This is nothing but a quick rant. More like a sucker-punch, really. While reading through Carson & Moo’s, An Introduction to the New Testament (as you do on a Wednesday morning), particularly the chapter on the Corinthian letters (go figure), I found this rather strange observation:
Both Corinthian epistles are occasional letters, that is, they are letters addressed to specific people and occasioned by concrete issues
–Carson-Moo, Introduction (2005), 415.
This is strange because, with the possible exception of Ephesians (though I’m not convinced that it is an exception), all of Paul’s letters are occasional. So why specifically designate–or single out–only the Corinthians letters as “occasional”? Is it because those letters address more problems in one go than the other letters do? If so, that in itself does not necessarily make them more “occasional” than the others and thus worthy of the description. It simply means the Corinthians had more problems, and the proliferation of problems in one location is (essentially) the occasion for writing… four letters.
Poor form, guys. Poor form.
 Admittedly, Carson-Moo acknowledge this point later (see 490), but they hardly do anything with it. In fact, the acknowledgement reads more like a throw-away line than anything else.