In the first chapter of this book I have shown, I believe convincingly, why sex knowledge is even more important for women than it is for men. I have examined carefully the books that have been written for girls and women, and I know that it is not bias, nor carping criticism, but strict honesty that forces me to say that I have not found one satisfactory girl's or woman's sex book. There are some excellent books for girls and women on general hygiene; but on sex hygiene, on the general manifestations of the sex instinct, on sex ethics-none. I have attempted to write such a book. Whether I have succeeded-fully, partially or not at all-is not for me to say, though I have my suspicions. But this I know: in writing this book I have been strictly honest with myself, from first page to last. Whether everything I have written is the truth, I do not know. But at least I believe that it is-or I would not have written it. And I can solemnly say that the book is free from any cant, hypocrisy, falsehood, exaggeration or compromise, nor has any attempt been made in any chapter to conciliate the stupid, the ignorant, the pervert, or the sexless. If this book should be instrumental, as I confidently trust it will, in destroying some medieval superstitions, in dissipating some hampering and cramping errors, in instilling some hope in the hearts of the hopeless, in bringing a little joy into the homes of the joyless, in increasing in however slight a degree the sum total of human happiness, its mission shall have been gloriously fulfilled.