Our reason, our knowledge of the method of Nature, declare for evolution; because here we are, here is this amazing world of life about us, and here it goes on through the action and interaction of purely physical and chemical forces. Life seems as natural as day and night, as the dews and the rain. Our studies of the past history of the globe reveal the fact that life appeared upon a cooling planet when the temperature was suitable, and when its basic elements, water and carbon dioxide, were at hand. How it began, whether through insensible changes in the activities of inert matter, lasting whole geologic ages, or by a sudden transformation at many points on the earth's surface, we can never know. But science can see no reason for believing that its beginning was other than natural; it was inevitable from the constitution of matter itself. Moreover, since the law of evolution seems of universal application, and affords the key to more great problems than any other generalization of the human mind, one would say on _a priori_ grounds that life is an evolution, that its genesis is to be sought in the inherent capacities and potentialities of matter itself. How else could it come? Science cannot go outside of matter and its laws for an explanation of any phenomena that appear in matter. It goes inside of matter instead, and in its mysterious molecular attractions and repulsions, in the whirl and dance of the atoms and electrons, in their emanations and transformations, in their amazing potencies and activities, sees, or seems to see, the secret of the origin of life itself. But this view is distasteful to a large number of thinking persons. Many would call it frank materialism, and declare that it is utterly inadequate to supply the spiritual and ideal background which is the strength and solace of our human life. IV