Frontispiece of the Index of Prohibited Books under Pope Benedict XIV

Wellcome Library, London

Frontispiece of the Index of Prohibited Books under Pope Benedict XIV, 1758

In the beginning was the Word. The trouble came afterward. How to teach the Word of God, how to translate Scripture, how to gloss and explain it: these were problems of grave concern to premodern Christians, and getting them wrong was beyond life-and-death. A bad reader’s soul was endangered for eternity. Angels didn’t have this problem. As Dante put it, angels “make themselves…completely known to each other,” communicating directly from divine spirit to divine spirit: a kind of transcendental laser beamed between celestial heads. But humans misunderstand; we grope for meaning; we struggle to be understood. From the beginning of the Catholic Church as an institution, churchmen sought to control the power of words—to shape good readers and eliminate bad ones. This meant censorship.

The Roman Index of Prohibited Books was first published in 1559. Catholic censorship persisted another four hundred years, making the Index the “longest-lived, and least understood” mechanism of censorship in history, as Robin Vose writes in a new book on the subject. At first, Catholic censorship was a relatively straightforward matter: all Protestant books, and all Protestant authors, were banned. So were books printed anonymously or without specifying a printer, date, or place of publication: these were too suspicious. It didn’t actually matter what books said; there were already too many for the Roman censors and theologians even to skim them all. By the end of the sixteenth century censors were simply copying titles from the Frankfurt Book Fair catalog into the Index. Soon, most regions—and many individual cities—had created their own indexes of prohibited books. They each had their own local persecutory flavor: in Spain, for example, the inquisitor general banned Islamic and Jewish writings, especially the Talmud. Local inquisitors in Mexico City banned books that inquisitors in Madrid found permissible.

The 1559 Index was a pet project of a conservative pope. Paul IV is maybe best known to history as the pope who had the Jews of Rome enclosed in a ghetto and gave freer rein to the persecutory impulses of the Roman Inquisition; he was hated by ordinary Romans of his own day, who burned the Inquisition office at his death. But the Index was also the culmination of pressures both inside and outside the Catholic Church, some of which had been mounting for centuries. The flourishing of heretical sects in medieval Southern Europe, such as the Cathars, and the Inquisition tribunals that arose to persecute them; the Reformation, and especially Luther’s mastery of the new technology of the printing press; the reforming voices inside the Catholic Church who sought theological uniformity and consistency: each contributed to the development of a universal Index for Catholic Europe. Soon the censors had an office in which to process great volumes of paperwork. The Congregation of the Index—a department of the Curia—was established in 1571; it worked closely with the Roman Inquisition and the Master of the Sacred Palace, the pope’s chief theologian. Everyone in Rome took a professional interest in heretical ideas.

As the initial upheavals of the Reformation settled, the congregation widened the scope of its censorship. The Index transformed from a catalog of heresies (in Oxford, librarians used the Index as a collector’s guide to the best Protestant scholarship) into an attempt to censor everything everywhere across the early modern Catholic world: literature, politics, art, history, and science. All came under the purview of the overworked and understaffed censors. In 1575 one Vatican official wrote in a letter that he wished “that for many years nothing be printed” so that he could catch up. Crushed under the tide of new books, censorship could be scattershot: books were censored when they happened to be translated into Italian or Spanish or French, when they happened to be sent to the congregation by an offended reader in Brussels or Paris or Lima, or when the censors happened to have a spare moment to look over the title page. Many books escaped unnoticed: the censors missed the conniving Moll Flanders, the outrageous exploits of Fanny Hill.

The church did, famously, take an interest in the new experimental science. In The Index of Prohibited Books, Vose traces the gradual hardening of scientific censorship across the late sixteenth and early seventeenth centuries, even as Rome itself became a home for scientific experiment. Copernicus was not placed on the Index until 1616, more than seventy years after he died. Galileo was both a victim of these more stringent attitudes and an example of the church’s leniency toward elite thinkers. (He was placed under house arrest, not burned at the stake like a common witch.) Throughout, Vose—a professor of history at St. Thomas University in New Brunswick, Canada—laments the unguessable damage done to the history of human thought by Catholic censorship, while also showing that the church’s theologian-inquisitors sometimes took more moderate, scholarly approaches to the suppression of knowledge.


