Secrets and Marvels

Albertus Magnus, the thirteenth-century polymath known as the Universal Doctor, had a problem. To some, he was the greatest natural philosopher of his age. To others, he was a dangerous sorcerer who built talking automatons, disguised himself as a midwife to learn forbidden secrets, and wrote books on summoning demons. Was Albertus Magnus a saint, or was he a sorcerer? The answer to this question would help define the very boundary between science and magic. In this episode, I bring you the story of Albertus Magnus and the Mirror of Astronomy.

Researched, written, and produced by Corinne Wieben with original music by Purple Planet.

Episode sources

Chapters

• 0:00 Pre-roll
• 0:08 Intro
• 2:03 The Crisis of Magic
• 8:31 The Mirror of Astronomy
• 16:32 Saint and Scientist
• 21:28 Conclusion
• 24:12 Outro

Transcript

Pre-roll
You’re listening to Enchanted, a podcast on the history of magic, sorcery, and witchcraft. I’m Corinne Wieben.

Intro
A Dominican friar, a talking mechanical head, and a reputation two hundred years in the making. In the winter of 1483, the city of Cologne staged an elaborate ceremony. Church bells rang, university scholars processed in full regalia, and the bones of Albertus Magnus (who had been dead for over two centuries) were ceremoniously moved to a place of honor within the Dominican church. But this wasn’t just a show of respect for a great mind. This was a rescue mission.

Albertus Magnus, the thirteenth-century polymath known as the Universal Doctor, had a problem. To some, he was the greatest natural philosopher of his age, the man who brought Aristotle to the Christian West. To others, he was a dangerous sorcerer who built talking automatons, disguised himself as a midwife to learn forbidden secrets, and wrote books on how to summon demons. By the late fifteenth century, his dual reputation threatened not just his legacy but the legitimacy of an entire religious order.

The Dominican friars of Cologne had to make a choice: Was Albertus Magnus a saint, or was he a sorcerer? And in answering that question, they would help define the very boundary between science and magic, a boundary that still shapes how we think about knowledge today. In this episode, I bring you the story of Albertus Magnus and the Mirror of Astronomy.

The Crisis of Magic
Albertus Magnus, or Albert the Great, died in 1280, widely respected as one of the greatest minds of his age. He had served as bishop of Regensburg, though he resigned the position after just a few years, preferring the quiet life of scholarship to the politics of ecclesiastical office. His former student, Thomas Aquinas, had become the most influential theologian in the Christian world. Albertus’s commentaries on Aristotle were taught in universities across Europe. But something strange happened in the decades and centuries after his death. Stories began to circulate: dark, fantastic stories that transformed the scholarly friar into something else entirely.

One of the most persistent legends claimed that Albertus had built a mechanical man, an android, capable of speech. According to the tale, Albertus labored for thirty years to create this automaton, which could answer questions and predict the future. The story goes that Thomas Aquinas, horrified by what he saw as a demonic creation, smashed the talking head with a hammer, crying out, “Get thee behind me, Satan!” Albertus supposedly lamented, “There goes the labor of thirty years!” Another rumor claimed that in his youth, Albertus had lived in Paris, where he used magic to seduce a princess. When the king discovered the affair and sent soldiers to arrest him, Albertus used a magical ball of yarn to escape, unrolling it as he fled until it created a path that led him safely away.

Perhaps most damaging was the accusation that Albertus had disguised himself as a woman to work as a midwife, learning the “secrets of women,” the intimate knowledge of pregnancy, childbirth, and female anatomy that was strictly forbidden to men. This rumor was particularly dangerous because it suggested that Albertus had transgressed not just intellectual boundaries but gender and social ones as well. Books circulated under Albertus’s name that he almost certainly didn’t write: the Semita Recta, a manual of alchemy that claimed one could transmute base metals into gold, Secreta Mulierum, a gynecological text filled with bizarre claims about female sexuality and reproduction, and Mirabilia Mundi, a book of “marvels” that described how to create magical talismans and invoke spirits. By the fifteenth century, Albertus Magnus had two reputations. To scholars, he was still the Doctor Universalis, the great synthesizer of Aristotelian philosophy. But to a broader public—and to a worrying number of practitioners of what was called “learned magic”—he was Albertus Magus: Albert the Magician.

