F. P. Ramsey is hardly a household name, even among philosophers, not nearly so well-known as his brother, Michael, who became Archbishop of Canterbury. The TLS reviewer of Frank Ramsey (1903-1930): A Sister’s Memoir captures something of his astonishing brilliance:

“In Cambridge in the 1920s, he singlehandedly forged a range of ideas that have since come to define the philosophical landscape. Contemporary debates about truth, meaning, knowledge, logic and the structure of scientific theories all take off from positions first defined by Ramsey. Equally importantly, he figured out the principles governing subjective probability, and so opened the way to decision theory, game theory and much work in the foundations of economics. His fertile mind could not help bubbling over into other subjects. An incidental theorem he proved in a logic paper initiated the branch of mathematics known as Ramsey theory, while two articles in the * Economic Journal * pioneered the mathematical analysis of taxation and saving . . . . A combination of quite exceptional mathematical ability and favoured background – his father was President of Magdalene College, Cambridge – meant that his reputation preceded him into Cambridge circles. By the time he became a mathematics undergraduate it was generally recognized, not least by Ramsey himself, that he was destined to solve fundamental problems. At the beginning of his second year, he was deemed the only person with enough mathematical logic and German to be trusted with the English translation of Wittgenstein’s * Tractatus * . In the spring term a review of Keynes’s * Theory of Probability * pointed the way to the concept of subjective probability. The following year he published a long article on the * Tractatus * for the philosophical journal * Mind * , and then spent a fortnight that summer in Austria discussing it with Wittgenstein himself. At this point he was still some months short of his twenty-first birthday.”

Ramsey died in 1930, age 26.