Opening

The Catholic Bible contains 73 books — 46 in the Old Testament, 27 in the New. Protestant Bibles contain 66, omitting seven Old Testament books and portions of two more. The seven additional books — Tobit, Judith, Wisdom, Sirach (Ecclesiasticus), Baruch, 1 and 2 Maccabees, plus the Greek additions to Esther and Daniel — are called deuterocanonical by Catholics ("second canon," because the canonical status was contested in the early centuries) and apocryphal by Protestants ("hidden away," with implication of non-canonical status).

This article reports how the canon was settled, by whom, on what authority, and where the Reformation's revision came from. LV reports; it does not teach.

1. There was no single agreed-upon canon at the time of Christ

The Jewish people in the first century did not have a fixed, unanimous canon. There were several streams.

The Septuagint (LXX) — the Greek translation of the Hebrew Scriptures completed in stages from c. 250 BC. The LXX included the books later called deuterocanonical. It was the Bible of the Greek-speaking diaspora and, importantly, the Bible of the early Christian Church and of the New Testament writers. When the New Testament quotes the Old, it quotes the Septuagint about three-quarters of the time, including readings that match the LXX against the later-stabilised Hebrew text §120.

The Palestinian Hebrew tradition — narrower, eventually formalised at or around the Council of Jamnia (Yavneh, c. AD 90-100) into 24 books (corresponding to the 39 Protestant Old Testament books with different counting). The Council of Jamnia is itself a contested historical hypothesis (modern scholarship debates whether it was a single defining council or a longer process), but by the second century the rabbinic tradition was working with this narrower list.

Sectarian variants — the Dead Sea Scrolls show that the Essenes possessed and venerated Jubilees, 1 Enoch, and other works not in either later canon (Dead Sea Scrolls, Community Rule 1QS). Different Jewish communities had different judgments about what was Scripture.

The Christian Church inherited the Septuagint. The deuterocanonical books were the Christian inheritance from the start.

2. The Fathers and the early canon

The earliest Christian canon lists already include the deuterocanonical books.

The Muratorian Fragment (c. AD 170) — the oldest surviving Christian canon list — names New Testament books and references the Wisdom of Solomon among the Old.

Origen (c. AD 185-254) lists the deuterocanonical books in his enumeration of Old Testament books while noting their disputed status in some Jewish quarters Origen, Letter To Africanus.

Athanasius's Festal Letter 39 (AD 367) — the earliest Christian listing of the New Testament 27 books that match the modern set. For the Old Testament, he distinguishes between books "used for reading" (which include the deuterocanonicals) and the canonical 22 of the Hebrew tradition — but the Letter is itself ambivalent on the deuterocanonicals' status Athanasius, Festal Letter 39.

The decisive ecclesial settlement came at three African councils.

Council of Rome (AD 382) — under Pope Damasus, with Jerome present. The list issued by Damasus (the Damasine list, sometimes called the Decree of Damasus) includes the 73 books that became the Catholic canon.

Council of Hippo (AD 393) — Augustine's local council. Same list.

Council of Carthage (AD 397, reaffirmed AD 419) — confirmed the same canon and sent it to the Pope for ratification.

Augustine treats the canon as settled: "as for the Christian writings — those which deserve to be received as authoritative — the canonical books are these…" and then lists the 73 Augustine, On Christian Doctrine 2.13. Pope Innocent I ratified the same list in his Epistula 6 to Exuperius of Toulouse (AD 405) 213.

The canon was not invented at Trent. It was settled in the late fourth century and held continuously for more than 1,100 years before the Reformation.

3. Jerome's hesitation and the libri ecclesiastici debate

Jerome, when commissioned by Damasus to produce the Latin Vulgate, expressed reservations about the deuterocanonical books. He preferred the Hebrew canon (Hebraica veritas) because, doing his translation work in Bethlehem, he was working from Hebrew texts and noting which books Jewish rabbis of his day did not regard as Scripture. In his prefaces, Jerome calls the deuterocanonicals libri ecclesiastici — "ecclesiastical books," used in the Church's liturgy and reading but distinct from his "Hebraica veritas" canon.

Yet Jerome translated them. They were in the Vulgate. They were read in the liturgy. Augustine corresponded with Jerome and pressed him to accept the broader canon as settled by the African councils. Jerome's reservation became a footnote in the manuscript tradition; the conciliar decision held.

