The essay closely investigates and questions the assumptions that Leninist theory is more or less a consistent whole, which must be accepted or rejected in its entirety, and that Bolshevik policy under Tsarism was the direct result of Leninist theory—that Bolshevism and Leninism are synonyms. It tries to determine the position of Lenin’s theory in its historical-materialist context, concentrating on his method of analysis and his theories of proletarian consciousness and the revolutionary party. It then deduces some important internal inconsistencies in Lenin’s methodology and organisational theory, and attempts to prove that Bolshevik practice was in no way Leninist. What then follows is a brief formulation of some consequences.