Heinrich Cornelius Agrippa von Nettesheim, better known as H.C. Agrippa, lectured at the University of Dole in Cologne, Germany in 1512. Two years earlier, while studying with polymath and cryptographer Johannes Trithemius, he revealed to his friend the earliest draft of De occulta philosophia libri tres (in English: Three Books Concerning Occult Philosophy). Trithemius was guardedly approving; he encouraged Agrippa to continue his voluminous research on the occult … but in secret, so as not to incur persecution for his fringe beliefs. He continued to work on his magnum opus for twenty years.
Agrippa was not given to secrecy. Due to his obvious occult inclinations, he was denounced as a “Judaizing heretic” by his peers. His later angry response to the university did not endear him to it any better.
Parting with the university on bad terms, Agrippa lead a wanderer’s life. He took a succession of odd jobs, each of which he was quietly denounced by and fired from for his public occult practices. With each firing came another vitriolic rebuttal.
Apart from a consistent pattern of spurious employment, Agrippa never suffered any of the persecution one would expect of someone espousing his beliefs at the time. (Laws prohibiting ritual magic would not be codified until decades after his death in 1535.) In fact, his openness inspired others to nurture an interest in esoteric knowledge. Among them was Johann Weyer, who, at the age of fourteen, became a live-in student of Agrippa’s in Antwerp, Belgium in 1529.
In 1545, Weyer was appointed town physician of Arnhem in the Netherlands. While in this station, he was called for expert consultation in the 1548 case of a suspected fortune teller. Being raised sympathetic to occult practice and embracing the scientific discipline his work as a physician demanded, Weyer broached the subject with skepticism few others held.
In 1550, Weyer moved to Cleves, Germany, where he served as court physician for Duke William the Rich. In 1563, he authored De Praestigiis Daemonum et Incantationibus ac Venificiis (in English: On the Illusions of the Demons and on Spells and Poisons), a point-by-point rebuttal of the Malleus Maleficarum. It included an appendix called the Pseudomonarchia Daemonum (in English: The False Kingdom of the Demons) describing the hierarchy of demons in Hell. His cited source manuscript was Liber Officiorum Spirituum, seu Liber dictus Empto. Salomonis, de Principibus & Regibus Daemoniorum (in English: Book of the offices of spirits, or the book called Empto. Salomonis concerning the princes and kings of the demons).
Despite being a fascinating glimpse into ancient demonic invocations, it was not Weyer’s intention to teach readers how to perform them, “lest anyone who is mildly curious, may dare to rashly imitate this proof of folly.”
Weyers was the first to submit a skeptical rebuttal to the religiously fueled paranoia of the time. However, it was but a whisper beneath the trumpeting of Christian zealotry.
Thus, the witch hunts continued, making it dangerous for others to step forward in kind until the last witch was executed in Europe – either in 1782 in Switzerland, or in 1811 in Prussia.