Sidney George Francis Guy Skinner "Francis" (1912–1941) was a friend, collaborator, and alleged lover of the Austrian philosopher Ludwig Wittgenstein. He was born in 1912 in Kensington, London, England. While studying mathematics at Cambridge in 1930, Skinner fell under Wittgenstein's influence and "became utterly, uncritically, and almost obsessively devoted to Wittgenstein.". Their relationship was characterized by Skinner's eagerness to please Wittgenstein and conform to his opinions. In 1934, the two made plans to emigrate to the Soviet Union and become manual labourers, but Wittgenstein visited the country briefly and realised the plan was not feasible - the Soviet Union might have allowed Wittgenstein to immigrate as a teacher, but not as a manual labourer.
Skinner graduated with a degree in Mathematics from Cambridge in 1933 and was awarded a postgraduate fellowship. For three years he used his fellowship assisting Wittgenstein in preparing a book on philosophy and mathematics (never published). During the academic year 1934-5 Wittgenstein dictated to Skinner and Alice Ambrose the text of the Brown Book. However, Wittgenstein's hostility towards academia resulted in Skinner's withdrawal from university, first to become a gardener, and later a mechanic (much to the dismay of Skinner's family). In the late 1930s though, Wittgenstein grew increasingly distant, until Skinner's death from polio in 1941.
In 2011 an extensive archive came to light, consisting of 170,000 words of handwriting and text plus mathematics. This apparently had mostly been dictated by Wittgenstein to Skinner, with annotations by both. The archive includes a long-lost so-called Pink Book. Wittgenstein had posted them to a friend of Skinner's days after his death.
- Monk, Ludwig Wittgenstein: The Duty of Genius, p. 331
- Monk, Ludwig Wittgenstein: The Duty of Genius, p. 334
- Wittgenstein L., The Blue and Brown Books, ed. by R. Rhees, London: Blackwell, 1958, preface p. v.
- "Lost archive shows Wittgenstein in a new light"