and Jude as Jesus’ “brothers” — are also called sons of Mary, wife of Clopas. This other Mary (Matthew 27:61, 28:1) is called Our Lady’s adelphe in John 19.

Matthew 13:55-56 and Mark 6:3 mention Simon, Jude and “sisters” along with James and Joseph, calling all adelphoi. Since we know for sure that at least James and Joseph are not Jesus’ blood brothers, the most likely interpretation of Matthew 13:55 is that all these “brothers” are cousins.

Data from the very early Church makes the matter even more clear, as to the “relative” status of these “brothers” Simon and Jude. Eusebius, in his History of the Church, documents Hegesippus (c. 110 – c. 180) as follows:

After the martyrdom of James and the conquest of Jerusalem which immediately followed, it is said that those of the apostles and disciples of the Lord that were still living came together from all directions with those that were related to the Lord according to the flesh (for the majority of them also were still alive) to take counsel as to who was worthy to succeed James.
They all with one consent pronounced Symeon, the son of Clopas, of whom the Gospel also makes mention; to be worthy of the episcopal throne of that parish. He was a cousin, as they say, of the Savior. For Hegesippus records that Clopas was a brother of Joseph.
The same author [Hegesippus] also describes the beginnings of the heresies which arose in his time, in the following words: ‘And after James the Just had suffered martyrdom, as the Lord had also on the same account, Symeon, the son of the Lord's uncle, Clopas, was appointed the next bishop. All proposed him as second bishop because he was a cousin of the Lord.’

Clopas was the brother of St. Joseph. That would make this “other Mary” (wife of Clopas) the Blessed Virgin Mary’s sister-in-law, and her sons (James and Joseph named), Jesus’ first cousins. It follows by analogy (Matthew 13:55; Mark 6:3) that Simon and Jude are also his first cousins. 

Scripture provides a bit more indirect evidence about Jude as well. If this is the same Jude who wrote the epistle bearing that name (as many think), he calls himself “a servant of Jesus Christ and brother of James” (Jude 1:1). Now, suppose for a moment that he was Jesus’ blood brother. In that case, he refrained from referring to himself as the Lord’s own sibling and chose instead to identify himself as James’ brother. This is far too strange and implausible to believe. 

Adelphos (“brother”) was used in the New Testament because it was following Aramaic/Hebrew cultural practice. They would use “brother” to indicate not just siblings but also cousins and even nephews (Abraham and Lot). We have to think how they thought then in that culture and with that language, not like we do today.

But even today we often use “brother” in the broader sense: “Band of brothers,” “Brother Jed will preach the sermon today,” “Brother” and “Sister” for monks and nuns (and non-literal “Father” for priests), “Am I my brother’s keeper?” and Ringo Starr (an only child) calling the Beatles his “brothers.”

“Cousin” appears four times in the entire Old Testament in the RSV (three of those in Jeremiah, another in Leviticus). But “brother[s]” appears 390 times, “brethren” 154 times and “sister[s]” 110 times. So by a 654-4 ratio, we have those terms (which at first glance sound like siblings) used over against “cousin.” Obviously, many times they were used for non-sibling relatives.

The New Testament (which came out of the same culture, and was Jewish-written save for Luke) totally reflects this. It has “brother[s]” 159 times, “brethren” 191, and “sister[s]” 24 times, while “cousin” appears exactly once (Colossians 4:10). So that's a 374-1 ratio (even more lopsided than the Old Testament), and for the entire Bible (minus the Deuterocanon), the numbers are 1028-5, or “cousin” used instead of “brother” or “sister” once in every 206 times a relative is mentioned.