Calibrated probabilities and the epistemology of disagreement

The epistemology of disagreement concerns the normative question of how you ought to revise your beliefs in a very specific epistemic context. Imagine that you and a peer form an opinion in isolation about whether P in response to mutually shared evidence, and you take your peer to be just as reliable as you about matters of this kind. How are you to respond should you subsequently discover that your peer disagrees with you? Advocates of the Equal Weight view state that in light of known peer disagreement about whether P, you ought to revise your opinion in such a way as to “split the difference” between your own view and that of your peer’s. Let us call this the Equal Weight rule, or EWR. At another extreme, a Stay the Course view advocates a rival rule, which we will call STC, where in light of known peer disagreement alone, you ought not revise your previously held opinion about whether P. Since STC only advocates maintaining an existing opinion in light of new 1 [Feldman, 2006], [Christensen, 2007], [Elga, 2007] 2 [Kelly, 2005] A more moderate view in the same spirit as the Stay the Course view, is defended in [Kelly, 2009]. Kelly’s concern is not primarily the advocacy of a rule like STC that applies in full generality to all cases of known peer disagreement. Rather for Kelly, considerations of who was the most rational in forming the original opinion about the matter can permit Staying the Course or something very close in some cases of known peer disagreement.