In the annals of Western esotericism, most names are shrouded in legend—figures like Hermes Trismegistus or Solomon, to whom texts were pseudonymously attributed to grant them ancient authority. Rarer still is the practicing sorcerer who wrote a manual under his own name, daring to codify the forbidden arts during an era of fire and fagot. Antonio da Montolmo (c. 1384–after 1394) is that rare figure. A university professor of astrology, he authored De occultis et manifestis ("On the Hidden and the Manifest"), a groundbreaking work that represents one of the earliest and most sophisticated attempts to create a unified theory of astral necromancy, weaving together threads from Solomonic magic, Arabic astrology, and Aristotelian cosmology into a coherent, scholarly system.

The Man and His Audacity: A Scholar in the Shadow of the Stake

To understand Antonio's boldness, one must appreciate his context. Just two generations earlier, in 1327, the brilliant but imprudent scholar Cecco d'Ascoli was burned at the stake in Florence, convicted of necromancy among other charges. Cecco had dared to lecture on astral magic, cloaking it in commentary. Antonio da Montolmo, occupying the very same chair of astrology at the University of Bologna that Cecco once held, did something more radical: he wrote a practical textbook on demonic magic and signed his name to it.

His career was one of orthodox prestige: a doctorate in arts, philosophy, and medicine, a professor of grammar and later astrology at Bologna, and later a professor at Padua. He wrote a conventional and popular textbook on judicial astrology. Yet, parallel to this public life, he composed De occultis et manifestis, a work that was "doubly impossible" for the 14th century:

1. It was an original occult treatise, not an attributed revelation from an ancient sage.
2. It openly discussed demonic conjuration, a capital crime under both canon and secular law.

Antonio even admits within the text to having successfully conjured spirits on rainy nights, a necromantic flex that was essentially a signed confession. That he apparently died peacefully, without prosecution, is a minor miracle and suggests his work remained a closely guarded secret among a literate elite.

De occultis et manifestis: The Blueprint for a System

The text is structured with Scholastic rigor, divided into four intended parts (the final "how-to" section is likely lost or was never completed):

1. Theoretical Foundations: The nature, location, and causal mechanics of "intelligences" (spirits/demons).
2. The Occult (Hidden) Operation: How these intelligences work through talismans and objects without manifesting visibly.
3. The Manifest Operation: How to conjure these intelligences to visible appearance.
4. Practical Execution: The lost section on rites, circles, and incantations.

At its heart, Antonio's system is built on a cosmological synthesis. He merges the Aristotelian-Ptolemaic model of the universe with demonological theology.

1. The Sublunar Prison: Following thinkers like Thomas Aquinas, Antonio places demons not in a mythological Hell, but in the sublunar realm—the region of change and corruption between the sphere of the Moon and the Earth. This is the "kingdom of the air" referenced in scripture (Ephesians 2:2).
2. Astral Sorting: These demons are not free-floating. Antonio systematizes them by binding them to astral influences. They are sorted, ranked, and empowered by the specific rays emanating from the planets, zodiac signs, and celestial directions.

The Three Orders of Intelligences: A Demonic Hierarchy

Antonio classifies the "intelligences" (a neutral term for what are clearly demonic entities) into three structured orders, creating a complex celestial bureaucracy:

1. The Cardinals of the Directions: The highest order is tied to the four cardinal points and their associated zodiacal triplicities (elemental groups). For example, the fiery signs (Aries, Leo, Sagittarius) govern the East. He identifies known Solomonic demons like Oriens (East) as chiefs of these orders. Their specific sin at the Fall determines their astral affiliation—a form of poetic, cosmic justice.
2. The Governors of the Zodiac: The second order derives from the Ars Almadel, a Solomonic text describing an altar for summoning angels. These "altitudes" are spirits tied to each zodiac sign. Antonio suggests one of these is assigned to each person at birth as a persecuting spirit, a dark inverse of a guardian angel, whose malice is calibrated to the individual's social rank.
3. The Planetary Pagan Gods: The third and most familiar order comprises the intelligences of the seven planets. These, Antonio states explicitly, are the very beings the ancient pagans worshipped as gods—Mars, Venus, Jupiter, etc. They are not the angels that move the spheres, but the sublunar, demonic entities that mediate the planets' influences on Earth.