Censors concerned themselves with all genres of reimagining the world, from science and political ballads to vernacular literature. Louis-Sébastien Mercier’s novel The Year 2440: A Dream If There Ever Was One (1771) tells of a Parisian who wakes up in a future society ruled by a philosopher-king, with no priests or monks, no slavery, no pastry chefs, no dance teachers, and no tobacco. (There is no accounting for utopian tastes.) It was, of course, included on the Index; Charles III of Spain was said to have burned a copy with his own hands. Other such fantasies, from Thomas More’s Utopia (1516) to Tommaso Campanella’s Città del sole (written in 1602 and printed in 1623)—which imagined a city whose walls were painted with all of human knowledge in images that “render learning easy” to its citizens—were banned too.

The promise of learning without mediation was as utopian as free love. Early modern works of transgressive fiction, from Ariosto’s Satire (1534) to Richardson’s Pamela (1740), often used sex to imagine new ways of living, and they too fell afoul of the censors. Sometimes the censors’ choices are not easily explained. Several of Nicolas Restif’s erotic works were banned, but Le pied de Fanchette (1769)a kind of extended foot-fetish fantasy in which a pretty orphan girl with shapely feet gets into all kinds of sexy scrapes—was not. Narrative literature, chivalrous romance, the erotic stories of Boccaccio: all were seized by authorities from ordinary Italians’ homes and stored in inquisitorial archives until they could be appropriately emended. The Florentines were so reluctant to trespass against their beloved Boccaccio that it took them until 1573 to come up with a copy that satisfied the censors: monks who smuggled girls into their cells were replaced with students sneaking girls into dormitories.

Censorship expanded geographically with the expansion of the Catholic Church. In the Americas, indigenous writing often confounded European expectations of what writing was. The Incan quipu is a recordkeeping device made of knotted and colored strings. Missionaries couldn’t censor something that they didn’t consider a form of writing to begin with, so they simply destroyed them. A few were preserved for elite European collections, where they became objects of scholarship, ripped from the people whose living histories they recounted. This pattern was repeated throughout the Americas, which partly explains why the Vatican holds one of the most important collections of Mayan, Aztec, and Incan texts and artifacts in the world. The irony is that because indigenous texts were left uncensored, they were never recorded on any kind of list, so their destruction was all the more total. There is no Q for Quipu in any Index.

Attitudes toward East Asian religious texts were considerably more accommodating. Early Orientalist scholars in Europe keenly collected and studied Latin digests of Confucian scholarship, and Catholic missionaries in China like Matteo Ricci argued that some Confucian texts might be profitably adapted within Catholic devotional writings to emphasize similarities between the two religions. But religious accommodation brought its own controversies, and the adaptations and compromises that missionaries developed in China were not always well received in Rome. In the end, Chinese Confucian texts were never censored, but European Catholic texts debating the accommodation of Confucianism were.

How effective was censorship? Did it stop ideas from circulating, and did it hinder literary and scientific thought? As Vose finds, these are nearly impossible questions to answer; it’s easier to say what censorship produced. Early modern censorship was not some Galilean drama of science versus faith: while stifling and suppressing some ideas, censorship allowed others to flourish. When a new book came to be censored, the Congregation of the Index published a broadsheet that would be nailed to church doors across Catholic Europe and the Americas; the ban was also announced from the pulpit. It’s easy to imagine that most of the laypeople who filed past the church door would never have heard of the banned book if not for the broadsheet; censorship could, paradoxically, create a wider audience for a dangerous idea.

The history of the Index bears on wider debates about the Catholic Church and its effects on the early modern world. While historians once focused on the church’s efforts to systematically correct, control, and standardize the beliefs and behaviors of the laity, new generations of historians are much more skeptical of its efficacy. In studies of almost every facet of early modern Catholic social control—such as local priests dealing with confessions of abortion and the operation of Inquisition tribunals—historians have qualified the impact of Catholic officials on everyday life and belief. There was an enormous gulf between the prescriptions of popes, bishops, councils, and priests and the practices and beliefs of the global laity—as there must have been, given the reach of Catholicism from Rome to Manila and Mexico City. Missionaries didn’t have to go that far from home to encounter unorthodox belief: Jesuits referred to rural southern Italy as “our Indies.”


