Plutarch Praecepta gerendae reipublicae 7

[7] Nevertheless, both taunts and raillery may sometimes be part of political discourse, so they proceed not to injury or scurrility, but are usefully spoken by him who either reprehends or scoffs. But these things seem most to be allowed in answers and replies. For in that manner to begin a discourse as if one had purposely prepared himself for it, is the part of a common jester, and carries with it an opinion of maliciousness; as was incident to the biting jests of Cicero, Cato the Elder, and Euxitheus, an intimate acquaintance of Aristotle,—all of whom frequently began first to jeer; but in him, who does it only in revenge, the seasonableness of it renders it not only pardonable but also graceful. Such was the answer of Demosthenes, when one that was suspected of thievery derided him for writing by night: I know that the keeping my candle burning all night is offensive to you. So when Demades bawled out, Demosthenes forsooth would correct me: thus would the sow (as the proverb has it) teach Minerva;—That Minerva, replied Demosthenes, was not long since taken in adultery. Not ungraceful also was that of Xenaenetus to those citizens who upbraided him with flying when he was general, ’Twas with you, my dear hearts. But in raillery great care is to be taken for the avoiding of excess, and of any thing that may either by its unseasonableness offend the hearers or show the speaker to be of an ungenerous and sordid disposition;—such as were the sayings of Democrates. For he, going up into the assembly, said that, like the city, he had little force but much wind; and after the overthrow at Chaeronea, going forth to the people, he said: I would not have had the state to be in so ill a condition that you should be contented to hear me also giving you counsel. For this showed a mean-spirited person, as the other did a madman; but neither of them was becoming a statesman. Now the succinctness of Phocion’s speech was admired; whence Polyeuctus affirmed, that Demosthenes was the greatest orator, but that Phocion spake most forcibly, for that his discourse did in very few words contain abundance of matter. And Demosthenes, who contemned others, was wont, when Phocion stood up, to say, The hatchet (or pruning-knife) of my orations arises.