Moulin Rouge photograph from the collection of Richard Freiherr von Krafft-Ebing, a German-Austrian psychiatrist and early sexologist. He is famous for his book Psychopathia Sexualis: eine Klinisch-Forensische Studie, first published in 1886.
The book was intended for the use of physicians, psychiatrists and judges (and written partly in Latin in order to discourage the general public from reading it), the book explores fetishism, sadism, masochism and homosexuality, as well as nymphomania and the most taboo inclinations.
For Krafft-Ebing, any desire for sex unrelated to procreation was a deviation from the heterosexual norm, making, for example, gay sex a “perversion” of the sexual instinct.
