Page:A History of Ancient Greek Literature.djvu/183

 ATTEMPTS AT SOLUTION 159 empty space is not admitted, nor yet his demand that ' that which is' must be round and at rest. Why should it ? As a matter of fact the things have innumerably different shapes and are always moving. Shape, size, and motion are all the qualities that they possess, and these are the only Natural Facts. All else is conventional or deriva- tive. The theory was originated by Leukippos of Abdera, but received its chief development from his great disciple Democritus, and from Epicurus. The Athenian Period of Philosophy Empedocles died about 430 B.C., and Anaxagoras was banished in 434. But for some years before this the reaction against cosmological speculation had begun. It was time to find some smaller truths for certain, instead of speculating ineffectually upon the great ones. The fifth century begins to work more steadily at parti- cular branches of science — at Astronomy, Mathematics, History, Medicine, and Zoology. This tendency in its turn is met and influenced by the great stream of the time. The issue of the Persian War, establishing Greek freedom and stimulating the sense of common nationality, had let loose all the pent- up force of the nation, military, social, and intellectual. Great towns were appearing. The population of Athens and the Piraeus had risen from 20,000 to about 100,000. Property was increasing even faster. The facilities for disposing of money were constantly growing ; commer- cial enterprises were on a larger scale and employed greater numbers both of free workmen and of slaves. Intercourse between the different cities was much com-