This book offers a new interpretation of the origins of Russian Marxism, placing it firmly within the folds of the western European socialist movement. Moira Donald argues that the chief theoretician of German Marxism, Karl Kautsky, was a primary influence on Lenin and the Russian Social Democratic Party, and that only the revolution of 1917 severed the Bolsheviks from mainstream orthodox Marxism.

Donald contends that Lenin's thought was neither original nor especially significant in the development of Marxism, but that his ability lay in adapting his ideas to fit his revolutionary strategy. She places Lenin's writings in their historical context, showing that they were written as individual pieces, each with a specific aim and often directed within the Party. Lenin was a tactician rather than a thinker, says Donald, and even those areas of his thought that seem most original—the party, the rule of the intelligentsia, and imperialism—reveal his significant debt to Kautsky. According to Donald, Lenin was not the only Russian Marxist to borrow ideas from Kautsky: Trotsky's theory of permanent revolution, which was to prove crucial when it was taken up by the Bolsheviks in 1917, was also influenced by Kautsky's thought.

Kautsky's relationship with the Russian Social Democratic Party has been widely underestimated because of the later split between them. Using a wide range of published and unpublished sources, Donald reveals how important Kautsky's role was in formulating the ideology of the Bolsheviks—the only effective revolutionary party in the socialist movement.