To Autolycus 3.2

Those who write ought themselves to have been eyewitnesses of what they affirm, or to have learned it accurately from those who saw it. In a way, those who write about what they cannot know are beating the air. What good did it do Homer to write of the Trojan War and deceive many people, or Hesiod his catalogue of the genealogy of the gods he names, or Orpheus his three hundred and sixty-five gods, whom at the end of his life he rejects, saying in his Testaments that God is one? What good did his description of the sphere of the heavens do Aratus, or those who wrote like him, apart from human glory, which they did not even receive as they deserved? And what truth did they tell? What good did their tragedies do Euripides and Sophocles and the other tragedians, or their comedies Menander and Aristophanes and the other comic poets, or their histories Herodotus and Thucydides? What good did his secret shrines and the Pillars of Heracles do Pythagoras, or Cynic philosophy Diogenes, or Epicurus his teaching that there is no providence, or Empedocles his teaching of atheism, or Socrates his swearing by the dog and the goose and the plane tree and by Asclepius, struck by lightning, and the spirits he used to invoke? Why did he die willingly, and what kind of reward did he hope to receive after death? What good did his learning do Plato, or their teachings the other philosophers, not to list them all, since they are many? We say these things to show how useless and godless their thinking is.