1 Review: Disagreement and Skepticism edited by Diego E. Machuca Guy Longworth University of Warwick To a first approximation, a disagreement is a case in which at least one individual believes that p and at least one individual believes that not-p; and a pair of individuals are one another’s peers, with respect to whether p, when and only when they have available to them the same evidence whether p and they possess equivalent epistemic virtues. Suppose that one is involved in a peer dispute. What responses are rationally permitted or required? According to one version of what is known as the Equal Weight View, if one believes that one is involved in such a peer dispute, one is rationally required to give equal weight to (what one knows or believes to be) any of the disputed beliefs that one lacks independent reason to discount. For example, if one believes that p, one knows that one’s peer believes that not-p, and one’s only reason for discounting their belief is one’s own belief that p, then one is rationally required to suspend belief. One question discussed in the collection is whether one or another form of the View is correct. Another concerns what would follow from endorsing the View. Would its acceptance, combined with the prevalence of disagreement in various domains of inquiry, lead to one or another form of scepticism? In recent years, there have been a slew of articles on this theme and two collections of essays. (Christensen and Lackey 2013; Feldman and Warfield 2010.) It would be natural to wonder whether there was a need for this volume. The essays are uniformly lucid and the argumentative moves that are considered are well handled. But I’d like to have seen more reflection on the basic assumptions guiding the various extant discussions. How are participants in the discussions thinking about evidence or reasons, and their bearing on what rationality demands? Are one’s reasons exhausted by what one knows or believes, or can they outstrip both? Is there an operative distinction between genuine reasons and what merely seem to be reasons? If there is, how does it figure in principles governing the dynamics of rationality? In what follows, I’ll briefly summarise what I took, on reading the collection, to be some central problems surrounding the View and its exploitation for sceptical purposes. Let me begin with problems surrounding the view. It’s plausible to assume that one’s reasons for belief supervene on one’s evidence together, perhaps, with one’s epistemic capacity to exploit that evidence. Now suppose that a peer is someone with the same evidence and epistemic capacity, and that one is in disagreement with such a peer. It seems that at least one disputant must be going beyond the evidence, at least on the assumption that the evidence can’t determine that it’s the case that p and determine that it’s the case that not-p. Suppose that the evidence decides in favour of only one of the disputant’s beliefs. In that case, the