To understand why this dual reputation became such a crisis, it helps to understand how dramatically attitudes toward magic were changing in fifteenth-century Europe. In the early Middle Ages, magic was largely seen as a peasant superstition, foolish errors made by the uneducated who still clung to pagan practices. If a farmer carved protective runes on his plow or a village woman whispered charms over a sick child, the Church might impose a light penance, but these were not considered grave threats to the faith. But by the thirteenth and fourteenth centuries, something had changed.

A massive influx of Arabic and Greek texts brought new knowledge to Christian Europe, including sophisticated traditions of astrology, alchemy, and what was called “image magic” or “talismanic magic.” These weren’t folk practices; they were learned disciplines that required literacy, mathematical skill, and philosophical knowledge. And they were being practiced not by ignorant peasants but by educated clerics: priests, friars, and university scholars. The Church found itself in a dilemma. Some of these practices seemed to operate through natural principles. If the stars influenced the weather, wasn’t studying that influence a form of natural philosophy? If certain herbs had healing properties, wasn’t that medical science? Where exactly was the line between legitimate investigation of nature’s “occult virtues” and forbidden sorcery?

Theologians developed a framework for answering this question. The key was the source of the power being invoked. If an effect came from the inherent, God-given properties of natural things—the heat of the sun, the attractive power of a magnet, the medicinal virtue of a plant—then studying and using those properties was legitimate natural philosophy. But if an effect required the intervention of a spiritual being, particularly a demon, then it was sorcery, pure and simple. The problem was determining which was which. Did a talisman carved with astrological symbols work because it captured the natural influence of the planets, or because a demon was secretly empowering it? Did an alchemical transmutation succeed through understanding the properties of matter, or through demonic assistance?

By the fifteenth century, Church authorities had largely settled on an answer: any ritual that involved invoking names, burning incense, reciting prayers or spells, or performing sacrifices was presumed to involve demonic cooperation. The demon might be compelled through magic circles and conjurations, or it might be willingly cooperating through a pact, but either way, such practices were absolutely forbidden.

And this is where Albertus Magnus became a problem.

The Mirror of Astronomy
Among the works attributed to Albertus Magnus was a text called the Speculum Astronomiae, the Mirror of Astronomy. Scholars still debate whether Albertus actually wrote it, but by the fifteenth century, it was firmly associated with his name. And it became one of the most important tools in defending his reputation. The Speculum was essentially a bibliography, a systematic guide to the literature on astrology and related arts. But it wasn’t just a list of books. It was a careful attempt to draw the line between legitimate and illegitimate practices.

The text divided astrological image magic into three categories.  First, there was “astronomical” or “mathematical” image magic. This involved creating talismans at specific astrological moments to capture the natural influence of the planets. For example, carving the image of a scorpion on a stone when the constellation Scorpio was in the ascendant, believing this would protect the wearer from scorpion stings. The Speculum deemed this potentially licit because it relied solely on the natural virtues of celestial bodies: no spirits, no prayers, no invocations. Second, there was “Hermetic” image magic. This involved not just astrological timing but also prayers to planetary spirits, offerings of incense, and various rituals. The Speculum condemned this as “abominable” because it clearly involved invoking spiritual entities. Third, there was “Solomonic” magic: the tradition of conjuring demons through magic circles, commanding them with secret names, and binding them to service. The Speculum called this “detestable” and utterly forbidden. By providing this careful taxonomy, the Speculum created a space for the legitimate study of celestial influences while clearly demarcating the boundaries of the forbidden. It said, in effect: “You can study the stars. You can investigate how planetary movements affect earthly things. You can even create talismans based on astrological principles, as long as you don’t invoke spirits, offer prayers to demons, or engage in ritual conjuration.”

For fifteenth-century defenders of Albertus, the Speculum was a godsend. It proved that Albertus himself had been concerned with distinguishing legitimate natural philosophy from demonic sorcery. If he had studied questionable texts, it was only to map out these boundaries, to know where the line was so he could warn others not to cross it. The man who orchestrated the 1483 ceremonial reinterment of Albertus’s bones was Jacob Sprenger, the Dominican Provincial Superior in Germany. Sprenger was a leading figure in the Observant reform movement, a group within the Dominican Order dedicated to strict adherence to religious rules, apostolic poverty, and moral discipline. Sprenger had a vision for reforming Christian society, and central to that vision was the eradication of magic. And here is the great historical irony: Sprenger was not just trying to save Albertus Magnus’s reputation. He was also, at roughly the same time, co-authoring the Malleus Maleficarum—the Hammer of Witches—one of the most influential witch-hunting manuals ever written.

