shakespearean or Shakespearean? homeric or Homeric? Now both of those adjectives are based on personal names, but there is also a specific corpus in mind in the case of each, as in the case of biblical or Biblical. I usually see the former, but quite often the latter occurs.
The SBL Handbook prefers lowercase biblical (App. A, p. 154), following the Chicago Manual of Style, where we find recommended “Bible; biblical” (14th ed. §7.87; p. 269). Here’s what the CMS says about capitalization of religious names and terms:
In few areas is an author more tempted to overcapitalize or an editor more loath to urge a lowercase style than in religion. That this is probably due to unanalyzed acceptance of the pious customs of an earlier age, to an unconscious feeling about words as in themselves numinous, or to fear of offending religious persons is suggested by the fact that overcapitalization is seldom seen in texts on the religions of antiquity or more recent localized, relatively unsophisticated religions. Is is in the contexts of Christianity, Judaism, Islam, Buddhism, and Hinduism that we go too far. The editors of the University of Chicago Press urge a spare, down style in this field as in others: capitalize what are clearly proper nouns and adjectives, and lowecase everything else except to avoid ambiguity (CMS 14, §7.77, p. 265; emphasis theirs).
Now as far as these prescriptive sources go, they’re fine. There are a couple of reasons, however, that I’m coming out in favor of uppercase Biblical, despite my purely aesthetic typographical preference for the title of this blog! Note the confused recommended “Bible; biblical” of CMS. Why this mix of cases? We all recognize with CMS that uppercase “Bible,” as the title of a particularly well-known book that is itself a collection of smaller books, is valid. And yet, illogically, the recommended adjective is the lowercase “biblical.” My issue with this particular “down style” is related to my discomfort with the neologism “biblioblog.” To my eye, “biblical” is too close to the generic “bibli-” usage, as in bibliophilia, bibliography, etc, implying a connection to books in general, while “Biblical” is quite a bit more obviously referring to that compendium “the Bible.” Similarly, in the above quotation, the CMS recommends “capitalize what are clearly proper nouns and adjectives.” Is “biblical” not an adjective in Chicago?