This edition is the first to publish three lectures which the philosopher and theologian Paul Tillich, who emigrated to the USA in 1933, delivered during a Guest Professorship at the Free University of Berlin between 1951 and 1958. The three lectures are entitled “Ontology” (1951), “The Human Situation in the Light of Theology and Existential Analysis” (1952), “The Ambivalence of Life Processes” (1958). Their common theme is the Doctrine of Man, which is developed from various perspectives.