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.” 3. Book Prohibitions Antedating the Roman Index. “The early days of the Church witnessed the earnest zeal of St. Paul,” when the Christians at Ephesus brought together all the superstitious books they had in their possession and burned them publicly. This example of loyalty to the Church cost them, as Holy Scripture says, between eight and nine thousand dollars. Such was the policy in regard to bad books at Ephesus at a time when the Apostle whom many love to call the most liberal and broadminded, ruled that part of the Church. Every subsequent age records similar measures of vigilance. The first General Council of Nicæa, in 325, besides proscribing the heresy of Arius, also issued a decree prohibiting the use of Arius’ book _Thalia_, which contained his heresy; indeed, at all times the condemnation of a heresy by the Church entailed the prohibition of the works propagating it. Pope St. Leo the Great, 440–461, does not hesitate to declare that one who reads forbidden books cannot be considered a Catholic.