The sex-education movement both in Europe and America had its origin as an attempt to check the spread of the venereal or social diseases. The idea that education should work for sexual morality for its own sake and not simply for protection against venereal diseases has only recently begun to appear in the literature of sex-education, and so far it seems to have made only a limited impression on many of those who have been active in the prophylactic campaign against social disease. In fact, the tardy recognition of the moral aim of sex-education makes it seem probable that very little interest would have been aroused in the movement if it had been organized on purely ethical grounds and without any reference to the sanitary problems of social diseases. To one who looks at sexual morality as a question of right conduct which brings its own rewards, it is a shock to find so many thinking people who accept calmly the traditional views of the relation of the sexes and seem to take no interest in the immorality of men except as it is likely to lead to venereal disease or to illegitimacy which demands forced marriage or monetary payments. The truth is that the civilized world at large is very far from a working code of sexual morals which will be practiced because of promised rewards rather than because of probable punishments. It is natural, then, that the sex-education movement should have started with a proclamation of physical punishments for immorality rather than an offer of ethical and psychical rewards for morality. [Sidenote: Both sanitary and moral.] However, the fact that sex-education, under the name of "sex-hygiene," was at first a sanitary propagandism need not interfere with the larger development of sex-education. It now seems probable that before many years pass we shall learn how to make a satisfactory combination of both the sanitary and moral sides of sex-education, and so it is best that the educational movement started on the foundation of the undisputed facts of sanitary science which have made a powerful impression on the people who do and who do not recognize a code of sexual morals. [Sidenote: Medical interest.]