Groundless knowledge : a Humean solution to the problem of skepticism

Abstract: The aim of the present study is to develop a solution to the problem of skepticism about the external world ("skepticism", for short), inspired primarily by Hume's "skeptical solution" to the problem of skepticism about induction, but also by epistemological externalism and Wittgenstein's discussion of skeptical doubts in On Certainty. The author accepts certain elements in P. F. Strawson's interpretation of Hume and Wittgenstein, but rejects the "psychological" argument against skepticism which Strawson ascribes to the two philosophers.The problem of skepticism is understood as that of showing that we can know what we in common sense claim to know about external objects, despite skeptical arguments to the contrary. A "moderate" skepticism is accepted, according to which it is possible that we are globally mistaken in our beliefs about external objects, and it is argued that there is in fact no conflict between this moderate skepticism and common sense. A distinc-tion is drawn between two types of "strong" skepticism, which does conflict with common sense: prescriptive skepti-cism, the recommendation to abandon our common sense ways of forming beliefs, by suspend-ing judgement or in other ways; and theoretical skepti-cism, the thesis that we can have no rational grounds for our beliefs about external objects. An argument against prescriptive skepticism is devel-oped, according to which each of three possible forms of prescriptive skepticism is unacceptable. An externalist argument against theoreti-cal skepticism is developed, according to which it is suffi-cient for knowledge that one is in fact not globally mis-taken, whether or not one has grounds for believing this to be the case. It is argued that this variant of externalism constitutes a form of natu-ralistic epistemology, and that it as such fills a gap in Quine's argument for the natu-ralization of epistemology. An interpretation of On Certainty is defended, according to which Wittgen-stein accepts a form of moderate skepticism and presents an argu-ment against strong skep-ticism similar to Hume's.