G. E. Moore's ‘A Defence of Common Sense’ has generated the kind of interest and contrariety which often accompany what is new, provocative, and even important in philosophy. Moore himself reportedly agreed with Wittgenstein's estimate that this was his best article, while C. D. Broad has lamented its very great but largely unfortunate influence. Although the essay inspired Wittgenstein to explore the basis of Moore's claim to know many propositions of common sense to be true, A. J. Ayer judges its (...) enduring value to lie in provoking a more sophisticated conception of the very type of metaphysics which disputes any such unqualified claim of certainty. (shrink)