In Forbidden Knowledge: Medicine, Science, and Censorship in Early Modern Italy (2020), Hannah Marcus found that censorship in fact “catalyzed” new conversations about medicine. By asking experts to weigh in on the content of potentially heretical medical knowledge, the church effectively convened a kind of learned society for medical discussion and debate. Similarly, elite scholars were not only censored by the church but used as experts to determine whether to ban a book or how to expurgate it—that is, how to eliminate troubling passages so that the book could circulate in revised form.

Yet censorship worked as intended for the relatively impoverished and unlearned. Ordinary Europeans cared less about Copernican astronomy than about the Word of God. Widespread access to Scripture, through translations of the Bible, was perhaps the most dangerous legacy of the early modern reformers. From the Catholic Church’s perspective, translations of the Latin Vulgate into vernacular European languages posed an enormous threat to the susceptible and unsuspecting layperson. Who had translated it, and what was their theological agenda?

According to the scholar Gigliola Fragnito, the most commonly seized and burned books by the Roman Inquisition were translations and vernacular adaptations of Scripture, which, along with popular forms of devotional writing like Books of Hours, were banned in all Catholic countries throughout the seventeenth century. The so-called semplice et indotti, the simple and unlearned laity, could not be trusted with the unmediated Word of God. In the 1590s the cardinal Gabriele Paleotti proposed an Index of Prohibited Art alongside the Index of Prohibited Books, since images, like vernacular books, were intrinsically dangerous: “After one single look people are able to understand.”

It wasn’t only smuggled heretical content but everyday uses of Scripture that the Church sought to control. In early modern Europe biblical verses decorated knives and were uttered as oaths during dice games. A Veronese man included in his notebook instructions to make a girdle inscribed with holy words from Psalms 1:3, for a pregnant woman to cinch around her belly: she “shall be as a tree which is planted beside a water course, which will bring forth its fruit in due season.” One decree from the Council of Trent curtailed Scripture “turned and twisted to scurrilous use, to wild and empty fancies, to flattery, detraction, superstitions, godless and devilish magic formulae, fortune telling, lotteries.”

While doctors, scientists, and aristocratic scholars could petition the Congregation of the Index to hold banned books in their private libraries, ordinary men and women in Catholic Europe had no such recourse. Some banned topics—such as forms of occult magic like divination, astrology, and hermeticism—were especially popular among elite scholars, yet laypeople couldn’t use scriptural amulets or charms for medical cures or good fortune. The Bible was translated by Catholic scholars into Polish, German, Hungarian, and Arabic, for use in conversion. But ordinary Italians were not authorized by the church to read a Bible in their own language until 1757.

The Index of 1559 was seventy pages long. By 1664 the Roman Index was four hundred pages; at the beginning of the eighteenth century, the Spanish Index reached a sprawling two thousand pages. Once, an Inquisition officer could carry a copy of the Index while he sniffed around the cargo unloaded on the docks in Lisbon or Naples. (Venetian booksellers were in the habit of dumping contraband books in the canal on the approach of priests.) Now the Index was a great unwieldy thing, able to be consulted only in scholarly reference libraries.

The totalizing ambitions of the scholar-censors in this period approaches a kind of Borgesian absurdity. After many years of argument among Catholic theologians about the finer points of free will and salvation (a sensitive topic since Luther), and after the creation of a papal office (the Congregation on the Assistance of Grace) specifically to deal with the debate, one pope after another simply gave up. First Clement VIII and then Paul V were defeated by the controversy and banned any further debate of free will. All books dealing with the so-called De Auxiliis controversy were censored. Censorship had become the domain of the Catholic scholar, and now the Catholic scholars were censoring themselves.

Vose’s book can make for uncomfortable reading for those of us who are the inheritors of that scholarly tradition, or who believe universities to be an uncomplicated home for liberal thought. The very first systematic indexes of censored books were not the work of maniacal monks but of university professors, in Paris in 1544 and Leuven in 1546, who sought to separate true Catholic theology from heretical or misguided ideas. The targets of their censorship? Mostly other professors of theology, from the Protestant (and so obviously heretical) Luther and Melanchthon to their very own colleagues, like the humanist Jacques Lefèvre d’Étaples, who produced French translations of the Bible.

