It is necessary to refer at length to one additional educational method which plays a very important part in sexual development, namely, punishment. The sexual perversions known by the names of sadism and masochism have of late attracted much attention from students of the sexual life. In sadism, sexual excitement occurs in association with the infliction of ill-treatment, humiliation, or pain upon others; in masochism the sexual excitement results from the experience of such ill-treatment, humiliation, or pain by the masochist in person. But in sadism, it is not essential that the sadist should himself play the active part; very often, the maltreatment by a second person of a third suffices to cause sexual excitement in the sadist who looks on. Masochistic and sadistic modes of sensibility are frequently associated in the same individual. As far as the relationship of these perversions to punishment is concerned, we learn from many adult masochists and sadists that their first experience of sexual excitement occurred when as children they received a whipping, or saw another child whipped--at school, for instance. The oft-quoted case of Rousseau has previously been mentioned in this work. It is thus evident that the subject of the punishment of children needs to be considered, not merely from the general educational point of view, but also from the special outlook of sexual education. The principal question is whether as a result of corporal punishment, either personally experienced or witnessed, an enduring sexual perversion may be induced in a child; and this problem must be carefully distinguished from another problem, which, however, is also of very great importance, namely, that of the sexual excitement which may be experienced by the person who inflicts the punishment. The significance of the materials available to guide us to a conclusion upon these questions, is not, however, perfectly clear in all cases. I may refer to what was said upon p. 130 _et seq._; and will here merely add that the question whether the infliction of corporal punishment really originates a perversion in the sufferer, or whether it merely awakens to activity a pre-existent tendency, and one which, in the absence of this particular exciting cause, would almost certainly have been awakened by some other and unavoidable cause, some influence acting from without--this is a question to which conflicting answers have been given.