Frank Plumpton Ramsey (/ˈræmzi/; 22 February 1903 – 19 January 1930) was a British philosopher, mathematician, and economist who made major contributions to all three fields before his death at the age of 26.

He was immensely widely read in English literature; he was enjoying classics though he was on the verge of plunging into being a mathematical specialist; he was very interested in politics, and well-informed; he had got a political concern and a sort of left-wing caring-for-the-underdog kind of outlook about politics.In 1923, Ramsey was befriended by Geoffrey and Margaret Pyke, then on the point of founding the Malting House School in Cambridge; the Pykes took Ramsey into their family, taking him on holiday and asking him to be the godfather of their young son.

'[3] Margaret wanted time to consider his proposition and thus began an uncomfortable dance between them, which contributed to Ramsey's depressive moods in early 1924; as a result, he travelled to Vienna for psychoanalysis.

Like many of his contemporaries, including his Viennese flatmate and fellow Apostle Lionel Penrose (also in analysis with Siegfried Bernfeld), Ramsey was intellectually interested in psychoanalysis.

In the summer of 1924, he continued his analysis by joining Reik at Dobbiaco (in South Tyrol), where a fellow analysand was Lewis Namier.

Ramsey returned to England in October 1924; with John Maynard Keynes's support, he became a fellow of King's College, Cambridge.

[10] Ramsey was then able, at the age of 19, to make the first draft of the translation of the German text of Ludwig Wittgenstein's Tractatus Logico-Philosophicus.

Wittgenstein made some corrections to the English translation in Ramsey's copy and some annotations and changes to the German text that subsequently appeared in the second edition in 1933.

Ramsey and John Maynard Keynes cooperated to try to bring Wittgenstein back to Cambridge (he had been a student there before World War I).

In the introduction to Philosophical Investigations Wittgenstein credits Ramsey's criticism of the Tractatus in the "interminable conversations" they had as having helped him realise "grave mistakes" within the work.

[11] Suffering chronic liver problems, Ramsey developed jaundice after an abdominal operation and died on 19 January 1930 at Guy's Hospital in London at the age of 26.

Other papers, including his diary and letters and memoirs by his widow Lettice Ramsey and his father, are held in the Modern Archives, King's College, Cambridge.

In 1926,[16] Ramsey proposed a simplification of the Theory of Types developed by Bertrand Russell and Alfred North Whitehead in their Principia Mathematica.

Ramsey responded to Keynes's urging by writing three papers in economic theory all of which were of fundamental importance, though it was many years before they received their proper recognition by the community of economists.

Ramsey suggested a way of deriving a consistent theory of choice under uncertainty that could isolate beliefs from preferences while still maintaining subjective probabilities,[25] although Ramsey later noted that "taking the whole field of chance events no generalizations about them are possible (consider e.g. infectious diseases, dactyls in hexameters, deaths from horse kicks, births of great men)".

[26] Despite the fact that Ramsey's work on probabilities was of great importance, no one paid any attention to it until the publication of Theory of Games and Economic Behavior by John von Neumann and Oskar Morgenstern in 1944 (1947 2nd ed.

)[citation needed], although after Ramsey's death, an approach to probability similar to his was developed independently by the Italian mathematician Bruno de Finetti.

This is applicable in situations where a (regulated) monopolist wants to maximise consumer surplus whilst at the same time ensuring that its costs are adequately covered.

[30][31] It employed, as Paul Samuelson described it, "a strategically beautiful application of the calculus of variations"[23] to determine the optimal amount an economy should invest rather than consume so as to maximise future utility, or as Ramsey put it, "how much of its income should a nation save?

"[32] The Ramsey model is today acknowledged as the starting point for optimal accumulation theory although its importance was not recognised until many years after its first publication.