The principles which should guide the moral education of our children--our boys and girls--must necessarily depend upon the views which we hold in relation to their adult life, as men and women; these views will unavoidably determine the course of practical education. Two great questions, therefore, naturally present themselves at the outset of every careful consideration of moral sexual education-- 1. What is the true standard for the relations of men and women--the type which contains within itself the germ of progress or continual development? 2. How can this standard be attained by human beings? The endeavour to ascertain the true answer in its bearing upon the growth of the young and the welfare of family life is the object of this essay. CHAPTER I _Physiological Laws which Influence the Physical and Mental Growth of Sex_ The very gradual growth of mankind from lower to higher forms of social life, makes the study of the relation of the sexes a very complicated one; but a sure guide may be found in the great truths of physiology, viewed in their broad relation to human progress, and it is on the solid foundation of these truths that correct principles of education must be based. The tendency of our age, in seeking truth, is to reject theories and study facts--facts, however, on the largest and most comprehensive scale. Every physician knows that nothing is more stupid than routine practice; nothing more unreliable than theories unsupported by well-observed facts; and, at the same time, nothing more misleading than partial facts. The laws of the human constitution itself, as taught by the most comprehensive investigations of science, must be carefully studied. We must learn what reason, observing the facts of physiology, lays down as the true laws which should govern the relations of men and women--laws whose observance will secure the finest development of our race, and serve as a guide in directing the education of our children. The relations of human beings to each other, depend upon the nature and requirements of individuals. It is, therefore, essential to know what the nature of the individual human being really is; how it grows and how it degenerates. Such knowledge must necessarily form the basis of all true methods of education. We find throughout Nature, that every creature possesses its peculiar type, towards which it must tend, if it is to accomplish the purpose of its creation. There is a capacity belonging to the original germ, which, if the necessary conditions are presented, will lead it through the various stages of growth and of development, to the complete attainment of this type. This type or pattern is the true aim of the individual. With the process by which it is reached, it constitutes its nature.