Any honest inquiry into the Primal Instincts of humanity will necessarily lead to a clearer understanding of their nature, their functions, and their potentialities, and so will help to pave the way for the appearance of a healthier and happier race of men.

The dictum "Learn to know yourself," inscribed on the Temple of Apollo at Delphi, has never been of more vital importance, both individually and nationally, than it is to-day, and the various schools of modern psychological thought, which are steadily opening up those hitherto scarcely explored regions whence flow the springs of human actions, are gradually clearing away the ignorance which has been the real cause of so much disease and distress.

The following chapters are to be welcomed particularly as an effort at the constructional reform of our treatment of one of our deepest and most powerful instincts. Even those who do not necessarily give assent to all the details in the line of argument therein pursued must surely approve the insistence upon the vital necessity of there being love in all sex relationships.

The word "sexual," though indispensable perhaps in such a book as this, invariably induces some measure of opposition by reason of the associations which it calls up, and so is often replaced by the cognate adjective "racial," which emphasizes the wider aims of Race Preservation rather than the narrower matter of the reproduction of individuals. It is not a matter of curing individual immorality, not even of explaining it only, it is the greater matter of laying a sound foundation for a practicable social morality that is the object of consideration here.

It is important that any such opposition should be neither hypocritical nor hyper-critical, for great national issues are at stake. Without the healthy mind there can be no healthy body, at any rate from the point of view of the community, and thus such a scientific inquiry as is set forth in these pages is definitely leading towards the production of a healthier nation.

The necessity of there being established a balance between an unlimited self-expression and a rigid self-repression is clearly indicated also, and the importance of self-control is not ignored here as it has been elsewhere, unfortunately, both as regards the individual's physical health and the weal of the community at large; for self-control is a vital essential in the health of a man just as it is a vital necessity for the continuance of a nation.

The following pages contain information and suggestions which should tend to the formation of a wiser and more hopeful outlook over the problems of sexual morality, and should therefore receive the careful consideration of all who have the interests of humanity at heart.