The modern view of history is vivified by a principle scarcely dreamed of before the middle of the last century; the conception which permeates all our interpretations of the story of the world, which illuminates our study of all its phases, was by our grandfathers apprehended either vaguely or not at all. For them, history dealt with a more or less random series of happenings, succeeding each other accidentally, unaccountably, and at haphazard; each single event, determined by causes peculiar to itself, was without relation to all the others. Political and social history, for example, was an account of battles, sieges, revolutions, governments; of kings, warriors, and statesmen. Its salient features were special occasions and individual men: Marathon and Waterloo, Alexander, Cæsar, Alfred, Napoleon. Of pervasive social movements, tendencies of human feeling and thought, developments of industries, institutions, laws, and customs by a gradual process in which great numbers of personally insignificant men played their part, little account was taken. Facts were facts, and had no hidden significance, no mutual interaction, no cumulative force, momentum, or direction. Far otherwise do we interpret the story of the world. Inspired by the great doctrine of the nineteenth century, the doctrine of evolution, first formulated by biology, but immediately applied to all realms of knowledge, we read in events a continuous movement, a coherent growth, a gradual, vast, and single process. For us, individual events and men sink into insignificance in comparison with the great drama of which they are only acts and actors. For us, great popular movements, instinctive strivings, of which the men and women under their sway were unconscious, vast blossomings of vital energy the roots of which were far below the surface of the human mind, rise into relief as the true interests of the historian, and we interpret all particular happenings and special persons in the light of these universal tendencies. In geology we trace the continuous formation of the earth through innumerable years; in zoology we study those slow but constant transformations of animals which are effected by natural selection and the survival of the fittest; in sociology we examine the painful yet inevitable crystallization out of the human spirit of such ideas as responsibility, liberty, justice; in philosophy we learn of the subtle implications of our nature, and so learning, substitute a human God for the idols of savages and the remote tyrannical deities of half-developed religions. There is not a branch of our thought in which this way of interpreting life as a process, this conceiving of it as dynamic and vital rather than static and inert, has not enlarged our outlook, deepened our sense of the sacredness and wonder of the universe, and filled our spirits with a new freedom, enthusiasm, and hope.