The Index of Forbidden Books and the Censorship of Magical Books

In 1559 Pope Paul IV issued an official list of authors and works that Catholics could not read, own or print. It was the first Roman Index of Forbidden Books, and it would be updated for four centuries, down to the last edition of 1948. For the history of books on magic and astrology this instrument was decisive: it established what could circulate freely and what had to vanish from the shelves.

From the Index of Paul IV to the Tridentine Index

The Index of 1559 was extremely severe. It divided authors into classes and condemned the entire output of some of them wholesale, including works that had nothing to do with religion. Among the names struck was Cornelius Agrippa, author of De occulta philosophia. The protests of booksellers and scholars were such that as early as 1564, after the close of the Council of Trent, a new, more detailed and less indiscriminate Index was published.

The Tridentine Index, approved by Pius IV, opened with ten general rules that applied even to books not listed by name. In 1571 Pius V set up a dedicated body, the Congregation of the Index, charged with updating the lists, examining new works and granting reading licences to those who, for reasons of study or office, needed to consult forbidden texts.

The Ninth Rule

For the occult arts the fundamental norm was the ninth rule. It forbade books of geomancy, hydromancy, aeromancy, pyromancy, onomancy, chiromancy and necromancy, together with those containing sorceries, poisonings, auguries, auspices and magical incantations. It also struck judicial astrology, that is, the claim to foretell through the stars future events depending on human will.

The rule made one important exception, however: writings on astrology useful for navigation, agriculture and medicine remained lawful. The distinction reflected an old debate, already present in the Speculum astronomiae, between a natural astrology compatible with faith and a divinatory one that threatened free will. In 1586 the bull Coeli et terrae of Sixtus V forcefully renewed the condemnation of divination.

Books Condemned and Books That Survived

Over the centuries many texts now studied as sources for the history of magic entered the Index. Trithemius's Steganographia was added in 1609, a few years after its first printing; the works of Giordano Bruno were banned in 1603. Other books were placed on the Index with the formula donec corrigatur, that is, until corrected, and circulated in expurgated editions with whole passages struck out.

The Index never managed to eliminate the condemned texts entirely. Many survived in private libraries, in Protestant countries or in manuscript copies, and at times the ecclesiastical tribunals themselves kept the copies they had seized. Paradoxically, condemnation aroused curiosity and made certain titles more sought after by collectors, who paid high prices for copies.

The Index lost its juridical force in 1966, with a notification of the Congregation for the Doctrine of the Faith following the Second Vatican Council. Its archives, opened to scholars in 1998, are now a precious source for understanding how people read and censored in the early modern age. For the historian of grimoires, the list of forbidden books is also, paradoxically, a map of those that were circulating.