All books which have been condemned either by the supreme pontiffs or by ecumenical councils before the year 1515 and are not contained in this list, shall be considered condemned in the same manner as they were formerly condemned.
The books of those heresiarchs, who after the aforesaid year originated or revived heresies, as well as of those who are or have been the heads or leaders of heretics, as Luther, Zwingli, Calvin, Balthasar Friedberg, Schwenkfeld, and others like these, whatever may be their name, title or nature of their heresy, are absolutely forbidden. The books of other heretics, however, which deal professedly with religion are absolutely condemned. Those on the other hand, which do not deal with religion and have by order of the bishops and inquisitors been examined by Catholic theologians and approved by them, are permitted. Likewise, Catholic books written by those who afterward fell into heresy, as well as by those who after their fall returned to the bosom of the Church, may be permitted if they have been approved by the theological faculty of a Catholic university or by the general inquisition.
The translations of writers, also ecclesiastical, which have till now been edited by condemned authors, are permitted provided they contain nothing contrary to sound doctrine. Translations of the books of the Old Testament may in the judgment of the bishop be permitted to learned and pious men only, provided such translations are used only as elucidations of the Vulgate Edition for the understanding of the Holy Scriptures and not as the sound text. Translations of the New Testament made by authors of the first class of this list shall be permitted to no one, since great danger and little usefulness usually results to readers from their perusal. But if with such translations as are permitted or with the Vulgate Edition some annotations are circulated, these may also, after the suspected passages have been expunged by the theological faculty of some Catholic university or by the general inquisition, be permitted to those to whom the translations are permitted. Under these circumstances the entire volume of the Sacred Books, which is commonly called the or parts of it, may be permitted to pious and learned men. From the Bibles of Isidore Clarius of Brescia, however, the preface and introduction are to be removed, and no one shall regard its text as the text of the Vulgate Edition.
Since it is clear from experience that if the Sacred Books are permitted everywhere and without discrimination in the vernacular, there will by reason of the boldness of men arise therefrom more harm than good, the matter is in this respect left to the judgment of the bishop or inquisitor, who may with the advice of the pastor or confessor permit the reading of the Sacred Books translated into the vernacular by Catholic authors to those who they know will derive from such reading no harm but rather an increase of faith and piety, which permission they must have in writing. Those, however, who presume to read or possess them without such permission may not receive absolution from their sins till they have handed them over to the ordinary. Bookdealers who sell or in any other way supply Bibles written in the vernacular to anyone who has not this permission, shall lose the price of the books, which is to be applied by the bishop to pious purposes, and in keeping with the nature of the crime they shall be subject to other penalties which are left to the judgment of the same bishop. Regulars who have not the permission of their superiors may not read or purchase them.
Those books which sometimes produce the works of heretical authors, in which these add little or nothing of their own but rather collect therein the sayings of others, as lexicons, concordances, apothegms, parables, tables of contents and such like, are permitted if whatever needs to be eliminated in the additions is removed and corrected in accordance with the suggestions of the bishop, the inquisitor and Catholic theologians.
Books which deal in the vernacular with the controversies between Catholics and heretics of our time may not be permitted indiscriminately, but the same is to be observed with regard to them what has been decreed concerning Bibles written in the vernacular. There is no reason, however, why those should be prohibited which have been written in the vernacular for the purpose of pointing out the right way to live, to contemplate, to confess, and similar purposes, if they contain sound doctrine, just as popular sermons in the vernacular are not prohibited. But if hitherto in some kingdom or province certain books have been prohibited because they contained matter the reading of which would be of no benefit to all indiscriminately, these may, if their authors are Catholic, be permitted by the bishop and inquisitor after they have been corrected.
Books which professedly deal with, narrate or teach things lascivious or obscene are absolutely prohibited, since not only the matter of faith but also that of morals, which are usually easily corrupted through the reading of such books, must be taken into consideration, and those who possess them are to be severely punished by the bishops. Ancient books written by heathens may by reason of their elegance and quality of style be permitted, but may by no means be read to children.
Books whose chief contents are good but in which some things have incidentally been inserted which have reference to heresy, ungodliness, divination or superstition, may be permitted if by the authority of the general inquisition they have been purged by Catholic theologians. The same decision holds good with regard to prefaces, summaries or annotations which are added by condemned authors to books not condemned. Hereafter, however, these shall not be printed till they have been corrected.
