Text Study & Censorship
Both internal and external books have been banned from Judaism throughout history.
Reprinted from The Jewish Religion: A Companion, published by Oxford University Press.
Censorship is the control of Jewish books to make sure that they do not contain material considered by those exercising the control to be injurious to religion and morals or harmful to the reputation of the Jewish people. In considering the question of censorship in Judaism, it must first be noted that there has never been anything like a universally recognized body of rabbis responsible for controlling the kind of literature that Jews produce. This is not to say that individual rabbis never sought to ban certain books but their power to do so was limited by the willingness of authors, publishers, and readers to obey the dictates of these rabbis.
The censorship that did exist was of two kinds--external and internal. External censorship was exercised by governmental bodies who ordered the excision from Jewish publications of passages held to be attacks on Gentiles or on the Christian faith. The Jewish authorities, too, anticipated this type of intervention by themselves deleting or altering such "dangerous" passages.
For instance, the words oved avodah zarah ("a worshipper of strange gods") in the Talmud was altered to read oved kokhavim u-mazalot ("a worshipper of stars and planets"), usually abbreviated to akum, an obviously safe reading since neither in the Roman Empire nor Babylon in Talmudic times nor in Christian Europe in the Middle Ages were Gentiles star worshippers. It is ironic that some Christian would-be censors read the word akum itself as an abbreviation of oved Christus u-Miriam ("worshipper of Christ and Mary"). The Talmudic saying (Yevamot 62b): "Any man without a wife lives without joy and without blessing" was changed to: "Any Jew without a wife," presumably to avoid giving offence to Christian celibates.
Internal censorship was imposed by rabbis who had the necessary power over books believed to contain heretical or immoral ideas. Whatever the meaning of the statement in the Mishnah (Sanhedrin 10: 1) that one who reads external books has no share in the World to Come (it probably referred to treating the books of the Apocrypha as sacred Scripture by reading them in public in the synagogue), it was extended by some in the Middle Ages and beyond to include all manner of books they held to be unwholesome.
The standard commentary to the Mishnah by the 15th century Italian scholar Obadiah Bertinoro remarks on "external books": "By this is meant the works produced by heretics, for example, the works of the Greek Aristotle and his associates. This prohibition extends to anyone who reads the histories of Gentile kings, love poems, and erotic writings, works which contain neither wisdom nor advantage but are simply a waste of time."