 In particular, the atomism of Democritus had substituted for a world-governing god the relation of cause and effect as the sources of all things.Democritus explained the widespread belief in gods as the result of fear of unusual and unaccountable phenomena in nature; and, starting from this principle, Diagoras, at a time when the ancient popular belief had already been shaken, especially in the minds of the young, came forward with the doctrine that there were no gods at all.His attacks seem to have been mainly directed against the dogmas of Greek theology and mythology, as well as against the established forms of worship, According to the fashion of the sophists, which is caricatured by Aristophanes in "The Clouds", he substituted the active powers of nature for the activity of the gods; and some isolated statements that have come down to us render it probable that he did this in a witty manner.