Here I am drawing from the insert used in our RCIA class…who decided which books belonged in the Bible…
"The early Christians had already accepted the list of Old Testament books in the Greek translation – which was the universal language in the world at that time – by as early as the middle of the first century A.D. Note that the spirit of a church, of a community is social, not solitary…
‘The New Testament list came in 393, when bishops gathered in the African city of Hippo and drew up a list of books considered to be inspired. Finally, the Council of Trent in 1546 declared this list to be the authentic collection, or the “canon” of sacred Scripture.’
Also note that as we Catholics, we believe the Sacred Scriptures are indeed inspired by God. But we do not believe that the Spirit of God had power over the human author and forced his hand, word by word. What we look at is context, analysis, the times the person lived in. Just like Christ said, do not call anyone Father but your Father in heaven’…some Protestants think we are contradicting Scripture by calling our priests Father…well then, don’t call your own natural father, ‘Father’…What Christ was referring to is not allowing anyone or anything take the place of God and His dominion.
'About the actual number of books…‘The Protestant Old Testament contains thirty-nine books, whereas the Catholic Old Testament has forty-six…’
‘In the early days of the Church, two versions of the Old Testament were used by the Jewish people. Greek speaking Jews outside of Palestine used a Greek translation of the Hebrew Old Testament, which contained the seven books of Tobit, Judith, Wisdom, Sirach, Baruch, and 1 and 2 Maccabees. Hebrew-speaking Jews in Palestine used a Hebrew Old Testament that did not contain these seven books.’
‘In the fourth century, St. Jerome translated the Hebrew version of the Old Testament into Latin and translated seven additional Greek Old Testament books into Latin. Jerome combined these books to make the Vulgate, the first complete Latin Bible.’
‘In the sixteenth century, the Protestant reformers made their own translation of the Bible into the German from the Hebrew, not the Greek, version. So the Protestant Old Testament looks like the Hebrew version, but lacks the seven books contained in the Greek and Catholic Old Testaments.’
‘In recent times, new translations of the Bible have been the result of cooperation between Catholics and Protestants.’
For additional information, ‘No originals of the Bible exist today, in part because they were written on papyrus, parchment, and leather, which disintegrated over time. Also, at times, the Roman emperors decreed the destruction of the sacred books of the Christians. Some ancient copies of the Bible that are still in existence are teh Sinaitic Manuscript (4th century A.D.) in the British Museum; the Vatican Manuscript (4th century A.D.) in the Vatican Library; the Alexandrine Manuscript (5th century), in the British Museum; the Dead Sea Scrolls (150 B.C.), which contain fragments of the Old Testament.’
As the Catholic Church has the mark of universality with the intent that Christ came for all men, it would be only reasonable that the Hebrew books in the universal language of Greek were drawn, and followed by the work of St. Jerome who combined both Hebrew translations.