_Purpose of Education_ The opening chapters of the _Great didactic_ treat of man as the highest, the most absolute, and the most excellent of created beings: of the life beyond as man’s ultimate end, and of this life as merely a preparation for eternity. The human being passes through three stages in his preparation for eternity—he learns to know himself, to rule himself, and to direct himself to God. Man’s natural craving is for knowledge,—learning, virtue, piety,—and the seeds of knowledge are implanted in every rational creature. The mind of man is unlimited in its aspirations. “The body is enclosed by small boundaries; the voice roams within wider limits; the sight is bounded only by the vault of heaven; but for the mind, neither in heaven nor anywhere outside of heaven can a boundary be fixed for it.” Man delights in harmony; and, as respects both his mind and his body, he is a harmony. Just as the great world itself is like an immense piece of clockwork, put together with many wheels and bells, and arranged with such art that, throughout the whole structure, one part depends upon another through the harmony and perfection of the movements—so it is with man. All this harmony and perfection is made possible through education. He gave no bad definition, remarks Comenius, who said that man was a “teachable animal.” But he must be taught, since he is born only with aptitudes. Before he can sit, stand, walk, or use his hands, he requires instruction. It is the law of all created things that they develop gradually and ultimately reach a state of perfection. Plato was right when he said, “If properly educated, man is the gentlest and most divine of created beings; but if left uneducated or subjected to a false training, he is the most intractable thing in the world.” Education is necessary for all classes of society; and this is the more apparent when we consider the marked individual differences to be found among human beings. No one doubts that the stupid need instruction that they may outgrow their stupidity. But clever and precocious minds require more careful instruction than dull and backward minds; since those who are mentally active, if not occupied with useful things, will busy themselves with what is useless, curious, and pernicious. Just as a millstone grinds itself away with noise if wheat is not supplied, so an active mind, if void of serious things, entangles itself with vain, curious, and noxious thoughts, and becomes the cause of its own destruction.