A distinguished political sociologist, Richard F. Hamilton is perhaps best known for Who Voted for Hitler? (1982). More recently his attention has shifted to the broader methodolog- ical issues raised by the empirical claims of sociological macrotheories. This critical study of three versions of Marx- ism-the original statement by Marx and Engels and two rival reformulations, by Eduard Bernstein at the end of the nineteenth century and by Lenin during World War I-is to be seen in the light of this concern.