It is well known that Jaspers drew lifelong inspiration from the social and political thought of Max Weber, his close friend at Heidelberg until Weber's death in June 1920. After beginning a training in psychiatry in 1906 and publishing an influential textbook on the discipline in 1913, Jaspers gravitated toward a career in philosophy over the course of World War I, dedicating his début work of philosophy, Psychologie der Weltanschauungen (1919) to Weber, who in turn cited the work in his famous 1920 “Preface” to “The Economic Ethics of the World Religions.” A regular guest at Max and Marianne Weber's salon on the Ziegelhäuser Landstraße from around 1910 onward, Jaspers would invoke Weber's name throughout his life, including most explicitly in a commemorative address in 1920, delivered a month after Weber's death, as well as in a later homage to the sociologist, published in 1932.

An initial interest of Jaspers's lay particularly in Weber's writings on concept formation in the social sciences, which attracted Jaspers as potential tools for the analysis of psychopathological phenomena; and there is even a possibility that Weber's term verstehende Soziologie may have owed something to Jaspers's conception of verstehende Psychologie in his 1913 guidebook on psychiatry. Reading Weber in essence as an existential philosopher, Jaspers took from Weber the central proposition that science and the intellect are not in a position to impart meanings of life but may nonetheless offer “means of selfreflection” as disciplines of thought—the value of reason in this sense being to prepare the individual for commitments of a nonrational kind. Rational analysis is the springboard for existential philosophy, enabling the thinking self to make the leap into forms of nonrational “illumination of existence,” each time by pushing different value-laden commitments to the point of utmost critical scrutiny.

Unmistakably documented in his texts, Jaspers's relationship to Weber is most evident in the abovementioned writings as well as in the first of the three volumes of Jaspers's main treatise on philosophy of 1931–32, entitled “Philosophical World-Orientation.” In particular, the Weberian roots of Jaspers's thinking about “limit situations” and nonrational value commitments have long been elaborated by scholars—among others notably by Dieter Henrich, Ernst Moritz Manasse and Joshua Derman.