From evidence to underdetermination : essays in the way of scepticism

Abstract

Scepticism about justification is the view that justification is impossible. Underdetermination scepticism is scepticism that turns on the idea that our beliefs are underdetermined by the evidence relative to certain sceptical hypotheses. This thesis provides an elucidation and a defence of underdetermination scepticism on an evidentialist framework for justification and a mentalist conception of evidence. The thesis consists of five chapters and a conclusion. Chapter 1 introduces the Underdetermination Argument for scepticism and explains the core concepts of the thesis. Chapter 2 explores the relationship between closure and underdetermination scepticism. Chapter 3 responds to the Infallibility Objection, the idea that the Underdetermination Argument is a bad argument because the inference from sameness of evidence to underdetermination presupposes infallibilism. Chapter 4 responds to the charge that the Underdetermination Argument relies on excessive demands on the cognitive accessibility of evidence. Chapter 5 responds to attempts to resist scepticism on the ground that it is a Moorean fact that our beliefs are justified. The conclusion reviews and generalizes the results of the previous chapters. The upshot is that a significant set of objections against underdetermination scepticism fails. At the end of the day, we might have to take the possibility of living with scepticism seriously – or at least more seriously than we thought.