There's something I've been thinking about, since my graduate student days, and I've been going back to it recently as part of a larger project. Most all scholars agree that Paul wrote Romans, 1 and 2 Corinthians, Galatians, Philippians, 1 Thessalonians, and Philemon. In fact, alongside Markan priority the judgment that Paul wrote these seven letters might well be close to the only "assured results" of two centuries of New Testament criticism. Yet, I wonder: how do we know that Paul wrote these seven letters?
It can't be enough that the letters identify Paul as the writer. Scholars, after all, consider it possible that some if not all of the remaining thirteen New Testament texts that identify Paul as the writer were not written by Paul, and will also dispute the authorship of the epistles of James, 1 and 2 Peter, and Jude. No, such attribution is certainly not a sufficient condition. It's probably not even a necessary condition: after all, texts such as 1 Clement or, to step outside of early Christianity, Plato's dialogues lack such attribution, and yet they the former is generally affirmed to be Clementine and some of the latter Platonic. So, that seems to be a bit of a dead end.
Perhaps it is because the undisputed epistles do not evince any anachronism. They do not demonstrably refer to anything after the period that Paul is known to have flourished. Is that however sufficient? Probably not. After all, a forgery could have originated during his lifetime, and moreover a text written after Paul's lifetime could still be free of anachronism. Freedom from anachronism is no doubt a necessary condition but sufficient? Probably not.
What about the extent to which these letters cohere with what we otherwise know about Paul, about his language, his teaching, his life? Well, that's a bit of a pickle. We would need an empirical basis for such a comparison, and really the only such basis that can be seriously entertained is the Acts of the Apostles. But here we run into problems. Historically biblical scholars have said that if there is a contradiction between the Acts and the undisputed epistles then the undisputed epistles must take priority. This however is simply to acknowledge that at least in some respects the letters and the Acts do not cohere. If the undisputed epistles and the Acts are acknowledged to contradict then the judgment is not that there is an absent of contradiction but rather that the degree of contradiction does not exclude Pauline authorship. What we find is that an absence of contradiction cannot be considered to be a sufficient condition, nor can it be considered a necessary condition, for it is a condition that is not satisfied despite the judgment that Paul wrote these texts. It is not a condition at all, it seems.
Perhaps it is the early external attestation to Pauline authorship? Well, there is early external attestation to the Markan authorship of the Gospel of Mark. This attestation is roughly coeval with and might even slightly pre-date that with regard to the undisputed Pauline epistles. Yet this is generally dismissed, so I wonder how much weight it can actually be made to hold in the case of any of the Pauline texts. Not to mention, it's hardly difficult to imagine that this early external attestation arose as a direct result of the fact that the letters identify Paul as the writer. Are the Christian writers doing anything more than exegesis here?
I am thus left to wonder? Is there any basis for the judgment that Paul wrote these seven texts beyond the fact that they are ascribed to Paul and are free from anachronism? Is it in fact the case that in the case of the undisputed Pauline epistles New Testament scholars proceed on the functional supposition that if these two conditions are met that it is reasonable to judge these texts to be Pauline creations? Is this judgment rendered even knowing that in fact forgery cannot yet be definitively ruled out? Because frankly I don't see any other grounds for the consensus judgment on authorship, aside from the theological privilege that several of these texts have received in Protestant (both conservative and liberal) circles.
If attribution and freedom from anachronism are the deciding factors then there are some interesting corollaries. The first, this judgment is dependent upon the supposition that the canonical Gospels and Acts present an essentially usable chronology for early Christianity. Why is this the case? Well, it turns out that we only know when Paul lived because of these texts. There is in fact nothing in the Pauline corpus that would allow us to significantly narrow down the period in which he flourished. For that we must turn to the data from the Gospels and the Acts. Yet any judgment about a freedom from anachronism depends upon an awareness of when Paul lived. Indeed, precisely to the extent that one evinces radical skepticism with regards to the basic chronology offered by the Gospels and Acts, to that extent one calls into question the basis by which we judge Paul to have been the author of any of the thirteen canonical epistles attributed to him.
A second corollary, and one more interesting from an epistemology perspective, is that we have decided that certainty is not necessary. Nothing has ruled out the possibility that these letters are frauds. In fact, given the nature of the data, I cannot readily conceive of any empirical test by which one could, beyond any reasonable doubt, rule out the possibility that one or more of the seven undisputed epistles is pseudo-Pauline. I'm not even sure if we can show it probable that Paul wrote these letters. Yet, despite such a limit stemming from our data we are prepared to judge that they are in fact Pauline. It seems to me that when it comes to these letter were are prepared to accept "plausibly Pauline" as functionally equivalent to "Pauline."
Three, we must consider whether we are engaged in special pleading when we then turn to other works of the New Testament and beyond. If "plausible" is sufficient in the case of these seven texts then one cannot insist upon "certain" when considering any of the others. And this is the question that really interests me: are we treating these seven epistles differently than we treat other New Testament literature? Are they are a privileged canon-within-the-canon, inherited from the Reformers, that none dare question, not even the most critical of scholars, whilst all those other texts, the ones that the Catholics loved, have to constantly struggle to prove their authenticity? Because from the perspective of this humble inquirer, it seems that the burdens of proof are differential: the seven epistles are presumed authentic until proven inauthentic, so much so that no one even bothers to argue the case, whilst the balance of the New Testament is presumed inauthentic until proven authentic. And a differential burden of proof is a problem.