Vladimir Ilyich Lenin, soon after he made his acquaintance with Marxism, became a disciple of Plekhanov. Plekhanov was widely respected, perhaps revered, by many of the generation of the 1890s who increasingly turned to Marxism, and who formed the basis of the Marxist groups which sprang up on Russian soil. Lenin's eventful revolutionary career and his theoretical development and innovations have been the subjects of many histories and interpretations, not all of which sufficiently emphasize his debt to Plekhanov. I propose simply to examine the theoretical work of Lenin in so far as it relates to the question of opposition; a question which arises sharply in the debates over the issue of party organization, around 1902–4, and in the debates over the political organization of the Soviet state after 1917. In both debates, and during both periods, and probably for his entire revolutionary career, Lenin consistently held two positions which coloured his views about everything else. The first position was that he alone, and often with his faction of Russian Social Democracy (although sometimes against it), embodied and represented the true interests of the proletariat. This position was not negotiable. The second was that any and all opposition to Lenin, on almost any matter, was class, that is, non-proletarian or bourgeois, opposition. Lenin adopted, at times, a more flexible approach to his opponents than this position might suggest; but the non-proletarian nature of opposition was implicit in all of Lenin's alliances and tactical manoeuvres.