In The Philosophy of Habermas Andrew Edgar covers the full range of Habermas's ideas from his early work on student politics, the public sphere, and the development of Marxist theory to his current work on communicative action, ethics, and law. Edgar examines Habermas's key texts in chronological order and charts and assesses the continuities and discontinuities in his thought, both in terms of subject matter and methodology. He also identifies Habermas's unfulfilled potential, or unresolved challenges remaining from earlier projects, highlighting those points in Habermas's career where clear choices of direction have been made and their implications evaluated.

Each chapter focuses on one or more key texts and can therefore be read as a self-standing essay on that key reading and the point that it represents in Habermas's development. However, material in each chapter also serves to identify the links between Habermas's texts and to give shape to Habermas's broader project. Some of the themes that are examined are Habermas's early reshaping of Marxist theory and practice, his characterization of critical theory, his conception of universal pragmatics, his theories of communicative action and discourse ethics, his accounts of the rationalization and colonisation of the lifeworld and his defence of the project of modernity. Edgar engages with Habermas's critics throughout and contrasts his views with the ideas of contemporaries such as Adorno, Gadamer, Foucault, Rawls, Luhmann and Rorty to give a clear sense of Habermas's place and importance in contemporary philosophy and social theory.