The Boston Collaborative Encyclopedia of Western Theology on Karl Rahner
Since Rahner’s superiors had decided that he would teach philosophy at Pullach, he returned home to Freiburg in 1934 to study for the doctorate in philosophy. During this time he delved more deeply into the philosophy of Kant and Maréchal, while at the same time attending seminars by Martin Heidegger. Rahner participated in the demanding seminar taught by Heidegger for two years, as a result of which he became one of the so-called, Catholic Heidegger School (an effort to unite Heideggerian insights with a reinterpretation of the thought of Thomas Aquinas), along with J.B. Lotz, G. Siewerth, B. Welte, and M. Müller. His philosophy dissertation Geist im Welt, an intriguing interpretation of Aquinas’s epistemology influenced by the transcendental Thomism of Joseph Maréchal and the existentialism of Martin Heidegger (that is, the relation between Aquinas’s notion of dynamic mind and Heidegger’s analysis of Dasein, or being-in-the-world), was ultimately rejected by his mentor Martin Honecker apparently because it was influenced too much by Heidegger and did not sufficiently express the Catholic neo-scholastic tradition. According to Vorgrimler, Honecker’s rejection of Rahner’s dissertation reflected the former’s antipathy toward Heidegger’s philosophy. Thirty four year later the Philosophical Faculty of the University of Innsbruck gave him an honorary doctorate for his philosophical works, especially for his failed dissertation, published in 1939 as Geist in Welt.
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Despite the rejection of his first dissertation in philosophy, Rahner’s interest in philosophy was still alive and even “almost superstitious”. During the summer of 1937 Rahner delivered a series of lectures to the Salzburg Summer School on "Foundations of a Philosophy of Religion," which were later published in 1941 as Hörer des Wortes (Hearers of the Word), which represented another step in the development of Rahner’s philosophical anthropology. This too represented a dialogue between Thomistic metaphysics and Heidegger’s phenomenological ontology. Rahner, using Heidegger’s notion that the question of the meaning of one’s being is preceded by a "pregrasp" of the world’s horizon of meaning, said that the search and longing of the human subject for meaning of experience is grounded in a "preconceptual" grasp of God’s infinite horizon of being as a condition (and fulfillment) of the human search for meaning.