This work showcases a prevailing view at its time regarding sexual behaviors that are considered 'deviant'. As the author states, “In the present work I sketch in broad outline those facts and observations which inspired me with the idea of making enquiry into the causes of sexual perversion, and this not merely under the influence of depravity and licentious excess; preferably, in fact I may say chiefly, I examine these causes as connected with a morbid condition of the organism, whether congenital or acquired.”