Shortly before the outbreak of the Peloponnesian War, Anaxagoras of Clazomenae was accused of impiety and had to leave Athens, where he had taken up his abode. The object of the accusation was in reality political; the idea being to hit Pericles through his friend the naturalist. What Anaxagoras was charged with was that he had assumed that the heavenly bodies were natural objects; he had taught that the sun was a red-hot mass, and that the moon was earth and larger than Peloponnese. To base an accusation of impiety on this, it was necessary first to carry a public resolution, giving power to prosecute those who gave natural explanations of heavenly phenomena. As to Anaxagoras’s attitude to popular belief, we hear next to nothing apart from this. There is a story of a ram’s head being found with one horn in the middle of the forehead; it was brought to Pericles, and the soothsayer Lampon explained the portent to the effect that, of the two men, Pericles and Thucydides, who contended for the leadership of Athens, one should prove victorious. Anaxagoras, on the other hand, had the ram’s head cut open and showed that the brain did not fill up the cranium, but was egg-shaped and lay gathered together at the point where the horn grew out. He evidently thought that abortions also, which otherwise were generally considered as signs from the gods, were due to natural causes. Beyond this, nothing is said of any attack on the popular belief on the part of Anaxagoras, and in his philosophy nothing occurred which logically entailed a denial of the existence of the gods. Add to this that it was necessary to create a new judicial basis for the accusation against Anaxagoras, and it can be taken as certain that neither in his writings nor in any other way did he come forward in public as a denier of the gods.