" The trade unionist tends to regard the intellectual as a utopian theorist lacking experience in the practical problems of the movement. The intellectual condemns the trade union leader as a bureaucrat. The recurrent conflicts between factions within the Bolshevik party in Soviet Russia were in part, at any rate, explicable as conflicts between the "party intellectuals", represented by Bukharin, Kamanev, Radek and Trotsky, and the "part machine" represented by Lenin, Sverdlov and Stalin. "

― Edward Hallett Carr , The Twenty Years' Crisis, 1919-1939: An Introduction to the Study of International Relations