In his new book The Idea of Justice, Amartya Sen argues that political theory should not consist only in the characterisation of ideal situations of perfect justice. In so doing, Sen is making, within the context of political theory, a similar argument to another he also made in economic theory, when crtiticising what he called the ?rational fool? of mainstream economics. Sen criticised the ideal and fictitious agent of mainstream economics, while advocating for a return to an integrated view of (...) ethics and economics, which characterised many classical political economists who inspired Sen's theory of justice, from Adam Smith to Karl Marx. I will examine Sen's revival of classical political economy, and argue that a revival of classical political economy, which was undertaken earlier by Piero Sraffa, has much potential for bringing a more plural and realist perspective to economics. (shrink)