The Patrologia Latina · Volume XVII
The Would-Be Ambrose
Volume 17 belongs to a man with no name: Ambrosiaster, the anonymous Roman of the 370s AD whose commentaries on all thirteen Pauline epistles — the earliest complete Latin commentary on Paul — traveled under Ambrose’s name for a thousand years. With them comes Migne’s appendix of sermons, treatises, acts, and hymns ascribed to Ambrose by the manuscripts. We are translating every one into English.
About this volume
The most influential author nobody can name
Somewhere in Rome, while Damasus was pope, an unknown writer worked through every letter of Paul from Romans to Philemon — sober, historical, lawyerly exegesis in an age of allegory. The Middle Ages read him as Ambrose; Augustine quoted him as "Hilary"; Erasmus proved he was neither, and scholarship has called him Ambrosiaster — the "would-be Ambrose" — ever since. His reading of Romans shaped Augustine on original sin; his text of Paul preserves the Old Latin Bible; his identity, after sixteen centuries of guessing, remains unknown.
The rest of the volume is Migne’s appendix of works the manuscripts handed down under Ambrose’s name: sermons of many later preachers, a treatise on the Trinity, the Acts of Saint Sebastian, On the Calling of All Nations — generally credited to Prosper of Aquitaine — a medieval exposition of the Apocalypse, prayers, and the larger collection of hymns attributed to Ambrose beyond his secure core. We publish them as what they are: the school and shadow of a great name.
As across the whole project, we translate the original works only, in fresh English, and give them away free to read.
Where to start
Three to begin with
The commentary
Commentary on Romans
Commentaria in Epistolam ad Romanos
The earliest Latin Romans commentary — the anonymous reading that shaped Augustine on original sin.
Read →The theology
On the Calling of All Nations
De Vocatione Gentium
Two books on grace and the salvation of the nations — handed down under Ambrose’s name, generally credited to Prosper of Aquitaine.
Read →The legend
The Acts of Saint Sebastian
Acta S. Sebastiani Martyris
The passion of the soldier-martyr shot with arrows — the ancient narrative behind a thousand paintings.
Read →The contents
36 works
Each is a fresh English translation from the Latin, free to read online, in the order Migne printed them.
- 01
On the Forty-Two Mansions of the Sons of Israel De XLII Mansionibus Filiorum Israel
An allegorical journey through Israel's forty-two wilderness campsites in Numbers, each station read as a stage in the soul's ascent to God.
42 ch. Read free → - 02
Commentary on the Epistle to the Romans Commentaria in Epistolam ad Romanos
The first complete Latin commentary on Romans, written at Rome in the age of Pope Damasus by an author later called Ambrosiaster.
18 ch. Read free → - 03
Commentary on the First Epistle to the Corinthians Commentaria in Epistolam I ad Corinthios
Ambrosiaster's verse-by-verse commentary on 1 Corinthians, unraveling Paul's answers to a divided church over factions, marriage, idol offerings, and the resurrection.
16 ch. Read free → - 04
Commentary on the Second Epistle to the Corinthians Commentaria in Epistolam II ad Corinthios
The earliest complete Latin commentary on Paul turns to his most personal epistle, on reconciliation, suffering, and the greater glory of the new covenant.
14 ch. Read free → - 05
Commentary on the Epistle to the Galatians Commentaria in Epistolam ad Galatas
Ambrosiaster's verse-by-verse defense of Paul's gospel of faith against the Galatians' slide back into circumcision and the Law.
6 ch. Read free → - 06
Commentary on the Epistle to the Ephesians Commentaria in Epistolam ad Ephesios
A verse-by-verse commentary on Ephesians with a striking excursus on how Church offices changed since apostolic times.
6 ch. Read free → - 07
Commentary on the Epistle to the Philippians Commentaria in Epistolam ad Philippenses
A verse-by-verse commentary on Philippians, weighing Christ's self-emptying and Paul's call to press on toward the prize.
4 ch. Read free → - 08
Commentary on the Epistle to the Colossians Commentaria in Epistolam ad Colossenses
Ambrosiaster's earliest complete Latin commentary on Paul answers false teachers luring the Colossians toward philosophy and the worship of stars and elements.
5 ch. Read free → - 09
Commentary on the First Epistle to the Thessalonians Commentaria in Epistolam I ad Thessalonicenses
Ambrosiaster's verse-by-verse commentary on Paul's earliest letter, explaining its teaching on the resurrection of the dead and the Lord's return in glory.
6 ch. Read free → - 10
Commentary on the Second Epistle to the Thessalonians Commentaria in Epistolam II ad Thessalonicenses
Ambrosiaster reads 2 Thessalonians as a coded prophecy of Rome's fall, the antichrist's rise, and a rule for idle believers.
4 ch. Read free → - 11
Commentary on the First Epistle to Timothy Commentaria in Epistolam I ad Timotheum
A verse-by-verse commentary on Paul's pastoral instructions to Timothy, covering church offices, widows, wealth, and false teaching.
7 ch. Read free → - 12
Commentary on the Second Epistle to Timothy Commentaria in Epistolam II ad Timotheum
Ambrosiaster traces Paul's last letter to Timothy, from the charge to preach the word to the apostle's testimony before his death.
4 ch. Read free → - 13
Commentary on the Epistle to Titus Commentaria in Epistolam ad Titum
Ambrosiaster closes his commentary on Paul's letters with practical instructions for Titus and warnings against false teachers troubling the churches of Crete.
