This ambitious book presents a complete spectrum of interpretations of Marx's economic theory and methodology. Informed by the current debate on the foundations of economic theory, the main emphasis is on analytical and textual argument to the rigorous exclusion of "ideological" debates. It presents new work by major scholars in the field including amongst others Mark Blaug, Walter Eltis, Samuel Hollander, Bruno Jossa, Giovanni Caravale and Pierangelo Garegnani. The diverse analytical threads are connected to present a coherent picture of some central aspects of Marx's theory. The book courses on Marxian economics, the history of economic thought, economic doctrines and advanced economic theory.