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Liber III · Black & White Magic

Liber III · Black & White Magic · Chapter VIII: Theories of Magic

Augustine's City of God on Magic, Demons and Theurgy

Augustine's City of God on magic explained: his attack on theurgy, Porphyry and the Hermetic Asclepius, demons and signs, and how it shaped medieval views.

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Augustine of Hippo's City of God (De civitate Dei), written between about 413 and 426, contains the most influential early Christian critique of magic. In it Augustine argued that the theurgy of the Neoplatonists, the animated statues of the Hermetic Asclepius and the rites of sorcerers all depended on demons, fallen angels who deceive humans and seek worship for themselves. This framework, together with his teaching that magical signs amount to a pact with demons, governed how Latin Christianity judged magic for roughly a thousand years.

Augustine and the Writing of The City of God§

Augustine (354–430) was born in Thagaste in Roman North Africa, taught rhetoric in Carthage, Rome and Milan, spent nine years as a Manichaean hearer, and was converted to Christianity in 386 under the influence of Ambrose of Milan and of Platonist books he read in Latin translation. From 395 or 396 until his death he was bishop of Hippo Regius. His debt to Platonism was lasting, and this makes his attack on the Platonists' religious practice all the more pointed: he admired their philosophy while rejecting their rites.

The Visigothic sack of Rome in 410 provoked the work. Pagans argued that the city had flourished under its gods and suffered now that Christian emperors had forbidden sacrifice. Augustine replied in twenty-two books. The first ten refute the claim that the gods should be worshipped either for prosperity in this life (books 1–5) or for happiness after death (books 6–10). The last twelve describe the origin, course and destiny of two "cities", the earthly city founded on love of self and the heavenly city founded on love of God. The discussion of magic falls largely within the second half of the polemical section, where Augustine confronts the most respectable pagan religion of his day, the Neoplatonism described in Neoplatonism and Theurgy.

Demons as False Mediators§

Augustine's starting point was Platonist demonology. Writers such as Apuleius of Madauros, whose treatise On the God of Socrates he discusses at length in book 8, taught that daimones were beings of air, between gods and humans, who carried prayers upward and benefits downward and took pleasure in rites, games and offerings. Augustine accepted that such beings existed but denied that they were good. For him they were the fallen angels of Christian tradition: their aerial bodies gave them speed, keen senses and long experience, which allowed them to predict events, work wonders and imitate miracles, but their will was perverse.

On this view the gods of the pagans and the spirits of the magicians were the same beings. Their delight in obscene festivals and blood sacrifice exposed their character, and their claim to mediate between humanity and God was false. The only true mediator, Augustine insisted, was Christ, who shared human nature without sin. Everything that followed in his analysis of magic rests on this identification of all non-Christian spiritual powers with demons. A wider account of the theme appears in Black Magic: A History.

Hermes Trismegistus and the Animated Statues§

In book 8 (chapters 23–26) Augustine turned to the Hermetic Asclepius, which he knew in Latin. He singled out two passages. The first describes how the Egyptian ancestors learned to make gods: they drew spirits into statues by sacred rites, so that the images could heal, prophesy and punish. Augustine read this as a frank admission that pagan idols were inhabited by demons, summoned by human art. The second passage is the lament in which Hermes foretells that Egypt will be abandoned by its gods and their worship forbidden.

Augustine interpreted the lament as demonic foreknowledge. Hermes, he said, grieved over a future he could foresee but not welcome: the triumph of Christianity and the end of the idols. Writing a generation after the destruction of the Serapeum, he could treat the prophecy as fulfilled. Elsewhere, in book 18, he dated Hermes Trismegistus after Moses, making the Egyptian sage a later and lesser figure than the Hebrew lawgiver. This chronology was overturned in the Renaissance, when admirers of Hermes placed him at the head of an ancient theology; the background is explained in The Hermetic Asclepius.

Porphyry, Goetia and Theurgy in Book 10§

Book 10 is Augustine's sustained engagement with theurgy. His main opponent was Porphyry (c. 234–c. 305), the pupil of Plotinus, whose works On the Return of the Soul and Letter to Anebo he quotes or paraphrases. Porphyry had allowed that theurgic rites could purify the lower, "spiritual" part of the soul and make it fit to see spirits and gods, while denying that they could lead the intellectual soul to God. His uncertainty was a gift to Augustine, who used it to argue that even the best pagan philosopher could not trust theurgy.

