 Despite the at times envenomed relations between them, however, Heidegger and Jaspers are usually associated with each other as the two founding fathers of existential philosophy in Germany. This interpretation of their philosophical status and relationship is at least questionable. Heidegger resented being described as an existentialist, and Jaspers, at least after 1933, resented being identified with Heidegger. Even during their early friendship Heidegger was very critical of Jaspers’s philosophy; he wrote a commentary on Psychology of World Views, in which he claimed that Jaspers’s methodological approach remained ensnared in the falsehoods of subjectivist metaphysics and Cartesian ontology, and that it illegitimately introduced the categories of Weberian sociology into philosophical analysis. Similarly, throughout his life Jaspers kept a book of critical notes on Heidegger, and he routinely described Heidegger’s fundamental ontology in a tone of moral-humanistic disapprobation. Nonetheless, there remains a residue of validity in the common association of Heidegger and Jaspers, and, although it requires qualification, this association is not in every respect misleading. Existentialism was, and remains, a highly diffuse theoretical movement, and it cannot be expected that two philosophers connected with this movement should hold similar views in all respects. However, existentialism had certain unifying features, and many of these were common to both Jaspers and Heidegger. In the early stages of its evolution, therefore, existentialism might be described as a theoretical stance which: a) moved philosophical discourse away from Kantian formalism and emphasized the belief that the content of thought must reside in particular experiences and decisions; b) followed Kierkegaard in defining philosophy as a passionate and deeply engaged activity, in which the integrity and the authenticity of the human being are decisively implicated; c) sought to overcome the antinomies (reason/experience; theory/praxis; transcendence/immanence; pure reason/practical reason) which determine the classical metaphysical tradition by incorporating all aspects (cognitive, practical and sensory) of human life in an encompassing account of rational and experiential existence. If this definition of existentialism is accepted, then the suggestion of a family connection between Jaspers and Heidegger cannot be entirely repudiated, for both contributed to the reorganization of philosophical questioning in the 1920s in a manner which conforms to this definition. Ultimately, however, relations between Heidegger and Jaspers degenerated to a terminal impasse, and after World War II Jaspers refused to explain or exonerate Heidegger’s political actions during the Nazi years and he even recommended to a de-Nazification committee that Heidegger should be suspended from his university teaching responsibilities.