Iwan Bloch (1872-1922) was a Berlin dermatologist and is often called the first sexologist. He discovered the Marquis de Sade's manuscript of The 120 Days of Sodom, which had been believed to be lost, and published it under the pseudonym Eugène Dühren in 1904.

In 1899 he had published Marquis de Sade: his life and works.

Together with Magnus Hirschfeld Bloch proposed the new concept of a science of sexuality: Sexualwissenschaft or sexology. In 1906 he wrote "The sexual life of our time; a complete encyclopedia of the sexual sciences in their relation to modern civilization".

Iwan Bloch began the publication of his "Handbuch der gesamten Sexualwissenschaft in Einzeldarstellungen" (Handbook of Sexology in its Entirety Presented in Separate Studies). Three volumes appeared, the project was aborted because of Bloch's untimely death.

• "Prostitution, vol. I" (1912) - Iwan Bloch
• "Homosexuality in Men and Women" (1914) - Magnus Hirschfeld
• "Prostitution, vol. II" (after 1922) - Iwan Bloch

Sexologists1872 births1922 deaths

Iwan Bloch | Iwan Bloch