Whatever may have been the private vogue of freethinking at Athens in the Periklean period, it was always a popular thing to attack it. Some years before or after the death of Perikles there came to Athens the alien Hippo, the first specifically named atheist [585] of Greek antiquity. The dubious tradition runs that his tomb bore the epitaph: "This is the grave of Hippo, whom destiny, in destroying him, has made the equal of the immortal Gods." [586] If, as seems likely, he was the Hippo of Rhegion mentioned by Hippolytos, [587] he speculated as to physical origins in the manner of Thales, making water generate fire, and that in turn produce the world. [588] But this is uncertain. Upon him the comic muse of Athens turned its attacks very much as it did upon Socrates. The old comic poet Kratinos, a notorious wine-bibber, produced a comedy called The Panoptai (the "all-seers" or "all eyes"), in which it would appear that the chorus were made to represent the disciples of Hippo, and to wear a mask covered with eyes. [589] Drunkenness was a venial fault in comparison with the presumption to speculate on physics and to doubt the sacred lore of the populace. The end of the rule of ignorance was that a theistic philosopher who himself discouraged scientific inquiry was to pay a heavier penalty than did the atheist Hippo. § 7 While Athens was gaining power and glory and beauty without popular wisdom, the colonial city of Abdera, in Thrace, founded by Ionians, had like others carried on the great impulse of Ionian philosophy, and had produced in the fifth century some of the great thinkers of the race. Concerning the greatest of these, Demokritos, and the next in importance, Protagoras, we have no sure dates; [590] but it is probable that the second, whether older or younger, was influenced by the first, who indeed has influenced all scientific philosophy down to our own day. How much he learned from his master Leukippos cannot now be ascertained. [591] The writings which went under his name appear to have been the productions of the whole Abderite school; [592] and Epicurus declared that Leukippos was an imaginary person. [593] What passes for his teaching was constructive science of cardinal importance; for it is the first clear statement of the atomic theory; the substitution of a real for an abstract foundation of things. Whoever were the originator of the theory, there is no doubt as to the assimilation of the principle by Demokritos, who thus logically continued the non-theistic line of thought, and developed one of the most fruitful of all scientific principles. That this idea again is a direct development from Babylonian science is not impossible; at least there seems to be no doubt that Demokritos had travelled far and wide, [594] whether or not he had been brought up, as the tradition goes, by Persian magi; [595] and that he told how the cosmic views of Anaxagoras, which scandalized the Athenians, were current in the East.