The Synthesis: Astrology as Demonic Technology

This is where Antonio's genius shines. He doesn't just list demons; he provides a dynamic, operational framework. His system answers critical practical questions for the working magician:

1. When is a demon most powerful? When its ruling planet is in its zodiacal domicile, or during its planetary day and hour. The magician must be a skilled astrologer to calculate these "elections."
2. How do you target a spell? By combining astrological sympathy. To harm an enemy, cast a spell when your ascendant sign is dominant and theirs is descending, infusing a talisman with that adversarial astral-demonological power.
3. What is the mechanism of magic? Antonio explains it through mediated causality. The demon (intelligence), itself composed of and powered by astral energy, manipulates the "occult virtues" within natural materials (herbs, stones) or directly acts on the human body and mind, which was itself imprinted with astral qualities at birth.

He distinguishes two parallel paths:

1. Pure Astral Magic: Imbuing a talisman at an auspicious moment, using only natural astral virtue. The demon remains occult (hidden).
2. Pure Necromancy: Conjuring a demon via Solomonic rites (circles, divine names, suffumigations) to compel it to act.
3. The Optimal Path: Combining both. Conjuring the demon of Mars, for instance, during the hour of Mars, on a Tuesday, while Mars is in Aries, to forge a sword or talisman for conquest. This synergy of stellar timing and demonic agency creates the most potent effect.

The Operator: The Exorcist as Spiritual Athlete

Antonio's text is also a psychological manual. The success of the operation depends critically on the state of the operator, whom he calls the Exorcist.

1. Purity & Contradiction: The Exorcist must be in a state of ritual purity—bathed, penitent, and reverent. Yet, paradoxically, Antonio notes that demons may appear more readily to those inclined to sin, as they see an opportunity for that soul's damnation. This aligns with Augustinian theology: all magic is a demonic long con for souls.
2. Confidence as a Catalyst: Borrowing from Galenic medical theory, Antonio emphasizes that the operator's unyielding confidence (fiducia) is a active ingredient in the magical operation. Doubt is a contaminant.
3. The Right Tools: He explicitly references the need for tools from the "Clavicula Salomonis" (Key of Solomon)—circles, pentacles, and divine names. The unending circle represents God's eternity and is the fundamental tool of binding. He notes that holy prayers (e.g., from the Mass) must be avoided, as they would drive the evil spirits away; instead, one uses "honors" and courtly incantations to entice them to manifest.

Legacy: The First Systematic Magical Game Engine

Antonio da Montolmo's De occultis et manifestis is more than a curio. It represents a pivotal moment in Western magic:

1. From Grimoire to Textbook: It moves magic from a collection of disparate, recipe-like spells (do X to get Y) to an integrated theoretical system with predictable rules.
2. A Scholarly Bridge: It stands as a testament to the serious, academic engagement with the occult in late medieval universities, synthesizing Arabic astral science (e.g., Al-Kindi's theory of rays), Solomonic grimoire traditions, and Christian demonology.
3. A Blueprint for the Future: His system prefigures the grand magical syntheses of the Renaissance, like those of Cornelius Agrippa and John Dee. He provided a "game engine" where planetary intelligences, zodiacal governors, and directional kings interact within a predictable, clockwork cosmos—a system where the magician, armed with astrological charts and holy names, could attempt to become a technician of the sublime.

In Antonio, we find not a shadowy witch, but a scholastic mind attempting to map the unmappable, to bring rational order to the realm of the demonic. His work is a daring and chilling monument to the human urge to systematize power, even when that power is forbidden, and its price, as he well knew, was one's eternal soul.