Cultural Revolution: The theory of the Cultural Revolution states that the proletarian revolution and the dictatorship of the proletariat does not wipe out bourgeois ideology—the class-struggle continues and even intensifies during socialism, therefore a constant struggle against these ideologies and their social roots must be conducted. Cultural Revolution is directed also against traditionalism. On Contradiction: Mao drew from the writings of Karl Marx, Friedrich Engels, Vladimir Lenin and Joseph Stalin in elaborating his theory. Philosophically, his most important reflections emerge on the concept of "contradiction". In two major essays, On Contradiction and On the Correct Handling of Contradictions Among the People, he adopts the positivist-empiricist idea (shared by Engels) that contradiction is present in matter itself and thus also in the ideas of the brain. Matter always develops through a dialectical contradiction: "The interdependence of the contradictory aspects present in all things and the struggle between these aspects determine the life of things and push their development forward. There is nothing that does not contain contradiction; without contradiction nothing would exist". Furthermore, each contradiction (including class struggle, the contradiction holding between relations of production and the concrete development of forces of production) expresses itself in a series of other contradictions, some dominant, others not. "There are many contradictions in the process of development of a complex thing, and one of them is necessarily the principal contradiction whose existence and development determine or influence the existence and development of the other contradictions". Thus the principal contradiction should be tackled with priority when trying to make the basic contradiction "solidify".