All books and writings dealing with geomancy, hydromancy, aeromancy, pyromancy, oneiromancy, chiromancy, necromancy, or with sortilege, mixing of poisons, augury, auspices, sorcery, magic arts, are absolutely repudiated. The bishops shall diligently see to it that books, treatises, catalogues determining destiny by astrology, which in the matter of future events, consequences, or fortuitous occurrences, or of actions that depend on the human will, attempt to affirm something as certain to take place, are not read or possessed. Permitted, on the other hand, are the opinions and natural observations which have been written in the interest of navigation, agriculture or the medical art.
In the printing of books or other writings is to be observed what was decreed in the tenth session of the Lateran Council under Leo X. Wherefore, if in the fair city of Rome any book is to be printed, it shall first be examined by the vicar of the supreme pontiff and by the Master of the Sacred Palace or by the persons appointed by our most holy Lord. In other localities this approbation and examination shall pertain to the bishop or to one having a knowledge of the book or writing to be printed appointed by the bishop and to the inquisitor of the city or diocese in which the printing is done, and it shall be approved by the signature of their own hand, free of charge and without delay under the penalties and censures contained in the same decree, with the observance of this rule and condition that an authentic copy of the book to be printed, undersigned by the author’s hand, remain with the examiner.
Those who circulate books in manuscript form before they have been examined and approved, shall in the judgment of the Fathers delegated by the council be subject to the same penalties as the printers, and those who possess and read them shall, unless they make known the authors, be themselves regarded as the authors. The approbation of such books shall be given in writing and must appear authentically in the front of the written or printed book and the examination, approbation and other things must be done free of charge.
Moreover, in all cities and dioceses the houses or places where the art of printing is carried on and the libraries offering books for sale, shall be visited often by persons appointed for this purpose by the bishop or his vicar and also by the inquisitor, so that nothing that is prohibited be printed, sold or possessed. All book-dealers and venders of books shall have in their libraries a list of the books which they have for sale subscribed by the said persons, and without the permission of the same appointed persons they may not under penalties of confiscation of the books and other penalties to be imposed in the judgment of the bishops and inquisitors, possess or sell or in any other manner whatsoever supply other books. Venders, readers and printers shall be punished according to the judgment of the same. If anyone brings into any city any books whatsoever he shall be bound to give notice thereof to the same delegated persons, or in case a public place is provided for wares of that kind, then the public officials of that place shall notify the aforesaid persons that books have been brought in. But let no one dare give to anyone a book to read which he himself or another has brought into the city or in any way dispose of or loan it, unless he has first exhibited the book and obtained the permission of the persons appointed, or unless it is well known that the reading of the book is permitted to all. The same shall be observed by heirs and executors of last wills, so, namely, that they exhibit the books left by those deceased, or a list of them, to the persons delegated and obtain from them permission before they use them or in any way transfer them to other persons. In each and all of such cases let a penalty be prescribed, covering either the confiscation of books or in the judgment of the bishops or inquisitors another that is in keeping with the degree of the contumacy or the character of the offense.
With reference to those books which the delegated Fathers have examined and expurgated or have caused to be expurgated, or under certain conditions have permitted to be printed again, the book-dealers as well as others shall observe whatever is known to have been prescribed by them. The bishops and general inquisitors, however, in view of the authority which they have, are free to prohibit even those books which appear to be permitted by these rules, if they should deem this advisable in their kingdoms, provinces or dioceses.
Moreover, the secretary of those delegated has by order of our most holy Lord [the pope] to hand over in writing to the notary of the holy universal Roman inquisition the names of the books which have been expurgated by the delegated Fathers as well as the names of those to whom they committed this task.
Source: Paul Halsall (trans.), “Ten Rules Concerning Prohibited Books Drawn up by the Fathers Chosen by the Council of Trent and Approved by Pope Pius,” in Internet History Sourcebooks Project, ed. Paul Halsall (New York: Fordham University, 1999).
NB: For the Latin version of the Tridentine Index see: Jésus Martínez de Bujanda (ed.), Index des livres interdits. Vol. VIII: Index de Rome: 1557, 1559, 1564. Les premiers index romain et l’index du Concile de Trente (Sherbrooke: Centre d’Études de la Renaissance, Librairie Droz, 1990), pp. 802–872.