This article seeks to demonstrate the metaphysical understanding of the theologian-philosopher Karl Rahner, thematized from a transcendental hermeneutics of man, condition of possibility of the discovery of its open structure at infinity of being, with the reflective locus the world in which existentially lives and makes history. From the reading of his major works “Hearer of the Word” and “Spirit in the World” we seek to trace the relationship between anthropology and metaphysics, which by the question, the man asserts his metaphysical structure open transcendentally to be, act the possibility condition to ask and every last seizure of beings in the world.