When we cast a glance upon the immense progress realized by the natural sciences in the course of the nineteenth century, and when we perceive the promises they contain for the future, we can not but feel deeply impressed by the idea that mankind is entering upon a new era of progress It has, at any rate, before it all the elements for preparing such a new era. In the course of the last one hundred years, new branches of knowledge, opening entirely new vistas upon the laws of the development of human society, have grown up under the names of anthropology prehistoric ethnology (science of the primitive social institutions), the history of religions, and so on. New conceptions about the whole life of the universe were developed by pursuing such lines of research as molecular physics, the chemical structure of matter, and the chemical composition of distant worlds. And the traditional views about the position of man in the universe, the origin of life, and the na...