Deuterocanon

The Catholic claim

The historic Christian Bible contains 73 books. The Catholic Old Testament includes Tobit, Judith, Wisdom, Sirach (Ecclesiasticus), Baruch (with the Letter of Jeremiah), 1–2 Maccabees, and the longer Greek forms of Daniel and Esther. That library stood as the Church’s received canon for over a millennium; dropping to 66 books was a sixteenth-century revision, not a recovery of Jesus’ table of contents.

These books are called deuterocanonical—“second canon”—not because they are second-class, but because their reception was clarified amid controversy. They belong to the canon the Church read in liturgy and defined against later deletions.

Biblical evidence

The New Testament writers inhabit the Septuagint (LXX)—the Greek Scriptures of Second Temple Judaism—not a closed Palestinian short list. Of roughly 350 Old Testament references in the New Testament, the large majority match Septuagint phrasing. Paul alone quotes the Old Testament scores of times with overwhelming LXX agreement. That Greek Bible world is broader than the later Masoretic table many Protestants treat as the only “Hebrew canon.”

The apostles also preach themes that sit naturally in the deuterocanon: Hebrews recalls the tortured who hoped in resurrection—language that fits 2 Maccabees; Wisdom shapes Christian speech about idolatry, creation, and the righteous sufferer; Sirach praises the God who reveals his works. Lack of a formal “as it is written” tag does not settle canonicity—Judges, Esther, Ecclesiastes, and other Protestant books are likewise never directly quoted.

Hebrews 11:35
“Women received their dead by resurrection. Others were tortured, not accepting their deliverance, that they might obtain a better resurrection.”
2 Maccabees 12:39-46
“It is therefore a holy and wholesome thought to pray for the dead, that they may be loosed from sins.”
Wisdom 2:12-20
“Let us lie in wait for the righteous man… Let us condemn him to a shameful death, for, according to what he says, he will be protected.”
Wisdom 13:1-9
“For all men were by nature foolish who were in ignorance of God, and who from the good things seen did not succeed in knowing him who is…”
Matthew 1:23
“Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel (which means, God with us).”
Romans 1:20-23
“For the invisible things of him since the creation of the world are clearly seen, being perceived through the things that are made,”

Quotation is not the canon test

Protestants often say the New Testament never quotes the deuterocanon, so those books cannot be Scripture. Apply the rule evenly: several books every Protestant accepts are also never directly quoted. Citation patterns show which Bible world the apostles lived in; they are not a published table of contents.

Tradition and magisterium

When confusion about which books belonged in Christian Scripture arose, the Church named the library it already used. The Council of Rome under Pope Damasus (382) published a complete catalog including the deuterocanonicals. Hippo (393) and Carthage (397)—with Augustine defending the Alexandrian inheritance—reaffirmed the same 73-book pattern and asked Rome’s confirmation that no other books be read in church as Divine Scripture.

Florence (1442), in the Bull of Union with the Copts, already declared this canon dogmatically—decades before Luther’s protest. Trent (1546) then issued a solemn definition when Reformation Bibles subtracted books and even questioned New Testament texts. Trent did not invent a new Old Testament; it anathematized rejection of the historic Christian library.

Jerome’s scholarly preference for Hebrew manuscripts is real—and so is his submission: “What sin have I committed in following the judgment of the churches?” He translated the books into the Vulgate and could quote Sirach as Scripture. Private academic hesitation is not the Church’s rule of faith.

History and development

The Septuagint—the Greek Old Testament produced mainly in Alexandria between roughly 250–100 BC—became Scripture for Greek-speaking Jews and then for the apostolic Church. Early Christians inherited that broader collection; later Jewish narrowing after the rise of the Church, and Protestant adoption of a shorter Hebrew list, do not rewrite the Church’s liturgical memory.

There was no single closed Jewish canon in Jesus’ day that matches the modern Protestant Old Testament. First-century Judaism was fragmented; later rabbinic discussions (often popularly labeled “Jamnia”) came after the Church was already reading the wider Greek Scriptures—and those rabbis were not the Church’s teaching office. The “400 silent years” slogan likewise fails: the New Testament itself shows living prophecy and expectation, not a sealed library waiting for Malachi’s last page.

