Isaak I. Rubin, author of numerous works in Marxist theory, explains the failure of the Austrian School's attempt to reduce political economy to individual psychology. Emphasising the sociological dimension of Marx's work, Rubin welcomes a new 'social direction' in the writings of Rudolf Stolzmann, Alfred Amonn and Franz Petry. These economists rejected Austrian individualism, but their works were often influenced by the ethical idealism of Kant and Hegel, resulting in detachment of the economy's social form from the material process of production. Rubin critically explores methodological differences between Marx and early twentieth-century critics and proponents of marginalist economic theory.