Johannes Trithemius (1462–1516) was a German Benedictine abbot, historian and book collector who wrote about secret writing and the powers of spirits. His work belongs to the Renaissance tradition in which theology, the study of nature and magic were closely connected. He was also an important early adviser to Heinrich Cornelius Agrippa, whose Three Books of Occult Philosophy would become a major work of Western esotericism.
Their connection is unusually easy to hear in their own words. In 1510, Agrippa sent Trithemius an early draft of that work. Recalling their conversations at Würzburg about magic and Kabbalah, he wrote that Trithemius’s encouragement had “put courage, and boldness into me.” Trithemius replied with praise, but urged him to reserve higher knowledge for “higher and secret friends only.” Both men were concerned with defending learned magic from the charge that it was merely superstition or dealings with demons. These are the kinds of conversations behind the books we collect.
Trithemius’s Steganographia takes up a particularly intriguing problem: how to communicate with someone at a distance without revealing the message to anyone else. Written around 1499–1500, it describes spirits, their ranks and the means of summoning them. Within those invocations, however, are instructions for concealing messages in writing. Someone who knows which letters to select can recover a second text from an apparently ordinary letter.
The work circulated in manuscript before it was printed in 1606. Its language of spirit communication helped give Trithemius a reputation for dangerous magic. The question for his readers was what, exactly, they had in front of them: instructions for summoning spirits, a system of secret writing, or a work in which the two were connected.
Our copy, published at Mainz in 1676, contains Wolfgang Ernst Heidel’s defense and commentary. Its red-and-black title page announces the case he intends to make: Trithemius has been condemned and misunderstood, and his work can be explained. By this point, keys to the first two books were already available. Heidel was joining an existing effort to make sense of the text, not revealing all its methods for the first time.
The red-and-black title page, Mainz, 1676. Early ink marks remain below Heidel’s name.
Look at the photograph of the opening of Book II. On the facing page is a Clavis, Latin for “key.” The book gives us both the difficult passage and help in reading it.
A printed key (Clavis) faces the opening of Book II, pp. 226–227.
Book III is stranger still, arranging numbers beside planetary signs and spirit names. Heidel solved its cipher, then concealed his explanation in another cipher. Thomas Ernst deciphered both in 1993; Jim Reeds independently worked out Trithemius’s system in 1998. Finding the ciphers does not settle every question about Trithemius’s religious and magical interests.
Planetary signs, spirit names and numbers in Book III, p. 298.
There is a lot to look at in this particular copy: the title’s emphatic printing, the keys and tables, and the early ink marks left by readers whose identities remain unknown. The half-calf binding is later; the leaves show browning and foxing. These photographs offer a way into a book that once asked its readers to decide where learned magic ended and hidden writing began.
See the 1676 Steganographia and full description — $3,200
Critical Apparatus
Read (free)
Agrippa and Trithemius, prefatory letters to Three Books of Occult Philosophy, in the 1651 English translation. Their exchange of 1510 recalls the conversations at Würzburg and Trithemius’s encouragement and advice on discretion.
Jesus College Libraries, “August 2015: Book of the Month — Steganographia by Johannes Trithemius (1606).” An illustrated introduction to an earlier edition and its keys. Its brief account of Book III’s modern decipherment omits Ernst’s earlier work.
Jim Reeds, “Solved: The Ciphers in Book III of Trithemius’s Steganographia,” Cryptologia 22, no. 4 (1998): 291–317. A free scan of the published paper, with a readable opening account of the controversy followed by the technical solution.
Go deeper
Noel L. Brann, Trithemius and Magical Theology: A Chapter in the Controversy over Occult Studies in Early Modern Europe (Albany: State University of New York Press, 1999). A sustained study of the religious and intellectual setting in which Trithemius’s work was written and debated.