One part of sexual education is made up by the question of the purposive sexual enlightenment of children--a matter much discussed at the present day. I have shown, on page 8, that this question is not, as many suppose, a new one. Those who have written on the subject of sexual enlightenment use this term with somewhat various meanings. As regards the extension of the term, it may be applied to either (or both) of two fields, which we may term the objective and the subjective aspects of the sexual life. To the objective side belong the physiological processes by means of which is effected the reproduction of organisms, whether plants, animals, or human beings. In explanation of these it is necessary to describe the reproductive organs, and the processes of conjugation, fertilisation, and fructification, as they have long been customarily taught in the botany class; and the nourishment of the nursing infant from the breast of the mother may also be described. To the subjective side, belong the relationships of the sexual processes to the individual organism, the good and the bad effects of the sexual impulse, &c. In this connexion, reference will be made to the dangers of masturbation, sexual excesses, pregnancy, venereal infection, and so on. By many writers, these two fields are not distinguished each from the other with sufficient clearness. The question, whether children should be taught about the methods of reproduction in plants, animals, and human beings, must not be confused with the question whether they should be taught about masturbation or the venereal diseases. It is possible to teach children that self-abuse is a harmful practice, without giving them any account of the physiological processes of reproduction; and, conversely, these processes may be described, without any special reference to the bearings of the matter on the individual life. Of course, the two fields are interconnected; and some writers suggest that in teaching children and young persons a proper respect for the genital organs, such teaching should be based upon a knowledge of the subsequent function of these organs in the work of reproduction. The individual processes cannot at once be referred to one field or the other; involuntary sexual orgasm, menstruation, the puberal development, inasmuch as they exhibit both a subjective and an objective aspect, belong to both fields. This is also true of the sexual act itself, in connexion with which, moreover, the principal difficulties of sexual enlightenment arise.