Navigate to the site's original language texts by using the Texts or Themes menus from the site homepage.
Ambrose letter to Emperor Theodosius after the massacre at Thessalonica
Apollinaris, Apollinarius, his teaching on Christology from fragments of his writings
Arius letter to Eusebius of Nicomedia as found in Theodoret and Epiphanius. Arius speaks about his Christology.
Athanasius on the atonement
Athanasius 39th Festal Letter stating the Canonical books of the New Testament
Augustine on how he was influenced by Ambrose from Confessions, 5. 13. 23 - 14. 25.
Augustine on his conversion from Confessions 8. 12. 28-30
Augustine on the episcopate
Augustine on free will
Augustine on Philosophy and Theology / Christianity and Pagan learning from De Doctrina Christiana (On Christian Doctrine), 40 (60, 61)
Augustine on The Relation of the Old and the New Testaments from De Utilitate Credendi 9.3.
Augustine on The Trinity from De Trinitate, 9
Barnabas, Epistle of, 9: 6-9, and 12: 1-7. The Greek text is from the Kirsopp Lake edition of the Apostolic Fathers.
Basil of Caesarea on ousia and hypostasis
Canons 1-6 of the Council of Ephesus, 431
Canons of the Council of Nicaea, 325
The Chalcedonian Definition
I Clement, 40 - 42, 44 about Christian Ministry at the end of the first century
Clement of Alexandria on Philosophy and Christianity
Creed of Nicaea in Greek and Latin - Greek text as agreed at Council of Nicaea in 325
Cyprian Letter to Pompey about Stephen's views on the baptism of "heretics" - Epistle 73 or 74, LXXIII or LXXIV
Cyprian Letter to Quintus about the baptism of "heretics" - Epistle 70 or 71, LXX or LXXI
Cyprian On the Unity of the Church
Cyril of Alexandria Twelve Anathemas against Nestorius
Cyril of Jerusalem on the significance of baptism from Mystagogica Catechesis, 1, 1-3 (Catechetical Lecture 19, XIX)
Cyril of Jerusalem on the Catholic Church from Catechetical Lecture, 18. 23 & 26
The Didache
Diognetus, Epistle to - chapters 5-7
Epiphanius - Marcellus of Ancyra apologia to Pope Julius (containing the Old Roman Creed)
Eusebius of Caesarea on the Canon of the New Testament, from Historia Ecclesiastica 3.25.
Eusebius of Caesarea on the Canonical Epistles of the New Testament (Peter and Paul), from Historia Ecclesiastica 3.3.
Eusebius of Caesarea - The Edict of Milan - translation into Greek from the Latin
Eusebius of Caesarea - Life of Constantine, Constantine's vision of the cross
Eusebius of Caesarea - Montanism - the Origins of, from Historia Ecclesiastica, 5.16
Eusebius of Caesarea - Origen's work on the Text of the Old Testament (his Hexapla), from Historia Ecclesiastica, 6.16
Eusebius of Caesarea - Persecution under Nero and the martyrdom of Peter and Paul, from Historia Ecclesiastica, 2.25
Gregory of Nazianzus on the Deity of the Holy Spirit
Gregory of Nazianzus Critique of Apollinaris and Apollinarianism, from letter 101 to Cledonius
Gregory of Nyssa on the self-emptying of the Godhead
Hadrian Rescript to Caius
Hilary of Poitiers on The Trinity: From De Trinitate, book 12. 52 and 57
Hippolytus writing about Callistus
Hippolytus on Montanist Prophets from Refutation of All Heresies, 8. 19.
Ignatius Letter to the Magnesians - about Christianity and Judaism (also whole letter)
Ignatius Letter to the Romans - chapter 5 about Martyrdom (also a link to complete text and translation)
Ignatius Letter to the Smyrnaeans - about Ministry and Sacraments (also whole letter)
Ignatius Letter to the Trallians - with a focus on Docetism (also whole letter)
Irenaeus about Basilides (Gnostic) from Adversus Haereses, 1.19.
Irenaeus about Ebionites from Adversus Haereses, 1.22.
Irenaeus on Tradition from Adversus Haereses, 3. 2. 1 - 3. 4. 2
Irenaeus on Marcion from Adversus Haereses, 1. 24
Irenaeus on Recapitulation in Christ from Adversus Haereses
Irenaeus "The Rule of Faith" from Adversus Haereses, 1. 2 - 3.
James, Protoevangelium of
Jerome Contra Joannem Hierosolymitanum, 7. (A negative attitude towards Origen)
Jerome Fragment of Letter 33 to Paula. (A positive attitude towards Origen)
Jerome Letter 22 to Eustochium (section 7), about Jerome's experiences as an ascetic in the desert
Jerome Letter 53 to Paulinus,
about the importance of scripture and how to understand it correctly
Jerome preface to the Four Gospels
John Chrysostom on free will and grace - Homily 16 on Romans 9
Justin Martyr on the possibility of Christians before Christ
Justin Martyr on Baptism from Apology 1. 61.
Justin Martyr on the celebration of the Eucharist and the pattern of Sunday of Worship from Apology 1. 65 - 67.
Lactantius Liber de Mortibus Persecutorum, XLIV. Constantine's heavenly vision before the battle of Milvian Bridge in 312.
Lactantius Liber de Mortibus Persecutorum, XLVIII. The Edict of Milan granting freedom of worship to Christians.
Leo - The Tome of Leo - Letter 28 to Flavian - Greek and Latin Text with English translation
Libellus from the period of persecution under the emperor Decius
Martyrdom of Polycarp
Muratorian Canon, both as found in Migne PL and in Gwatkin Selections from Early Christian Writers.
Nicene Creed in Greek and Latin - as agreed at the Council of Constantinople in 381
Old Roman Creed - forerunner of the Apostles Creed - Greek and Latin texts
Optatus on the origins of the Donatist Controversy from De Schismate Donatistarum
Origen from De Principiis 4. 2. 4 (in Greek) - how to understand the Scriptures - threefold understanding
Origen from De Principiis 4.16 about the Parabolic Element in Scripture.
Pelagius on free will
Pirminius, Abbas - the apostles' creed
Pliny Letter to Trajan in Latin about the treatment of Christians in Bithynia
Rufinus on the apostles' creed
Socrates' description of the start of the Arian controversy
Socrates on John Chrysostom and the statue of Eudoxia
From Socrates Historia Ecclesiastica, The Letter of the Council of Nicaea to the Egyptian Church
Tertullian passage from Apologeticus pro Christianis (Apology), 29 - 32 - about Christians and loyalty to the Emperor.
Tertullian on the Incarnation from Apologeticus pro Christianis (Apology), 21: 10-14
Tertullian on Marcion from Adversus Marcionem, 1.19, 1.27, 3.8
Tertullian on Marcion from De Praescriptione Haereticorum, 30
Tertullian on philosophy and Christianity
Tertullian on the Trinity from Adversus Praxeam, chapters 2 & 3
Theodoret Letter 180 to Domnus, on the death of Cyril of Alexandria
Trajan reply to Pliny in Latin about the treatment of Christians in Bithynia