The Trinity in History is the first volume in a new series by Robert M. Doran that uses the thought of Bernard Lonergan to develop a unified field structure for systematic work in theology. Building on his successful and thought-provoking Theology and the Dialectics of History and What Is Systematic Theology?, Doran works out a starting point for a contemporary theology of history and proposes a new application of the 'psychological analogy' for understanding the Christian doctrine of the Trinity. Advancing the work of Lonergan, Augustine, and Thomas Aquinas, The Trinity in History also enters into conversation with contemporary philosophical emphases, especially with the mimetic theory of noted anthropological philosopher Rene Girard. Doran suggests several refinements of Lonergan's notion of functional specialization - developing a perspective for including the data of various religious traditions in theological construction, and establishing this theory's relevance for contemporary interreligious dialogue.

The second volume of Robert M. Doran's magisterial The Trinity in History continues his exploration of the Trinitarian theology of Bernard Lonergan, focusing now on the notions of relations and persons and connecting the systematic proposals with the so-called "Third Quest for the Historical Jesus." Doran not only interprets Lonergan's major work in Trinitarian theology and Christology but also suggests at least a twofold advance: a new version of the psychological analogy for understanding Trinitarian doctrine and a new starting point for the whole of systematic theology. He links these theological concerns with Rene Girard's mimetic theory, proposes a theory of history based in Lonergan's scale of values, and creates a link between exegetical and historical scholarship and systematic theology.