Are there degrees of belief?

Abstract

John Maynard Keynes claimed that not all probabilities were comparable. Frank Ramsey argued that they were, and that Keynes's views to the contrary rested on a confusion of degree of entailment and degree of belief. We will argue that Keynes and Ramsey largely talked past each other, and yet that there are issues of great significance underlying their dispute. In particular, the simple principle of maximizing expected utility may be seen in a new light as one step of a rich and complex process. © 2003 Published by Elsevier B.V.