The concept of degrees of uncertainty in Keynes, Shackle, and Davidson

The aim of this piece is to discuss in what extent one can find - in the works of Shackle and Davidson - an understanding of uncertainty capable of both comprehend the concept of probable knowledge and admit the existence of degrees of 'true uncertainty'. Sharing the opinion of other scholars (Runde, 1990; Dow, 1995, and Dequech, 1997), we think that it is possible to find this definition of uncertainty in Keynes's works, and so make a point to the understanding of uncertainty as a concept feasible to be graded. Moreover, we claim that this concept is not incompatible with the understanding of the social reality as a nonergodic process. To sustain this claim, we will discuss Davidson's and Shackle's views and show that in their writings there are some elements that support our main point.