The rise to dominance of marginalist economics coincided with a major increase in the spread of socialist ideas. As many socialist and Marxist thinkers were preocuppied with economic questions this was scarcely a development that could be ignored. Socialists either had to defend Marxist economics against marginalist criticism or show that socialism and marginalism were compatible. This volume explores the varied socialist responses in a number of major European countries including Italy, France, Russia and German speaking countries.