The need of such guidance as you give is very evident. After all, instinct in man is all insufficient to determine social behaviour, and there is need of instruction in the highest of physiological functions, that of reproduction, as there is in the lower functions of eating and drinking--the only difference being that in the former instruction can be deferred to a later age. And there is no doubt that in this case it is better to acquire knowledge by instruction than by a type of experience which is nearly always sordid and may be fraught with danger to the health of the individual and of the family. At the present time it is of vital importance to the State that its marriages should be fruitful--in children, happiness, and efficiency (and all three are closely connected). If your book helps in securing this object, your trouble will not have been in vain. Believe me, Yours very truly, ERNEST H. STARLING. Author's Preface More than ever to-day are happy homes needed. It is my hope that this book may serve the State by adding to their numbers. Its object is to increase the joys of marriage, and to show how much sorrow may be avoided. The only secure basis for a present-day State is the welding of its units in marriage; but there is rottenness and danger at the foundations of the State if many of the marriages are unhappy. To-day, particularly in the middle classes in this country, marriage is far less really happy than its surface appears. Too many who marry expecting joy are bitterly disappointed; and the demand for "freedom" grows; while those who cry aloud are generally unaware that it is more likely to have been their own ignorance than the "marriage-bond" which was the origin of their unhappiness. It is never _easy_ to make marriage a lovely thing; and it is an achievement beyond the powers of the selfish, or the mentally cowardly. Knowledge is needed and, as things are at present, knowledge is almost unobtainable by those who are most in want of it. The problems of the sex-life are infinitely complex, and for their solution urgently demand both sympathy and scientific research. I have some things to say about sex, which, so far as I am aware, have not yet been said, things which seem to be of profound importance to men and women who hope to make their marriages beautiful. This little book is less a record of a research than an attempt to present in easily understandable form the clarified and crystallised results of long and complex investigations. Its simple statements are based on a very large number of first-hand observations, on confidences from men and women of all classes and types, and on facts gleaned from wide reading. My original contributions to the age-long problems of marriage will principally be found in Chapters IV., V., and VIII. The other chapters fill in what I hope is an undistorted picture of the potential beauties and realities of marriage.