In the first half of the 1960s I studied political science, philosophy and sociology at German and American universities. Among the academics who influenced me most as a student were Iring Fetscher, Ralf Dahrendorf, Max Horkheimer, Theodor W. Adorno, Jürgen Habermas, Anatol Rapoport and especially Karl W. Deutsch. A lasting intellectual impact, though from a distance, came from Samir Amin, in my opinion a most important academic intellectual in the southern hemisphere. These names represent the theoretical and political influences that have characterized my later work: critical assessment of ideologies and critical theory, combined with social science understood as scientific effort based on experical evidence. These are the foci of the various fields I have worked in since the mid-1960s, reflected in different analytical approaches and determined to a large extent by specific issues.