People and social systems strive, in their self-presentation, as we have already shown, to draw a consistent picture of themselves and make it socially accepted. Since other people and social systems also have an interest in building up reliable expectations with regard to the people around them, in seeing them as enduring identities, there develops in social intercourse a type of expressive language which enables actions to be attributed to people or social systems, and not only causally but, indeed, also symbolically, as expressing their essence, their self.

Niklas Luhmann, Trust and Power, loc. 292