 The central idea in Jaspers’s philosophy of religion is the concept of philosophical faith, set out most extensively in Der Philosophische Glaube (Philosophical Faith, 1948) and Der Philophische Glaube angesichts der christlichen Offenbarung (Philosophical Faith in face of Christian Revelation, 1962). This notoriously difficult concept contains a number of quite distinct meanings. First, it means that true philosophy must be guided by a faith in the originary transcendence of human existence, and that philosophy which negatively excludes or ignores its transcendent origin falls short of the highest tasks of philosophy. Second, however, it also means that true philosophy cannot simply abandon philosophical rationality for positively disclosed truth-contents or dogma, and that the critical function of rationality has a constitutive role in the formation of absolute knowledge. In this respect, Jaspers revisited some of the controversies concerning the relation between religion and philosophy which shaped the philosophy of the Young Hegelians in the 1830s. Like the Young Hegelians, he insisted that faith needs philosophy, and faith devalues its contents wherever these are dogmatically or positively proclaimed. Third, then, this concept also indicates that the evidences of faith are always paradoxical and uncertain and that those who pursue knowledge of these contents must accept an attitude of philosophical relativism and discursive exchange: if faith results in dogmatism, it immediately undermines its claims to offer transcendent knowledge. The concept of philosophical faith is thus proposed, not as a doctrine of factual revelation or accomplished transcendence, but as a guide to transcendent communication, which balances the element of disclosure in faith with a critical philosophical veto on the absolutism of religious claims, and which consequently insists that transcendent knowledge must be accepted as relative and incomplete. In this regard, Jaspers held the religious aspects of his philosophy on a fine dialectic between theological and anthropological assertions. He implied, at one level, that purely secularist accounts of human life occlude existence against its originary transcendent possibilities and freedoms. At the same time, however, he also suggested that pure theological analysis closes humanity against the relativity and precariousness of its truths, and against the communicative processes through which these truths are disclosed. Only philosophy which can at once embrace and relativize secularism and embrace and relativize religion is able to undertake adequate existential inquiry, and philosophy which, in either direction, abandons the dialectical edge between these two commitments ceases to be genuine philosophy.