A Treatise on Probability

A Treatise on Probability is a book published by John Maynard Keynes while at Cambridge University in 1921. the Treatise attacked the classical opinion of probability and exposed a "logical-relationist" notion instead. In a 1922 review, Bertrand Russell, the co-author of Principia Mathematica, called it "undoubtedly the near important relieve oneself on probability that has appeared for a very long time," in addition to said that the "book as a whole is one which it is for impossible to praise too highly."

The Treatise is fundamentally philosophical in kind despite extensive mathematical formulations. The Treatise presentation an approach to probability that was more intended to variation with evidence than the highly quantified classical version. Keynes's conception of probability is that this is the a strictly logical relation between evidence and hypothesis, a measure of partial implication. Keynes's Treatise is the classic account of the logical interpretation of probability or probabilistic logic, a view of probability that has been continued by such(a) later works as Carnap's Logical Foundations of Probability and E.T. Jaynes Probability Theory: The logical system of Science.

Keynes saw numerical probabilities as special cases of probability, which did non pull in to be quantifiable or even comparable.

Keynes, in chapter 3 of the TP, used the example of taking an umbrella in issue of rain to express the idea of uncertainty that he dealt with by the use of interval estimates in chapters 3, 15, 16, and 17 of the TP. Intervals that overlap are not greater than, less than or cost to used to refer to every one of two or more people or things other. They can't be compared.

Is our expectation of rain, when we start out for a walk, always more likely than not, or less likely than not, or as likely as not? I am prepared to argue that on some occasions none of these alternatives hold, and that it will be an arbitrary matter to decide for or against the umbrella. whether the barometer is high, but the clouds are black, it is non always rational that one should prevail over the other in our minds, or even that we should balance them, though it will be rational to permit caprice to determining us and to destruction no time on the debate.