Russian Marxism is the outcome of two distinct traditions, namely, nineteenth-century Russian radicalism and Western European Marxism. In this paper I shall briefly trace its descent from these traditions and try to distinguish those features of it which differentiate it both from the older radicalism and from the Marxism of Marx and Engels. I shall deal in turn with three main topics, the nineteenth-century radical tradition, early Russian Marxism, and finally, Leninism.

I propose in this article to reconsider, in the light of some recent developments in the theory of knowledge, certain general questions about the nature of duty. In particular, I propose to consider the question of the relation between our moral duties on the one hand, and our knowledge or ignorance of facts and of moral principles on the other.