Apart from the demands of general culture there are other reasons why sexual enlightenment is desirable. These chiefly concern the subjective aspects of the sexual life, whilst the objective processes serve principally for preparatory instruction. First of all, grounds of health have to be considered. It may be desirable to enlighten the child regarding the dangers of masturbation, those of ordinary illegitimate sexual intercourse, and those of sexual excesses. No detailed discussion of these points is here necessary, since they have been dealt with before at considerable length, especially on p. 180 _et seq._ Here I will merely point out that this aspect of enlightenment affects the entire future of the child and the family it will one day have. The first consideration here is the danger of venereal infection, and it is this danger, in close association with the other prophylactic efforts of our time, which has given rise to the recent movement in favour of sexual enlightenment. In this connexion the dangers may be explained that threaten the male from gonorrhoeal infection, not only in his own person, but also in the persons of his future wife and children. The wife may be infected by the husband, and the visual powers of the new-born child may also be endangered. Ophthalmia of the new-born, which often leads to blindness, commonly depends upon conjunctival infection received during the act of parturition. Syphilis was referred to on p. 192. Here it may be added that still-births and abortion and miscarriage may result from syphilitic infection either of the mother or of the embryo. Or the child may be born alive, but suffering from syphilitic infection. Even when no actual infection of the offspring results, syphilis favours the occurrence of a general degeneration of the progeny. If we desire to safeguard human beings against such dangers as these, we shall feel it necessary to enlighten them before it is too late; and in view of the fact that from a single act of intercourse infection may result by which the health may be permanently injured, such enlightenment is no less necessary for girls than for boys.