You know the word brother has a broader meaning because it doesn't fit into your traditions.
And since the Bible nowhere resolves this ambiguity, by for instance calling James a son of Mary, why do you assume this one usage?
And it's just that reason the Bible nowhere resolves this ambiguity, because there is no ambiguity other then for those who are trying to wedge it into their puzzle when it doesn't fit.
Anyone who believes that Mary and Joseph had a perfectly normal marriage after Jesus was born, has no problem understanding Matthew and Mark's identification of Mary's birth children and Jesus brother's and sisters.
It's you who has the square block and the round hole, not me.
JH :)
No, we know the word "brother" has a broader meaning cause the Bible uses the very word in that way. You yourself admit that its use needs to be clarified.
So why do you assume a narrow meaning when it is entirely within reason that the broader meaning is intended? Semitic language doesn't even have seperate words for "brother" and "kin." Our attempts to choose one word or the other are because we can seperate the notions.
You need to heed the Bible and the existing lingustic and cultural traditions that demonstrate this very same thing in action.
The basic fact is that no matter how an American in the 21st Century reads the word "brother," what a semitic person meant by "brother" 2000 years ago is entirely different.
They don't share your presumptions. An American who points at someone and says "that is my brother" means one thing. A Hebrew 2000 years ago means something else. Your refusal to see this is typical of the myopic view of the Sola Scripturist.
SD
Saint Cleophas (First Century). Saint Cleophas was one of the greatest brothers and husbands and fathers and grandfathers who has ever been in the history of the world. His brother was Saint Joseph, the virginal spouse of the Blessed Virgin Mary. His wife was Saint Mary of Cleophas, whose feast day is April 9. Three of his sons, Saint Simon, Saint James the Less and Saint Jude--and two of his grandsons, Saint James the Greater and Saint John--were Apostles of Jesus. They are called in Holy Scripture, "the brethren of Our Lord." His daughter, Mary Salome, the mother of Saint James the Greater and Saint John, is also a saint. Her feast day is October 22. Still another son, Joseph Barsabas, who is called in Holy Scripture, "the Just," and who was one of the two nominated to take the place of the traitorous Judas Iscariot, is a saint and has a feast day on July 20. Saint Cleophas was one of the two disciples Our Lord met on the road to Emmaus on the day of His Resurrection, as we are told in the Gospel of Saint Luke, Chapter 24. Our Lord stopped to have supper with these two disciples. At the end of the meal Jesus blessed bread and gave them His Sacred Body to eat. And Saint Luke tells us that "they knew Him in the breaking of bread." Saint Cleophas was murdered by the Jews in the very house in which he had been host to Our Lord on the first Easter Sunday.