Passage 6.18.5
φαίνεται δὲ καὶ ἄνδρα ὁ Ἀναξιμένης ἐχθρὸν οὐκ ἀμαθέστατα ἀλλὰ καὶ ἐπιφθονώτατα ἀμυνάμενος. ἐπεφύκει μὲν αὐτὸς σοφιστὴς καὶ σοφιστῶν λόγους μιμεῖσθαι· ὡς δέ οἱ διαφορὰ ἐς Θεόπομπον ἐγεγόνει τὸν Δαμασιστράτου, γράφει βιβλίον ἐς Ἀθηναίους καὶ ἐπὶ Λακεδαιμονίοις ὁμοῦ καὶ Θηβαίοις συγγραφὴν λοίδορον. ὡς δὲ ἦν ἐς τὸ ἀκριβέστατον αὐτῷ μεμιμημένα, ἐπιγράψας τοῦ Θεοπόμπου τὸ ὄνομα τῷ βιβλίῳ διέπεμπεν ἐς τὰς πόλεις· καὶ αὐτός τε συγγεγραφὼς ἦν καὶ τὸ ἔχθος τὸ ἐς Θεόπομπον ἀνὰ πᾶσαν τὴν Ἑλλάδα ἐπηύξητο.
Anaximenes also appears to have avenged himself upon a personal enemy in a way not only clever but exceedingly spiteful. He was naturally skilled as a sophist and adept at imitating the writings of other sophists. When he had become embroiled in a conflict with Theopompus, the son of Damasistratus, he composed a book defamatory of the Athenians, the Spartans, and the Thebans alike; and having imitated Theopompus' style with the utmost precision, he put Theopompus' name upon the work, distributing it among the various cities. Thus he both published his own composition and effectively spread ill-feeling toward Theopompus throughout all of Greece.