Open a Protestant Bible and a Catholic Bible side by side and you will find the same Old and New Testaments — almost. The Catholic Bible contains seven (or more) additional Old Testament books that Protestant Bibles omit. These are the books at the centre of one of the Reformation's sharpest debates.
The numbers
| Protestant | Catholic | |
|---|---|---|
| Old Testament | 39 books | 46 books (39 + 7 Deuterocanonical + longer forms of Esther and Daniel) |
| New Testament | 27 books | 27 books — identical |
| Total | 66 | 73 |
The Deuterocanonical books
The seven extra books in the Catholic Old Testament are: Tobit, Judith, 1 Maccabees, 2 Maccabees, Wisdom (of Solomon), Sirach (Ecclesiasticus) and Baruch, plus additions to Esther and to Daniel (including the famous Susanna and Bel and the Dragon).
"Deuterocanonical" means "second canon" — a later term reflecting the disputed status of these books. They were written in Greek in the centuries just before Christ and appear in the Septuagint, the ancient Greek translation of the Hebrew Bible that most early Christians used.
Why the split?
The Jewish canon
By the 1st century AD, mainstream Judaism had settled on the 24-book canon that became the Tanakh, and it excluded books not preserved in Hebrew. Early Christian usage followed the Septuagint instead — which is why these books were in Christian Bibles from the beginning.
The Reformation
In the 16th century, reformers like Martin Luther and John Calvin argued that only the Hebrew canon was authoritative, and moved the disputed books into an appendix (Luther's Bible placed them between the Testaments). The Catholic Church, at the Council of Trent (1546), formally affirmed all 73 books as equal canon. The Church of England kept them as optional reading — hence the "Apocrypha" section in older Anglican and Protestant King James Bibles.
Where do the Orthodox fit?
Eastern Orthodox canons are slightly larger still — up to 79 books, including 3 Maccabees, 1 Esdras and Psalm 151, and treating the Septuagint as the standard Old Testament text. The New Testament is again identical, 27 books, across every Christian tradition.
Do the differences matter today?
For most doctrine, remarkably little — the New Testament is identical everywhere. But the Deuterocanonical books are far from marginal: the doctrine of purgatory draws on 2 Maccabees 12, the name of God in Sirach echoes Job, the Maccabees books underlie the Jewish festival of Hanukkah, and "A faithful friend is the medicine of life" (Sirach 6:16) is quoted in every tradition.
Read the Deuterocanon
The classic English Douay-Rheims translation includes all 73 books and is in the public domain — free to read online at FourFaiths, alongside the 66-book King James Version and the 77-book Orthodox canon.