Jonathan Vogel

Crispin Wright tried to refute classical 'Cartesian' skepticism contending that its core argument is extendible to a reductio ad absurdum (_Mind<D>, 100, 87-116, 1991). We show both that Wright is mistaken and that his mistakes are philosophically illuminating. Wright's 'best version' of skepticism turns on a concept of warranted belief. By his definition, many of our well-founded beliefs about the external world and mathematics would not be warranted. Wright's position worsens if we take 'warranted belief' to be implicitly defined by the general principles governing it. Those principles are inconsistent, as shown by a variant of Godel's argument. Thus the inconsistency Wright found has nothing to do with the special premises of Cartesian skepticism, but is embedded in his own conceptual apparatus. Lastly, we show how a Cartesian skeptic could avoid Wright's critique by reconstructing a skeptical argument that does not use the claims Wright ultimately finds objectionable.

Michael WiIliams maintains that skepticism about the extemal worId is vitiated by a commitment to foundationalism and epistemological realism. (The latter is, approximately, the view that there is such a thing as knowledge of the extemal world in general, which the skeptic can take as a target). I argue that skepticism is not encumbered in the ways Williams supposes. What matters, first of all, is that we can’t perceive the difference between being in an ordinary environment and being in the sort of situation the skeptic describes (e.g. having one’s brain manipulated by deceitful experimenters). This point can be upheld without embracing any substantial foundationalist tenet, such as the existence of basic beliefs, the availabiIity of something “given,” or the epistemic priority of experience. As to “epistemological realism,” I find that Williams has offered no principled way to distinguish between ordinary chaIIenges to knowledge and skeptical challenges which, supposedly, have no cIaim on our concem.