＜特別寄稿＞認識論的実在論－懐疑論と認識論の将来に関するウイリアムズの診断－

Abstract

Even after 'the death of epistemology as the first philosophy' was pronounced by Quine or Rorty, Michael Williams, the author of Unnatural Doubts and editor of Skepticism, takes still now epistemological problems raised by skepticism as not pathologic and pseudo-problematic, but authentic and serious in spite of their unnaturalness, which bring new lights to the nature of knowledge by theoretical diagnosis about them. His analyses about Cartesian 'dreaming argument' and 'Agrippa problem' concerning Moore's proposition go to the root of skepticism in the 'epistemological realism', namely hidden presumptions about the priority of the experiential knowledge to the knowledge about the objective world, and its objective status as 'natural kinds' or 'an universal order of representations' in the project of modern epistemology. Williams recognizes this realism in the theory of 'underdetermination' of hypothesis by evidences, which makes skeptical situations like 'brains in a vat' possible. As to the case of dreaming argument, Williams takes the externalist position and the closure of knowledge under known entailment at once, in order to keep the causal relationship between environment and the contents of a belief independent from the logical implication on one side and the restricted validity of the skeptical argument of this type in its context on another side. And 'Agrippa problem' as a difficulty of infinite regress of justification in the case of Moore's proposition forces both 'foundationalism' and 'coherentism' to be fallen into a dilemma, a sort of circularity or idealism without necessary external constraints, so that here also epistemological realism about basic belief as a sort of factual proposition in both epistemology and skepticism should be abandoned. Williams conceives his contextualist model of justification as the third type of epistemology inspired by Sellers-Brandom's 'defect and challenge' language game, in which the reasons of beliefs must be given against opponents about their epistemic responsibility and adequate grounding. It is worth considering at least tentatively Williams's contextualism as a candidate for a contemporary epistemology in the time of pragmatism and naturalism.