Abstract

This chapter addresses an ambiguity in some of the literature on rational peer disagreement about the use of the term 'rational'. In the literature 'rational' is used to describe a variety of normative statuses related to reasons, justification, and reasoning. This chapter focuses most closely on the upshot of peer disagreement for what is rationally required of parties to a peer disagreement. This follows recent work in theoretical reason which treats rationality as a system of requirements among an agent's mental states. It is argued that peer disagreement has either no, or a very limited, affect on what rationality requires of an agent in a given circumstance. This is in part because of difficulties generated by a novel example of evidence of evidence of p being evidence against p. This example calls into question the mechanisms whereby peer disagreement might affect what is rationally required of an agent. The chapter also reevaluates the importance of actual peer disagreement against the backdrop of prior expectations about whether disagreement is believed to be likely, arguing that peer disagreement is most likely to change what is rationally required of an agent when it is believed to be unlikely.