A History of Magic and Experimental Science, Volume 2 (of 2) / During the First Thirteen Centuries of Our Era

by Lynn Thorndike

CHAPTER XLI

JOHN OF SALISBURY

His picture of the learned world—Chief events of his life—General character of the Polycraticus—Magic, maleficia, and mathematica—Use of Isidore on magic—Relation of Thomas Becket to John’s discussion—Inconsistent Christian attitude toward superstition—Divine and natural signs—Miracle and occult virtue—Interpretation of dreams—Dreams of Joseph and Daniel—The witchcraft delusion—Prevalence of astrology—John’s attack upon it—Does astrology imply fatal necessity?—John’s lame conclusion—Other varieties of magic—Thomas Becket’s consultation of diviners—Witch of Endor: exorcisms—Divination from polished surfaces—Natural science and medicine—Summary.

His picture of the learned world.

In 1159 John of Salisbury completed his two chief works, the Metalogicus and the Polycraticus.[461] In the former he tells the interesting story of his education in the schools of northern France, and describes the teachers and methods of the humanistic school of Chartres and the schools of logic at Paris. This valuable picture of educational conditions in the middle of the twelfth century has already supplied us with a number of bits of information concerning authors of whom we have treated. Its importance in the history of the study of the classics and of scholasticism has long been recognized, and its content has often been reproduced in secondary works, so that we need not dwell upon it specifically here.[462] Moreover, although John spent some twelve years in his studies in France, he appears from his own statements to have passed from the study of logic and “grammar” to that of theology without devoting much attention to natural science,[463] although he received some instruction in the Quadrivium from Richard Bishop and Hardewin the Teuton. He was, it is true, according to his own statement, a pupil of William of Conches for three years, but he always alludes to William as a grammarian, not as a writer on natural philosophy and astronomy. This one-sided description of William’s teaching warns us not to place too implicit faith in John’s account of the learned world of his times. Even if reliable as it stands, it is not in itself a complete or adequate picture. In the Polycraticus, however, he engages in a rather long discussion of magic, astrology and other forms of divination which it behooves us to note.

Chief events of his life.

John tells us that he was a mere lad when in 1136 he first came from England to Gaul to hear the famous Abelard lecture. Like many medieval students, he was or soon came to be in a needy condition and eked out a living at one time by tutoring the sons of nobles. During the time that had elapsed between his long training in the liberal arts and theology and his writing of the Metalogicus in 1159, he had led a busy life in the employ of Theobald, archbishop of Canterbury, crossing the Alps ten times, journeying twice all the way from England to Apulia, and frequently traveling about England and what is now France (John says, “the Gauls”—Gallias). In 1159 he addressed the Polycraticus to Thomas Becket, then absent with Henry II as his chancellor at the siege of Toulouse. Thomas was just about John’s age and, before he became chancellor in 1154 at the age of thirty-six, had been like John first a student and then in the employ of Archbishop Theobald. John sided with Thomas Becket in the struggle with Henry II, retired to France, and returned to England with him in 1170. In 1176 he crowned his career by becoming bishop of Chartres where perhaps some years of his early studies had been spent. His death was in 1180.

General character of the Polycraticus.

In the Metalogicus John tells us that he has scarcely touched a book of logic since he left the palaestra of the dialecticians so many years ago, but he returns to the subject again in that work. In the Polycraticus his literary tastes and interests are more manifest. He writes a good Latin style and shows a wide acquaintance with classical authors and ancient history as well as with patristic literature. The character and content of the Polycraticus is more clearly suggested by its sub-title, “Courtiers’ Trifles and Philosophers’ Footprints” (De nugis curialium et vestigiis philosophorum). In part it is satirical, although there is considerable serious discussion of the state and philosophy and much moralizing for the benefit of contemporary courts and statesmen. John confesses that the entire work is little more than a patch-work of other men’s opinions, sometimes without specific acknowledgment of the authorities. He professes to believe that Thomas will recognize the sources of these passages without being told, while other readers who are more ignorant will be thereby spurred on to wider reading. These quotations, moreover, are either from ancient classical or comparatively early Christian writers. John does not epitomize recent literature and thought, although he makes application of the thought of the past to contemporary society and politics, and although he shows some acquaintance with the works of contemporary writers such as Bernard Silvester. In the main his attitude is essentially conservative; he repeats traditional views in an attractive but somewhat dilettante literary form, with such rational criticism as a study of the classics might be expected to produce when qualified by scrupulous adherence to medieval Christian dogma. This is especially true of his discussion of the magic arts and astrology.

Magic, maleficia, and mathematica.

John begins to discuss magic in the first of the eight books of the Polycraticus after a few chapters have been taken up with such other triflings of courtiers as hunting, dicing, music, and theatrical shows and spectacles. More harmful than the illusions of the stage, he declares, are those of the magic arts and various kinds of disreputable mathematica, long since forbidden by the holy fathers who knew that all these artificia, or rather maleficia arose from a fatal familiarity of men and demons.[464] John thus takes as practically synonymous the three terms, magica, mathematica and maleficium. He presently explains that the word mathesis in one sense denotes learning in general, but that when it has a long penultima, it signifies the figments of divination,[465] which belong under magic, whose varieties are many and diverse. Thus magic is John’s most general and inclusive term for all occult arts.

Use of Isidore on magic.

