The Tension in Wittgenstein's Diagnosis of Scepticism

I argue that Wittgenstein's rejection of scepticism in On Certainty rests on the view that epistemic concepts such as 'doubt,' 'knowledge,' 'justification,' and so on, cannot be intelligibly applied to the common sense propositions that traditional sceptical arguments appear to undermine. I detect two strands in On Certainty in support of this view. I attempt to show that neither of these strands adequately establishes the thesis, and that they point to a tension in Wittgenstein's treatment of scepticism. I argue that the first strand is dogmatic, but accords with the constraints of Wittgenstein's method, while the second strand avoids the dogmatism of the first at the cost of violating these constraints.