Epistemically different epistemic peers

Abstract

As an inescapable part of our lives, disagreement has been widely debated in philosophy over the past fifteen years. More precisely, epistemologists have been focusing on whether reasonable disagreement between two agents who are – or who, at least, recognize each other as being – peers on a proposition p is possible, i.e. whether rationality standards allow both the agents to steadfastly hold on to their initial credence on p or they require them to conform to a common credence, upon discovering the disagreement. Call these positions, respectively, the non-conformist and the conformist view. Some support for the latter might come from the field of information economics in which a substantial body of literature (Aumann 1976, Polemarchakis & Geneakoplos 1982) shows that, if two agents under spe- cific circumstances don’t adopt a common credence upon discovering the disagreement on p, then at least one if them is irrational. In this essay, I claim that the disagreement formally described in information economics can be considered as a case of peer disagreement. Firstly, I argue that the epistemic agents as they are characterized in Aumann’s formal result are peers and, in doing so, I put forward a formal definition of peerhood. Secondly, I show that the technical requirements with which the epistemic agents as described by Aumann have to comply don’t undermine their being peers nor do they interfere with the standard disagreement narrative. Thirdly, I claim that the peer disagreement cases for which Aumann’s theorem holds not only tell against the nonconformist view, but that also show the limitations of some of the extant replies within the conformist position.