From the first Christian generations, deuterocanonical books are treated as authoritative: the Didache leans on Sirach; Clement of Rome quotes Wisdom as God’s word; Polycarp places Tobit beside the apostles’ letters; Barnabas and Irenaeus handle Wisdom and the longer Daniel as prophetic Scripture.

The Didache
Didache 4:5 · A.D. 70
“You shall not waver with regard to your decisions [Sir. 1:28]. Do not be someone who stretches out his hands to receive but withdraws them when it comes to giving [Sir. 4:31]”
This earliest Christian “church order” treats Sirach as standard, authoritative wisdom for discipleship—already Scripture in the Church’s ethical life alongside the New Testament era.
The Letter of Barnabas
Letter of Barnabas 6:7 · A.D. 74
“Since, therefore, [Christ] was about to be manifested and to suffer in the flesh, his suffering was foreshown. For the prophet speaks against evil, ‘Woe to their soul, because they have counseled an evil counsel against themselves’ [Is. 3:9], saying, ‘Let us bind the righteous man because he is displeasing to us’ [Wis. 2:12.]”
Barnabas cites Wisdom as “the prophet” next to Isaiah. Wisdom 2’s righteous sufferer mocked as God’s child also foreshadows the Passion language of Matthew 27—prophetic Scripture, not optional legend.
Clement of Rome
Letter to the Corinthians 27:5 [ca. A.D. 80]
“By the word of his might [God] established all things, and by his word he can overthrow them. ‘Who shall say to him, “What have you done?” or who shall resist the power of his strength?’ [Wis. 12:12]”
The earliest post-apostolic Roman witness quotes Wisdom 12:12 as the sovereign voice of God—unquestioned Holy Scripture for a bishop writing while apostles’ memory was still living.
Polycarp of Smyrna
Letter to the Philippians 10 · A.D. 135
“Stand fast, therefore, in these things, and follow the example of the Lord, being firm and unchangeable in the faith, loving the brotherhood [1 Pet. 2:17]. . . . When you can do good, defer it not, because ‘alms delivers from death’ [Tob. 4:10, 12:9]. Be all of you subject to one another [1 Pet. 5:5], having your conduct blameless among the Gentiles [1 Pet. 2:12], and the Lord may not be blasphemed through you. But woe to him by whom the name of the Lord is blasphemed [Is. 52:5]!”
John’s disciple quotes Tobit—“alms delivers from death”—in the same exhortation as 1 Peter and Isaiah. Tobit functions as Scripture in apostolic preaching, not as a late Catholic insert.
Irenaeus
Against Heresies 4:26:3 · A.D. 189
“Those . . . who are believed to be presbyters by many, but serve their own lusts and do not place the fear of God supreme in their hearts, but conduct themselves with contempt toward others and are puffed up with the pride of holding the chief seat [Matt. 23:6] and work evil deeds in secret, saying ‘No man sees us,’ shall be convicted by the Word, who does not judge after outward appearance, nor looks upon the countenance, but the heart; and they shall hear those words to be found in Daniel the prophet: ‘O you seed of Canaan and not of Judah, beauty has deceived you and lust perverted your heart’ [Dan. 13:56]. You that have grown old in wicked days, now your sins which you have committed before have come to light, for you have pronounced false judgments and have been accustomed to condemn the innocent and to let the guilty go free, although the Lord says, ‘You shall not slay the innocent and the righteous’ [Dan. 13:52, citing Ex. 23:7]”
Irenaeus cites Daniel 13 (Susanna)—part of the longer Greek Daniel—as “Daniel the prophet” with full scriptural force. Deuterocanonical material is already “the Word” against corrupt leaders in the second century.

Mastery and practice

To master this topic, teach it simply, answer Protestant objections without caricature, and connect the canon question to authority: who guards the table of contents?

Evidence of mastery: name the deuterocanonical books; show that Trent defended older reception against subtraction; explain why the apostles’ Septuagint world and early councils matter more than a quotation checklist; ask whether God left a self-compiling Bible or a Church to receive Scripture.

Could the learner defend the 73-book canon charitably while affirming that Catholics and Protestants already share 66 books as common ground?

Name the deuterocanonical books and what “deuterocanonical” means
Refute “Catholics added books at Trent” with Rome/Hippo/Carthage/Florence
Answer the quotation fallacy and the Jamnia / “silent years” slogans
Explain why Church reception, not a verse, settles the table of contents

Common objections

Catholics added books at the Council of Trent.

