Richard E. Braithwaite on J. M. Keynes's A Treatise on Probability and Logical Theory of Probability: Ignorance is Bliss

Abstract

Richard E Braithwaite’s Oct,1931 review article in Mind on Jefferys’ work on probability also summarized what the current assessment of Keynes’s A Treatise on Probability and logical theory of probability was. This assessment is based on a complete and total ignorance on Braithwaite’s part about what Keynes actually accomplished in the A Treatise on Probability. He had no idea about what an interval valued, indeterminate probability is. He had no idea about how Keynes built on Boole’s upper-lower bound approach. He had no idea about the concept of the weight of the evidence, w, and how it is connected to the size of the difference between the lower and upper bound. He apparently forgot that Keynes’s logical approach to probability was carefully laid out in 1907 and 1908, which would be 12 or 13 years before Harold Jeffreys published his articles in 1919 with Wrinch.

Finally, Braithwaite had no idea about how to compare objects using a relation of similarity and/or dissimilarity which, of course, is the basic requirement needed for pattern recognition, which is recognized as fundamental by cognitive psychologists and cognitive scientists if decision makers are to successfully use their intuition and induction. He is totally oblivious to the connection between degrees of similarity and Keynes’s logical probability relations. In short, he was an ignorant fool who failed abysmally, like Hugh Townshend, to make use of the clues Keynes periodically sent his way.

Keywords: indeterminate probability, interval valued probability, Boole, wieght of the evidence

JEL Classification: B10, B12, B16, B22