Marx, in his theory of historical materialism, argues that political and historical events result from the conflict of social forces. His theory focuses on class struggles and human attempts to control and dominate the natural environment. The profits obtained by capitalists result from the exploitation of workers. This conflict will lead to a revolution in which workers control the state. Thus, capitalism will be replaced by socialism. The result is freedom for all. In the Soviet Union, the lower class overthrew the ruling class and created a new mode of production. This new economic base then determined the political, social and ideological changes in its society. The failure of the Soviet Union impacts the validity of Marxist historical materialism because it discredits materialist ideas.