The Bolshevik Menace of Anthropological Mathematics: Ramsey and Wittgenstein

Wittgenstein said (at some point between 1937and 1944) that ‘mathematics is after all an anthropological phenomenon’. This was an about-face from the view of mathematics expressed in the Tractatus, where he had said that mathematics consisted of ‘equations’. This paper argues that the shift was caused by Wittgenstein’s most important interlocutor, the great Cambridge mathematician, philosopher, and economist, Frank Ramsey, who died in 1930 at the age of 26. Both Ramsey and Wittgenstein came to see in 1929 that anthropological mathematics, or intuitionism, or what Ramsey called a ‘human logic’, fit better with the philosophical picture they were starting to develop. My argument in this paper is that by ‘anthropological’, Wittgenstein meant ‘human’, as Ramsey used the term.