Index of Forbidden Books (2023)

Q: Since there isn’t an Index of Forbidden Books any more (or at least I assume there isn’t), does canon law say anything about books that Catholics are not supposed to read? Or does the Church hold that we can pick up any book we want now? Are we allowed to read heretical books, for example? –Eric

A: Eric is referring to the former Index Librorum Prohibitorum, or “Index of Forbidden Books,” an official list of books which Catholics were not permitted to read. The Index was first created in the 16^th century, when the Church was dealing with the effects of the protestant reformation, and it became necessary to warn the Catholic faithful that there were books in circulation that were contrary to the Catholic faith. The Index continued to exist for over 400 years, and was finally abolished by Pope Paul VI.

During the four centuries in which the Index was in use, hundreds of books were read by Vatican censors, and their content examined for issues relating to faith and morals. Heretical works which were placed on the Index included works describing in approving terms the teachings of Luther and Calvin, as well as the writings of Cornelius Jansen generations later. Some books were banned for their sexually explicit, immoral content (like the memoirs of Casanova); others could not be read because they promoted scientific positions which the Church held to be contrary to revealed truths (like the work of Galileo). A few might be surprising to many Catholics: Victor Hugo’s Les Miserables, for example, was on the Index because it called into question both the need to respect lawful authorities and the laws themselves, and the consequent need to obey them.

Practically speaking, it was impossible for the censors to keep up with every potentially objectionable book from every part of the world; thus if a bad book was not brought to their attention, it naturally did not make the list! As a result, while the Index was constantly being updated, even after each revision Catholics could safely presume that it still remained incomplete.

When the Index was abolished in the 1960’s, this did not imply that Catholics were no longer discouraged from reading heretical or immoral material. True, there is no longer a complete, official list of books that are to be avoided; but to be fair, given the practical inadequacies of the Index, there really never was!

The guidance that the Church gives the faithful today is couched in terms that are not only broader; they are also worded positively rather than negatively. In other words, instead of telling us which books we cannot read, the code contains several canons explaining who has the right to authorize the publication of books that we can.

For starters, canon 825.1 tells us that Bibles and any other books of Sacred Scripture must have the approval of either the Apostolic See (i.e., the Vatican) or the Conference of Bishops. (The role of a Bishops’ Conference was discussed in more detail in “Are Catholics Supposed to Abstain from Meat Every Friday?”) In other words, if a “Catholic edition” of the Scriptures is to be printed and sold, its text/translation first has to be reviewed by competent ecclesiastical authority. And it is our bishops who have the power and the responsibility to see to it that Bibles and other scriptural books that will be used by Catholics are accurate, for it is their duty in general to ensure that the faithful are not harmed by the content of books that treat of matters of faith and morals (c. 823). Readers who own a Catholic edition of the Bible can look inside the fly-leaf and see that it has indeed been reviewed by the U.S. Conference of Catholic Bishops, if not by the Vatican itself. In contrast, non-Catholic editions of the Bible contain no such approbation, and should not be used by Catholics—for not only does one occasionally encounter faulty translations in such editions, but entire books of Scripture, rejected by protestant leaders like Martin Luther, may be missing altogether!

Publication of liturgical books, such as the Roman Missal—that big red volume from which the priest reads at the altar while celebrating Mass—is, not surprisingly, strictly regulated by the Church. It is the duty of the Bishops’ Conference to compile translations from the official Latin into the vernacular, and these translations must also be reviewed by the Vatican (c. 838.2 and .3). Most readers are presumably aware that here in the United States, we are in the process of implementing a new English translation of the Missal, after its re-translation was completed under the oversight of the U.S. bishops and reviewed by Rome. If someone were conceivably to translate his own version of the Mass and publish it himself, Catholics would not be permitted to use it!

As for Catholic catechisms, canon 827.1 notes that these too cannot be used by the faithful unless they have been approved by the local bishop. The same holds true of any book intended for use as a school text on any religious or moral subject, such as theology, church history, or canon law; these must receive the approval of church authorities before they are used in any class that purports to convey Catholic teaching (c. 827.2). Note that if books on these subjects are intended and used simply for private reading, the law on textbooks does not apply.

But this is not the case with prayer books: whether they are intended for public or private use, Catholic prayer books can only be published with the permission of the diocesan bishop (c. 826.3). Here in the U.S., one occasionally encounters prayer books which were written for Catholics yet printed by private lay-groups without this permission—and this is a direct violation of the law. It is, after all, relatively easy for a theologically questionable prayer or two to be included in a book purporting to contain prayers suitable for Catholics; the bishop, therefore, must review such books to ensure that they include nothing objectionable, which might confuse and/or harm the faith of the Catholic laity.

When a book in any of these categories has in fact received the necessary approval, up front near the title page it normally will say imprimatur, a Latin word meaning “it may be printed.” This is an official indication that the proper Catholic authorities have indeed reviewed it and found it suitable for use by Catholics.

Nowadays, one of the more common scenarios in which these laws need to be followed with care involves books printed by and for Catholics about alleged apparitions and the “messages” that are purportedly conveyed by Jesus, Mary, and other saints to mankind. No matter how well intentioned and devout the writers of these books may be, they cannot on their own authority publish books for Catholics declaring that, for example, “the Virgin Mary wants us all to say the following prayer, which she recited to me herself,” or “Jesus declared that the Church must stop doing X.” Once again, only the bishop has the authority—the same authority that Christ gave to the original Twelve Apostles!—to make a determination that such apparitions and messages that purportedly state Divinely revealed truths are in fact authentic, and can be disseminated among the Catholic faithful. Simple, uneducated Catholics can all too easily be confused and led into potentially serious error by the official, definitive tone of such writings, many of which have been established after investigation by the Catholic hierarchy to be absolutely false. (Here is a good example of an American “apparition” condemned decades ago by the diocesan bishop as false—yet “Catholic” books on the bogus “messages,” which are of course printed without the approval of the bishop, can nevertheless still be purchased there!)

True, in some cases books are written about alleged apparitions which have not yet been investigated by the local bishop, and in these books one may encounter a front-page disclaimer, saying that the author respectfully submits to whatever future decision the Catholic Church will eventually make as to the authenticity of the book’s claims. But there are plenty of other “Catholic” books about unverified visions and apparitions in circulation which indicate nothing of the kind, and Catholics should be wary.

We can see that while the Index is no longer used, it is still possible and necessary to determine whether many books on topics relating to our faith are suitable for Catholics. If a book contains a declaration that it has been reviewed and approved by the Catholic hierarchy, we know that Catholic theologians working for our bishops have determined that it is consistent with the teachings of the Church. But if a book from any of the categories outlined above is lacking such approval, Catholics would do well to avoid it, and choose instead to purchase and/or read one that does.

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