 In 1989, he was conferred the "Habilitation" (German post-doctoral qualification) from the Philosophy Department of Ludwig Maximilian University of Munich.After a one-year visiting professorship at Minnesota State University, he was appointed Chair of the Center for Ethics in the Bio Sciences at Eberhard Karls University of Tübingen.From 1993 to 2003, he held a Chair of Philosophy at the University of Göttingen, before he became Chair of Political Theory and Philosophy at Ludwig Maximilian University of Munich.