There are many matters of detail in Plato's scheme of military training that well deserve consideration, but cannot be even touched upon here. Before we leave it, however, we may give the dates at which the different branches of education are to begin. Care of the body begins at birth, story-telling with the third year, gymnastics with the seventh, writing and reading with the tenth, letters and music with the fourteenth, mathematics with the sixteenth, military drill, which for the time supplants all other training, with the eighteenth. When the young people reach the age of twenty, those who show no great capacity for science, but are manly and courageous, are assigned to the soldier class, and start on a course of higher education in military training, while those who evince great intellectual ability become novices in the ruling class, and begin a curriculum in science, which lasts till the close of their thirtieth year. This course includes arithmetic, geometry, and astronomy, the only sciences at that time cultivated, and aims at impressing upon the youthful mind the unity and harmony of the physical or phenomenal universe. At the age of thirty, those students who do not show any particular aptitude for higher studies are drafted off into the lower public offices, while those who do, pass five years in the study of dialectics, whereby they rise to pure ideas. They are then, from their thirty-fifth to their fiftieth year, made to fill the higher public offices, in which they take their orders directly from the sages. During this period they put their acquirements to a practical test, and so come really and fully into possession of them. At the end of their fiftieth year, after half a century of continuous education of body, mind, and will, they are reckoned to have reached the vision of the supreme good, and therefore to be fit to enter the contemplative ruling class. They are now free men; they have reached the goal of existence; their life is hidden with God; they are free from the prison of the body, and only remain in it voluntarily, and out of gratitude to the State which has educated them, in order to direct it, in accordance with absolute truth and right, toward the Supreme Good.