Written in 1975 as a birthday greeting to the theologian Hans Urs von Balthasar, Klaus Hemmerle?s Theses Towards A Trinitarian Ontology is of the highest theological moment as a key source text for the recent widespread interest in the idea of a ?Trinitarian ontology.? Drawing on Hemmerle?s deep familiarity with German Idealism, the Theses sketch an ontology beginning not from invariance, but from ?self-giving,? from kenosis, and articulate a distinctively Trinitarian response to the aporias of early twenty-first-century thought?a response for which only Love can credibly be understood as the meaning of Being. ?Hemmerle?s Theses, presented as a gift to Balthasar on his seventieth birthday, are in turn reflections on the gift, or more precisely, trinitarian self-giving to the world and human being. Authentic gifts are truly astonishing. Theses reflects Balthasar to himself while showing him a way forward towards Theologik 2 & 3 in which he formulated his own ontology of trinitarian love as it expresses itself in salvation history, thereby providing the horizon for all deep questioning into Being, beings, and their relation. This trinitarian ontology is an answer to Heidegger and Hegel, as well as a step beyond neo-Scholasticism?s insistence on deductive method and on divine unity rather than on process and relation. Furthermore, Hemmerle?s trinitarian ontology has the capacity to unite theory and praxis, individual and community, church and world. His Theses also suggests the emergence of a contest within Catholicism between strict phenomenology (later given expression to by Jean-Luc Marion) and a looser phenomenology that requires ontological specification. It is not going too far to say that Hemmerle?s gift is itself a figure of the gift of which he speaks, and represents a genuine participation in it.??CYRIL O?REGAN, author of The Heterodox Hegel and Gnostic Apocalypse ?At last, Klaus Hemmerle?s crucial little work is fully available in English, in a fine translation. His vision of a fully trinitarian ontology points the way forward, not just for theology, but for thinking in general.??JOHN MILBANK, author of Theology and Social Theory and Beyond Secular Order