Guido Carpi's book is a short essay on the history of Russian Marxism - from the early circles to Stalin. In this study, Marxism is considered as an indissoluble unity of practice and theory, formed in tense discussions and political struggle between representatives of different movements (Bolsheviks, Mensheviks, Socialist Revolutionaries, etc.), and the emphasis is on the pre-October period. The Soviet officialdom redrawn this story beyond recognition, and this book is essentially the first attempt at its consistent reconstruction.