Undercutting Underdetermination‐Based Scepticism

Abstract According to D uncan P ritchard, there are two kinds of radical sceptical problem; the closure‐based problem, and the underdetermination‐based problem. He argues that distinguishing these two problems leads to a set of desiderata for an anti‐sceptical response, and that the way to meet all of these desiderata is by supplementing a form of W ittgensteinian contextualism (which can undercut the closure‐based problem) with disjunctivist views about factivity (to undercut the underdetermination‐based problem). I agree that an adequate response should meet most of the initial desiderata P ritchard puts forward, and that some version of W ittgensteinian contextualism shows the most promise as a starting point for this, but I argue, contra P ritchard, that the addition of disjunctivism is unnecessary and potentially counter‐productive. If we draw on lessons from M ichael W illiams's inferential contextualism then it is both possible, and preferable, to meet the most important of P ritchard's desiderata, undercutting both closure‐based and underdetermination‐based sceptical problems in a unified way, without the need to resort to disjunctivism.