[Causes of abnormal sexual behavior (author's transl)]

There is no doubt that there are sexual disorders which are diseases, i.e. they need medical aid. As with every disease, also in sexual disorders investigation of the most probable causes has particular theoretical and practical value. Etiological investigations in this field stumble against special difficulties; compared to other fields of sex research they have been neglected up to now or were too concentrated in one direction. It is suggested that in every sexual disorder requiring treatment etiology should be gone into more deeply than hitherto. From animal experiments and human cases four different etiological possibilities can be deduced.