Dio Chrysostom

“Should you be willing to read [Xenophon's Anabasis] very carefully you shall discover how ... to deceive one’s enemies to their harm and one’s friends to their advantage, and to speak the truth in a way that will not pain those who are needlessly disturbed by it.”

“You are devoted to interests from which it is impossible to gain intelligence or prudence or a proper disposition of reverence toward the gods, but only stupid contention, unbridled ambition, vain grief, senseless joy, and raillery and extravagance.”

“If in the guise of philosophers, they [declaim speeches] with a view to their own profit and reputation, and not to improve you, that indeed is shocking. For it is as if a physician when visiting patients should disregard their treatment and their restoration to health, and should bring them flowers and courtesans and perfume.”