An Essayistic Summary of Demoniality; or, Incubi and Succubi by Sinistrari of Ameno

 

 

Introduction: Demoniality as a Distinct Sin

The seventeenth-century treatise Demoniality; or, Incubi and Succubi occupies a curious position in the history of Christian demonology. Written by the Franciscan theologian and inquisitorial consultant Ludovico Maria Sinistrari, the work attempts to analyze a phenomenon widely reported in medieval and early modern Europe: sexual encounters between humans and supernatural beings.

Sinistrari’s central thesis is that intercourse with demons constitutes a specific moral category—“demoniality”—distinct from other forms of sexual sin, such as bestiality or fornication. The treatise thus represents not merely a catalog of demonological folklore but an attempt at systematic classification within scholastic moral theology.

The author’s approach is simultaneously theological, juridical, and proto-anthropological. Drawing on biblical exegesis, scholastic authorities, historical reports, and alleged eyewitness accounts, he attempts to determine:

1. Whether incubi and succubi truly exist.

2. What kind of beings they are ontologically.

3. How they interact physically with humans.

4. Whether such intercourse produces offspring.

5. What moral and theological consequences arise from such encounters.

At its core, the treatise is an attempt to reconcile empirical testimony with Christian metaphysics.

 

I. The Ontological Problem: What Are Incubi and Succubi?

The starting point of Sinistrari’s argument is the observation that numerous historical reports describe beings who visit humans at night and engage in sexual acts with them. Rather than dismissing these stories as hallucination or illusion, he assumes they refer to real entities whose nature must be determined.

Traditional demonology interpreted these beings simply as devils assuming corporeal form. Sinistrari challenges this view. He proposes that the incubus or succubus may not be identical with the fallen angels of orthodox demonology.

Instead, he suggests the possibility of a third order of rational beings, distinct from both humans and angels. These creatures would:

• Possess material bodies, unlike purely spiritual demons.

• Have rational souls, like humans.

• Be capable of reproduction and mortality.

The treatise famously begins with the proposition that there exist “rational creatures besides man, endowed like him with a body and a soul, that are born and die.”

This radical speculation moves the work beyond conventional demonology into what might be called early speculative anthropology.

 

II. The Distinction Between Demons and Incubi

Sinistrari draws a careful distinction between two categories of supernatural beings:

1. Diabolical Demons

These are the fallen angels of Christian theology. Their functions include:

• Temptation of humans

• Possession

• Spiritual deception

• Participation in witchcraft

They are purely spiritual beings and cannot naturally reproduce.

2. Incubi and Succubi

These beings differ significantly:

• They possess physical bodies

• They interact sexually with humans

• Their motivation is primarily carnal appetite

• They do not necessarily act in explicit rebellion against God

According to Sinistrari, the behavior of incubi suggests they are closer to mischievous or lustful nature-spirits than to metaphysical embodiments of evil. Some demonologists even regarded them as potentially redeemable beings.

This distinction allows Sinistrari to treat demoniality not simply as diabolical possession but as inter-species sexuality.

 

III. The Physiology of Demonic Intercourse

One of the most controversial sections of the treatise concerns the mechanics of reproduction between humans and these entities.

Medieval theologians had long debated how demons could engage in sexual acts if they were purely spiritual. The prevailing scholastic theory, inherited from Thomas Aquinas, proposed a complicated mechanism:

1. A succubus collects semen from a human male.

2. The demon transforms into an incubus.

3. The semen is implanted into a woman.

Sinistrari accepts parts of this explanation but elaborates it extensively.

He argues that the incubus possesses:

• a temporary corporeal body

• the ability to simulate human physiology

• sufficient materiality to interact physically with human beings

He also discusses numerous alleged cases of supernatural impregnation, suggesting that demonial offspring could theoretically exist.

 

IV. Historical Testimonies and Case Studies

To support his thesis, Sinistrari collects a large number of reported encounters between humans and incubi.

These narratives often share recurring features:

• The entity appears at night.

• It resembles a beautiful human figure.

• It visits the same person repeatedly.

• Physical evidence of intercourse is allegedly present.

Examples include stories of:

• young women visited by invisible lovers

• nuns reporting nightly encounters

• mysterious figures disappearing when confronted

Such cases were taken seriously in early modern ecclesiastical courts and sometimes appeared in witchcraft trials.

Sinistrari treats these accounts as empirical data, attempting to identify patterns that reveal the nature of these beings.

 

 

V. Demoniality in Moral Theology

A major aim of the treatise is juridical: to determine how demoniality should be classified within Christian moral law.

Prior theologians often categorized intercourse with demons under bestiality, because it involved union with a non-human creature.

Sinistrari rejects this classification.

His reasoning is subtle:

• Bestiality involves intercourse with an irrational animal.

• Incubi are rational beings.

• Therefore the act cannot be classified as bestiality.

Instead, he defines a distinct category: demoniality.

This new category has implications for confession, penance, and ecclesiastical jurisprudence.

