The rationale for writing a book about these two authors1 appears to be offered on the very first pages: ‘For the recovery of the empiricist outlook…and for the flowering of this tradition in the first half of the present century, we have mainly to thank the University of Cambridge: and among Cambridge philosophers, in the first instance, Bertrand Russell and G.E.Moore.’ This, then, would seem to be the general plot-the rescue by two brave knights of British thought which ‘had fallen very largely under the spell of Hegel’ (which we also learn on the first page of the first chapter).