This book surveys revolutionary socialist ideas and engages a gallery of contentious political thinkers, offering an indispensable assessment of the place of revolutionary collectives in this radical tradition. Beginning with a broad and informative survey of scholarship on V.I. Lenin and “Leninism,” Le Blanc goes on to explore the multifaceted “collective” qualities of the Russian Bolshevik organization. He then turns his attention to several of its central figures as well as a rich variety of activist-intellectuals who in one way or another continued to engage with Lenin’s perspectives after his death, including Leon Trotsky, Alexander Bogdanov, Georg Lukács, Antonio Gramsci, Rosa Luxemburg, Karl Korsch, and Daniel Bensaïd. The volume concludes by considering related questions which have more recently posed problems within left-wing organizations, gesturing toward the dynamics and needs of future struggles.