Canonicity and the problem of circular reasoning

In this two-part analysis, (1) "Canon to the right of them; canon to the left of them," and (2) "Canon in front of them, rode the six hundred," the Pontificator offers a fine examination of two Protestant criteria for the determination of canonicity, (1) self-authentication and (2) apostolic authorship or authorization. The basic question, of course, centers on the authority to define canonicity. The question of pseudonymity that he treats in his second post is a secondary detail, and I won't address it here. Rather, I wish to comment briefly on the question of circular reasoning that he raises in his second post.

First, the claim is sometimes made that the Catholic Church is circular in appealing to Scripture to support her authority and then claiming the final say in how to interpret Scripture. But there is no circularity here, first, because she does not claim sola scriptura; and, second, because if she has the authority she claims, the case is no different logically from that of the NT writers appealing to the Old Testament (OT) for support while claiming divine warrant for their NT interpretations. Read more.