There is a passage of Plutarch's tract "De Profectibus in Virtute 7 " in which Sophocles discusses his own growth as a writer. A likely source of this material for Plutarch was the "Epidemiae" of Ion of Chios, a book that recorded many conversations of Sophocles; but a Hellenistic dialogue about tragedy, in which Sophocles appeared as a character, is also plausible. The former is a likely candidate to have contained Sophocles' discourse on his own development because Ion was a friend of Sophocles, and the book is known to have been used by Plutarch. Though some interpretations of Plutarch's words suggest that Sophocles says that he imitated Aeschylus, the translation does not fit grammatically, nor does the interpretation that Sophocles said that he was making fun of Aeschylus' works. C. M. Bowra argues for the following translation of the line: