Mastering the full range of subjects taught in medieval universities normally required many years of hard and expensive study. From the thirteenth century on, however, an anonymous work known as the Ars notoria promised, through diagrams, incantations, and arcane rituals, to rapidly transmit to scholars the total knowledge of anything they might need. Condemned by church authorities, the fifty-six extant manuscripts nevertheless testify to the seductiveness of that offer.¹

Its complex diagrams were at the center of its appeal. Unlike diagrams in other magical texts, those in Ars notoria do not illustrate what the text is seeking to communicate. Nor do they act as models to be replicated in three-dimensional form as pieces of magical equipment.² Instead, they supposedly work almost in the same way as religious icons. That is, faithful possession and use of them can offer direct contact with powerful and benign supernatural forces — and ultimately even with God. The diagrams themselves are the route to magic and consist of arrangements of symbolic and geometric forms, patterns, and symbols, interspersed with “words”, which are frequently unintelligible combinations of letters.³ Practitioners who opened their minds to receive and imprint these labyrinthine images, while reciting complex verbal formulae and strings of mysterious, almost unpronounceable words and names, are engaging in a significant act of trust.

Several factors made the Ars notoria fundamentally different from other magical texts. First, this is not a text in conflict with the church. In fact, the rituals framing and shaping usage of the images are presented as extremely pious, and the texts to be recited are identified as prayers. The alien words, names, and characters are explained as coming from ancient languages such as Greek, Hebrew, and “Chaldean”, and are claimed to preserve both the names of angels and words used to communicate with them. Second, the advantages offered are relatively virtuous: contact with spiritual beings and full knowledge of the subjects taught in medieval universities. Such claims cut little ice with thirteenth-century theologians, however, who saw clear links to things condemned as superstitious and demonic by St Augustine, despite the text’s assertion that it contains wisdom revealed to King Solomon.

St Thomas Aquinas was worried enough by the Ars notoria to name and condemn it specifically in his Summa theologiae — one of the most authoritative summaries of Christian teaching. He dealt with the very serious issue of superstition in Book Two, Part 2 — Question 96 is effectively devoted to the Ars notoria. Aquinas’ conclusion is wholly negative: the “art” is both “unlawful and futile”. It is futile because it cannot deliver what it promises. Still more seriously, its “signs” are neither understood by humans (like ordinary words and letters) nor sent by God (as sacraments are), and thus are precisely the type of thing that lures humans into contact and compact with demons.

That may seem a conclusive case for the rejection of the Ars notoria, especially as Aquinas’ objections were echoed by other major theologians. However, the number of surviving medieval copies of the work, and the fact that it was copied and owned in religious institutions until the end of the medieval period, show that the church ultimately had neither the interest nor ability to stamp it out. Moreover, it was translated in the early modern period and also went into print, demonstrating an ongoing — and more widespread — interest. The copy of Ars notoria now in Yale University Library is accepted as the earliest known manuscript version, and it has been suggested that it was produced in the setting of the University of Bologna. It was likely intended for a university master — probably at Bologna — since to use it requires considerable preparation, experience, and confidence.

Advanced training was indeed necessary. The Ars notoria operates in ways that cannot be simply understood by human reason. Statements on the origins and power of the treatise’s contents are interspersed among texts to be recited as prayers (orations) and lists of mysterious words. To make things more complicated, the order in which passages are to be used is not always entirely clear. Even the correct pronunciation of the names would be a matter of concern, as a short quotation from the first “prayer” will show: “Phos, Megale, Patir, Ymos, Ebel, Eber, Helioth, Gezei, Salatial, Sadim, Helgyo, Megis, Micton, Esel, Gecor, Granal, Semaranxai, Gelsemana, Arasamion, Sale, Patir, Agion, Atnas, aminb.”⁴

Materials for the improvement of the would-be practitioner come first: the acquisition of the “general” gifts of memory, intelligence, and eloquence, drawing upon the “figures or prayers called triumphales by Solomon”. With this stage achieved, the practitioner can move on to the “specials”. The process, however, cannot be rushed, since the “triumphals” must be repeated on eight days within a complete lunar month. The first performance should take place on the fourth day, and is repeated on the eighth, twelfth, sixteenth, twentieth, twenty-fourth, twenty-eighth, and thirtieth days. It is worth pointing out that the use of lunar days would be familiar to clerics trained in the liturgical calendar of the Church, as well as to astronomers, so this would not in itself appear sinister, despite Aquinas’ reservations. The “specials” begin with the three fundamental arts of the university syllabus: Grammar, Eloquence/Rhetoric, and Dialectic, which were collectively known as the trivium. Interestingly, the text devotes a good deal of space to these, despite their relatively low status. They are then more briefly followed by materials for a rather unorthodox version of the more advanced subjects of study: Philosophy, Medicine, Music, Geometry, Mathematics, and Theology.⁵

The eightfold recitation of the “triumphals” gives a month-long structure to the core ritual of the Ars notoria, linked to the days of the Moon (i.e. the days of a lunar month, starting at new moon). These could be identified using a standard liturgical calendar and did not require direct observation. These recitations could be interwoven with performance of the “specials”, although the linking of all this to the images is not yet entirely clear. Logically enough, the “specials” are followed by texts to ensure success in the combined usage of the prayers, names, and images.

A diligent practitioner will gain expertise in the process of working through the rituals for each art. The first, Grammar, has three images, which are to be looked deeply into (the Latin word is inspectio) in a specified order and separately from the recitations of the preliminary prayers. These “lookings” are to take place in the evenings, with the first image being the focus of days one to fourteen of the chosen month. The words incorporated into the image are to be read out or recited twenty-four times, and books of grammar are to be opened and briefly looked at during this time.

Then the image itself is to be looked into, piously and solemnly, twelve times. From then until the twenty-eighth day, the second figure is to be added, and the work required increases. Each figure is looked at twenty times, and there are to be thirty recitations of the texts. On the last two days, all three figures are to be used, looked into twelve times each, with thirty-seven recitations of the prayers.

For some users, the rituals were so powerful that they seemed demonic. One of these was Brother John, an early fourteenth-century monk of the abbey of Morigny, near Étampes. John’s account of his introduction to the text, his powerful attraction to it, and the terrifying experiences he underwent while using it, was given in several chapters of John’s own, visionary work, the early fourteenth century Liber florum celestis doctrine.⁶

The great attraction of the Ars notoria for John was its promise of quick access to advanced scholarly knowledge. He recounts his continuing wish to study, and how he was lent a copy of a book of necromancy by “a certain cleric”. He copied much of it and wanted more. This led to an encounter with a “medical expert” from Lombardy, who informed John that what he needed was the Ars notoria, and that a copy of it was to be found within the walls of the school (at Orléans) where John had been sent. These details provide important evidence of the liminal status of works of ritual magic. They were recognised as dangerous, and were far from being officially approved, and yet were well known, owned and recommended by educated individuals, including monks and clerics.

For John, the Ars notoria was dangerous not in some abstract way, but very directly. He confesses that it struck him at first as beautiful and holy, and seemed to offer miraculous gifts rather than demonic temptations. It became apparent, however, that the book was utterly deceptive, a work of the Devil, a “sick pleasure” that was actually fatally poisonous to the soul, not only to the body.

John records that the Ars notoria was especially attractive because he could not afford all the books needed for his studies, nor the many lectures. He seems to have abandoned his official course, wishing to take advantage of the promise of knowledge of all the sciences, and devoted himself to working with the Ars. He even used the Ars to teach his younger sister Latin and introduce her to magic. He believed he had worked out how to make the rituals work — and followed one (unnamed) ritual for a whole lunar month, ending correctly on the night before the new moon. That night, John experienced a disturbingly ambiguous vision, in which three figures (whom he at first thought to be the Trinity) ordered him to continue using the book for a further eight days. Further troubling visions ensued, in which arrogant figures demanded worship — something that was clearly against true religion. Gradually it became clear to John that the book hid invocations to demons within what appeared to be beautiful prayers. And yet, like any addict, John found it almost impossible to give up the Ars notoria completely; it was only when the visions became directly life-threatening that the Virgin, with St John the Evangelist as her intermediary, appeared and made it clear that, as John says, “the Ars notoria was deeply evil”.

This revelation, however, only inspired John to go back to direct study of necromancy: he even boasts of his success in composing a new work of his own, as well as of making the magical Rings of Solomon. Further visionary experiences were required before he resolved to give up necromancy completely. He then went on to put together a new, short, and clear collection of thirty prayers that he believed would lead to a genuine knowledge of all that the Ars notoria had falsely promised. John was to work on, and expand, this for a considerable length of time, and it gained a wide readership in its own right despite being condemned and burned at the University of Paris in 1323.

John of Morigny’s adaptation of the Ars notoria would prove the only one to face such measures. However, evidence that the full version of the Ars notoria was attractive but over-demanding is found in the number of shortened and simplified versions that appeared in the later Middle Ages. These tended both to focus on more limited goals and to require considerably less time from their users. A popular promise was to improve memory, and some versions of the Ars notoria circulated under the title of Art of Memory.

Indeed, the Ars notoria’s complex mix of liturgical rituals, ambivalent “angel names”, and challenging figures retained its fascination into the Renaissance and was apparently not affected by the Reformation. The text remained one of the most prominent works of ritual magic, and continued to be edited and abbreviated, despite growing anxiety about the supposed activities of demonically manipulated witches.⁷ Part of the attraction may have been a hope of social mobility for those who could not afford to go to university. The Ars was translated out of the learned language of Latin, and also went into print. The early modern version in English is still available.⁸ The fact that printers felt safe in producing and selling copies of this work suggests that those who could afford and use such a book did not feel vulnerable to accusations of witchcraft. A new, more educated and ambitious readership was growing for texts that offered increased knowledge and success through the use of magic.