Leo XIII, Constitution on the Prohibition and Censure of Books (Officiorum ac Munerum)

Leo XIII, Pope. Leo, Bishop. Servant of the Servants of God. For Perpetual Memory of the Matter.

Of the offices and duties which ought to be preserved most diligently and most holily in this apostolic height, this is the head and this the sum: to watch constantly and to strive with every effort that the integrity of faith and of Christian morals receive no detriment. And this, if ever at any other time, is especially necessary in this time, when, minds and morals having been unbridled by license, almost every doctrine which Jesus Christ, the Savior of men, entrusted to His Church to be guarded for the salvation of the human race is called into daily contest and danger. In this contest indeed the cunning and arts of harming of the enemies are varied and innumerable; but among the first is the intemperance, full of dangers, of writing and of disseminating among the public things which have been badly written. For nothing can be thought more pernicious for staining souls through contempt of religion and through many allurements of sinning. Wherefore the Church, fearing so great an evil, and as guardian and vindicator of the safety of faith and morals, very early understood that remedies against a pest of this kind had to be taken; and for that reason it perpetually strove for this, that, as far as lay in it, it might prohibit men from the reading of bad books, that is, from this worst poison. The times nearest the origins saw the vehement zeal of blessed Paul in this matter; and every following age in like manner perceived the vigilance of the holy Fathers, the commands of bishops, and the decrees of Councils.

But especially the monuments of letters testify with how great care and diligence the Roman Pontiffs watched in this matter, lest the writings of heretics creep about unpunished, to the public evil. Antiquity is full of examples. Anastasius I condemned the more pernicious writings of Origen, Innocent I those of Pelagius, Leo the Great all the works of the Manichaeans by a grave edict. Known also on the same matter are the decretal letters concerning books to be received and not to be received, which Gelasius gave opportunely. Similarly, in the course of ages, the sentence of the Apostolic See struck the pestilent books of the Monothelites, of Abelard, Marsilius of Padua, Wycliffe, and Hus.

But in the fifteenth century, once the new art of books was discovered, not only was action taken against bad writings which had seen the light, but provision began to be made lest any of that sort thereafter be published. And not some light cause, but altogether the protection of honesty and public salvation during that time demanded this providence; because too many had quickly turned an art best in itself, parent of the greatest utilities, born for propagating the Christian humanity of nations, into a vast instrument of ruins. The evil of bad writings, by the very speed of spreading, was greater and more swiftly effected. Therefore, by a most salutary counsel, both Alexander VI and Leo X, our predecessors, brought forth fixed laws, assuredly congruent with those times and morals, which would contain book printers in their office.

Soon, when a graver storm arose, it was necessary much more watchfully and strongly to prohibit the contagions of evil heresies. For this reason the same Leo X, and afterwards Clement VII, most gravely sanctioned that it should be lawful for no one to read or retain the books of Luther. But when, on account of the unhappiness of that age, the impure filth of pernicious books had grown beyond measure and had pervaded every part, there seemed to be need of a broader and more present remedy. This remedy indeed our predecessor Paul IV first applied opportunely, namely by proposing a list of writers and books from the use of which the faithful ought to beware. Not very long afterwards the Fathers of the Tridentine synod took care that the growing license of writing and reading be restrained by a new counsel. For by their will and command the prelates and theologians chosen for this not only gave their labor to increasing and polishing the Index which Paul IV had published, but also wrote rules to be observed in the edition, reading, and use of books; to which rules Pius IV added the strength of apostolic authority.

But the account of public salvation, which had begotten the Tridentine rules at the beginning, as the ages slipped by, likewise commanded that something be renewed in them. Wherefore the Roman Pontiffs, and by name Clement VIII, Alexander VII, Benedict XIV, knowing the times and mindful of prudence, decreed several things which had value for explaining them and adapting them to the time.

These things brilliantly confirm that the principal cares of the Roman Pontiffs were perpetually placed in this: that they should defend from the civil society of men errors of opinions and corruption of morals, this twin stain and ruin of states, customarily begotten and disseminated by bad books. Nor did the fruit fail the labor, as long as in administering commonwealths the eternal law presided over the reason of commanding and prohibiting, and rulers of states agreed in one with the sacred power.

No one is ignorant of the things which followed afterwards. Namely, when day by day the circumstances of things and men had gradually changed, the Church did this prudently according to its custom, which, with the nature of the times having been examined, seemed more expedient and useful for the salvation of men. Several prescriptions of the rules of the Index, which seemed to have fallen away from their former opportuneness, it either itself removed by decree, or, when custom and usage prevailed somewhere, it benignly and at the same time providently allowed to become antiquated. In more recent memory, by letters given to the archbishops and bishops from the pontifical principate, Pius IX mitigated rule X in great part. Moreover, when the great Vatican Council was now near, he gave this business to learned men chosen for preparing arguments: that they should weigh and evaluate all the rules of the Index, and should render judgment as to what had to be done concerning them. They judged, with sentences agreeing, that they had to be changed. Very many of the Fathers openly professed that they both thought the same and were asking this from the Council. There exist letters of the Bishops of France on this matter, whose sentence is that it is necessary and must be done without delay, that those rules and the whole matter of the Index be restored in an entirely new manner, better adapted to our age and easier to observe. At that time the same was the judgment of the Bishops of Germany, plainly asking that the rules of the Index "be submitted to recent revision and reduction." With these agree very many bishops from Italy and other regions.

All these, indeed, if account is taken of the times, of civil institutions, and of popular morals, ask things plainly equitable and consonant with the maternal charity of holy Church. For in so swift a course of minds, there is no field of the sciences in which letters do not run forth more licentiously; thence the daily filth of most pestilent books. But what is graver, in so great an evil, public laws not only connive, but give great license. Hence, on the one side, the souls of very many are held in suspense in religion; on the other, there is an unpunished abundance of reading whatever one wishes.

Therefore, judging that these inconveniences must be remedied, We have thought two things had to be done, from which a norm of acting in this kind, certain and clear, may be available to all. Namely, We ordered the Index of prohibited reading of books to be most diligently revised; then, when it should be mature, to be published after it had been so revised. Besides, We applied our mind to the rules themselves, and We decreed that, their nature remaining unharmed, they be made somewhat milder, so plainly that to obey them, provided one is not of bad disposition, cannot be grave and arduous. In this We not only follow the examples of our predecessors, but imitate the maternal zeal of the Church: which indeed seeks nothing so much as to show itself benign, and has always cared, and cares, to heal those born from itself in such a way that it lovingly and zealously spares their weakness.

And so, after mature deliberation, and with the Cardinals of the Holy Roman Church from the sacred Council for marking books having been employed, We have resolved to publish the General Decrees which are written below and joined together with this Constitution: which same sacred Council is hereafter to use exclusively, and which Catholic men throughout the whole world are to obey religiously. We will that these alone have the force of law, with the rules published by command of the most holy Tridentine synod, observations, instruction, decrees, warnings, and every other statute and command of our predecessors on this matter being abrogated, with the one exception of the Constitution of Benedict XIV, Sollicita ac provida, which, just as it has been in force up to now, so We will to remain entirely in force hereafter.