The sources of scepticism

It is claimed that the radical sceptical problem that is the focus of much of contemporary epistemological discussion in fact divides into two logically distinct sub-problems - a formulation that turns on the closure principle and a second formulation which turns on the underdetermination principle. The Wittgensteinian account of the structure of rational evaluation is set out, and it is shown how this proposal - at least when properly formulated - can deal with closure-based radical scepticism. It is also claimed, however, that this account fails to gain any purchase on underdetermination-based radical scepticism. The antidote to this latter form of radical scepticism lies elsewhere - with, it is suggested, epistemological disjunctivism.