Among his students were Heinrich Cornelius Agrippa (1486---1535) and Paracelsus (1493---1541). Trithemius was a writer focusing on "steganography" (cryptography). His most famous work, Steganographia, ended up on the Index Librorum Prohibitorium in 1609. On the surface, the book appears to be about black magic, in particular using spirits to communicate across vast distances. But the black magic is merely a cover for the real contents of the work, which deal with cryptography and steganography---or for those of us with pudding in our heads, codes and ciphers.
It is interesting that Trithemius chose to disguise his writings about secret writings inside a cover text about black magic and spirit (angelic/demonic) messengers. It is the cover text that got him into trouble. His teachings included oaths of secrecy and "delibately obscure discussions of the technique" (as one writer put it). Trithemius also encouraged Classical learning and everyday subjects, believing that they were necessary to those who were involved in theological pursuits. It is not hard to imagine Trithemuis getting into trouble over his ideas.
(I will admit that I am puzzled about why he didn't pick a different subject. Then again, there is another possibility...)
Steganographia was not printed until 1606, though the unfinished manuscript was circulated in manuscript form. Of course, from a Golden Dawn viewpoint, Polygraphia (1518) is the more important work.
|The important page from Polygraphia.|
|A page from Steganographia.|
|Another page from Steganographia.|
|One can understand why Johannes Trithemuis got into trouble.|
|Ah, boyhood memories.|
Yet the existence of the book in both libraries create a trust problem when it comes to the various stories that Westcott told about the Cipher Manuscript. One of the stories says that Mackenzie had seen the Cipher Manuscript and had "expressed ignorance of it and wonder." Yet Mackenzie would have been able to decipher it easily, even without a key---a key, he just happened to have in his own library. And Mackenzie, like Westcott, was a member of many societies and Orders and a collector of esoteric lore. I am not sure that Mackenzie could have expressed ignorance and wonder over the Cipher Manuscript...but that is a subject for another day.