Although he rejected explicit religious doctrines, including the notion of a personal God, Jaspers influenced contemporary theology through his philosophy of transcendence and the limits of human experience. Mystic Christian traditions influenced Jaspers himself tremendously, particularly those of Meister Eckhart and of Nicholas of Cusa. He also took an active interest in Eastern philosophies, particularly Buddhism, and developed the theory of an Axial Age, a period of substantial philosophical and religious development. Jaspers also entered public debates with Rudolf Bultmann, wherein Jaspers roundly criticized Bultmann's "demythologizing" of Christianity. (See "Myth and Christianity: An Inquiry into the Possibility of Religion without Myth" – a debate between Jaspers and Bultmann, The Noonday Press, New York, 1958)