In my book on Probability and social science, I thought that Ramsey laid the foundations of the subjective approach to probability, while Kolmogorov axiomatized objective probability and Keynes laid the foundations of the logicist approach to probability.
Curiously Keynes abandoned a number of his ideas on probability after Ramsey's critique. However with Jeffreys and Cox this epistemic approach became the leading one.
It is not well established why Keynes abandoned this epistemic approach after Ramsey's criticisms. May be while Keynes believed that his probability theory faced theoretical difficulties, he was however dissatisfied with Ramsey's inability to distinguish between personal opinion and rational belief.