When reading Matthew 13:55-56 in the ESV Study Bible, the following note appears regarding the reference to Jesus' brethren or (brothers and sisters):
"His brothers and his sisters refers to other children born to Joseph and Mary after the birth of Jesus. Some interpreters, seeking to defend a doctrine of the “perpetual virginity of Mary,” have suggested that these were cousins, or children of Joseph from another marriage, but no evidence in the Greek words adelphoi (“brothers”) and adelphai (“sisters”), or in any other historical information, gives support to that view. For Mary to have sexual relations with her husband, Joseph, and to bear children, would contribute to her holiness, not detract from it (cf. Gen. 1:28; 1 Cor. 7:3–5; 1 Tim. 5:14)"
How, then, does the Church uphold oppositional dogma to the above Protestant position, namely the Perpetual Virginity of The Blessed Virgin Mary? According to the notes in the Ignatius Catholic Study Bible New Testament, the authors state the following:
"The Church maintains, however, that Jesus' Mother, Mary, remained a virgin throughout her life. These so-called brethren of Jesus are thus his relatives but not children of Mary. Four observations support the Church's tradition: (1) These brethren are never called the children of Mary, although Jesus himself is (Jn 2:1; 19:25; Acts 1:14). (2) Two names mentioned, James and Joseph, are sons of a different "Mary" in Mt 27:56 (Mk 15:40). (3) It is unlikely that Jesus would entrust his Mother to the Apostle John at his Crucifixion if she had other natural sons to care for her (Jn 19:26-27). (4) The word "brethren" (Gk. adelphoi) has a broader meaning than blood brothers. Since ancient Hebrew had no word for "cousin", it was customary to use "brethren" in the Bible for relationships other than blood brothers. In the Greek OT, a "brother" can be a nearly related cousin (1 Chron 23:21-22), a more remote kinsman (Deut 23:7; 2 Kings 10:13-14), an uncle or a nephew (Gen 13:8), or the relation between men bound by covenant (2 Sam 1:26; cf. 1 Sam 18:3). Continuing this OT tradition, the NT often uses "brother" or "brethren" in this wider sense. Paul uses it as a synonym for his Israelite kinsmen in Rom 9:3. It also denotes biologically unrelated Christians in the New Covenant family of God (Rom 8:29; 12:1; Col 1:2; Heb 2:11; Jas 1:2; CCC 500)."
That the above authors of the ESV Study Bible state there is "no evidence" or "historical information" that supports the above exegesis is blatantly inaccurate, for Scriptural references supporting the Church's position abound. Furthermore, the Early Church Fathers both taught and defended this Marian dogma. Please see the following source for the Early Church Fathers' position: http://www.newadvent.org/fathers/3007.htm
Tradition, through the guidance of the Holy Spirit, has maintained that Our Blessed Mother was a virgin throughout her life, even after the birth of Our Lord. That the authors of the ESV Study Bible point the proverbial finger at Catholic dogma and refer to it as "other interpreters" is very anti-Catholic and non-ecumenical. This Protestant argument could have been stated in a more neutral, Rogerian way that would present their editors' position without inaccurately denouncing the Catholic position. Although the ESV Study Bible contains so much rich content and, at times, accurate, insightful exegesis, moments like the above comment on Matthew 13:55-56 are a discredit. Unfortunately, most of the Catholic-focused scriptural passage analyses in the ESV Study Bible are either glossed over or crudely analyzed. See the ESV Study Bible notes for John 6:53-64 for more mistaken, disconnected exegesis from that of Jesus' actual words. I can only pray that the scholars who edited the ESV Study Bible, through their sincere love of Our Lord, find and seek truth and cease to implicitly attack Catholic traditional views.