The Roman Index of Forbidden Books (Betten)/Section I/Chapter 2
2. The Power of the Church.
That the Church has the right to legislate on the publication and use of all books that touch on questions of faith and morals, must be evident to every Catholic. It is a truth clearly contained in the words of Christ to St. Peter: "Feed my lambs, feed my sheep," and in the duty imposed on the Apostles of "teaching the faithful to observe all, whatsoever I have commanded you."
The fact that general councils as well as many popes have issued laws and decrees regarding books, is sufficient evidence of their power and of their commission to do this. This very fact must also convince us that the observation of these laws must be salutary and conducive to the welfare of the Church at large and of the individual Christian.
The inventions, discoveries and progress of our times can introduce no change in this respect. The human mind is still as prone to err and as much subject to the persuasive influence of books as it ever was. Good books are as useful to-day as they were in olden times, and objectionable writings have the same deplorable effects they had a thousand years ago.
Nor can the Church, possessing the power to watch over our reading, neglect to make use of this power when the salvation of souls calls for its exercise. Bad literature is one of the worst enemies of mankind. The Church can never allow it to corrupt the hearts of her children or to undermine the foundation of their faith, without at least raising a warning voice.
How great are the precautions the civil authorities take in case of an epidemic; yet, no matter how seriously the precautions hamper traffic and trade, we find them reasonable. We should even censure our executive and legislative officers if they omitted to take proper precautions. But, says Pope Leo, in the Constitution Officiorum ac munerum, nothing can be conceived more pernicious, more apt to defile souls than uncurbed license in the writing and disseminating of bad books. "Therefore," he continues, "the Church, whose office it is to watch over the integrity of faith and morals, has ever striven, as far as in her power lay, to restrain the faithful from the reading of bad books as from a deadly poison."