Zeno of Elea, the friend and pupil of Parmenides, born B.C. 500, brought nothing new to the system, but invented _Dialectics_, that logic which afterwards became so powerful in the hands of Plato and Aristotle, and so generally admired among the schoolmen. It seeks to establish truth by refuting error by the _reductio ad absurdum_. While Parmenides sought to establish the doctrine of the _One_, Zeno proved the non-existence of the _Many_. He denied that appearances were real existences, but did not deny existences. It was the mission of Zeno to establish the doctrines of his master. But, in order to convince his listeners, he was obliged to use a new method of argument. So he carried on his argumentation by question and answer, and was, therefore, the first who used dialogue as a medium of philosophical communication. [Footnote: Cousin, _Nouveaux Fragments Philosophiques_.] [Sidenote: Empedocles.--Love the moving cause of all things.] Empedocles, born B.C. 444, like others of the Eleatics, complained of the imperfection of the senses, and looked for truth only in reason. He regarded truth as a perfect unity, ruled by love,--the only true force, the one moving cause of all things,--the first creative power by whom the world was formed. Thus "God is love," a sublime doctrine which philosophy revealed to the Greeks. [Sidenote: The loftiness of the Eleatic philosophers.] Thus did the Eleatic philosophers speculate almost contemporaneously with the Ionians, on the beginning of things and the origin of knowledge, taking different grounds, and attempting to correct the representations of sense by the notions of reason. But both schools, although they did not establish many truths, raised an inquisitive spirit and awakened freedom of thought and inquiry. They raised up workmen for more enlightened times, even as scholastic inquirers in the Middle Ages prepared the way for the revival of philosophy on sounder principles. They were all men of remarkable elevation of character as well as genius. They hated superstitions and attacked the Anthropomorphism of their day. They handled gods and goddesses with allegorizing boldness, and hence were often persecuted by the people. They did not establish moral truths by scientific processes, but they set examples of lofty disdain of wealth and factitious advantages, and devoted themselves with holy enthusiasm to the solution of the great questions which pertain to God and nature. Thales won the respect of his countrymen by devotion to studies. Pythagoras spent twenty-two years in Egypt to learn its science. Xenophanes wandered over Sicily as a rhapsodist of truth. Parmenides, born to wealth and splendor, forsook the feverish pursuit of sensual enjoyments to contemplate "the quiet and still air of delightful studies." Zeno declined all worldly honors to diffuse the doctrines of his master. Heraclitus refused the chief magistracy of Ephesus that he might have leisure to explore the depths of his own nature.