Such discussions served as a counterweight to political authority and happened physically in face-to-face meetings in coffee houses and cafes and public squares as well as in the media in letters, books, drama, and art.

It also satisfied the rigorous requirements for a professorship in Germany; in this system, independent scholarly research, usually resulting in a published book, must be submitted, and defended before an academic committee; this process is known as Habilitationsschrift or habilitation.

This first major shift occurred alongside the rise of early non-industrial capitalism and the philosophical articulation of political liberalism by such thinkers as Hobbes, Locke, Montesquieu (See: The Spirit of the Laws), Rousseau, and then Kant.

The second part of Habermas' account traces the transition from the liberal bourgeois public sphere to the modern mass society of the social welfare state.

Paralleling this philosophical progression against classical liberalism were major socio-economic transformations based on industrialization, and the result was the rise of mass societies characterized by consumer capitalism in the twentieth century.

This shift, according to Habermas, can be seen as part of a larger dialectic in which political changes were made in an attempt to save the liberal constitutional order, but had the ultimate effect of destroying the bourgeois public sphere.

[4] Habermas drew on the cultural critiques of critical theory from the Frankfurt School,[5][6] which included important thinkers such as Theodor Adorno, who was one of his teachers at the Institute for Social Research from 1956 to 1959.

Habermas began his habilitation during this period, but due to intellectual tensions with the Institute's director, philosopher and sociologist Max Horkheimer, he moved to the University of Marburg, where he completed the work under Wolfgang Abendroth.