Seventy years ago Charles Darwin published his book, "The Origin of Species," in which he defied the theological dogma of his time by the shocking idea that life had evolved by many stages of progress from the diatom to man. This of course did not conform to the story of the Garden of Eden, and so "Darwinism" was fought as an invention of the devil, and in the interior of America there are numerous sectarian colleges where the dread term "evolution" is spoken in awed whispers. Only the other day I read in my newspaper the triumphant proclamation of some clergyman that "Darwinism" had been overthrown. This reverend gentleman had got mixed up because some biologists were disputing some detail of the method by which the evolution of species had been brought about. Do species change by the gradual elimination of the unfit, or do they change by sudden leaps, the "mutation" theory of de Vries? Are acquired powers transmitted to posterity, or is the germ plasm unaffected by its environment? Concerning such questions the scientists debate. But the fact that life has evolved in an ordered series from the lower forms to the higher, and that each individual reproduces in embryo and in infancy the history of this long process--these facts are now the basis of all modern thinking, and as generally accepted as the rotation of the earth. You may study this process of evolution from the outside, in the multitude of forms which it has assumed and in their reactions one to another; or you may study it from the inside in your own soul, the emotions which accompany it, the impulse or craving which impels it, the _elan vital_, as it is called by the French philosopher Bergson. The Christians call it love, and Nietzsche, who hated Christianity, called it "the will to power," and persuaded himself that it was the opposite of love.