f pernicious in all directions, there appeared to be need of a more complete and efficacious remedy. This remedy Our predecessor, Paul IV, was the first to employ, by opportunely publishing a list of books and other writings against which the faithful should be warned. A little later the Council of Trent took steps to restrain the ever-growing incense of writing and reading by a new measure. At its command and desire, certain chosen prelates and theologians not only applied themselves to increasing and perfecting the Index which Paul IV. had published, but also drew up certain rules to be observed in the publishing, reading, and use of books; to which rules Pius IX added the sanction of his apostolic authority.
The interests of the public welfare, which had given rise to the Tridentine Rules, necessitated in the course of time certain alterations. For which reason the Roman Pontiffs, especially Clement VIII, Alexander VII, and Benedict XIV, mindful of the circumstances of the period and the dictates of prudence, issued several decrees calculated to elucidate these rules and to accommodate them to the times.
The above facts clearly prove that the chief care of the Roman Pontiffs has always been to protect civil society from erroneous beliefs and corrupt morals, the twin causes of the decline and ruin of States, which commonly owes its origin and its progress to bad books. Their labors were not unfruitful, so long as the divine law regulated the commands and prohibitions of civil government, and the rulers of States acted in unison with the ecclesiastical authority.
Every one is aware of the subsequent course of events. As circumstances and men's minds gradually altered, the Church, with her wonted prudence, observing the character of the period, took those steps which appeared most expedient and best calculated to promote the salvation of men. Several prescriptions of the rules of the Index,