Two Roads to Skepticism

Abstract

There are two main roads to skepticism about knowledge of the external world: a low road and a high road. The low road rests on a common but unconvincing philosophical ploy: redefining a key term to gain support for a controversial claim. Many skeptics advance their skepticism by redefining what knowledge is, specifically, by raising the standards for knowledge beyond plausibility. This strategy amounts to a low victory by high redefinition — really no victory at all. And it suffers from all the disadvantages of the fallacy of ignoratio elenchi by redefinition. Notable low-road skeptics include Descartes in the opening Meditations, David Hume, Peter Unger (1975), and Barry Stroud (1984). Part 1 of this paper assesses Stroud’s central argument for skepticism. It shows that the low road is really a dead end, that the low road is altogether ineffective against the nonskeptic.

A version of this paper was presented at the 1989 University of Rochester Conference on Skepticism. Dorit Bar-On was the commentator, and the paper has benefited from her comments as well as from discussion with Robert Audi. Some of this paper draws on my book, Knowledge and Evidence (Cambridge/New York: Cambridge University Press, 1989).