Guest Scholar, Institute for Society, Ethics & the Life Sciences, Hastings-on-Hudson, New York, March-April 1979

Fellow, Woodrow Wilson International Center for Scholars, Smithsonian Institution, Washington, D.C., May-December 1979

Cecil Green Visiting Professor, University of British Columbia, Vancouver, October-November 1981

Visiting Distinguished Humanist, University of Colorado, Boulder, January-May 1984

Distinguished Visiting Professor, University of California, Irvine, April-June 1987

Italian National Research Council Visiting Scholar, University of Rome 'La Sapienza', May 1991

Erskine Fellow, University of Canterbury, Christchurch, March 1997

Ferrater Mora Chair of Contemporary Thought, University of Girona, June 2003