Along with political freedom went mental freedom. Interchange of opinion took place easily and continually between all grades of the free community. The general obligation to promote the social, commercial, and military well-being of the state stimulated discussion and gave to debate the piquancy and solemnity of serious issues. A Greek might be poor, but he could hold up his head with the richest as a member of the citizen army and the citizen electorate; and in the citizen assembly he need not be a gray-beard to be reckoned wise. Mental ability became the test of worth, and the benumbing tyranny of tradition was overthrown; at least its unquestioned rule was at an end. Custom must henceforth submit to criticism and seek to justify itself. Enterprise, enquiry, innovation became the order of the day. It was the emancipation of the human intelligence. Moreover, since the rough work of society was performed by the slave population, Greek citizens found much leisure at their disposal. Herein was obviously a danger, but also an opportunity; and fortunately the genius of the people was not found wanting, so that, in the early days the Greeks turned their leisure to good purpose, physical and intellectual. Part of their leisure was devoted to physical exercises, running, wrestling, boxing, throwing the _discus_, chariot-racing; and in the healthful competition of these games in stadium and hippodrome they found continual pleasure. But their ardour for mental exercise was even keener. They began to think with restless energy and with brilliant results; men of genius, poets, historians, philosophers, and artists, by their matchless achievements raised the intellectual interests of their contemporaries to an extraordinary extent. In general, the Greeks acquired a wonderful feeling for proportion and natural rhythmic beauty. “Nothing in excess” became their motto, but what was meant thereby was no timid mediocrity, but an avoidance of extreme, wherever the extreme was grotesque or foolish. Men sought an equipoise of perfection, and felt infinite delight in the increasing measure of their success. Within a few hundred years the Greeks had produced masterpieces of art and literature which few nations have been able even to rival, none to surpass.