ABSTRACT
Ludwig Wittgenstein's opinion of G. E. Moore was ambivalent. This chapter considers the relation between Moore's defence of common sense, N. Malcolm's interpretation of it and Wittgenstein's On Certainty. It discusses Wittgenstein's qualms about the ontological conclusion of Moore's proof, namely the statement 'There is an external world'. The chapter then turns to Wittgenstein's reflections on the commonsense premises of the proof, and in particular to his suggestion that these are certain but cannot be known. It addresses Wittgenstein's own line against scepticism, according to which scepticism undermines the very framework within which doubt makes sense. Finally, the chapter recommends another way of responding to scepticism, one which combines Moore's method of differential certainty with Wittgenstein's insights into the special status of hinge propositions. On Certainty consists of selections from hand-written notebooks that date from the beginning of 1950 to Wittgenstein's death in April 1951.
