Jürgen Habermas (b. June 18, 1929) is a philosopher and sociologist. He was professor of philosophy at the universities of Heidelberg and Johann Wolfgang Goethe in Frankfurt. He was director of the Max Planck Institute for the study of the Scientific-Technological World. Habermas has written numerous books in the field of philosophy and social theory, the best known of which is The Theory of Communicative Action.