Ovidians continue to be puzzled by the 404-line speech put into the mouth of Pythagoras in book 15 of the Metamorphoses. Questions of literary decorum and quality are insistently raised: how does the philosopher's popular science consort with the predominantly mythological matter of the preceding fourteen books? Do Pythagoras' revelations provide some kind of unifying ground, a ‘key’, for the endless variety of the poem? Can one take the Speech as a serious essay in philosophical didactic, or is it all (...) a mighty spoof, as intentionally laughable, perhaps, as the imperial panegyric with which the narrative of book 15 concludes? Or should we beware of imposing modern tastes on Ovid's original audience, and respect the Hellenistic and Roman predilection for scientific poetry? This article seeks to establish further contexts for the evaluation of the Speech of Pythagoras through a study of Ovid's allusive practice within the Greco-Roman tradition of hexameter epos. The figure who provides a foundation for Ovid's construction of his own poetic genealogy turns out to be the Greek philosophical poet Empedocles. The resulting reflections on Ovid's manipulation of generic conventions may be timely in the light of the recent appearance of sophisticated and fresh approaches to the question of whether the Metamorphoses is, or is not, an epic. (shrink)