The functions of the family in a highly differentiated society are not to be interpreted as functions directly on behalf of the society, but on behal… - Talcott Parsons

Ideology is a system of beliefs, held in common by the members of a collectivity.

A theoretical system does not merely state facts which have been observed and that logically deducible relations to other facts which have also been observed. In so far as such a theory is empirically correct it will also tell us what empirical facts it should be possible to observe in a given set.

Every social system is a functioning entity. That is, it is a system of interdependent structures and processes such that it tends to maintain a relative stability and distinctiveness of pattern and behavior as an entity by contrast with its - social or other - environment, and with it a relative independence from environmental forces. It "responds", to be sure, to the environmental stimuli, but is not completely assimilated to its environment, maintaining rather an element of distinctiveness in the face of variations in environmental conditions. To this extent it is analogous to an organism