Further, because the problem of sex can only be solved by the cooperation of the sexes working together in mutual understanding it is right that men should know a good deal about women's bodies and vice versa. Such knowledge almost always begets sympathy and a certain intelligent tenderness. The lack of it has often led to unconscious cruelties, to misunderstandings, and even to serious mistakes. To mention one instance only, how can men be expected to treat the other sex with true consideration if they do not know that once a month for a period women ought to be saved from fatigue and strain? And yet there are many adult men in that position of ignorance. But though the detailed facts are all clean, and really easy to be understood, the manner in which they are conveyed into our minds is of vital importance. I do not think they can be fully conveyed through any printed page. They are too delicate for such handling. They are not truly conveyed unless behind the mere words which express them there is a reverent soul that can impart the right tone and emphasis to them. I would quite gladly attempt to put them all down here could I only be assured that my words would only be read by men or women when alone and in a reverent mood. That being impossible I can only begin by insisting that they ought to be known. And this I can also do--I can assure all young people who read these pages that there is nothing whatever in the facts of the case to be afraid of--nothing that they cannot know with perfectly clean minds. There are no terrible mysteries in the matter. There are no horrors in normal sex life. The truth even about the ultimate intimacies of body between men and women is that when truly achieved they are beautiful, and holy, and happy.