u/EclecticReader39

Thales and the natural philosophers get credit for banishing the gods from the workings of the natural world, but it was Hippocrates who extended this fight to the field of medicine. In advancing the idea that all disease has an underlying natural cause, he also exposed the mechanism whereby charlatans of every kind maintain their false credibility. 

Diagoras of Melos, the West’s first recorded atheist, hit upon the cognitive bias at the heart of superstition more than two-and-a-half millennia before modern psychology would formally recognize it. Diagoras had discovered survivorship bias. 

Diagoras knew the gods were not real; they were human inventions supported with cherry-picked examples of divine favor. He was so sure about this that he chopped up a statue of Heracles to cook a meal and mocked the cult of Demeter and Persephone. And yet nothing happened to him. This brave demonstration of his atheism is an important lesson even today.