Hume's Skepticism with Regard to Reason

This chapter examines in detail Hume's most radical skeptical argument, one intended to show that reasoning, when allowed to pursue its own principles without restraint, will inevitably destroy all beliefs based upon reasoning. The key ideas in Hume's argument are, first, that reflections on the fallibility of our rational faculties will reduce all claims to demonstrative knowledge to questions of probability; second, that further reflections on human fallibility lower the level of probabilities themselves until, finally, through reiterating these diminutions, the level of confidence in our original knowledge will be reduced, as Hume puts it, to nothing. The chapter spells out this argument, evaluates it, and, though rejecting it, points out its centrality in Hume's reflections.