Venerable Brothers, Greetings and Apostolic Blessing.

The well-being of the Christian community which has been entrusted to Us by the Prince of shepherds and the Guardian of souls requires Us to see to it that the unaccustomed and offensive licentiousness of books which has emerged from hiding to cause ruin and desolation does not become more destructive as it triumphantly spreads abroad. The distortion of this hateful error and the boldness of the enemy has so increased, especially at this time, in sowing weeds among the wheat either in word or in writing that unless We lay the scythe to the root and bind up the bad plants in bundles to burn, it will not be long before the growing thorns of evil attempt to choke the seedlings of the Lord Sabaoth. For accursed men who have given themselves over to myths and who do not uphold the stronghold of Sion from all sides vomit the poison of serpents from their hearts for the ruin of the Christian people by the contagious plague of books which almost overwhelms us. They pollute the pure waters of belief and destroy the foundations of religion.

They are abominable in their activity. Secretly sitting in ambush, they draw arrows out of the quiver which they shoot at the righteous in the dark. They have not restrained their impious minds from anything divine, holy, and consecrated by the oldest religion of all time; rather in their attack they have sharpened their tongues like a sword. They have run first of all against God in their pride. Armed with a thick neck, they have strengthened themselves against the Almighty. They raise again from the ashes the absurdities of the impious which have been destroyed so often. They deny God even though He makes Himself known everywhere and comes before their eyes daily, not because of the dullness of their mind, but only on the urging of their depraved will. Or else they represent God Himself as lazy and indolent. They do not respect His providence nor do they fear His justice. They preach with a detestable and insane freedom of thought that the origin and nature of our soul is mortal although it was created in the image of the supreme creator little lower than the angels. Whether they think matter has been created or foolishly imagine that it is eternal and independent of the causes, they consider that nothing else exists in this universe. Or else if they are forced to admit that spirit exists with matter, they exclude the soul from the spirit's heavenly nature. They are unwilling to understand that in this very weakness of which we are formed something spiritual and incorruptible abides in us. By its power we know, act, will, look to the future, attend to the present, and remember the past.

On the other hand, there are others who, even if they judge correctly that the fog of earthly reasonings should be dispelled and the smoke of worldly wisdom should be driven from the eye of enlightened faith, still dare to examine with human measures the hidden mysteries of faith which surpass all understanding. Having become investigators of greatness, they are not afraid of being overwhelmed by its glory. They ridicule the faith of simple people. They lay open the mysteries of God. They rashly discourse on questions concerning the highest matters. The bold mind of the enquirer takes everything for itself, examines everything, reserves nothing for faith, and deprives faith of merit by seeking proof for it in human reason.

Should we not also be angry with those who use the most wicked indecency of word and example to corrupt pure and strict morals by mortal sin, who recommend to the minds of the unwary an accursed license of living, and who cause an extreme loss of faith? Then consider how they sprinkle their writings with a certain refined splendor, a seductive pleasantness of speech and allurement so as to penetrate more easily into the readers' minds and infect them more deeply with the poison of their error. Thus they will give the snake's poison in the cup of Babylon to the unwary who are seduced and blinded by their smooth speech and so do not recognize the poison that kills them. Finally, who can avoid deep sadness when he sees the bitter enemy exceed the bounds of modesty and due respect and attack with the publication of outrageous books now in open battle, now in dissimulated combat the very See of Peter which the strong redeemer of Jacob has placed as an iron column and as a bronze wall against the leaders of darkness. Perhaps they are led on by the desperate thought that if they shatter the head of the Church, they will be able more freely to tear to pieces its members.