Recent Work on Radical Skepticism

This discussion surveys recent developments in the treatment of the epistemologi-cal problem of skepticism. These are arguments which attack our knowledge of certain truths rather than, say, our belief in the existence of certain entities. In particular , this article focuses on the radical versions of these skeptical arguments, arguments which purport to show that knowledge is, for the most part, impossible, rather than just that we lack knowledge in a particular discourse. Although most of the key recent developments in this area have taken place since the late 1980s and early 1990s, it is necessary to also discuss some of the movements that have developed since 1970 in order to give these recent developments the necessary setting. The date of 1970 is dictated by the publication in that year of Fred Dretske's seminal article " Epistemic Operators , " which both pushed a " relevant alternatives " theory of knowledge to the fore of discussion and also brought into focus one possible line of argument against the so-called " closure " principle for knowledge. In so doing, it provided one of the main sources of response to the emergent interest in the " infallibilist " motivation for radical skepticism, as expressed by, for example, Peter Unger (1971; 1975). As argued below, this relevant alternatives model was developed along two extremely influential lines in subsequent discussion. On the one hand, we find the first wave of relevant alternatives theorists that includes Dretske (1971) himself and Robert Nozick (1981), who both advocate a modal theory of knowledge that results in the rejection of the principle that knowledge is " closed " under known entailment (the so-called " closure " principle for knowledge). On the other hand, we have the later wave of relevant alternatives theorists, and in particu-, who opt for an explicitly contextualist thesis that retains closure. This type of theory in turn evolved into the kind of sophisticated con-textualism (henceforth, " semantic " contex-tualism) advocated by such figures as Keith DeRose (1995), David Lewis (1996) and Cohen himself that is currently in vogue in the literature. Due to its dominance in the recent debate , this relevant alternatives movement in contemporary epistemology will be the focus for this discussion. Nevertheless, this