Patristics or patrology is the study of the early Christian writers who are designated Church Fathers. The names derive from the combined forms of Latin pater and Greek pat?r (father). The period is generally considered to run from the end of New Testament times or end of the Apostolic Age (c. AD 100) to either AD 451 (the date of the Council of Chalcedon) or to the Second Council of Nicaea in 787.
The Church Fathers are generally divided into the Ante-Nicene Fathers, those who lived and wrote before the Council of Nicaea (325) and the Nicene and Post-Nicene Fathers, those who lived and wrote after 325. Also, the division of the Fathers into Greek and Latin writers is also common. Some of the most prominent Greek Fathers are Justin Martyr, Athanasius of Alexandria, Basil of Caesarea, Gregory of Nazianzus, John Chrysostom, Cyril of Alexandria, and Maximus the Confessor. Among the Latin Fathers are Tertullian, Cyprian, Jerome, Ambrose of Milan, Augustine of Hippo, and Gregory the Great.
There were also Church Fathers who wrote in languages other than Greek or Latin, such as Coptic, Syriac, Ge'ez, and Armenian, among others.[a] Historically, Chalcedonian Christians have had less interest in these authors since the associated churches ended up rejecting the councils of Chalcedon (becoming Oriental Orthodox), or Ephesus (becoming the Church of the East). Recently this has begun to change, with the cooling of tensions between these branches of Christianity and the Western and Byzantine ones. There are Eastern Catholics who follow Oriental rites while remaining in communion with Rome, and at least one organization argues that Eastern and Oriental Orthodox Christians now share the same faith.
Major focuses for these theologians during the period are, in chronological order, Christianity's relationship with Judaism; the establishment of the New Testament canon; apologetics (the 'defense' or 'explanation' of Christianity); and doctrinal discussions that sought to achieve consistency of faith, in particular within the Christianised Roman Empire. Following the scholar of Christianity Alister McGrath (1998), several major areas of theology can be seen to have developed during the Patristic Period: the extent of the New Testament canon, the role of tradition, the fixing of the ecumenical creeds, the two natures of Christ, the doctrine of the Trinity, the doctrine of the Church, and the doctrine of divine grace.
The terms neo-patristics and post-patristics refer to recent theologies according to which the Church Fathers must be reinterpreted or even critically tested in light of modern developments since their writings reflected that of a distant past. These theologies, however, are considered controversial or even dangerous by orthodox theologians.
Some scholars, chiefly in Germany, distinguish patrologia from patristica. Josef Fessler, for instance, defines patrologia as the science which provides all that is necessary for the using of the works of the Fathers, dealing, therefore, with their authority, the criteria for judging their genuineness, the difficulties to be met within them, and the rules for their use. But Fessler's own Institutiones Patrologiae has a larger range, as have similar works entitled Patrologies, for example, that of Otto Bardenhewer (tr. Shahan, Freiburg, 1908). Catholic writer Karl Keating argues that patrology is the study of the Early Fathers and their contemporaries as people, and the authenticity of the works attributed to them. Patristics, on the other hand, is the study of their thought.
On the other hand, Fessler describes patristica as that theological science by which all that concerns faith, morals, or discipline in the writings of the Fathers is collected and sorted. The lives and works of the Fathers are also described by a non-specialized science: literary history. These distinctions are not much observed, nor do they seem very necessary; they are nothing else than aspects of patristic study as it forms part of fundamental theology, of positive theology, and of literary history.
Most patristic texts are available in their original languages in Jacques Paul Migne's two great patrologies, Patrologia Latina and Patrologia Graeca. For Syriac and other Eastern languages the Patrologia Orientalis (Patrologia Syriaca earlier) is less complete and can be largely supplemented by the Corpus Scriptorum Christianorum Orientalium. Noted collections containing re-edited patristic texts (also discoveries and new attributions) are the Corpus Christianorum, Sources Chrétiennes, Corpus Scriptorum Ecclesiasticorum Latinorum, and on a lesser scale Oxford Early Christian Texts, Fontes Christiani, and Études Augustiniennes.