Karl Jaspers is not a well-known political thinker despite his undeniably powerful impact on postwar German politics. Indeed, a whole range of Jaspers's postwar interventions—his response to the question of German guilt, his active commitment to European integration and liberal values as well as his call for radical democracy in domestic affairs—are indicative of the direct and indirect ways in which Jaspers has shaped political culture in the Federal Republic of Germany and beyond. Yet, these interventions took place when Jaspers was already in his sixties. Before he penned political treatises and delivered radio lectures as one of Germany's most prominent postwar public intellectuals, Jaspers was recognized chiefly in two different roles: as an inadvertent pioneer of German existentialism alongside Martin Heidegger, and as a staunch defender of Max Weber's legacy against the dominant school of neo-Kantianism. His engagement with politics, and even more so with political economy, had been minimal in his writings. Trained as a psychiatrist, his ill health precluded a medical career, prompting him to shift to philosophy. Within that framework, he distinguished himself as a phenomenological psychologist and metaphysician, an existentialist philosopher with a markedly Kantian inflection, and a scholar of religion.

Initially, Jaspers did not think of himself as a political thinker either. Born in Bismarck's Germany in 1883, it was only as he endured the pain and suffering caused by decades of war, the failure of Germany's intellectual and political elite as well as personal adversities, above all the imminent threat to his Jewish wife and to their personal survival in Heidelberg, that he returned to Weber in a distinct political key. This shift also came in response to longstanding critiques from friends and colleagues, such as Dolf Sternberger, Herbert Marcuse and Georg Lukács, who reproached his existential philosophy for its ahistorical and bourgeois individualism. Now, after World War II had come to an end, Jaspers changed course. He faulted himself for having mistakenly “put thinking in the place of action” and asserted that philosophy can only prove itself in politics.