Trent defined what the Church had long received in liturgy and earlier councils—Rome, Hippo, Carthage, and even Florence decades before Luther. “Added” is the wrong verb: the Reformation removed books from a wider Christian inheritance; Trent refused the removal. Late solemn definition under controversy is not invention of the list—any more than defining the Trinity invents God.

Jesus and the apostles only used the Hebrew (Protestant) canon.

Luke 24:44 is not a closed table of contents. Jesus summarizes the Scriptures that point to him—“Law… Prophets… Psalms”—in a common Jewish way of speaking; he is not listing every inspired book or freezing a 39-book Protestant Old Testament. In Luke 24:27 he already spoke of “all the Scriptures” as Law and Prophets; adding “Psalms” highlights the wisdom writings, not a rigid three-shelf canon that excludes the deuterocanon. First-century Judaism was not unanimous (Pharisees, Sadducees, Essenes differed), and the apostles’ Septuagint world included the wider Greek books the early Church kept reading. Fathers who cite those books as Scripture never treated Luke 24:44 as a veto—and if “Law + Prophets + Psalms” were an exhaustive closed list, it would also leave no room for the New Testament itself.

The “Abel to Zechariah” line (Luke 11:51 / Matt 23:35) is rhetorical span—“from the first martyr to a later prophetic murder”—not a decree that 2 Chronicles is the last inspired book. Matthew even says “Zechariah son of Barachiah,” which does not neatly equal Jehoiada’s son in Chronicles; many readers take the point as the fullness of prophetic martyrdom, not a precise Hebrew binding order. Even an allusion to one Jewish ordering would not prove those were the only inspired books: a universally closed Jewish canon matching today’s Protestant list did not exist in Jesus’ day, and later rabbinic narrowing came after the Church was already using the Septuagint. Jesus and the apostles live in that Greek scriptural world—echoes of Maccabean hope in Hebrews 11 and the righteous sufferer in Wisdom 2 fit the wider Bible the Church received, not a later short list.

The New Testament never quotes the deuterocanonicals.

Direct quotation is not the test of canonicity. Several books Protestants accept—Judges, Ruth, Esther, Ecclesiastes, Song of Songs, and others—are likewise never directly quoted in the New Testament. The apostles’ Bible world is still the broader Greek Scriptures, and early Fathers cite Wisdom, Sirach, Tobit, and Maccabees as Scripture. Apply the quotation rule evenly, or drop it.

Jerome rejected the deuterocanonicals.

Jerome preferred Hebrew manuscripts as a scholar and hesitated over some Greek books—academic preference, not the Church’s final rule. He submitted to the judgment of the churches, translated the books for the Vulgate, and could quote Sirach as Scripture. “Jerome rejected them” is a slogan that erases his own practice and the councils he ultimately followed.

The Jews were entrusted with the oracles of God—so their canon settles ours.

Romans 3:2 says Israel was entrusted with the oracles of God—a real honor—and it does not hand Christians a closed 39-book table of contents dated to Jesus’ lifetime. First-century Judaism was not unanimous on the full library (Sadducees, Pharisees, and other groups differed), and the “oracles” Paul praises are God’s revelation, not a later rabbinic shortlist. The Church received the Scriptures through the apostles’ Septuagint world and Christian liturgy; she does not outsource the New Covenant’s canon to post-apostolic Judaism that also rejected the Gospel. If Jewish custody alone fixed the Christian Old Testament, the New Testament itself would never have been added—and the Church’s reception of the wider Greek books would be ruled out by an authority that is not her Magisterium.

Sources

Citations for this article. Browse the full bibliography to see every place each source is used across the library.

Catechism

CCC 120

Complete list of sacred books

It was by the apostolic Tradition that the Church discerned which writings are to be included in the list of the sacred books. This complete list is called the canon of Scripture.…

CCC 120. Canon

Open source Also in bibliography

Catechism

CCC 138

Apostolic Tradition discerned the canon

The Church accepts and venerates as inspired the 46 books of the Old Testament and the 27 books of the New.

CCC 138. Discernment

Open source Also in bibliography

Catechism

CCC 702

Spirit and the Word in the Old Testament

From the beginning until "the fullness of time," the joint mission of the Father's Word and Spirit remains hidden, but it is at work. God's Spirit prepares for the time of the Messiah.…

CCC 702. Preparation

Open source Also in bibliography

Scripture