To understand this apparent contradiction, we need to understand what Sprenger was really doing. He wasn’t defending magic; he was defining it out of existence in certain contexts while condemning it more harshly in others. Sprenger commissioned two Dominican friars to write formal biographies of Albertus Magnus, what were called vitae or “saint’s lives.” These weren’t just hagiographies meant to praise a holy man. They were carefully constructed legal and theological arguments designed to rescue Albertus from the charge of sorcery. The first biography was written by Peter of Prussia around 1487. Peter took a scholastic, analytical approach. He methodically examined every accusation against Albertus and every suspicious text attributed to him. His central argument was what he called the “Goliath’s Sword” defense. Just as David used Goliath’s own sword to behead the giant, Peter argued, Albertus studied the texts of magic only to destroy their power. He read books on necromancy not to practice the art but to understand it well enough to refute it. He investigated astrological images not out of sinful curiosity but as a work of virtue, to protect the faithful by clearly distinguishing legitimate science from demonic deception. Peter was meticulous. He created an authoritative list of Albertus’s genuine works, explicitly rejecting texts like the Semita Recta as fraudulent. He pointed to passages in Albertus’s authentic writings where the scholar had condemned certain magical practices. He used the Speculum Astronomiae to show that Albertus himself had provided the very framework for distinguishing legitimate astrology from forbidden magic.

The second biography, written by Rudolph of Nijmegen around 1490, took a different approach. Where Peter had been analytical, Rudolph was rhetorical and persuasive, writing in a more accessible style for a broader audience. Rudolph particularly focused on the damaging accusation that Albertus had worked as a midwife. He deployed what we might call the “expertise versus practice” defense. Does writing about plants make you a gardener? Does writing about sailing make you a sailor? Does writing about sin make you a sinner? Rudolph pointed out that the Church Fathers themselves had written extensively about carnal sins, not because they practiced them, but because they needed to understand and condemn them. Similarly, Albertus’s knowledge of gynecology and embryology was purely intellectual, gained through the study of medical texts and natural philosophy, not through any improper practice.

Together, Peter and Rudolph constructed a portrait of Albertus as the model Observant Dominican. They emphasized his years of traveling on foot and begging for bread from door to door in apostolic poverty. They highlighted his resignation from the bishopric of Regensburg, portraying it as a humble rejection of worldly power in favor of scholarly contemplation. They even recounted a story in which Albertus ordered the exhumation of a deceased friar who had violated the vow of poverty by hiding a private stash of money, demonstrating his zeal for religious discipline. What these biographers were doing was “disenchanting” Albertus Magnus. They were systematically removing the magical elements from his legend and replacing them with a narrative of scientific curiosity bounded by orthodox piety.

Saint and Scientist
But this was about more than one man’s reputation. In defending Albertus, the Dominican friars were defining the very nature of legitimate knowledge. If Albertus Magnus, the greatest natural philosopher of his age, was a sorcerer, then natural philosophy itself was suspect. If studying the stars, investigating the properties of minerals, or seeking to understand the hidden powers of nature inevitably led to demonic cooperation, then the entire project of scientific inquiry was fundamentally dangerous. The Observant friars needed to prove that you could be a brilliant investigator of nature without making a pact with the Devil. They needed to show that knowledge itself, the “desire to know” that Albertus had celebrated, was not inherently sinful, as long as it was pursued within proper boundaries.

This had profound implications for how magic was understood and prosecuted. Throughout the Middle Ages, “learned magic,” the kind practiced by educated clerics, had often been treated relatively leniently. It was seen as an intellectual error, a misguided curiosity. Practitioners might be disciplined, but they weren’t usually executed. But by the fifteenth century, this was changing. Church authorities increasingly argued that all effective magic required demonic cooperation. And cooperation with demons wasn’t just an error; it was apostasy, the complete rejection of the Christian faith in favor of allegiance to Satan.

