The great disciple of Plato was Aristotle, and he carried on the philosophical movement which Socrates had started to the highest limit that it ever reached in the ancient world. He was born at Stagira B.C. 384, of wealthy parents, and early evinced an insatiable thirst for knowledge. When Plato returned from Sicily he joined his disciples, and was his pupil for seventeen years, at Athens. On the death of Plato, he went on his travels, and became the tutor of Alexander the Great, and B.C. 335, returned to Athens, after an absence of twelve years, and set up a school, and taught in the Lyceum. He taught while walking up and down the shady walks which surrounded it, from which he obtained the name of Peripatetic, which has clung to his name and philosophy. His school had a great celebrity, and from it proceeded illustrious philosophers, statesmen, historians, and orators. He taught thirteen years, during which he composed most of his greater works. He not only wrote on dialectics and logic, but also on physics in its various departments. His work on "The History of Animals" was deemed so important that his royal pupil presented him with eight hundred talents-- an enormous sum--for the collection of materials. He also wrote on ethics and politics, history and rhetoric; letters, poems, and speeches, three fourths of which are lost. He was one of the most voluminous writers of antiquity, and probably the most learned man whose writings have come down to us. Nor has any one of the ancients exercised upon the thinking of succeeding ages so great an influence. He was an oracle until the revival of learning. [Sidenote: Genius of Aristotle.] "Aristotle," says Hegel, "penetrated into the whole mass, and into every department of the universe of things, and subjected to the comprehension its scattered wealth; and the greater number of the philosophical sciences owe to him their separation and commencement." [Footnote: Hagel is said to have comprehended Aristotle better than any modern writer, and the best work on his philosophy is by him.] He is also the father of the history of philosophy, since he gives an historical review of the way in which the subject has been hitherto treated by the earlier philosophers. "Plato made the external world the region of the incomplete and bad, of the contradictory and the false, and recognized absolute truth only in the eternal immutable ideas. Aristotle laid down the proposition that the idea, which cannot of itself fashion itself into reality, is powerless, and has only a potential existence, and that it becomes a living reality, only by realizing itself in a creative manner by means of its own energy." [Footnote: Adolph Stahr, Oldenburg.] [Sidenote: Vast attainments of Aristotle.]