This collection documents examples of distinctively Catholic theological beliefs or doctrines in the Eastern Church fathers; that is, ones in harmony with historic Catholic teaching but differing in some way from one or more strains of Protestant theology or Eastern Orthodox views. Quotations will be drawn from the Three Holy Hierarchs of Eastern Christian Tradition: St. Basil the Great (c. 330-379), St. John Chrysostom (c. 345-407), and St. Gregory Nazianzen (c. 330-c. 390). St. Athanasius (c. 297-373) is usually added to this list, and these are the Four Great Eastern Doctors of the Church. Additionally, the following four fathers are included: St. Cyril of Alexandria (c. 376-444), St. Ephraim (c. 306-373), St. Cyril of Jerusalem (c. 315-387), and St. John Damascene (c. 676-749). All eight men are Doctors of the Catholic Church. Quotations are drawn from public domain works and are found online at the Christian Classics Ethereal Library website.

For anyone to be called a Father involves these four conditions. First, he must be an Author, whose works are still extant. The fathers are important because they are quoted as authorities in theology. Obviously, then, they are all people who wrote works that we can quote. St Antony the Hermit, St Lawrence, St Sebastian are not fathers because they have left no writings. Secondly, he must be a Catholic, who lived in the communion of the Church, whose writings are correct and orthodox. Otherwise the writer’s authority is of no value as a witness of the Catholic faith. Apollinaris of Laodicea († c. 390) and Tertullian († 240) were learned and prolific authors; but they are not fathers because they were heretics. Thirdly, a father is a person of eminent sanctity as well as learning. The title is an honourable one given only to saints, or rather it includes and involves the title of saint. So Clement of Alexandria († c. 217) and Origenes († 254) are not strictly fathers, because they are not saints. As a matter of fact, the root of the matter in this case, too, is the want of orthodoxy that prevents them from being either saints or fathers. The fourth criterion is antiquity. This is the most difficult one to determine exactly. Aeterna Press

Lives and writings of ten great leaders: Clement of Alexandria, Athanasius, Basil the Great, John Chrysostom and others. In them we see the apostolic fire become crystallized not only into dogma and external order but also into some of the world's great religious literature.

The Christian Church has no shortage of revered figures and saints, but it is difficult to find one that had a more decisive impact on the course of the Church's history than Augustine of Hippo. Augustine was a bishop of Hippo Regius in Africa, but his works, sermons and writings helped hold the Church together even as the Western Roman Empire was in its death throes, to the extent that every major branch of Christianity recognizes him today. The Catholic Church has venerated him as a saint and a Doctor of the Church, Orthodox Christians also consider him a saint, and Protestants and Calvinists cite him as one of the fathers and inspirations of the Protestant Reformation. In many respects, Augustine has provided the theological bedrock for Christians for nearly 1600 years, and as theologian John Leith noted in 1990, "Augustine, the North African of Berber descent, is today the spiritual father of multitudes who are remote indeed from him racially, politically, and culturally." Augustine's voluminous writings also had the effect of making him one of antiquity's most influential philosophers. Though he will always be remembered within the context of Christianity, Augustine studied the works of Virgil, Cicero, and the ancient Greek philosophers, providing a critical bridge between religious and secular philosophy that would in turn inspire St. Thomas Aquinas and similar thinkers. In addition to framing the concept of original sin, it was Augustine who first wrote at length on the theory of just war. Paul Henry, S.J. noted, "In the history of thought and civilization, Saint Augustine appears to me to be the first thinker who brought into prominence and undertook an analysis of the philosophical and psychological concepts of person and personality. These ideas, so vital to contemporary man, shape not only Augustine's own doctrine on God but also his philosophy of man..." Augustine's legacy would have been impressive for anybody to accomplish, but it was made all the more amazing by the fact that he spent most of his early years living irreverently. Though raised a Christian, he abandoned his faith until he was in his early 30s, and one of his prayers would become notorious: "Grant me chastity and continence, but not yet" He was teaching rhetoric in Africa before a series of experiences led to his conversion back to Christianity in 386, thus spending the last 45 years of his life in the service of God.