People of the Revolution and the USSR
- Ferdinand Lassalle Ferdinand Lassalle Founder of the ADAV, Germany's first workers' party
- Vera Ivanovna Zasulich Вера Ивановна Засулич From a narodnik revolver to Marxist criticism, half a century of one woman's revolutionary life
- Eduard Bernstein Eduard Bernstein Founder of Marxist revisionism and evolutionary socialism, author of The Preconditions of Socialism
- Karl Johann Kautsky Karl Johann Kautsky Chief theoretician of orthodox Marxism in the Second International, founding editor of Die Neue Zeit, editor of Marx's Capital Vol. IV
- Lev Grigorievich Deitch Лев Григорьевич Дейч Co-founder of the Emancipation of Labour group and a Menshevik pioneer at the origins of Russian Marxism
- Georgi Valentinovich Plekhanov Георгий Валентинович Плеханов The father of Russian Marxism: against his own pupils’ revolution
- Alexander Lvovich Parvus Александр Львович Парвус Co-author of permanent revolution who arranged Lenin's sealed train: the 'merchant of revolution'
- Väinö Voionmaa Väinö Voionmaa A historian who linked scholarship with social democracy
- Sergei Nikolayevich Bulgakov Сергей Николаевич Булгаков The Marxist economist who became a priest and built the theological system of Sophia
- Nikolai Nikolaevich Sukhanov Николай Николаевич Суханов Author of 'Notes on the Revolution' and agrarian economist in whose apartment the Bolshevik CC voted for armed uprising
- Pitirim Alexandrovich Sorokin Питирим Александрович Сорокин SR leader imprisoned by both Tsar and Bolsheviks, who became founder of Harvard's sociology department
- E. H. Carr E. H. Carr Author of the 14-volume History of Soviet Russia; diagnosed a "latent incompatibility" between NEP markets and planning
- Roderick MacFarquhar Roderick MacFarquhar Harvard sinologist whose Origins of the Cultural Revolution trilogy and Mao’s Last Revolution dissected China’s elite politics
- Samuel Farber Samuel Farber American sociologist who reopened the debate on the Cuban Revolution