He was in charge of the Max Planck Institute in Starnberg (near Munich) in 1971, and worked there until 1983, two years after the publication of his main work, "The Theory of Communicative Action". Habermas then returned to his chair at Frankfurt as head of the Institute for Social Research. After retiring from Frankfurt in 1993, Habermas wrote many books and articles. In 1986, he received the Gottfried Wilhelm Leibniz Prize of the , which is the highest honour awarded in German research. He is a "Permanent Visiting" Professor at Northwestern University in Evanston, Illinois, and "Theodor Heuss Professor" at The New School, New York.