Why did Karl Jaspers leave Germany for a professorship in Basel in 1948?

In the spring of 1948, Karl Jaspers accepted a professorship in Basel, Switzerland, primarily due to his disappointment with the postwar situation in Germany.1

Following the war, Jaspers had dedicated his efforts to the moral and political rebirth of the German people and the rebuilding of the university system. He advocated for the de-Nazification of teaching staff and argued that acknowledging national guilt was essential for Germany's recovery, as outlined in his work The Question of German Guilt. However, he found that his ideas regarding moral regeneration attracted little attention, and his efforts to reform the university were hindered by the limited number of non-compromised professors.1

Beyond his frustration with the lack of progress in Germany, Jaspers hoped that moving to Basel would provide him with the peace of mind necessary to revise his philosophical approach. His departure was viewed by many as a betrayal, but it ultimately allowed him to transition his focus toward "world philosophy," a mode of thinking aimed at fostering a free world order and communication among all mankind.1