Graduate in Law, University Frankfurt, Germany, 1962. Master of Laws, Harvard University, 1965. Doctor iuris, University Frankfurt, 1971.
Research fellow Max Planck Institute, Frankfurt, Germany, 1968—1979. Professor law University Bielefeld, Germany, 1979—1999. Justice Federal Constitutional Court, Karlsruhe, Germany, 1987—1999.
Professor law Humboldt University, Berlin, since 2000. Rector Wissenschaftskolleg Institute for Advanced Study, 2001—2007. Member board governors ZDF - German television, Mainz, 2002—2007.
Member, president advisory board numerous orgsn.
Member of Berlin-Brandenburg Academy of Sciences, Academia Europaea, American Academy Arts and Sciences.