How the ideals of physical preformed those of moral and mental training in the land and day of Socrates is seen in the identification of knowledge and virtue, "_Kennen und Können_." [To know and to have the power to do] Only an extreme and one-sided intellectualism separates them and assumes that it is easy to know and hard to do. From the ethical standpoint, philosophy, and indeed all knowledge, is the art of being and doing good, conduct is the only real subject of knowledge, and there is no science but morals. He is the best man, says Xenophon, who is always studying how to improve, and he is the happiest who feels that he is improving. Life is a skill, an art like a handicraft, and true knowledge a form of will. Good moral and physical development are more than analogous; and where intelligence is separated from action the former becomes mystic, abstract, and desiccated, and the latter formal routine. Thus mere conscience and psychological integrity and righteousness are allied and mutually inspiring.
Not only play, which is the purest expression of motor heredity, but work and all exercise owe most of whatever pleasure they bring to the past. The first influence of all right exercise for those in health is feeling of well-being and exhilaration. This is one chief source of the strange enthusiasm felt for many special forms of activity, and the feeling is so strong that it animates many forms of it that are hygienically unfit. To act vigorously from a full store of energy gives a reflex of pleasure that is sometimes a passion and may fairly intoxicate. Animals must move or cease growing and die. While to be weak is to be miserable, to feel strong is a joy and glory. It gives a sense of superiority, dignity, endurance, courage, confidence, enterprise, power, personal validity, virility, and virtue in the etymological sense of that noble word. To be active, agile, strong, is especially the glory of young men. Our nature and history have so disposed our frame that thus all physiological and psychic processes are stimulated, products of decomposition are washed out by oxygenation and elimination, the best reaction of all the ganglionic and sympathetic activities is accused, and vegetative processes are normalized. Activity may exalt the spirit almost to the point of ecstasy, and the physical pleasure of it diffuse, irradiate, and mitigate the sexual stress just at the age when its premature localization is most deleterious. Just enough at the proper time and rate contributes to permanent elasticity of mood and disposition, gives moral self-control, rouses a love of freedom with all that that great word means, and favors all higher human aspirations.