sadist: [19] The terms sadist and sadism commemorate the so-called Marquis de Sade (in fact he was a count), the French writer who lived between 1740 and 1815. Towards the end of the 18th century he produced several pornographic novels, whose theme of sexual gratification through (among other things) the inflicting of pain led in the late 19th century to the use of his name by psychiatrists to describe such behaviour. By the 1930s sadism had become a general term for ‘gratuitous cruelty’. [sadist etymology, sadist origin, 英语词源]