rationalskepticism.org

archibald wrote:'First, why does Jude call himself “the brother of James” rather than “the brother of Jesus”? As Bauckham points out, “Palestinian Jewish-Christian circles in the early church used the title ‘brother of the Lord’ not simply to identify the brothers, but as ascribing to them an authoritative status, and therefore the brothers themselves, not wishing to claim an authority based on mere blood-relationship to Jesus, avoided the term.”5 Such restraint would especially be appropriate if one were writing to Gentiles,6 for Gentilic entrance into a covenant relationship with Israel’s God was now, for the first time, not based on proselytization (in which circumcision would be required), but simply faith. Thus, the very self-identification which opens this epistle not only indicates humility on Jude’s part, but also speaks of authenticity.'

http://bible.org/seriespage/jude-introd ... nd-outline

Daniel B Wallace, who I think I may refer to as an 'Academy scholar', on why the writer of Jude is likely to be the authentic brother of Jesus. Really, I think we can say that the methodology here is of the highest order. It is in favour of the writer of this being the actual brother of Jesus precisely because he doesn't say so.

Incidentally, the chap Bauckham he refers to is also what we might call a fully paid up academy member, and this is how his methodology works:

'While James assumed pre-eminent leadership at the centre of the Christian movement, the other brothers of Jesus worked as travelling missionaries. We know this from an incidental, but revealing, reference to them by Paul. In 1 Corinthians 9 Paul maintains that, although he has waived his right as an apostle to be supported by his converts at Corinth, he has this right, just as much as the other apostles do. It was an accepted principle in the early Christian movement that travelling missionaries had a right to food and hospitality from the Christian communities among whom they worked. Evidently, wives who accompanied their husbands on missionary travels also had this right. Paul attributes both the right to support and the right to be accompanied by a wife to 'the other apostles and the brothers of the Lord and Cephas' (1 Cor. 9:5). In instancing, among the apostles, the brothers of the Lord and Cephas (Peter), Paul intends to associate himself with people whose claim to apostleship and its rights was unquestioned and unquestionable. The Lord's brothers must have been so well known as travelling missionaries that they, along with Peter, were the obvious examples for Paul to choose, even when speaking to the Christians in Corinth.'

http://www.biblicalstudies.org.uk/artic ... ckham.html

Here, a complete lack of any decent evidence that Jesus' brothers were famous travelling missionaries is neatly set aside in favour of some time travel mind reading. Very impressive, not least beause, quite the opposite of the reasoning of the first guy (Wallace, who says that 'the brothers themselves, not wishing to claim an authority based on mere blood-relationship to Jesus, avoided the term'), Bauckham rests his case on the opposite idea that their siblinghood status was so well known to the converts in Corinth, that they didn't need to be introduced.