From 1963 to 1988 Fetscher was Professor of Political Science and Social Philosophy at the Goethe University Frankfurt. He is identified with the "second generation" of the Frankfurt School, along with Jürgen Habermas and Alfred Schmidt. Leszek Kołakowski, while taking Fetscher to be a distinguished historian of Marxism with a critical but positive attitude, did not see him as of the Frankfurt School more than notionally.
