1949, summer term
Freie Universität Berlin
1950, February-June
Notre Dame University, Indiana, USA
1956, March-June
Stanford University, California, USA
1962, March-June
Stanford University, California, USA
1967, October
University of Toronto, Canada (“Centennial Professor”)
1970, July-August
Liturgy in Santa Fe, New Mexico, USA (Priest-Course)
1973
Christian Commonwealth Institute, El Escorial, Spain
1975
Christian Commonwealth Institute, El Escorial, Spain
1987, February
International Academy of Philosophy, Liechtenstein.