Most forms (all?) of biblical criticism are illegitimate. Sure, they reveal many helpful facets that sometimes go unnoticed, but as any student knows–especially those who have an eye towards ministry and interact with real people (biblical scholars rarely do)–these forms of criticism are utterly useless to the church.
One form of criticism, though, appeared to put the breaks on this type of reading, and has become the de facto reading of almost all evangelicals. All evangelicals employ a type of canonical criticism. They face the fact that whatever else higher criticism may say the underlying communities or editorial processes that go into the formation of the text, the truth of the matter is it is simply speculation and assumes a number of materials we no longer have (the laughable existence of “Q,” for example).
Canonical criticism urges us to deal with the text as we have it. (As a sidebar: does inerrancy presuppose a form of canonical criticism? Second note: does the grammatical historical hermeneutic likewise assume a form of canonical criticism?)
The one problem with canonical criticism, though, is it presupposes what it has never (and can never) prove. It assumes definite horizons to its interpretation (the canon, books of the bible). The difficulty is different communities have different canons, and who gets to make the call? Further with what tools does this community get to make the call?
I am not denying a place for canonical criticism. In a sense, traditionalists all use a form of canonical criticism. It is inevitable. It is not, however, self-evidencing. Canonical criticism does note a solution inherent to its definition. Canonical critics urge us to deal with the canon as the finished and received product. Of course. That raises the next questions: who finished it, who passes it down, and who receives it? Canonical criticism cannot answer those questions, and as I think they admit, nor should they.