develops in the young man and young woman at puberty is not to be used for selfish gratification, is not primarily a source of pleasure, but has a very direct relation to the health, intelligence, and happiness of others.  This relation may be enforced by a simple study of succeeding generations of flowers and the ways in which forms, colors, and sizes originate and are handed down from generation to generation in wonderful variety.  Or it may be illustrated from an observation of the beginnings of sex in infusoria; how tiny animals in stagnant water grow to full size and each divides simply into two to form a new generation; how this simple asexual process continuing for several generations results in growing weakness and old age, steadily decreasing size, steadily decreasing vitality until there comes a time when one infusorian unites with another.  There sex begins.  That union of two individuals is required to restore youth, to refresh vitality and energy, and to produce greater variety in the forms of life.  When a boy or girl knows these simple facts, he is better able to understand the power of reproduction than he can possibly be if they are not before him, or if all he has heard has been ceaseless reiteration of the pleasures of selfish indulgence of sex appetite.

Finally, when the boy and the girl come into later adolescence and face manhood and womanhood, they are ready to know some of the larger social aspects of sex.  They are ready to know of the diseases brought on by perverted sex habits; of the frightful waste of those who give themselves to licentiousness, the frightful waste of strength and youthful energy not only in those that actually go down, but in those that survive.  More than that, seeking right relations of themselves to society, they need to know the social aspects of sex.  The young man needs to know what it means for a woman to bear a child; he needs to know the social and economic dependence of the pregnant woman and of the young mother, so that he may realize what the power of fatherhood means in the actual work of society.  I cannot imagine any man talking glibly of the necessary evil, or of man’s inability to control sex passions, if he knows the social facts of sex.  Any young man who knows even a part of the burden his mother bore for him, if he has a spark of manhood in his being, is surely fortified against temptation to selfish indulgence.  If, beyond that, he can see the relation of the home to society, the relative steadiness and dependability of a worker with a wife and children, who bears the home burdens in a man’s way, as compared with the floating, homeless wanderer who walks our streets; if he knows these central facts and the dependence of the home upon the faithfulness of the man and the presence of the man, if he has a spark of patriotism in his heart, he must realize in his thought and in his practice the necessity for the socialization of that passion which, though it begin in individual and selfish forms, issues in such fateful social consequences.