_De divinatione_ takes the form of a supposititious conversation, or better, informal debate, between the author and his brother Quintus. In the first book Quintus, in a rather rambling and leisurely fashion and with occasional repetition of ideas, upholds divination to the best of his ability, citing many reported instances of successful recourse to it in antiquity. In the second book Tully proceeds with a somewhat patronizing air to pull entirely to pieces the arguments of his brother who assents with cheerful readiness to their demolition. On the whole the appeal to the past is the main point in the argument of Quintus. What race or state, he asks, has not believed in some form of divination? “For before the revelation of philosophy, which was discovered but recently, public opinion had no doubt of the truth of this art; and after philosophy emerged no philosopher of authority thought otherwise. I have mentioned Pythagoras, Democritus, Socrates. I have left out no one of the ancients save Xenophanes. I have added the Old Academy, the Peripatetics, the Stoics. Epicurus alone dissented.”[1259] Quintus closes his long argument in favor of the truth of divination by solemnly asserting that he does not approve of sorcerers, nor of those who prophesy for the sake of gain, nor of the practice of questioning the spirits of the dead—which nevertheless, he says, was a custom of his brother’s friend Appius.[1260] [Sidenote: Cicero attacks past authority.] When Tully’s turn to speak comes, he rudely disturbs his brother’s reliance upon tradition. “I think it not the part of a philosopher to employ witnesses, who are only haply true and often purposely false and deceiving. He ought to show why a thing is so by arguments and reasons, not by events, especially those I cannot credit.”[1261] “Antiquity,” Cicero declares later, “has erred in many respects.”[1262] The existence of the art of divination in every age and nation has little effect upon him. There is nothing, he asserts, so widespread as ignorance.[1263] [Sidenote: Divination distinct from natural science.]