The fact is that these questions, which are agitating us to-day, have agitated the world ever since it has been a world of life at all. The difference is that whereas we seek to deal with them consciously, voluntarily, and deliberately, throughout by far the greater part of the world's life they have been dealt with unconsciously, by methods of trial and error, of perpetual experiment, which has often proved costly, but has all the more clearly brought out the real course of natural progress. We cannot solve problems so ancient and deeply rooted as those of sex by merely rational methods which are only of yesterday. To be of value our rational methods must be the revelation in deliberate consciousness of unconscious methods which go far back into the remote past. Our conscious, deliberate, and purposive methods, carried out on the plane of reason, will not be sound unless they are a continuation of those methods which have already, in the slow evolution of life, been found sound and progressive on the plane of instinct. This must be borne in mind by those people--always to be found among us, though not always on the side of social advance--who desire their own line of conduct in matters of sex to be so closely in accord with natural and Divine law that to question it would be impious. A medical friend of my own, when once in the dentist's chair under the influence of nitrous oxide anaesthesia (a condition, as William James showed, which frequently leads us to believe we are solving the problems of the universe), imagined himself facing the Almighty and insistently demanding the real object of the existence of the world. And the Almighty's answer came in one word: "Reproduction." My friend is a man of philosophic mind, and the solution of the mystery of the world's purpose thus presented to him in vision may perhaps serve as a simple and ultimate statement of the object of life. From the very outset the great object of Nature to our human eyes seems to be primarily reproduction, in the long run, indeed, an effort after economy of method in the attainment of an ever greater perfection, but primarily reproduction. This tendency to reproduction is indeed so fundamental, it is impressed on vital organisation with so great a violence of emphasis, that we may regard the course of evolution as much more an effort to slow down reproduction than to furnish it with any new facilities.