A discussion between Wittgenstein and Moore on certainty (1939): From the notes of Norman Malcolm

In April 1939, G. E. Moore read a paper to the Cambridge University Moral Science Club entitled 'Certainty '. In it, amongst other things, Moore made the claims that: (i) the phrase 'it is certain' could be used with sense-experience-statements, such as 'I have a pain', to make statements such as 'It is certain that I have a pain'; and that (ii) sense-experience-statements can be said to be certain in the same sense as some material-thing-statements can be-namely in the sense that they can be safely counted on. When Moore later read his paper to Wittgenstein, Wittgenstein took violent exception to it, and the two entered into a heated exchange. The only known notes of this exchange are a previously unpublished verbatim record of part of it, taken by Norman Malcolm. This paper is an edition of Malcolm's notes. These notes are valuable for both philosophical and scholarly reasons. They give us a glimpse of a sustained exchange between Wittgenstein and a real-life interlocutor; they contain a defence by Wittgenstein of the idea that a word's use can illuminate its meaning; and they provide evidence of Wittgenstein's philosophical engagement with the topic of certainty, and with Moore's thought on it, long before he began to write the notes which make up On Certainty, in 1949.