Socrates held the Sophists in aversion, and in opposition to their selfish expediency taught the purest system of morals that the world had yet known, and which has been surpassed only by the precepts of the Great Teacher. He thought himself to be restrained from entering upon what was inexpedient or wrong by a tutelary spirit. He believed in the immortality of the soul and in a Supreme Ruler of the universe, but sometimes spoke slightingly of the temples and the popular deities. This led to his prosecution on the double charge of blasphemy and of corrupting the Athenian youth. The fact that Alcibiades had been his pupil was used to prove the demoralizing tendency of his teachings. He was condemned to drink the fatal hemlock. The night before his death he spent with his disciples, discoursing on the immortality of the soul. PLATO.--Plato (429-348 B.C.), "the broad-browed," was a philosopher of noble birth, before whom in youth a brilliant career in the world of Greek affairs opened; but, coming under the influence of Socrates, he resolved to give up all his prospects in politics and devote himself to philosophy. Upon the condemnation and death of his master he went into voluntary exile. In many lands he gathered knowledge and met with varied experiences. He visited Sicily, where he was so unfortunate as to call upon himself the resentment of Dionysius, tyrant of Syracuse, through having worsted him in an argument, and also by an uncourtly plainness of speech. The king caused him to be sold into slavery as a prisoner of war. Being ransomed by a friend, he found his way to his native Athens, and established a school of philosophy in the Academy, a public garden close to Athens. Here amid the disciples that thronged to his lectures, he passed the greater part of his long life,--he died 348 B.C., at the age of eighty-one years,--laboring incessantly upon the great works that bear his name. [Illustration: PLATO.] Plato imitated in his writings the method of Socrates in conversation. The discourse is carried on by questions and answers, hence the term _Dialogues_ that attaches to his works. He attributes to his master, Socrates, much of the philosophy that he teaches: yet his _Dialogues_ are all deeply tinged with his own genius and thought. In the _Republic_ Plato portrays his conception of an ideal state. He was opposed to the republic of Athens, and his system, in some of its main features, was singularly like the Feudal System of Mediæval Europe. The _Phædo_ is a record of the last conversation of Socrates with his disciples--an immortal argument for the immortality of the soul.