Who decided which books belong in the Bible, and why does the Catholic Bible have more books?

The Catholic Church decided, in a series of councils beginning with the Council of Rome in 382 under Pope Damasus, and the Catholic Bible is not larger because Catholics added books at Trent but because the Protestant Reformers removed seven Old Testament books that the Church had already been treating as Scripture for eleven centuries. Somebody had to decide. No book of the Bible contains an inspired table of contents, and no list dropped out of heaven. If you want an inerrant canon, you need an infallible judge, because best guesses will never settle the question of what is and is not the word of God. That judge is the Church, acting the way a judge in a courtroom acts: the evidence is laid before him, and then he renders the decision that binds. Here is the actual history, and it is not the history most people are given. In 382 the Council of Rome, under Pope Damasus, approved the canon we have today. The Council of Hippo did the same in 393, and the Councils of Carthage followed in 397 and again in 419. In 405 Pope Innocent I approved the same list in a letter to a Gallican bishop. The Second Council of Nicaea approved it in 787, and the Council of Florence approved it again in the 1440s. Saint Augustine, writing to Manichaeus in 397, tells him that he accepts the canonicity of the book of Acts on the authority of the Catholic Church, and that is the very year of the third conciliar statement on the canon. So when a Protestant apologist tells you that Trent was the first council to put the deuterocanonical books into Scripture, that is simply false. What was new at Trent, in Session IV on April 8, 1546, was the form of the decision. Those earlier councils had given the same list without formally using the words "canon" or "canonical," and doubts had persisted. Trent issued the final, dogmatic, infallible decree, with anathemas attached for anyone who disputed either the protocanonical or the deuterocanonical books. Vatican I ratified that same canon in Session III in 1870. I will be honest about the doubts, because the Protestant will raise them anyway. Jerome had reservations about the deuterocanonicals. So did Cardinal Cajetan, the same Cajetan who was one of the fiercest defenders of Catholic orthodoxy against Luther, and so did Erasmus. Pope Gregory the Great doubted the canonicity of 1 Maccabees. A Latin Catholic Bible printed at Nuremberg in 1527 marked those books as not canonical. None of that embarrasses me. It illustrates the point: until the Church makes a clear, detailed, unambiguous and infallible statement, theological questions get argued ad infinitum and sometimes ad nauseam. That is exactly why Trent was necessary. And if you want to play the game of citing a Father who doubted a book, remember that Athanasius, who opposed the deuterocanonicals, also opposed the book of Esther, which sits in the Protestant Bible today. Now, why the seven extra books. Before Christ there were two bodies of Jewish Scripture in circulation. The Palestinian Jews used the Hebrew; the Alexandrian Jews used the Greek, which contained the books Protestants call apocryphal. Out of roughly 350 Old Testament citations in the New Testament, about 300 come from the Greek. Clement of Rome sets the story of Judith beside the story of Esther. Sirach is cited by the Epistle of Barnabas and by the Didache, Tobit by Polycarp. Our oldest great manuscripts of the Greek Bible, including Codex Sinaiticus, contain Tobit, Judith, and 1 and 2 Maccabees. That is not proof of canonicity by itself, but it is strong circumstantial evidence that the apostolic generation regarded these books as Scripture. The usual Protestant reply is that the Jews had already closed their canon and excluded them. But the rabbinic gathering at Jamnia came after the destruction of the Temple, and those rabbis had neither the standing nor the authority to fix the canon for the Christian Church. The Jews were the custodians of the Old Testament; they were not the authority in the New. And Jamnia settled less than is claimed: the sacredness of Esther, Ecclesiastes, and the Song of Solomon was still disputed by some rabbis into the second century, and none of those three is quoted in the New Testament. One clarification I insist on, because it is often muddled. The Septuagint as a translation is not inspired. The Church's canonical lists never included "the Septuagint" as such; they listed books. The Greek translation was a good rendering of the Hebrew and was more widely used by the Alexandrian Jews, and when the Holy Spirit chose to quote the Greek form of a verse in the New Testament, that was his decision and we stand behind it. That is a different claim from saying the translation itself was inspired. And do not forget that the New Testament had its own disputed books: Hebrews, James, 2 Peter, 2 and 3 John, Jude, and the Apocalypse. They were heavily contested among the early Christians, and they were finally and formally canonized at the same Council of Trent. If the Church had no authority to settle the canon, the Protestant has no grounds for his twenty-seven either.