"True, but to establish your point that Mary was not a perpetual virgin"
And you have to prove that they were not Mary's sons to prove this "perpetual virgin" theory. The evidence is stronger that they were her sons than that they were Joseph's just by the fact that when they are mentioned in the gospels it is always with her and they could never be called as His brothers if they were not Mary's sons.
Absolutely false! In Hebrew/Aramaic as well as in Greek, but also in Serbian and other languages of that region (to this day) they could be called His brothers if they were only His half-brothers, or first cousins.
I believe A8 already made this disticntion. But they are never identified as "Mary children," as Christ is undoubtedly identified as "Mary's Son."
That is not true.
And you have to prove that they were not Mary's sons to prove this "perpetual virgin" theory. The evidence is stronger that they were her sons than that they were Joseph's just by the fact that when they are mentioned in the gospels it is always with her
The Catholic Church is not bound your Protestant invention of 'sola scriptura'. We have the testimony of the fathers and the councils:
The Liturgy of St. James [the Just] calls her the "ever-virgin Mary".
Tertullian tells us of the "Antidicomarianites" who developed out of the Ebionites. The Ebionites claimed that Jesus was the natural child of Joseph and Mary. The Antidicomarianites claimed that Mary gave birth to other children. They denied the formula "ever-Virgin Mary" used in the Greek and Roman Liturgies.
The Acts of Peter of Alexandria (bishop from 300-311) refer to Mary as "mother of God, and Ever-Virgin Mary".
Aphraates (who died roughly in the 330s) affirmed Mary's perpetual virginity.
Athanasius (born c. 296; died 2 May, 373) in his Discourse Against the Arians, says, "He took true human flesh of Mary Ever-Virgin"
Ephanius in 374 AD says that Christ was "born of holy Mary ever-virgin".
St. Jerome wrote his tract, "The Perpetual Virginity of Blessed Mary: Against Helvidius" in 383 AD.
Jovinianus was condemned as heretic in 390 AD (by Pope Siricius at a synod held at Rome) for denying, among other things, the perpetual virginity of Mary. Jovinianus was subsequently condemned by St. Ambrose (bishop of Milan), for the same reasons.
Siricius (392 AD) writes to Anysius (bishop of Thessalonica) and tells him that Anysius has "rightly abhorred" the notion that "from the same virginal womb, from which according to the flesh Christ was born, another offspring was brought forth."
The Account of St. John the theologian of the falling asleep of the Holy Mother of God (400 AD) calls her "ever-virgin Mary".
Augustine, in his work "Of Holy Virginity" (401 AD) holds the position that Mary remained a virgin. (See also his lib. I contra Julian., ii)
Pope Leo I (bishop from 440-461 AD) refers to Mary as "blessed Mary ever Virgin".
The Council of Chalcedon (451 AD) refers to her as the "blessed and ever Virgin Mary".
John II (533-535) refers to Mary as "ever virgin".
The Second Council of Constantinople (553 AD) calls her "the holy, glorious, and ever-virgin Mary, the Mother of God"
The Gospel of the Nativity of Mary (date unknown) says that she is "ever-virgin".
The Lateran Council of 649 refers to Mary as "holy Mary, ever virgin and immaculate".
Canon 1 of the Council in Trullo (692 AD) calls her the "immaculate ever-virgin".
John the Damascene (b. 676, d. 754-787) calls her "holy ever-virgin Mother"
The Second Council of Nicea (787 AD) calls her "holy ever-virgin Mary, truly and properly the Mother of God".
-A8