Professors were deeply invested in controlling their own curricula, which were used to train the next generation of theologians. Vose argues that this form of early modern censorship is similar to contemporary academic peer review: anyone who has been on the sharp end of peer review can appreciate that the difference between academic judgment and inquisitorial persecution is a matter of degree. The history of Catholic censorship, Vose suggests, is less one of religious fanaticism than of an evolving program of “honest discernment of good from bad spiritual, intellectual, literary and cultural productions.” Vose wants us to believe that Catholic censorship was at times more benign than we typically suppose. But more unsettling is the long history of repression within our supposedly liberal institutions, universities very much included.

Vose’s The Index of Prohibited Books is not the first history of Catholic censorship, but it’s the first in English to present the often arcane workings of theologians and scholars in a straightforward narrative for a nonspecialist readership. Vose is evenhanded, lamenting the consequences of censorship while carefully distinguishing its early modern form from the more familiar authoritarian types of censorship that came later. For Vose, totalitarian censorship—the generalized destruction and suppression of Orwell’s nightmares—was a different thing altogether from the episodic, incoherent, contradictory practice of Catholic censorship, for all the universalizing ambitions of the popes. He wields a light touch when it comes to drawing lessons about our own “cancel culture.” His main lesson seems to be that Index censorship was “driven and limited by the decisions of individuals and groups” and so subject to change, including of a progressive kind.

Coming after hundreds of pages of burned books and burned radical thinkers, that lesson was a bit deflating. Even the more ordinary laments of early modern readers seem to warrant something more full-throated. Francesco Redi, a doctor, wrote in a letter in 1670:

I believe that my soul will certainly be lost to perdition on account of prohibited books. If instead of creating Adam God had created me in Eden, and if instead of prohibiting me from eating that fig and that apple he had prohibited me from reading books, I am so weak that I surely would have done worse than Adam.

Can any reader of a literary magazine say they aren’t stung by that letter? What would it have felt like to believe not only one’s freedom but one’s mortal soul endangered by reading a book?

The history of the Index is barely even history. The Congregation of the Index was suppressed only in 1966. Catholic censors were central to the formulation of the Hays Code, which strictly regulated Hollywood films from 1934 until its influence waned in the late 1950s. (Point 10 of the code forbade “ridicule of the clergy.”) One Catholic apologist tried to make the case for the Index as late as 1943 with a pamphlet called The Index: Candle-Snuffer or Beacon? That was after modern censors had added Stendhal, Balzac, Flaubert, and Gide to the Index. Graham Greene, who had converted to Catholicism, was privately chastised by the Holy Office in 1953 for depicting a drunken priest in The Power and the Glory. He promised never to do it again. Our ability to write a history of Catholic censorship was, until very recently, censored by the church: the archive of the Congregation of the Index was not open to most researchers until 1998.

As I scrolled through scans of printed Indexes, nearly all of which are available online, I wondered about all those authors and titles, many of which would have been lost to history if they had not been included on the Index. Possibilities of alternative worlds, alternative futures, flicker from the thousands of pages of banned books and authors and subjects: magic, flashing weapons in forbidden duels, female authors whose names are otherwise unattested, the colonization of the moon, utopian ideas, love letters, escapist romance, erotic tales, madrigals. The Indexes are a counter-archive of European history.

More difficult to account for is the toll of self-censorship: the art and literature that was never made, the religious and scientific ideas that remained unwritten—unthought, even—because of the existence of the Index, the congregation, and the Inquisition tribunal. This counterfactual European history is a history of the obscure, the impracticable, the unrecorded. It is so elusive as to remain nearly unimaginable. But for every erotic novella or psalm-inscribed jewel on the Index, a crack appears in the edifice of our historical imagination. Some light gets in. The censor is crowded out by the apparition of what might have been.

In 1574 inquisitors came to the door of Domenico, a cobbler in Spilimbergo, in the far northeast of Italy. They seized and destroyed the only three books that Domenico owned: Orlando Furioso, the Decameron, and the New Testament. Domenico responded: “I swear I shall never read again.” This was the tragedy of censorship, an unbearable narrowing of the spiritual and cultural lives of ordinary people. But I also hear in Domenico’s words his own intolerance: an intolerance of suppression, a disobedience of power. Domenico would not be told how to read. He would rather not read at all.