Marxism-Leninism reveals the universal laws governing the development of history of human society. It analyzes the contradictions inherent in the capitalist system that it is incapable of resolving internally and shows that socialist society will inevitably replace capitalist society and ultimately develop into communist society. Karl Marx and Friedrich Engels cofounded the theory of the proletarian political party, in which they expounded the basic tenets of the Marxist theory of party building and laid the theoretical basis for building the proletarian party. This constitutes the first monument of the Marxist theory of party building. In his practical work of leading the socialist revolution and construction in Russia, Lenin both adhered to the basic tenets of the Marxist theory of party building and creatively solved a series of new problems arising in the building of the proletarian party. His foremost achievement was the creation of a preliminary theory for the building of the proletarian party in office, which constitutes the second monument of the Marxist theory of party building.
The Chinese Communists have untiringly striven to integrate Marxism with the concrete practice in China and adapted it to Chinese conditions. Combining Marxism-Leninism with the concrete practice of the Chinese revolution, the first generation of the CPC's central collective leadership, with Comrade Mao Zedong as its core, settled such basic questions as the nature, motive force and object of the new-democratic revolution and the road to socialism in China. And Mao Zedong Thought was thus established, which is Marxism-Leninism applied and developed in China. Mao Zedong Thought consists of theoretical principles concerning the revolution and construction in China, which have been proved correct by practice, and the lessons of experience learned therein; and it constitutes the crystallized, collective wisdom of the CPC. On the basis of the Marxist-Leninist theory of party building and China's specific conditions, Mao Zedong established the theory for building a proletarian party in a semi-colonial, semi-feudal society constituted mainly of peasants and petty bourgeoisie. The most outstanding contributions Mao Zedong made to the Marxist theory of party building are: First, he placed great emphasis on the purpose of building the Party, which is to serve the people wholeheartedly; and second, he attached great importance to improving the Party's style of work and insisted that the Party be built ideologically first. Mao Zedong's theory of party building is the first historic leap of the Marxist theory of party building in China.