It was about that time [415 BCE] that the poet Diagoras of…

““It was about that time [415 BCE] that the poet Diagoras of Melos was proscribed for atheism, he having declared that the non-punishment of a certain act of iniquity proved that there were no gods. It has been surmised, with some reason, that the iniquity in question was the slaughter of the Melians by the Athenians in 416 BCE, and the Athenian resentment in that case was personal and political rather than religious. For some time after 415 the Athenian courts made strenuous efforts to punish every discoverable case of impiety; and parodies of the Eleusinian mysteries were alleged against Alcibiades and others. Diagoras , who was further charged with divulging the Eleusinian and other mysteries, and with making firewood of an image of Herakles, telling the god thus to perform his thirteenth labour by cooking turnips, became thenceforth one of the proverbial atheists of the ancient world, and a reward of a silver talent was offered for killing him, and of two talents for his capture alive; despite which he seems to have escaped.””

— J. M. Robertson