This is a central historical concept of Structural Transformation of the Public Sphere. The relationship between public and private is dynamic and complex. Habermas traces the two concepts back to ancient Greece, then through the hierarchical world of the Middle Ages, where public and private had no separate existence. Only with the development of a modern state and economy did public and private assume their currently recognized form. “Public” relates to public authority the state, while “private” relates to the economy, society, and the family. “Public” and “private” are defined and separated in terms of law, and of institutions. There are characteristic functions of the public and private realms. The public sphere exists as part of the private world that moves into the public domain.

The key shift in the modern world is the loss of the distinction between the two terms. Interest groups from either side of the public-private divide operate together. Public and private are replaced by one massive “societal” complex that is in some respects like the feudal state of the Middle Ages. When this happens, the public sphere in its traditional form is no longer possible.