You know what, I shouldn’t have put “no presuppositions.” I think for certain types of biblical study (historical basically) it is the ideal to have no presuppositions, but ultimately it is impossible.
As for the early church, I don’t really know how things were back then. Do you know what I mean? Obviously it seems compelling that people in the middle of the second century were attributing these books to the apostles, because it was probably only 75 years or so since they were written, but the historical distance of 75 years was much more then than it is now. They didn’t properly record these things, and it is quite possible that the early church just believed the letters themselves (I am pretty sure that all of the peter and john epistles state the name of who it was from…this could be totally wrong, but at least some of them say who it is from). We know now that it was somewhat common back then to put other people’s names on documents to make them more authoritative. Think about the gospel of Thomas or mary magdeline…those names are only added to make the gospel sound more authoritative. Also, it is almost a general consensus among scholars that at least some of Paul’s letters are not actually by Paul. So, it is not much of a stretch to believe that it became tradition that John and Peter actually wrote these letters just because that is who it says has written them at the beginning of the epistles.
Anyway, I haven’t done any of this research, I don’t really know anything about it at all, just what scholars believe. And I feel as though in matters of history, authorship, and things of that nature, the secular scholars are likely going to be most accurate because church doctrine and interpretation are likely not going to bias their interpretations. BUT, this method has its limitations as well…basically they just look at the history of it, but do not look at what it actually means and its significance (which is what is really important). But in terms of history, I like the historical critical method.