Saint Jerome, The Perpetual Virginity of Blessed Mary, Against Helvidius:
17. Innumerable instances of the same kind are to be found in the sacred books. But, to be brief, I will return to the last of the four classes of brethren, those, namely, who are brethren by affection, and these again fall into two divisions, those of the spiritual and those of the general relationship. I say spiritual because all of us Christians are called brethren, as in the verse, "Behold, how good and how pleasant it is for brethren to dwell together in unity." And in another psalm the Saviour says, "I will declare your name unto my brethren." And elsewhere, John 20:17 "Go unto my brethren and say to them." I say also general, because we are all children of one Father, there is a like bond of brotherhood between us all. Isaiah 66:5 "Tell these who hate you," says the prophet, "you are our brethren." And the Apostle writing to the Corinthians: 1 Corinthians 5:11 "If any man that is named brother be a fornicator, or covetous, or an idolater, or a reviler, or a drunkard, or an extortioner: with such a one no, not to eat." I now ask to which class you consider the Lord's brethren in the Gospel must be assigned. They are brethren by nature, you say. But Scripture does not say so; it calls them neither sons of Mary, nor of Joseph. Shall we say they are brethren by race? But it is absurd to suppose that a few Jews were called His brethren when all Jews of the time might upon this principle have borne the title. Were they brethren by virtue of close intimacy and the union of heart and mind? If that were so, who were more truly His brethren than the apostles who received His private instruction and were called by Him His mother and His brethren? Again, if all men, as such, were His brethren, it would have been foolish to deliver a special message, "Behold, your brethren seek you," for all men alike were entitled to the name. The only alternative is to adopt the previous explanation and understand them to be called brethren in virtue of the bond of kindred, not of love and sympathy, nor by prerogative of race, nor yet by nature. Just as Lot was called Abraham's brother, and Jacob Laban's, just as the daughters of Zelophehad received a lot among their brethren, just as Abraham himself had to wife Sarah his sister, for he says, Genesis 20:11 "She is indeed my sister, on the father's side, not on the mother's," that is to say, she was the daughter of his brother, not of his sister. Otherwise, what are we to say of Abraham, a just man, taking to wife the daughter of his own father? Scripture, in relating the history of the men of early times, does not outrage our ears by speaking of the enormity in express terms, but prefers to leave it to be inferred by the reader: and God afterwards gives to the prohibition the sanction of the law, and threatens, Leviticus 18:9 "He who takes his sister, born of his father, or of his mother, and beholds her nakedness, has commited abomination, he shall be utterly destroyed. He has uncovered his sister's nakedness, he shall bear his sin."
18. There are things which, in your extreme ignorance, you had never read, and therefore you neglected the whole range of Scripture and employed your madness in outraging the Virgin, like the man in the story who being unknown to everybody and finding that he could devise no good deed by which to gain renown, burned the temple of Diana: and when no one revealed the sacrilegious act, it is said that he himself went up and down proclaiming that he was the man who had applied the fire. The rulers of Ephesus were curious to know what made him do this thing, whereupon he replied that if he could not have fame for good deeds, all men should give him credit for bad ones. Grecian history relates the incident. But you do worse. You have set on fire the temple of the Lord's body, you have defiled the sanctuary of the Holy Spirit from which you are determined to make a team of four brethren and a heap of sisters come forth. In a word, joining in the chorus of the Jews, you say, "Is not this the carpenter's son? Is not his mother called Mary? And his brethren James, and Joseph, and Simon, and Judas? And his sisters, are they not all with us? The word all would not be used if there were not a crowd of them." Pray tell me, who, before you appeared, was acquainted with this blasphemy? Who thought the theory worth two-pence? You have gained your desire, and have become notorious by crime. For myself who am your opponent, although we live in the same city, I don't know, as the saying is, whether you are white or black. I pass over faults of diction which abound in every book you write. I say not a word about your absurd introduction. Good heavens! I do not ask for eloquence, since, having none yourself, you applied for a supply of it to your brother Craterius. I do not ask for grace of style, I look for purity of soul: for with Christians it is the greatest of solecisms and of vices of style to introduce anything base either in word or action. I have come to the conclusion of my argument. I will deal with you as though I had as yet prevailed nothing; and you will find yourself on the horns of a dilemma. It is clear that our Lord's brethren bore the name in the same way that Joseph was called his father: Luke 1:18 "I and your father sought you sorrowing." It was His mother who said this, not the Jews. The Evangelist himself relates that His father and His mother were marvelling at the things which were spoken concerning Him, and there are similar passages which we have already quoted in which Joseph and Mary are called his parents. Seeing that you have been foolish enough to persuade yourself that the Greek manuscripts are corrupt, you will perhaps plead the diversity of readings. I therefore come to the Gospel of John, and there it is plainly written, John 1:45 "Philip finds Nathanael, and says unto him, We have found him of whom Moses in the law, and the prophets did write, Jesus of Nazareth, the son of Joseph." You will certainly find this in your manuscript. Now tell me, how is Jesus the son of Joseph when it is clear that He was begotten of the Holy Ghost? Was Joseph His true father? Dull as you are, you will not venture to say that. Was he His reputed father? If so, let the same rule be applied to them when they are called brethren, that you apply to Joseph when he is called father.
19. Now that I have cleared the rocks and shoals I must spread sail and make all speed to reach his epilogue. Feeling himself to be a smatterer, he there produces Tertullian as a witness and quotes the words of Victorinus bishop of Petavium. Of Tertullian I say no more than that he did not belong to the Church. But as regards Victorinus, I assert what has already been proved from the Gospel— that he spoke of the brethren of the Lord not as being sons of Mary, but brethren in the sense I have explained, that is to say, brethren in point of kinship not by nature. We are, however, spending our strength on trifles, and, leaving the fountain of truth, are following the tiny streams of opinion. Might I not array against you the whole series of ancient writers? Ignatius, Polycarp, Irenæus, Justin Martyr, and many other apostolic and eloquent men, who against Ebion, Theodotus of Byzantium, and Valentinus, held these same views, and wrote volumes replete with wisdom. If you had ever read what they wrote, you would be a wiser man. But I think it better to reply briefly to each point than to linger any longer and extend my book to an undue length.