These terms were first coined by the British sociologist David Lockwood, in order to indicate what he saw as fundamental problems in both the normative functionalist theories of the 1950s, and the conflict theories of writers such as Ralf Dahrendorf and John Rex, which set out to criticize functionalist approaches.
Social integration refers to the principles by which individuals or actors are related to one another in a society; system integration refers to the relationships between parts of a society or social system. Despite the use of the word ‘integration’ there is no assumption that the relationships so described are harmonious. The terms social integration and system integration can embrace both order and conflict, harmony and contradiction.
The major source of social integration which sociologists have identified in advanced capitalist societies is the class system. In feudal society, the system of estates played an equivalent role, as did caste in Indian society. In general (and following Max Weber's precepts about social stratification), status-based societies are likely to lead to harmonious forms of social integration, and class societies to conflictual forms of social integration. System integration, on the other hand, is a reference to the way in which different parts of a social system (its institutions) interrelate. Any adequate macrosociological theory of change must attempt to link social integration with system integration. However, in Lockwood's original essay on social integration and system integration, he noted how conflict theorists emphasize the conflict between groups of actors as the basic motor of social change, while normative functionalists downplay the role of actors and seek to emphasize the (functional or dysfunctional) relationships between the institutions of society. For Lockwood, neither approach is adequate, precisely because each deals with only one side of the agency versus structure problem or couplet. The task of sociological theory is to overcome this dualism.
Beyond this, Lockwood's distinction points to those crucial features which need to be examined in any theory of social change. To illustrate this he notes how Karl Marx's theory of capitalist society refers to growing class antagonisms (social integration) which are related to the contradictions between the forces of production and the relations of production (system integration). That is, for Marx, system contradictions are linked to the actions of groups who respond to the contradictions by seeking to change or preserve the existing society. It is contradictions at the system level which lead to social (class) conflict: system integration is related to social integration. More recently, Anthony Giddens has also sought to use this distinction. Initially he employed it in a similar manner to Lockwood, but in his more recent work he seeks to use it as a way of replacing the micro versus macro distinction (and, thereby, the problems of agency and structure). Social integration comes to refer to situations where actors are physically ‘co-present’ and system integration to where they are not. This is unsatisfactory because face-to-face interactions (co-presence) are not confined to micro-processes. (Consider, for example, a meeting in Britain between the Secretary of State for Employment and the General Secretary of the Trades Union Congress, to discuss industrial relations law.)