TO the historian of thought and culture the key to the nineteenth century is found in the scientific renaissance. The multifarious results of this movement, the evidences of which are apparent in every aspect of our complex civilization, are yet to be appraised. It is the story of the subjection of power, a symphony in iron and steel which has been summed up in the word industrialization. That, however, is but the introductory chapter; the sequel concerns more elusive but ultimately more important factors. It is the chronicle of new thought-patterns, of new ideals, of a subtly transformed outlook upon life. Among the many influences which contributed to this revised Anschauung was the doctrine of evolution, at once the parent and the offspring of the scientific advance.