Augustine explicitly refused the distinction that theurgists drew between their art and sorcery. Ancient writers separated goēteia, the base magic of the conjurer, from theourgia, the divine work of the philosopher. Augustine said that both were practised through demons and that the honourable name of theurgy merely concealed the same dependence. He cited a story from Porphyry about a man in Chaldaea whose efforts to purify a soul were blocked by a jealous rival who had bound the powers with stronger prayers, and asked what kind of gods could be constrained by envy and adjuration. Theurgy, he concluded, offered a counterfeit purification. The philosophers it opposed, including Iamblichus, had argued the reverse: that the gods themselves gave the symbols of the rites.

Miracles, Angels and the Magicians of Pharaoh§

Against theurgy Augustine set the miracles of the Bible. The good angels, he argued, perform wonders only to direct worship to God, never to themselves, whereas demons seek honour and sacrifice. The contest between Moses and the magicians of Pharaoh, who could imitate some of his signs but not all, served as his model: the same outward effects might be produced by God or by demons, and only the intention and object of worship distinguished true religion from magic.

Signs, Pacts and Illusions: Augustine's Theory of Magic§

The City of God develops ideas that Augustine had set out earlier, especially in On Christian Teaching (begun about 397). There he classed amulets, ligatures, charms, the observation of omens and astrology as "superstition" and described them as signs agreed upon between humans and demons, a kind of faithless friendship or pact. The power of such practices lay not in nature but in the communication they established with spirits. In book 21 of The City of God he restated the principle: demons are attracted by various stones, herbs, woods, animals, songs and rites, not as animals are drawn by food but as spirits are drawn by signs.

This semiotic theory had large consequences. It meant that even apparently harmless charms implied a relationship with demons, whatever the user intended. Augustine applied related reasoning to astrology in book 5, where he used the different lives of twins, such as Esau and Jacob, to argue against fate written in the stars, and to stories of transformation in book 18. Discussing tales of Italian innkeepers who turned travellers into beasts and the Golden Ass of Apuleius, he concluded that demons could not change one created nature into another; they could at most create illusions in the imagination. His analysis is set alongside other ancient and modern models in Theories of Magic.

Legacy in Medieval and Early Modern Europe§

Augustine's views became authoritative through compilation. Isidore of Seville's Etymologies in the early seventh century drew on them in defining magicians, and in the twelfth century Gratian's Decretum, the foundation of medieval canon law, included Augustinian texts on superstition and divination. Thomas Aquinas built on the idea of pact, distinguishing an express pact made openly with demons from a tacit pact implied by using signs and rites that have no natural power. The doctrine that magical effects come from demons, not from words or figures, became standard in theology.

The same framework shaped the late medieval and early modern prosecution of witchcraft. The Malleus Maleficarum (1486) cites Augustine repeatedly, and debates about whether witches truly flew or transformed into animals turned on his teaching about demonic illusion. Renaissance magicians who wished to revive Hermetic and Neoplatonic practice had to navigate his condemnation. Marsilio Ficino, discussing the animated statues of the Asclepius in his Three Books on Life (1489), was careful to frame his astrological and natural magic as distinct from the demonic rites Augustine had denounced; see Marsilio Ficino.

Modern historians, including Valerie Flint and Richard Kieckhefer, regard Augustine as a decisive figure in the definition of magic as a religious deviation rather than a technical art. His arguments were polemical, and they flattened the variety of pagan practice, but their clarity and the authority of their author gave them an extraordinary life.

Frequently asked questions§

What does Augustine say about magic in The City of God?§

He argues that all magic, including the theurgy of the philosophers, works through demons, who deceive people and seek worship. Magic therefore cannot purify the soul or lead it to God, and its wonders are either demonic deeds or illusions.

Why did Augustine criticise the Hermetic Asclepius?§

The Asclepius describes Egyptians drawing spirits into statues and laments the coming end of the old gods. Augustine took the first as proof that idols housed demons and the second as a demonic prophecy of Christianity's victory.

What is the demonic pact in Augustine's thought?§

In On Christian Teaching Augustine described charms, amulets and omens as signs agreed between humans and demons, a kind of pact. Later theologians, especially Thomas Aquinas, developed this into the doctrine of express and tacit pacts that underlay medieval and early modern laws against magic.

Did Augustine believe in demons?§

Yes. He believed demons were fallen angels with subtle aerial bodies, able to move swiftly, perceive keenly and work illusions, though unable to change the nature of created things or act without God's permission.

Sources and further reading§