This theological shift had devastating consequences. If all magic involved demonic pacts, then all practitioners of magic, whether learned clerics or village cunning folk, were apostates and heretics. And heresy was a crime punishable by death. The Malleus Maleficarum that Sprenger was writing even as he defended Albertus embodied this new, harsher approach. It argued that witchcraft, which it defined as sorcery combined with a pact with the Devil, was the worst of all heresies. It provided detailed instructions for interrogating, trying, and executing suspected witches. By “disenchanting” Albertus Magnus, by proving that his investigation of nature was not magic, the Dominican friars were ironically helping to make the definition of magic narrower and more dangerous. They were creating a clear space for “natural philosophy” by pushing everything else into the category of demonic sorcery.

The campaign to clear Albertus Magnus’s name had mixed results in his own time. In 1484, the friars submitted a formal petition to Pope Innocent VIII requesting Albertus’s canonization. The Pope didn’t grant full canonization—that wouldn’t come for another four and a half centuries—but he did permit local veneration of Albertus as a blessed figure in Cologne and Regensburg. But the intellectual work of Peter of Prussia and Rudolph of Nijmegen had a lasting impact. Their biographies established the “official” understanding of Albertus Magnus as a pious scholar who had investigated nature within the bounds of Christian orthodoxy. The list of authentic works they created helped to separate Albertus’s genuine philosophical achievements from the magical texts falsely attributed to him.

Over the following centuries, the magical legends gradually faded. Albertus came to be remembered primarily as a great natural philosopher and theologian. And in 1931, Pope Pius XI finally granted what the fifteenth-century Dominicans had sought: Albertus Magnus was canonized as a saint and declared a Doctor of the Church. In 1941, Pope Pius XII went further, naming Albertus the patron saint of the natural sciences. Albertus Magnus, once suspected of sorcery, became the Church’s official champion of scientific inquiry. But perhaps there’s a deeper truth here. The fifteenth-century campaign to save Albertus wasn’t really about separating science from magic; those categories didn’t exist yet in the modern sense. It was about drawing a line between knowledge pursued in service of understanding God’s creation and knowledge pursued through alliance with demons.

Conclusion
The story of Albertus Magnus and his fifteenth-century defenders reminds us that the boundary between science and magic wasn’t always clear, and it certainly wasn’t natural. It had to be constructed, argued over, and defended. Was Albertus Magnus a saint or a sorcerer? To his medieval contemporaries, the question mattered intensely because how you answered it determined whether the investigation of nature was a pious act or a demonic one. The Dominican friars of fifteenth-century Cologne chose to see him as a saint, a scholar whose curiosity about the natural world was a form of devotion to understanding God’s creation.

In defending Albertus, the Dominican friars were arguing that the natural world operated according to its own God-given laws, laws that could be studied and understood through observation and reason. They were creating a space where nature could be investigated without constantly worrying about demonic interference. Paradoxically, by working so hard to keep God and natural law separate from demonic magic, they were helping to create a view of nature as a self-contained system, a “disenchanted” world where natural phenomena had natural causes. In doing so, they helped to define a space for natural philosophy that would eventually evolve into modern science. But they also contributed to a narrower, more dangerous definition of magic, one that would fuel centuries of witch trials and persecution.

Albertus Magnus himself, had he witnessed these debates, might have appreciated the irony. After all, he was a man who believed that understanding the world required looking at it directly, questioning received wisdom, and following the evidence wherever it led, even to uncomfortable places. In the end, perhaps the greatest magic Albertus Magnus performed wasn’t building a talking mechanical head or flying on a magical staff. It was helping to create a way of thinking about nature that would eventually transform the world, not through incantations and talismans, but through observation, reason, and the relentless human desire to understand.

Outro
If you enjoyed this episode, you can subscribe to Enchanted wherever you listen. This episode was produced by me with original music by Purple Planet. You can find them at purple dash planet dot com. If you want to learn more be sure to check out the sources link in the show notes. Special thanks to Enchanted’s Patreon patrons for supporting the production of this and every episode. If you want to support Enchanted, please visit patreon dot com slash enchantedpodcast. If you’re looking for a way to support the show that won’t cost you anything, you can always give Enchanted: The History of Magic & Witchcraft a five-star rating on Apple Podcasts, Podchaser, Audible, or wherever you listen and recommend it to your friends. You can get in touch with me via email at enchantedpodcast at gmail dot com or follow on Bluesky at enchantedpodcast. As always, for more information and special features, visit enchantedpodcast dot net. I’m Corinne Wieben. Thank you for listening and stay enchanted.