The Claims of Common Sense investigates the importance for the social sciences of the ideas developed in Cambridge philosophy between the two World Wars. John Coates examines the thought of Moore, Ramsey, Wittgenstein and Keynes, and offers new evidence that there was a far closer collaboration among them than has hitherto been supposed. He then proposes that Wittgenstein’s and Keynes’s ideas on the economy of ordinary language present a way of bridging the current gap between the philosophy and practice of social science.