Most of the discussions of the education of young men for moral living have centered around the problem of keeping him from physical sexual activity. So far as society is concerned, this is the great desideratum. So far as the individual life is concerned, it is important that self-control should extend to mental imagery. Professors Geddes and Thomson have well said, in "Sex," that "while anatomical chastity is a moral achievement, it is not the deepest virtue. The incisive declaration: 'Whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart' expresses an even more searching standard, and modern science brings home to us the radical importance of our reflex thought and deep-down impulses, which appear to bulk largely in molding our lives and the lives of those who may spring from us." In language adapted to the understanding of average young men, this idea should be emphasized. In the opinion of some physiologists the greatest harm done to the individual who has long been a victim of masturbation is in the centering of the attention on imaginary sexual situations. This is especially true of mental masturbation. Hence, the relation of masturbation to the possible establishment of a disordered mental state should be known by adolescent boys and young men. [Sidenote: Control of thoughts.] It appears from the experience of many men that strenuous work and play are the only efficient weapons for driving sexual images into the background of the mind. This applies not only to sordid and lewd thoughts of unchaste sexual situations, but also to the mental images that are inevitably associated with the purest affection and which should be trained to obey when calm reason so orders. The following literature will be especially helpful to young men: W.S. Hall's "Sexual Hygiene for Men," or his "Sexual Knowledge"; Exner's "The Rational Sex Life for Men"; Morrow's "The Young Man's Problem," and "Health and Hygiene of Sex for College Students"; King's "Fight for Character" (Y.M.C.A.); and the chapter on Ethics of Sex in "Sex" by Geddes and Thomson. FOOTNOTES: [17] The first three pamphlets are published by the Society of Sanitary and Moral Prophylaxis (New York); the Exner pamphlets by the Association Press (New York). [18] This is really not surprising if we remember the peculiarities of human instincts mentioned in an earlier lecture (Sec. 3). IX SPECIAL SEX-INSTRUCTION FOR MATURING YOUNG WOMEN [Sidenote: Parents would limit knowledge of daughters.]