the expression of this relation; and, again, because they represent the most intense effect that one person, either with or without coitus, can exert on another.
The cases in which sadism and masochism occur simultaneously in one individual are interesting, but they present some difficulties of explanation. Cases 49, 50, 58, etc., are of this kind, and also particularly Case 30. From the latter it is evident that it is especially the idea of subjection that, both actively and passively, forms the nucleus of the perverse desires. Traces of the same thing are also to be observed, with more or less clearness, in many other cases. At any rate, one of the two perversions is always markedly predominant.
Owing to this marked predominance of one perversion, and the later appearance of the other, in such cases it may well be assumed that the predominating perversion is original, and that the other has been acquired in the course of time. The ideas of subjection and maltreatment, colored with lustful pleasure, either in an active or passive sense, have become deeply impressed in such an individual.
Occasionally the imagination is tempted to try the same ideas in an inverted rôle. There may even be realization of this inversion. Such attempts in imagination and in acts, however, are usually soon abandoned as inadequate for the original inclination.
Masochism and sadism also occur in combination with contrary sexual instinct, and, too, in association with all forms and degrees of this perversion. The individual of contrary sexuality may be a sadist as well as masochist (comp. Cases 48 and 49 and numerous cases in the following series of cases of contrary sexual instinct).
Wherever a sexual perversion has developed on the basis of a neuropathic individuality, sexual hyperæsthesia, which may always be assumed to be present, may induce the phenomena of masochism and sadism—now of the one, now of both combined, one arising from the other. Thus masochism and sadism appear as the fundamental forms of psycho-sexual perversion,
