A new edition of Augustine's influential philosophical and theological treatise.

The following dissertation concerning the Trinity, as the reader ought to be informed, has been written in order to guard against the sophistries of those who disdain to begin with faith, and are deceived by a crude and perverse love of reason. Now one class of such men endeavor to transfer to things incorporeal and spiritual the ideas they have formed, whether through experience of the bodily senses, or by natural human wit and diligent quickness, or by the aid of art, from things corporeal; so as to seek to measure and conceive of the former by the latter. Aeterna Press

"As the psalms are a microcosm of the Old Testament, so the Expositions of the Psalms can be seen as a microcosm of Augustinian thought. In the Book of Psalms are to be found the history of the people of Israel, the theology and spirituality of the Old Covenant, and a treasury of human experience expressed in prayer and poetry. So too does the work of expounding the psalms recapitulate and focus the experiences of Augustine's personal life, his theological reflections and his pastoral concerns as Bishop of Hippo."--Publisher's website.

Augustine inaugurated the project of constructing models of the Trinity in language drawn from Platonic and Aristotelian philosophy, especially the conceptual framework of Aristotle's Categories. He used the Aristotelian notions of substance and relation to set up a model whose aim was not so much to demystify the Trinity as to demonstrate the logical consistency of maintaining that there is one and only one God at the same time as maintaining that there are three distinct persons, each of whom is God. Standing against this tradition are various heretical accounts of the Trinity. The book also analyzes these traditions, using the same techniques. All these accounts of the Trinity are evaluated relative to the three constraints under which they were formed, bearing in mind that the constraints on philosophical theorizing are not limited to internal consistency but also take note of explanatory power.

Saint Augustine of Hippo (/ɔːˈɡʌstɪn/; 13 November 354 - 28 August 430 AD) was a Roman African, early Christian theologian and philosopher from Numidia whose writings influenced the development of Western Christianity and Western philosophy. He was the Bishop of Hippo Regius in North Africa and is viewed as one of the most important Church Fathers in Western Christianity for his writings in the Patristic Period. Among his most important works are The City of God, De Doctrina Christiana and Confessions. Augustine imagined the Church as a spiritual City of God, distinct from the material Earthly City.

On the Trinity is a Latin book written by Augustine of Hippo to discuss the Trinity in context of the logos. Although not as well known as some of his other works, it is arguably his masterpiece and of more doctrinal importance than the Confessions or City of God.

Since the nineteenth century, many philosophical and theological commentators have sought to trace lines of continuity between the Trinitarian thought of Augustine of Hippo (354–430) and G. W. F. Hegel (1770–1831). Many contemporary Christian theologians have also criticized Augustine's Trinitarian theology generally and his doctrine of the Holy Spirit more specifically through this historical lens. At the same time, Hegelian Trinitarian conceptual dynamics have come to exert a strong influence over contemporary Trinitarian theology. In Life in the Spirit, Douglas Finn seeks to redress several imbalances with respect to Augustine, imbalances that have one of their hermeneutic causes in a Hegelian-influenced theological tradition. Finn argues that common readings of Augustine focus too much on his De Trinitate, books 8–15, betraying a modern—and to some extent Hegelian—prejudice against considering sermons and biblical commentaries serious theological work. This broadening of Augustinian texts allows Finn to critique readings of Augustine that, on the one hand, narrow his Trinitarian theology to the so-called psychological analogy and thus chart him on a path to Descartes and Hegel, or, on the other hand, suggest he sacrifices a theology of the Trinitarian persons on the altar of divine substance. Augustine's Trinitarian theology on Finn's reading is one fully engaged with God's work in history. With this renewed understanding of Augustine's Trinitarianism, Finn allows Augustine to interrogate Hegel with his concerns rather than only the other way around. In this ambitious study, Finn shows that Hegel's rendition of Christianity systematically obviates whole swaths of Christian prayer and practice. He does this nonpolemically, carefully, and with meticulous attention to the texts of both great thinkers.