The canon of biblical books is frequently cited as a parallel to a unitary literary canon that, though often presumed, is in fact not to be found. The biblical canon was created for the purpose of forestalling change and exiling competition. There are at least ten kinds of literary canons, all ultimately resulting from selections made for such distinct purposes as providing models, transmitting a heritage, creating common frames of reference, logrolling, legitimating theory, historicizing, and pluralizing. Canons formed for any of these purposes necessarily yield to change over time and compete with one another at any given time. We can reasonably expect neither the abolition of selective canons nor agreement on a single one; we can, however, seek clarity about purposes.