This book argues for substantial and pervasive convergence between Thomas Aquinas and Karl Barth with regards to God's relation to history and to the Christocentric orientation of that history. In short, it contends that Thomas can affirm what Barth calls "the humanity of God." The argument has great ecumenical potential, finding fundamental agreement between two of the most important figures in the Reformed and Roman Catholic traditions. It also contributes to contemporary theology by demonstrating the fruitfulness of exchanging metaphysical vocabularies for normative. Specifically, it shows how an account of God's mercy and justice can resolve theological debates most assume require metaphysical speculation.