None of the predecessors of Plato had constructed a system of philosophy. What they had produced, and in great abundance, were isolated philosophical ideas, theories, hints, and suggestions. Plato was the first person in the history of the world to produce a great all-embracing system of philosophy, which has its ramifications in all departments of thought and reality. In doing this, Plato laid all previous thought under contribution. He gathered the entire harvest of Greek philosophy. All that was best in the Pythagoreans, the Eleatics, Heracleitus, and Socrates, reappears, transfigured in the system of Plato. But it is not to be imagined, on this account, that Plato was a mere eclectic, or a plagiarist, who took the best thoughts of others, and worked them into some sort of a patch-work philosophy of his own. He was, on the contrary, in the highest degree an original thinker. But like all great systems of thought, that of Plato grows out of the thought of previous thinkers. He does indeed appropriate the ideas of Heracleitus, Parmenides, and Socrates. But he does not leave them as he finds them. He takes them as the germs of a new development. They are the foundations, below ground, upon which he builds the palace of philosophy. In his hands, all previous thought becomes {165} transfigured under the light of a new and original principle. 1. Life and Writings. The exact date of the birth of Plato is a matter of doubt. But the date usually given, 429-7 B.C. cannot be far wrong. He came of an aristocratic Athenian family, and was possessed of sufficient wealth to enable him to command that leisure which was essential for a life devoted to philosophy. His youth coincided with the most disastrous period of Athenian history. After a bitter struggle, which lasted over a quarter of a century, the Peloponnesian war ended in the complete downfall of Athens as a political power. And the internal affairs of the State were in no less confusion than the external. Here, as elsewhere, a triumphant democracy had developed into mob-rule. Then at the close of the Peloponnesian war, the aristocratic party again came into power with the Thirty Tyrants, among whom were some of Plato's own relatives. But the aristocratic party, so far from improving affairs, plunged at once into a reign of bloodshed, terror, and oppression. These facts have an important bearing upon the history of Plato's life. If he ever possessed any desire to adopt a political career, the actual condition of Athenian affairs must have quenched it. An aristocrat, both in thought and by birth, he could not accommodate himself to the rule of the mob. And if he ever imagined that the return of the aristocracy to power would improve matters, he must have been bitterly disillusioned by the proceedings of the Thirty Tyrants. Disgusted alike with the democracy and the aristocracy he seems to have retired into seclusion. He never once, throughout his