Born in Kiel in 1943.
Study of philosophy, with English and political science as secondary subjects. (Universität Kiel, Ecole Pratique des Hautes Etudes, VIe Section, Paris, Scottish Universities‘ Summer School, Edinburgh).
1966-1971: Assistant at the Philosophical Institute of the University of the Sarre, Saarbrücken (Chair Prof. Ilting).
June 1967 „Dr.phil.“ by the Faculty of Philosophy of the University of Kiel.
1971-1978: Assistant Professor at the department for the history of Psychology of the Psychological Institute of the Free University of Berlin.
November 1973 „Habilitation“ for Philosophy by the Faculty for Philosophy and the Social Sciences of the Free University of Berlin; since then teaching as „Privatdozent“ [Senior Lecturer] at the Institute of Philosophy of the Free University of Berlin.
May 1976-September 1977: Extraordinary Professor in the Department for Social Sciences of the Faculty for Economy of the University of Coimbra, Portugal.
1980-1984: Scientific Collaborator in research projects on labour politics at the Science Centre Berlin, as well as in the Faculty for Political Sciences of the Free University of Berlin.
1981-1984: Executive editor of the monthly „Moderne Zeiten“, Hannover.
June 1984-October 1989: ‘Alternate member’ for the Greens in the European Parliament.
1989-1994: Free-lance Lecturer and Consultant, co-founder of euroCom. Society for European Communication.
1994-1999: Member of the European Parliament for the German Greens.
Since 1998: Several honorary activities at the Humanist Association of Germany (HVD). Since 2006 he is president of the Humanist Academy of Germany (HAN) since January 2010 he is President of the HVD; from 2008-2012 he presided over the German Co-ordination Council of Secular Organizations (KORSO).
Since October 1999: Co-founder and director of „inEcom. Institute for European Communication“, Berlin. Cooperations with the Social Research Centre (Sozialforschungsstelle), Dortmund, the Confederation of German Trade Unions (DGB), section Berlin-Brandenburg, and the Free University of Berlin (FU Berlin).
May 2003-October 2006: Co-ordinator of the thematic network “Sustainability Strategy” at the Free University of Berlin (5th Framework Program for Research and Technological Development of the EU)
November 2007: Nomination to honorary professor of philosophy at the Free University of Berlin
Consultant editor to the Journals „Historical Materialism“, London, „Écologie et politique“, Paris, „Cosmopolitiques“, Paris, „Das Argument“, Hamburg.