In the progress of the thought of the generation, say, from 1870 to the present day, the conception of evolution has been much changed. The doctrine of evolution has itself been largely evolved within that period. The application of it has become familiar in fields of which there was at first no thought. The bearing of the acceptance of it upon religion has been seen to be quite different from that which was at first supposed. The advocacy of the doctrine was at first associated with the claims of naturalism or positivism. Wider applications of the doctrine and deeper insight into its meaning have done away with this misunderstanding. Evolution, as originally understood, was as far as possible from suggesting anything mechanical. By the term was meant primarily the gradual unfolding of a living germ from its embryonic beginning to its mature and final stage. This adult form was regarded not merely as the goal actually reached through successive stages of growth. It was conceived as the end aimed at, and achieved through the force of some vital or ideal principle shaping the plastic material and directing the process of growth. In short, evolution implied ideal ends controlling physical means. Yet we find with Spencer, as prevailingly also with others in the study of the natural sciences, the ideas of end and of cause looked at askance. They are regarded an outside the pale of the natural sciences. In a very definite sense that is true. The logical consequence of this admission should be merely the recognition that the idea of evolution as developed in the natural sciences cannot be the whole idea.