This paper gives an introduction to the life and academic achievements as well as the political views and successes and failures of the professor of economics and social democratic politician Karl Schiller. It illustrates his endeavors to integrate the market orientation of the Freiburg School with Keynesianism and his conception of economic policy making built upon these theoretical foundations. Schiller used insights from Keynesianism to successfully combat the recession in Germany in 1966 but failed when it came to use this approach during the inflationary period of the 1970s. He contributed to making the policy stance of the Social Democratic Party of Germany more market friendly but failed due to the recurrence of Marxist ideology in the party, among other reasons.