The relation of evolution to man has so far been a very much more complex and disturbing matter than the relation of gravitation to man. Its significance in relation to the very existence of man is pregnant with opportunities for trouble. Emotions, traditions, old beliefs, religion, and especially formal theology, are involved. Our anthropocentric system of world philosophy, outgrowth of centuries of self-worship, feels itself assailed. The reaction is one of anger and fear. Is man after all not a unique, specially created being, around whom and for whom an all-powerful Creator has produced the rest of life and the world? Evolution comes as the iconoclast to rob man of his sacred isolation.