Leninism

Political doctrine based on Marxism as developed by Vladimir Ilich Lenin. It emphasized the role of the revolutionary party guided by the "correct" theory in the Communist seizure and consolidation of power. Party members would be professional and class-conscious revolutionaries organized on the basis of "democratic centralism" whose tasks would be to bring revolutionary consciousness, discipline, organization, and Marxist theory to the working class, to provide "a concrete analysis of the concrete situation". Without such a centralized party, the proletariat would never go beyond the limitations of "economic struggles" such as strikes for higher wages. After the seizure of power, the party would establish the "dictatorship of the proletariat"—in practice, the dictatorship of the party purporting to speak on behalf of that class—and rule the country until the completion of the transition to socialism.

After the establishment of the Communist International (the Third International), these organizational principles—the product of specific Russian conditions which had forced revolutionaries into clandestinity—were adopted by all Communist parties. The Leninist canon was absorbed into Marxism as "Marxism-Leninism" and was reinterpreted in various and contrasting ways by Lenin's followers, including Antonio Gramsci, Joseph Stalin, Leon Trotsky, and Mao Zedong. Since then, Leninism has been associated with orthodox, centralist forms of Communism.

Leninism also contributed a theory of imperialism, originally devised in 1916 and seeking to explain the causes of World War I. This theory held that the consequence of the long-term tendency for the rate of profit to fall led capitalists to form cartels and develop "monopoly capitalism", whose most prominent feature was the integration of financial and industrial capital. Accordingly, this new imperialist stage of capitalism saw the acquisition of colonies, the division of the world among the main European powers, and the ensuing conflicts between them which led to the war.