He finished his "habilitation", or highest academic degree, in political science at the University of Marburg under the Marxist Wolfgang Abendroth. His "habilitation" work was entitled, "" (published in English in 1989 titled "The structural transformation of the public sphere: an inquiry into a category of bourgeois society"). In 1961, he became a "privatdozent" in Marburg. He began working as a "extraordinary professor" (professor without a chair) of philosophy at the University of Heidelberg. Hans-Georg Gadamer and Karl Löwith got him this job. In 1964 Habermas returned to Frankfurt to take over Horkheimer's job in philosophy and sociology.