This one-volume reference work provides the first encyclopedic treatment of the life, thought, and influence of Augustine of Hippo (A.D. 354-430), one of the greatest figures in the history of the Christian church. The product of more than 140 leading scholars throughout the world, this comprehensive encyclopedia contains over 400 articles that cover every aspect of Augustine's life and writings and trace his profound influence on the church and the development of Western thought through the past two millennia. Major articles examine in detail all of Augustine's nearly 120 extant writings, from his brief tractates to his prodigious theological works. For many readers, this volume is the only source for commentary on the numerous works by Augustine not available in English. Other articles discuss: Augustine's influence on other theologians, from contemporaries like Jerome and Ambrose to prominent figures throughout church history, such as Gregory the Great, Aquinas, Luther, Calvin, and Harnack; Augustine's life, the chaotic political events of his world, and the church's struggles with such heresies as Arianism, Donatism, Manicheism, and Pelagianism; Augustine's thoughts about philosophical problems (time, the ascent of the soul, the nature of truth), theological questions (guilt, original sin, free will, the Trinity), and cultural issues (church-state relations, Roman society).

Luigi Gioia provides a fresh description and analysis of Augustine's monumental treatise, De Trinitate, working on a supposition of its unity and its coherence from structural, rhetorical, and theological points of view. The main arguments of the treatise are reviewed first: Scripture and the mystery of the Trinity; discussion of 'Arian' logical and ontological categories; a comparison between the process of knowledge and formal aspects of the confession of the mystery of the Trinity; an account of the so called 'psychological analogies'. These topics hold a predominantly instructive or polemical function. The unity and the coherence of the treatise become apparent especially when its description focuses on a truly theological understanding of knowledge of God: Augustine aims at leading the reader to the vision and enjoyment of God the Trinity, in whose image we are created. This mystagogical aspect of the rhetoric of De Trinitate is unfolded through Christology, soteriology, doctrine of the Holy Spirit and doctrine of revelation. At the same time, from the vantage point of love, Augustine detects and powerfully depicts the epistemological consequences of human sinfulness, thus unmasking the fundamental deficiency of received theories of knowledge. Only love restores knowledge and enables philosophers to yield to the injunction which resumes philosophical enterprise as a whole, namely 'know thyself'.