Leontius Of Byzantium (485-543) was a Byzantine monk and theologian who provided a breakthrough of terminology in the 6th-century Christological controversy over the mode of union of Christ's human nature with his divinity. He did so through his introduction of Aristotelian logical categories and Neoplatonic psychology into Christian speculative theology. His work initiated the later intellectual development of Christian theology throughout medieval culture. Brian E. Daley provides translation and commentary on the six theological works associated with the name of Leontius of Byzantium. The critical text and facing-page translation help make these works more accessible than ever before and provide a reliable textual apparatus for furture scholarship of this key writing. "This impressive volume provides the full text, in Greek with an English translation on facing pages, of six polemical works attributed to an accomplished sixth-century monastic theologian. It also includes much of the necessary textual arcana, such as an account of the manuscript tradition, marginal scholia, previous editions, dubious fragments attributed to the same author, and some truly remarkable scholarship identifying the sources of the texts quoted in Leontius' florilegia ... This at last is the edition of Leontius for theologians to read and cite from now on." -- Fred Sanders, International Journal of Systematic Theology Brian E. Daley, SJ, Catherine F. Huisking Professor of Theology, University of Notre Dame Brian E. Daley, SJ, is Catherine F. Huisking Professor of Theology at the University of Notre Dame. He is a historical theologian, who specializes in the study of the early Church, particularly the development of Christian doctrine from the fourth to the eighth centuries. His publications include Light on the Mountain: Greek Patristic and Byzantine Homilies on the Transfiguration of the Lord (St Vladimir's Seminary Press, 2013) and Hope of the Early Church: A Handbook of Patristic Eschatology (Baker, 2002). In 2014, he co-edited The Harp of Prophecy: Early Christian Interpretation of the Psalms with Paul R. Kolbet (University of Notre Dame Press, 2014).