 That Aristotle also viewed the two major phases of Parmenides’ poem as dual accounts of the same entity in different aspects is perhaps most apparent in his characterization of Parmenides, in the course of the discussion at Metaphysics 1.5.986b27–34, as having supposed that “what is is one in account but plural with respect to perception.” Theophrastus likewise seems to have adopted such a line. Alexander of Aphrodisias quotes him as having written the following of Parmenides in the first book of his On the Natural Philosophers: