The Myth that Ramsey Destroyed and Demolished Keynes’s Logical Theory of Probability is Easily Dismissed as a Fairy Tale by Anyone who has read Parts II-V of the A Treatise on Probability (1921)
41 Pages Posted: 29 Jun 2020
Date Written: June 4, 2020
Ramsey’s many ,many confusions and errors about Keynes’s logical theory of Probability all stem from his failure to a) read more than just the first four chapters of Keynes’s A Treatise on Probability(1921),b) his gross ignorance of Boole’s logical theory of probability that Keynes had built on in Parts II,III,IV,and V of the A Treatise on Probability,c) his complete and total ignorance of real world decision making in financial markets(bond, money, stocks, commodity futures),government,industry and business,and d) his complete and total ignorance of the role that intuition and perception played in tournament chess competition under time constraint,a role that was taught to J M Keynes by his father ,J N Keynes,who was a rated chess master who played first board for Cambridge University in the late 1870’s and early 1880’s.
Anyone who has read Parts II,III,IV and V of the A Treatise on Probability can avoid making the type of errors that have recently shown up again in C.Misak’s( 2020) biography of Ramsey,where it is asserted that Ramsey easily demolished Keynes’s logical theory of probability or S Bradley’s (2019) historical foray into the beginnings of imprecise probability,which are based on B.Weatherson’s (2002 ) bizarre claims that the “modern” theory of imprecise probability, which uses interval valued probability defined by lower and upper probabilities,as well as Kyburg’s own deficient knowledge base,can be used to help explain Keynes’s strange ,unfathomable and mysterious beliefs in “ non numerical” probabilities.
Of course,since Keynes’s work in the A Treatise on Probability in Parts II-V is directly based on Boole’s theory of interval valued probability that defined lower and upper probabilities in chapters 16 -21 of the 1854 The Laws of Thought,what Weatherson(2002) and Bradley (2019)are doing is to reinvent the wheel,not knowing that the wheel had already been invented thousands of years before them.This error can be directly traced to both Weatherson’s and Bradley’s extremely limited understanding of Keynes’s introductory,initial,beginning approach to the use of interval valued probability that takes place in chapter III of the A Treatise on Probability on pp.30 and 34,which are the same pages emphasized by philosophers,for example, such as H E Kyburg and I J Good.
Keywords: imprecise probability,lower and upper bounds,interval valued probability,non additive and additive probability
JEL Classification: B10, B12, B14, B16, B18, B20, B22
Suggested Citation: Suggested Citation