Karl Marx viewed social conflict not merely as an occasional disruption but as the fundamental driving force behind all historical development and social change. His theory, known as historical materialism, posits that the primary determinant of social structure and change is the economic organization of society, specifically the 'mode of production.'

Marx argued that every historical epoch is characterized by a specific mode of production (e.g., feudalism, capitalism), which consists of the 'forces of production' (technology, labor, resources) and the 'relations of production' (the social organization of labor, property ownership, and class relations). In every class-based society, these relations of production inherently create antagonistic interests between different social classes.

Under capitalism, this fundamental conflict exists between the bourgeoisie (the owning class, who control the means of production) and the proletariat (the working class, who own only their labor power). The bourgeoisie exploits the proletariat by extracting surplus value from their labor, paying them less than the value they create. This inherent exploitation and inequality lead to a fundamental contradiction within the capitalist system.

Marx believed that this class struggle is not just an incidental feature but an essential, inevitable, and ultimately revolutionary element. As the forces of production develop, they eventually come into conflict with the existing relations of production. For example, capitalism's drive for efficiency and accumulation leads to the concentration of wealth and the immiseration of the working class, creating conditions for heightened class consciousness among the proletariat. This growing awareness of their shared exploitation and common interests transforms the 'class in itself' (a group sharing a common economic position) into a 'class for itself' (a group organized and conscious of its revolutionary potential).

Social change, according to Marx, occurs when these contradictions and conflicts reach a critical point, leading to a revolutionary overthrow of the existing social order. The proletariat, through revolution, would seize the means of production, abolish private property, and establish a classless, communist society. This revolutionary conflict is not destructive in a purely negative sense; rather, it is a necessary and progressive step in the historical evolution of society, leading to a higher, more equitable stage of human development. Thus, for Marx, social conflict, particularly class struggle, is the engine of history, constantly pushing societies from one mode of production to the next.