VI. The Cosmological Hypothesis: Intermediate Species

Perhaps the most fascinating aspect of the treatise is its speculation that incubi may belong to a hidden species inhabiting the margins of the natural world.

Sinistrari entertains the possibility that they are:

• terrestrial but elusive beings

• part of an unknown biological order

• capable of reproduction and death

Such speculation echoes medieval traditions about:

• satyrs

• fauns

• sylphs

• other elemental spirits

The implication is remarkable: humanity may not be the only rational species on Earth.

 

VII. Witchcraft, Sabbats, and Sexual Pacts

The treatise also addresses the role of incubi within witchcraft traditions.

According to Sinistrari:

• witches and magicians sometimes enter into sexual pacts with demons

• these acts form part of the infernal covenant

• sexual intercourse serves as a ritual of allegiance

Such claims align with earlier demonological works, especially those describing the witches’ sabbath.

Yet Sinistrari again distinguishes between true diabolical demons and incubi driven primarily by sensuality.

 

VIII. Theological Implications

Sinistrari’s theory raises profound theological questions:

1. If incubi possess rational souls, can they be saved?

2. Are they descendants of fallen angels?

3. Do they belong to a separate creation of God?

The author does not fully resolve these questions but suggests that these beings may inhabit a liminal metaphysical state, neither damned nor redeemed.

This ambiguity reflects a broader tension in early modern demonology between orthodox theology and empirical curiosity.

 

IX. Intellectual Context

The treatise emerges from the intellectual climate of seventeenth-century Catholic Europe.

During this period:

• demonology was treated as a legitimate branch of theology

• exorcists collected testimonies of supernatural encounters

• witchcraft trials generated extensive documentation

Sinistrari himself served as a consultant to the Roman Inquisition and was widely regarded as an authority on sexual sins and demonic phenomena.

His work therefore reflects both scholastic reasoning and the investigative culture of inquisitorial courts.

 

 

X. Modern Interpretation

From a modern perspective, the treatise can be interpreted in several ways:

1. Psychological interpretation
   Incubus encounters resemble sleep paralysis and hypnagogic hallucinations.

2. Anthropological interpretation
   The narratives reflect cultural mechanisms for explaining sexuality and nocturnal experiences.

3. Mythological interpretation
   Incubi belong to a long tradition of erotic spirits found in many cultures.

4. Historical interpretation
   The treatise reveals how early modern theology attempted to integrate folklore into scholastic frameworks.

 

Conclusion

Demoniality; or, Incubi and Succubi is more than a curiosity of early demonology. It represents an attempt to construct a systematic ontology of supernatural sexuality within the framework of Catholic scholastic thought.

Sinistrari’s analysis moves beyond mere superstition by attempting to reconcile:

• empirical testimony

• theological doctrine

• moral jurisprudence

• speculative natural philosophy

The result is a work that occupies a fascinating borderland between theology, folklore, and proto-anthropology.

Ultimately, the treatise reveals the intellectual ambition of early modern demonology: to map the hidden inhabitants of the cosmos and their relationship to humanity.

 

Biography of Ludovico Maria Sinistrari

Ludovico Maria Sinistrari (Ameno, February 26, 1632 – Ameno, March 6, 1701) was an Italian theologian and writer. Born in the small town of Ameno in northern Italy, Sinistrari studied in Pavia before entering the Order of Friars Minor in 1647. He later taught philosophy and theology to students in Pavia, attracting a number of pupils who were drawn by his growing reputation as a scholar.

Sinistrari eventually served as a consultant to the Supreme Sacred Congregation of the Roman and Universal Inquisition in Rome. He was regarded as an authority on exorcism and carefully described the effects—observed during exorcistic rites—of various plants and substances, including cubeb pepper, cardamom, ginger, and nutmeg.

He was also widely considered an expert in demonology and in sins related to sexuality in all their permutations. His work included investigations of individuals accused of having sexual relations with demonic beings. Allegations of this kind later became a recurring element in the inquisitorial proceedings against those accused of witchcraft.

His sister, Anna Maria, was the mother of the historian Lazzaro Agostino Cotta.

Works

Sinistrari was an author whose writings unfortunately helped shape the intellectual framework of inquisitorial thought in the seventeenth century—especially concerning incubi, succubi, and other demons believed to roam the earth, as well as sexual practices regarded as sinful.

Among his principal works are:

• De Daemonialitate et Incubis et Succubis (On Demoniality, Incubi, and Succubi).

• Lascivia, a treatise on sexual sins, particularly homosexuality.

• Peccatum Mutum (The Silent Sin), published only in 1893, dealing specifically with sodomy.

• De delictis et poenis tractatus absolutissimus (A Most Complete Treatise on Crimes and Punishments), begun in 1688 and completed in 1700, one year before his death.

Although the latter work had been commissioned by the Franciscan order as a general penal code for the community, and despite Sinistrari’s service to the Inquisition, the book was later placed on the Index Librorum Prohibitorum in 1709 and prohibited because it addressed sensitive issues concerning the qualifications and authority of judges.

This article is part of VAMZZZ’s ongoing exploration of occult traditions, folklore, and esoteric history.

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