As our knowledge expands we become more and more impressed with the narrow limits placed on this expansion, with our insuperable impotence in so many respects. To a child, who knows little and accomplishes little, his inability, his helplessness, does not give much concern. It is the prevalent, one may even say normal, condition of his life, and therefore scarcely gives rise to unpleasant feelings. But the experienced adult, in the full consciousness of his knowledge, of the advantage which this gives to him, strives to know everything, to extend his power over everything. And he is constrained to learn that he will never come near this end. His prescience, the source of so much pleasant feeling, becomes thus a source of immense unpleasantness. Highly important relations of things remain in almost total darkness. Not even the next day’s weather can be foretold, not the issue of the imminent battle, not the bent of the woman he woos. How numerous are the things against which he is almost powerless: human enemies, wild beasts, storm, earthquake, fire, flood, famine, a host of diseases, and last of all the inevitable death. He foresees all the terrors, aware of their power over him. This must fill his life with anxiety and bitterness. “He whose eye is so keen that he sees the dead in their graves, no longer sees the flowers blooming.” Other evils have their sources, not directly in the mind’s foreseeing, but in the limitations of foreseeing activity. The most fundamental aims of human activity are self-preservation and the preservation of the species. But our feelings indicate that a third class of activities are essential for the completeness of human life, although their contribution to self-preservation and to preservation of the race seems to be limited. The aim of these activities perhaps is only a training of our powers of attention, of unifying in consciousness a number of impressions which indirectly might benefit the two aims first mentioned. Even primitive man devotes a considerable part of his activity to the production of these effects--esthetic impressions from colors, from tones, from symmetry, from rhythm. He ties feathers into his hair, dyes his clothes, and constructs his implements in symmetrical design without being forced by their use to do this. He works rhythmically, either himself or with others; he dances, thus uniting successive movements into regularly repeated groups. But those activities which serve the purpose of self-preservation and race-preservation directly, often occupy his mental energies so exclusively that no time is left for the exercise of these esthetic tendencies. Their suppression then results in deeply felt unpleasantness.