Harvard University | Columbia University | Yale University | University of Paris | Cologne | New York University | Stanford University | Princeton University | University of Cambridge | University of Pennsylvania | University of Michigan | University of Chicago | University of California, Berkeley | University of Toronto | Cornell University | University of Oxford | University of London | University of Oslo | Cambridge University | University of Southern California | McGill University | Johns Hopkins University | Northwestern University | University of California | Brown University | University of Queensland | University of Minnesota | University of Washington | University of Notre Dame | University College London |
He studied the humanities at the Fragerherren gymnasium of Zwolle, philosophy and jurisprudence at Cologne University, where he became doctor of philosophy and both branches of law, and also licentiate of theology; he also taught peripatetic philosophy at the Montanum gymnasium there.
From 1968 to 1969 he was an assistant at the Department for African Studies of the Cologne University, from 1969 to 1972 he was a lecturer and from 1975 to 1978 visiting professor at the University of Nairobi.
He has held visiting professorships at Harvard University, in the Department of the History of Science, and at Cologne University, in the Research Institute "Media, Culture, Communication."