In a new major work of critical recollection, Dimitris Milonakis and Ben Fine show how economics was once rich, diverse, multidimensional and pluralistic. The book details how political economy became economics through the desocialisation and dehistoricisation of the dismal science, accompanied by the separation of economics from other social sciences, especially economic history and sociology. It ranges over the shifting role of the historical and the social in economic theory, the shifting boundaries between the economic and the non-economic, all within a methodological context. Schools of thought and individuals, that have been neglected or marginalised, are treated in full, including classical political economy and Marx, the German and British Historical Schools, American institutionalism, Weber and Schumpeter and their programme of Sozialökonomik , and the Austrian School. Developments within the mainstream tradition from marginalism through Marshall and Keynes to general equilibrium theory are also scrutinised, and the clashes between the various camps from the famous Methodenstreit of the 1880s to the fierce debates of the 1930s and beyond brought to the fore.