3 ch. Read free → - 14
Commentary on the Epistle to Philemon Commentaria in Epistolam ad Philemonem
A verse-by-verse reading of Paul's shortest letter, on his appeal for the runaway slave Onesimus.
7 min Read free → - 15
A Treatise on the Trinity De Trinitate Tractatus
A doctrinal treatise defending the coequal, coeternal Trinity against Arian and Sabellian error, and the true resurrection of the flesh.
29 ch. Read free → - 16
On the Orthodox Faith, Against the Arians De Fide Orthodoxa contra Arianos
A confession of faith defending the Nicene term "of one substance" against Arian objections, transmitted under Ambrose's name.
8 ch. Read free → - 17
On the Dignity of the Priesthood De Dignitate Sacerdotali
A bishop's charge to his fellow bishops on the honor of the episcopate, closing in a fierce denunciation of those who buy ordination with money.
6 ch. Read free → - 18
To a Devoted Virgin Ad Virginem Devotam
A stern exhortation warning a consecrated virgin away from worldly companionship and back to prayer, fasting, and chastity.
2 ch. Read free → - 19
Sermons Hitherto Ascribed to Saint Ambrose Sermones S. Ambrosio Hactenus Ascripti
Sixty-three sermons for the Christian year—Advent through saints' feasts—transmitted under Ambrose's name but written by later, largely unidentified authors.
65 ch. Read free → - 20
Letters Separated from the Ambrosian Collection Epistolae ex Ambrosianarum Numero Segregatae
Passion narratives of Roman and Milanese martyrs and a collection of moral maxims, transmitted under Ambrose's name but set apart from his genuine letters.
3 ch. Read free → - 21
Two Prayers Before Mass Precationes Duae
Two devotional prayers for a priest's preparation before Mass, the second unfolding into a meditation on the seven principal vices and the Last Judgment.
2 ch. Read free → - 22
Exposition on the Seven Visions of the Apocalypse Expositio super Septem Visiones Libri Apocalypsis
A verse-by-verse allegorical commentary on Revelation that divides the book into seven visions and reads hidden meanings in nearly every number and image.
8 ch. Read free → - 23
Concerning Repentance, Book I De Poenitentia Liber Unus
Ambrose's foundational defense of confession and penitence, arguing through scriptural examples that no sinner lies beyond the reach of God's mercy.
32 ch. Read free → - 24
On the Holy Spirit, in One Book De Spiritu Sancto Libellus Unus
A concise Trinitarian argument for the Holy Spirit's full divinity, drawn from Paul, the Gospels, and Isaiah's vision of the seraphim.
18 min Read free → - 25
On the Harmony of Matthew and Luke in the Genealogy of Christ De Concordia Matthaei et Lucae in Genealogia Christi
A short treatise reconciling Matthew's and Luke's divergent genealogies of Christ through natural descent, adoption, and a levirate marriage.
7 min Read free → - 26
On the Dignity of the Human Condition De Dignitate Conditionis Humanae
A short treatise distinguishing the soul's Trinity-mirroring image from the God-likeness won through charity, justice, patience, and mercy.
3 ch. Read free → - 27
Exorcism Exorcismus
A short rite of exorcism, traditionally transmitted under Ambrose's name, invoking Christ's power to expel Satan from the possessed.
3 min Read free → - 28
The Acts of Saint Sebastian Acta S. Sebastiani Martyris
A fifth-century passion narrative recounting the martyrdom of Saint Sebastian and the conversions of the household and prefect he brought to faith.
110 ch. Read free → - 29
On the Conflict of Vices and Virtues De Vitiorum Virtutumque Conflictu
A later medieval treatise, cast as a dialogue between the vices and their opposing virtues, from the appendix of works traditionally ascribed to Ambrose.
25 ch. Read free → - 30
On the Calling of All Nations De Vocatione Gentium Libri Duo
A two-book meditation on how God's will to save all nations meets his mysterious, unequal distribution of grace.
19 ch. Read free → - 31
On the Morals of the Brahmans De Moribus Brachmanorum
A legendary account of the ascetic Brahmans of India, framed around Alexander the Great's encounter with the sage Dandamis.
45 min Read free → - 32
Letters of Certain Philosophers Philosophorum Aliquot Epistolae
A Latin collection of legendary letters among Thales, Solon, Pythagoras, Plato, and other ancient Greek sages and rulers, transmitted under Ambrose's name.
27 ch. Read free → - 33
Two Letters Concerning a Monk Possessed by a Demon Epistolae Duae de Monacho Energumeno
Two short letters ascribed to Ambrose defend a demon-afflicted monk's purity and rebuke an old cleric for reaping a neighbor's field on the Lord's day.
2 ch. Read free → - 34
An Explanation of the Creed to Candidates for Baptism Explanatio Symboli ad Initiandos
Ambrose's baptismal homily walking candidates through the Apostles' Creed clause by clause, with his instruction that it must be memorized, never written down.
10 min Read free → - 35
Letter to Jerome on the Faith Epistola de Fide ad Hieronymum
A short creedal letter on the two natures of Christ, addressed to Jerome and traditionally transmitted under Ambrose's name.
7 min Read free → - 36
Hymns Attributed to Saint Ambrose Hymni S. Ambrosio Attributi
Eighty-two Latin hymns for the daily hours, feast days, and hardships of the Church, collected under Ambrose's name though few can be securely traced to him.
82 ch. Read free →
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