16 Now here we have the explanation of what I am endeavouring to show, how it is that the sons of Mary, the sister of our Lord's mother, who though not formerly believers afterwards did believe, can be called brethren of the Lord. Possibly the case might be that one of the brethren believed immediately while the others did not believe until long after, and that one Mary was the mother of James and Joses, namely, “Mary of Clopas,” who is the same as the wife of Alphæus, the other, the mother of James the Less.
In any case, if she (the latter) had been the Lord's mother S. John would have allowed her the title, as everywhere else, and would not by calling her the mother of other sons have given a wrong impression. But at this stage I do not wish to argue for or against the supposition that Mary the wife of Clopas and Mary the mother of James and Joses were different women, provided it is clearly understood that Mary the mother of James and Joses was not the same person as the Lord's mother.
How then, says Helvidius, do you make out that they were called the Lord's brethren who were not his brethren? I will show how that is. In Holy Scripture there are four kinds of brethren— by nature, race, kindred, love. Instances of brethren by nature are Esau and Jacob, the twelve patriarchs, Andrew and Peter, James and John. As to race, all Jews are called brethren of one another, as in Deuteronomy, “If your brother, an Hebrew man, or an Hebrew woman, be sold unto you, and serve you six years; then in the seventh year you shall let him go free from you.”
And in the same book, “You shall in anywise set him king over you, whom the Lord your God shall choose: one from among your brethren shall you set king over you; you may not put a foreigner over you, which is not your brother.” And again, “You shall not see your brother's ox or his sheep go astray, and hide yourself from them: you shall surely bring them again unto your brother. And if your brother be not near unto you, or if you know him not, then you shall bring it home to your house, and it shall be with you until your brother seek after it, and you shall restore it to him again.”
And the Apostle Paul says, “I could wish that I myself were anathema from Christ for my brethren's sake, my kinsmen according to the flesh: who are Israelites.” Moreover they are called brethren by kindred who are of one family, that is πατρία, which corresponds to the Latin paternitas, because from a single root a numerous progeny proceeds. In Genesis we read, “And Abram said unto Lot, Let there be no strife, I pray you, between me and you, and between my herdmen and your herdmen; for we are brethren.”
And again, “So Lot chose him all the plain of Jordan, and Lot journeyed east: and they separated each from his brother.” Certainly Lot was not Abraham's brother, but the son of Abraham's brother Aram. For Terah begot Abraham and Nahor and Aram: and Aram begot Lot. Again we read, “And Abram was seventy and five years old when he departed out of Haran. And Abram took Sarai his wife, and Lot his brother's son.” But if you still doubt whether a nephew can be called a son, let me give you an instance. “And when Abram heard that his brother was taken captive, he led forth his trained men, born in his house, three hundred and eighteen.”
And after describing the night attack and the slaughter, he adds, “And he brought back all the goods, and also brought again his brother Lot.” Let this suffice by way of proof of my assertion. But for fear you may make some cavilling objection, and wriggle out of your difficulty like a snake, I must bind you fast with the bonds of proof to stop your hissing and complaining, for I know you would like to say you have been overcome not so much by Scripture truth as by intricate arguments.
Jacob, the son of Isaac and Rebecca, when in fear of his brother's treachery he had gone to Mesopotamia, drew near and rolled away the stone from the mouth of the well, and watered the flocks of Laban, his mother's brother. “And Jacob kissed Rachel, and lifted up his voice, and wept. And Jacob told Rachel that he was her father's brother, and that he was Rebekah's son.” Here is an example of the rule already referred to, by which a nephew is called a brother. And again, “Laban said unto Jacob.
Because you are my brother, should you therefore serve me for nought? Tell me what shall your wages be.” And so, when, at the end of twenty years, without the knowledge of his father-in-law and accompanied by his wives and sons he was returning to his country, on Laban overtaking him in the mountain of Gilead and failing to find the idols which Rachel hid among the baggage, Jacob answered and said to Laban, “What is my trespass? What is my sin, that you have so hotly pursued after me?
Whereas you have felt all about my stuff, what have you found of all your household stuff? Set it here before my brethren and your brethren, that they may judge between us two.” Tell me who are those brothers of Jacob and Laban who were present there? Esau, Jacob's brother, was certainly not there, and Laban, the son of Bethuel, had no brothers although he had a sister Rebecca.
Source: The Perpetual Virginity of Blessed Mary (New Advent)