 It also a fact of life that humans disagree with each other. How should an agent modify her credences (if at all) when she disagrees on some claim with an epistemic peer—someone who has the same evidence as her, and whom she regards as equally good at evaluating that evidence? The literature on this topic is huge (see Kopec and Titelbaum (2016) for a survey, and the entry on  disagreement),  and it connects in important ways with the interpretations of probability. Intuitively, we feel that disagreement with an epistemic peer rationally calls for moving one’s opinion in the direction of theirs, since disagreement with a peer seems to be evidence that one has made a mistake in evaluating one’s initial evidence. As Kelly (2010) argues, this ‘conciliationist’ intuition appears to commit us to the evidential interpretation of probability, with the common evidence bestowing a unique probability on the disputed claim. (See Titelbaum 2016 for dissent; for a recent defense of the Uniqueness Thesis more generally, see Horowitz and Dogramaci 2016; for a recent criticism, see Schoenfield 2014.) The intuition also appears to commit us to probabilistic enkrasia: the view that our credences are beholden to our attitudes about evidential probabilities, in much the same way as the Principal Principle portrays our credences as beholden to our attitudes about chances. (See Christensen 2013 and Elga 2010 for versions of probabilistic enkrasia principles.) Let’s grant that disagreement with a peer about some claim is evidence that one has made a mistake regarding it. This should affect one’s opinion in it only if one’s attitude about the correct way to evaluate the evidence constrains one’s attitude about the claim. However, probabilistic enkrasia has been criticised (see Williamson 2014; Lasonen-Aarnio 2015). 