4. Trent's definition

The Reformation in the sixteenth century reopened the question. Luther, working from Erasmus's Greek New Testament and the Hebrew Old Testament, sided with Jerome's Hebraica veritas and removed the deuterocanonical books to a separate appendix in his 1534 German Bible (he called them "Apocrypha: books which are not held equal to the Holy Scriptures, and yet are useful and good to read"). Subsequent Protestant Bibles increasingly omitted them entirely.

The Council of Trent (Session IV, 1546) responded by formally defining the canon for the Catholic Church:

"If anyone does not accept all these books in their entirety, with all their parts, as they have been accustomed to be read in the Catholic Church and as they are contained in the old Latin Vulgate edition, as sacred and canonical, and knowingly and deliberately rejects the aforesaid traditions: let him be anathema." TrentSess4 Decree-On-Sacred-Books

Trent did not invent the canon. Trent ratified, with conciliar authority, what had been Catholic practice for 1,100 years.

5. Did the Reformers actually have a "shorter" canon?

Strictly speaking, the Reformers did not unite on a single Old Testament canon. Luther's German Bible included the deuterocanonicals as an appendix until the nineteenth century. The original 1611 King James Bible included them between the Testaments 39Art 6. The Anglican 39 Articles describes them as books the Church reads "for example of life and instruction of manners" but does not "apply them to establish any doctrine."

The full removal of the deuterocanonicals from Protestant Bibles is largely the work of the British and Foreign Bible Society in the early 1800s, on financial grounds (cheaper to print) and theological pressure from the Westminster Confession's narrower canon Westminster 1.3.

6. The New Testament canon

The New Testament 27 books were a longer process. Books with universal acceptance from the second century: the four Gospels, Acts, Paul's thirteen letters, 1 Peter, 1 John. Books with disputed reception: Hebrews (Western Church doubted Pauline authorship), James (Eastern Church received it later), 2 Peter (the most-disputed book in the New Testament), 2-3 John, Jude, Revelation (suspected by some Eastern Fathers due to its apocalyptic genre and use by chiliasts).

By the time of Athanasius's Festal Letter 39 (AD 367) and the African councils (AD 382-419), the 27-book list was fixed. The same conciliar process that defined the Old Testament defined the New.

7. What was excluded and why

The Christian community read and venerated many works the conciliar canon excluded. The exclusion was not arbitrary. The standard was conformity to the regula fidei (the rule of faith) and apostolic origin or apostolic-era authorship.

The Gospel of Thomas — a sayings collection from c. AD 140, found at Nag Hammadi in 1945 (Apoc Thom 22). It was excluded because of its Gnostic theology (Saying 114: "Every female who makes herself male will enter the Kingdom" — incompatible with Genesis and the Resurrection texts) and its lack of apostolic-era reception.

The Protoevangelium of James — a second-century narrative expanding Mary's biography. Pious in tone, but not received as canonical because of historical uncertainties.

The Shepherd of Hermas — second-century apocalyptic, included in the Codex Sinaiticus but rejected by most Eastern Fathers and the African councils because of its later date and uncertain authorship.

1 Enoch, Jubilees — Old Testament pseudepigrapha (Pseudep 1En 14:3) (Pseudep Jub 23:1). Read by some early Christians (Jude even quotes 1 Enoch 1:9 at Jude 14-15) but never canonical for the wider Church.

The Church's exclusion of these is not a blanket rejection of their value as historical documents; it is the recognition that they are not Scripture.

8. What this article does not claim

It does not catalogue every textual variant in the deuterocanonical books. It does not adjudicate the question of whether Daniel's Greek additions (Bel and the Dragon, Susanna, the Prayer of Azariah and Song of the Three Young Men) belong to the original Daniel or are later expansions — a question of textual scholarship rather than canonicity. It does not enter recent ecumenical conversations between Catholics and various Protestant communions on canonical questions, which proceed under different assumptions.

Closing

The Catholic canon of Scripture — 73 books, Old and New — was settled in the late fourth century by the African councils and ratified by Pope Innocent I. It was held by the entire Christian Church (East and West) for more than a thousand years before the Reformation revised the Old Testament. Trent did not invent the canon; Trent defined what the Church had always held. The canon is the Church's gift to the world: the books in which God has spoken, identified by the authority Christ left to settle such questions §120 DV §11.

— The Editors, LumenVeritatis