In this important volume Habermas outlines the views which form the basis of his critical theory of modern societies. The volume comprises five interlocking essays, which together define the contours of his theory of communication and of his substantive account of social change. 'What is Universal Pragmatics?' is the best available statement of Habermas's programme for a theoryof communication based on the analysis of speech acts. In the following two essays Habermas draws on the work of Kohlberg and others to develop a distinctive account of moral consciousness and normative structures. 'Toward a Reconstruction of historical Materialsim' takes these issues further, offering a wide-ranging reconstruction of Marx's historical materialsim understood as a theory of social evolution. The final essay focuses on the question of legitimacy and on the legitimation problems faced by modern states. This book is essential reading for anyone concerned with the key questions of social and political theory today.