At the beginning of the nineteenth century, several works were published by physicians trying to explain, in an increasingly systematic manner, the emergence of psychic derangements with sexual disorders. A contribution to this development was provided by Joseph Häussler with his monograph 'On the relation of the sexual system to the psyche in general and to cretinism in particular' (1826). Häussler was interested in whether the sexual system was the cause of psychic disturbance. He accused some sexual behaviours and exercises (e.g., onanism and unsatisfied sexual instinct) of being causes, but, nonetheless, accepted that morphological deviations of the sexual organs could also evoke mental diseases. Furthermore Häussler attempted to determine if stimulation of the sexual system could cure psychic illnesses. Finally, he dealt with sexual conditions in the mentally ill. A complete chapter was devoted to cretins and their sexuality.