INDEX OF FORBIDDEN BOOKS
A list of books that Catholics were forbidden by ecclesiastical authority to read or retain without authorization. The books so condemned were considered heretical, dangerous to morals, or otherwise objectionable. The Index was published by authority of the Holy Office. After the Second Vatican Council its publication was discontinued, but a new set of regulations was published by the Holy See, giving specific norms on the reading of books that are dangerous to Catholic faith or to Christian morality.