Kautsky was considered the premier Marxist theoretician after the death of Marx and Engels and the 'pope of Marxism'. His intellectual work was instrumental in the Second International and Orthodox Marxism.
Lenin was a prolific political theoretician and philosopher who wrote about the practical aspects of carrying out a proletarian revolution; he wrote pamphlets, articles, and books, without a stenographer or secretary, until prevented by illness.[1] He simultaneously corresponded with comrades, allies, and friends, in Russia and world-wide. His Collected Works comprise 54 volumes, each of about 650 pages, translated into English in 45 volumes by Progress Publishers, Moscow 1960–70.[2]
^Триумф и Трагедия – И. В. Сталин: политический портрет. (Triumph and Tragedy – I. V. Stalin : A Political Portrait) Дмитрий Волкогонов (Dmitri Volkogonov). Book 1, Part 1, p. 110. Новости Publications. Moscow. 1989.