=Plato’s System of Education for the Three Classes of Society.=--But the believers in the old traditions and institutional morality felt that Socrates was atheistic and immoral. They persuaded Athens to give him the hemlock, and thus destroyed the man who might have proved her savior. A pupil, Plato (427-347 B. C.), undertook to continue his work, but his aristocratic birth and temperament caused him to underestimate the intelligence of the masses. He held that they were incapable of attaining to ‘knowledge’--that they possessed only ‘opinion.’ In his most famous dialogue, _The Republic_, he endeavors to show that the ideal state can exist only when the entire control of the government is entrusted to the ‘philosophers,’ or intellectual class, who alone possess ‘real knowledge.’ Those who are to compose the three classes of society Plato would have selected during the educational process on the basis of their ability. For all boys up to eighteen years of age he prescribes an education similar to that in vogue in the palaestra, didascaleum, and gymnasium, except that he would somewhat expurgate the literary element, and would confine the musical training to the simpler melodies and instruments. The youths who prove capable of going beyond this lower education are next to take up the cadet training between eighteen and twenty, but those who are incapable of further education are to be relegated to the industrial class. During the cadet period are to be determined those capable of going on with the higher education of philosophers, while those who here reach their limit become members of the military class. [Sidenote: Higher education for philosophers:] [Sidenote: (1) mathematical subjects;] [Sidenote: (2) dialectic.] As Athenian education did not extend beyond the twentieth year, Plato is here obliged to invent a new course of study that will enable the future philosophers to acquire the habit of speculation. This additional course, he declares, should also be graded, in order that a further test of intellectual and moral qualities may be made. Arithmetic, plane and solid geometry, music, and astronomy, are to occupy the first ten years of the course. These subjects, however, are not to be studied for calculation or practical purposes of any sort, but entirely from the standpoint of theory or the universal relations underlying them, since only thus can they furnish a capacity for abstract thought. After this, at thirty, the young men who can go no further, are to be placed in the minor offices of the state, while those who have shown themselves capable of the study of dialectic, go on with that subject for five years longer. It then becomes the duty of these highest philosophers to guide and control the state until they have reached the age of fifty, when they may be allowed to retire. [Sidenote: Return to subordination of the individual;] [Sidenote: neglect of human will;] [Sidenote: failure to see all human traits in each individual;]