Encyclopedia - Yahoo! Reference: "In theory dialectical materialism is meant to provide both a general world view and a specific method for the investigation of scientific problems. The basic tenets are that everything is material and that change takes place through 'the struggle of opposites.' Because everything contains different elements that are in opposition, 'self-movement' automatically occurs; the conflict of opposing forces leads to growth, change, and development, according to definite laws. Communist scientists were expected to fit their investigations into this pattern, and official approval of scientific theories in the USSR was determined to some extent by their conformity to dialectical materialism (see Lysenko, Trofim Denisovich). Use of these principles in history and sociology is sometimes called historical materialism. Under these doctrines the social, political, and intellectual life of society reflect only the economic structure, since human beings create the forms of social life solely in response to economic needs. Men are divided into classes by their relations to the means of production�land and capital. The class that controls the means of production inevitably exploits the other classes in society; it is this class struggle that produces the dynamic of history and is the source of progress toward a final uniformity. Historical materialism is deterministic; that is, it prescribes that history inevitably follows certain laws and that individuals have little or no influence on its development. Central to historical materialism is the belief that change takes place through the meeting of two opposing forces (thesis and antithesis); their opposition is resolved by combination produced by a higher force (synthesis). Historical materialism has had many advocates outside the Communist world"