“As we commemorated in 2025 the 1700th anniversary of the First Council of Nicaea, author James Likoudis left us a legacy of timely analysis and rationale for navigating a path to unity between the Catholic and Orthodox Churches. Likoudis, coming from his personal faith experience, encourages readers to reflect without prejudice on the doctrinal riches of both Greek and Latin saints who expressed unity in belief prior to the schism of 1054. His model for reunion in our times echoes Pope Paul VI’s call to ‘Let fall the barriers’ and realize Jesus’s prayer to His Father ‘. . . that they may all be one . . . that they may be brought to perfection as one . . .’ (John 17:21–23).”

“Likoudis’s work is a charitable and thoughtful investigation of issues that have divided the Church for nearly a thousand years. His analysis, as well as the presentation of under-utilized medieval texts like Kydones’s Apologia, provide a useful framework for any serious Christian working to restore unity in Christ’s universal Church.”

“James Likoudis devoted much of his adult life to seeking an end to the Byzantine Greek schism. Raised in the Greek Orthodox Church, Dr. Likoudis entered into full Catholic communion as a young man after being convinced that Petrine primacy corresponds to the will of Christ for a visible head of his Church. Ending the Byzantine Greek Schism provides much support for Catholic teachings on papal primacy and the double procession of the Holy Spirit (the Filioque), which are doctrines that most Eastern Orthodox continue to resist. This volume also includes texts from Demetrios Kydones, St. Thomas Aquinas, St. Peter Damian, and John de Fontibus, OP, that are not well known. These texts provide sound arguments in defense of the Catholic faith that should help to end the Byzantine Greek Schism.”

“In his book, James Likoudis (himself a convert from Eastern Orthodoxy to Catholicism) assembled something of an anthology of texts (many from the thirteenth and fourteenth century) defending the Catholic claim against Eastern Orthodox arguments. Many of these texts are ones which ordinary readers may have never seen before, and they are supplemented by Likoudis’s own argument and analysis. If you’re interested in Catholic–Orthodox apologetics, or the ‘ecumenism of love,’ this book is a helpful resource!”

“In this well-written book, James Likoudis demonstrated the doctrinal incoherence and irrationality of what has been aptly termed the Byzantine Greek Schism. He shows convincingly that the divine primacy of the See of Rome in the Church and the dual procession of the Holy Spirit are dogmatic truths lived and professed in the Church long before the tragic schism between the churches solidified. Likoudis’s book should be read by all Christians, and especially by those Eastern Orthodox seeking a serene examination of the doctrinal issues still dividing their churches from full communion with the Apostolic See.”

“Despite the fact that James Likoudis and I had some very deep disagreements about both theology and history, he was always very gracious to me personally. In an age where polemics is often coupled with an appalling lack of Christian charity, his kindness toward those with whom he differed stood out. The works of Aquinas, Kydones, and Peter Damian offered in this book are important texts in the history of medieval Latin–Byzantine relations, and having English-language translations is something for which Christians both East and West should be grateful.”

“The late Dr. James Likoudis was a giant in the field of Catholic and Orthodox dialogue, and this publication displays why that is. Likoudis provides the reader with a fourteenth-century Greek convert’s apologetic for his conversion to Catholicism—which both Catholics and Orthodox today would find beneficial. He also offers several additional medieval sources the reader will find indispensable in understanding the complexities of the debate between Catholics and Orthodox on the Filioque. This is all supplemented by his own essays. For anyone who longs for the ending of this ancient schism, Dr. Likoudis’s work is essential reading.”