Piero Sraffa (1898-1983): who was this Italian economistmostly unknown for the big public, who characterized the Europeanthought not merely in political economy, but also in philosophy andpolitical theory ? Fully a man of his times, Sraffa left a mark onhis contemporaries and gave birth to the neo-ricardian school whichover the last 50 years continued the Prelude to a Critique ofEconomic Theory laid down by the Italian economist. This bookprovides a biography, a discussion of his contribution and athematic section about the contacts Sraffa had with three importantfigures of the last century: J.M.Keynes, L.Wittgenstein andA.Gramsci.