The account of magic in John’s ninth, tenth, eleventh, and twelfth chapters is largely derived without acknowledgment from that of Isidore of Seville.[466] We have already seen how this became a stock description of the subject copied with little change by successive writers and embodied in the decretals of the church. It is rather surprising that a writer as well versed in the classics as John is generally supposed to be should not have borrowed his account more directly from some such ancient Latin writers as Pliny and Apuleius. John, however, alters the wording and arrangement and consequently the emphasis considerably. He makes it seem, for example, that several magic arts, which really have nothing to do with predicting the future, are sub-varieties of divination. He also adds some new varieties to Isidore’s list of practitioners of the magic arts. The vultivoli try to affect men by making images of them from wax or clay. Imaginarii, on the other hand, make images with the intent that demons should enter these images and instruct them in regard to doubtful matters. Besides interpreters of dreams (conjectores) and chiromancers John further mentions specularii who practise divination by gazing into polished surfaces such as the edges of swords, basins, and mirrors. It was this art that Joseph is described as exercising or pretending to exercise, when he charged his brothers with having made off with the cup in which he was wont to practice divination. The thirteenth and closing chapter of John’s first book is a long list of omens from Roman history and Latin literature, especially Vergil.

Relation of Thomas Becket to John’s discussion.

In the second book he resumes the same subject after a brief and somewhat apologetic preface in which he states that all things are of use to the wise man. Therefore he responds with alacrity to Thomas Becket’s request that he publish his trifles, introducing interpreters of dreams and astrologers with some other triflers. We shall later meet with some further explanation of Thomas’ interest in such matters. It is perhaps significant that John further expresses his confidence that Thomas will faithfully protect those in whom he has inspired boldness of utterance,[467] but it would be too much to assume from it that John fears any persecution because he discusses such subjects. More likely he merely shares the common medieval fear of the envious bite of critics and reviewers, or wishes to remind Thomas of his need of his patronage. At any rate he closes the prologue with the request that Thomas will correct any mistake in either book.

Inconsistent Christian attitude toward superstition.

In opening his second book John subscribes to the proverb that he who trusts in dreams and auguries will never be secure and asks—like Cicero in his De divinatione[468]—what possible connection there can be between sneezes, yawns, and other such things accepted as signs and the events which they are supposed to signify. With Isidore and Augustine[469]—although he names neither—he rejects those empty incantations and superstitious ligatures which the entire medical art condemns, although some call them physica.[470] This seems like an admirable approach to an attitude of rational criticism, but John after all may be merely repeating others’ statements like a parrot, and he entirely spoils its effect by what he goes on to say. He believes that the cloak of St. Stephen raised the dead, and that such practices as saying the Lord’s prayer while plucking or administering medicinal herbs, or wearing or hearing or repeating the names of the four evangelists,[471] are not only allowable but most useful. He adds further that the force of all omens depends upon the faith of the recipient.

Divine and natural signs.

Although opposing faith in omens and augury, John admits that God provides signs for His creatures, such as those of the weather which sailors and farmers learn by experience and the birds are not ignorant of, or the indications by which doctors can prognosticate the course of diseases. Unfortunately the demons also are able to show signs and thus lead men astray. Mention of signs which preceded the fall of Jerusalem then leads John into a digression for several chapters concerning the horrors of the siege itself and Vespasian and Titus, a passage which was very likely inserted because Henry II and Becket were at that very time engaged in laying siege to Toulouse.

Miracle and occult virtue.

Returning to the subject of signs, John interprets the verse in Luke, “There shall be signs in sun and moon and stars” as having reference to unnatural signs, and the obscuration of the sun during Christ’s passion as not a natural eclipse.[472] John explains that by nature he means “the accustomed course of things or the occult causes of events for which a reason can be given.”[473] If, however, we accept Plato’s definition of nature as the will of God there will be no unnatural events. But John would distinguish between the gradual growth of leaves and fruit on tree or vine by means of roots drawing nutriment from earth’s vitals and sap produced within the trunk, which is indeed marvelous and has the most occult causes, and the performance of the same process without any interval of time, which he regards as a miracle and of a divine height which transcends our understanding. After drawing this distinction between divine miracle and wonders wrought by occult virtues in nature John returns again to the subject of signs.

Interpretation of dreams.

For some chapters the topic of dreams and their interpretation absorbs his attention,[474] and at first he discusses in an apparently credulous and approving tone “the varied significations of dreams, which both experience approves and the authority of our ancestors confirms.”[475] He explains that now the dream concerns the dreamer himself, now someone else, now common interests, sometimes the public or general welfare; and he quotes Nestor to the effect that “trust is put in the king’s dream concerning public matters.”[476] After referring credulously to the Sibylline verses predicting Christ’s incarnation, passion, and ascension, John continues his exposition of the interpretation of dreams. He explains that the season of year when one dreams, the place where one dreams, and the personal characteristics of the dreamer must all be taken into account; that sometimes interpretations should be by contraries, and again from like to like. But then he checks himself with the words: “But while we pursue these traditions of the interpreters, I fear lest we deservedly seem not so much to trace the art of interpretation, which is either no art at all or an idle one, as to dream ourselves.” He adds further, “Whoever fastens his credulity to the significations of dreams evidently wanders as far from sincere faith as from the path of reason.”[477]

Dreams of Joseph and Daniel.

John then attacks the Dream-Book of Daniel, which he says “circulates impudently among the hands of the curious” and gives a specific interpretation for each thing imagined by the dreamer. He denies the truth and authority of the book and argues at some length that neither Joseph nor Daniel would have composed such a work, and that they interpreted dreams by divine inspiration, not by any occult art learned in Chaldea or Egypt. In the first place, the method of interpretation set forth in this book is faulty and crude. The remainder of John’s argument is worth quoting in part:

“Daniel indeed had the grace to interpret visions and dreams, which the Lord inspired in him, but it is inconceivable that a holy man should reduce this vanity to an art, when he knew that the Mosaic law prohibited any of the faithful to heed dreams, being aware how Satan’s satellite for the subversion of men is transformed into an angel of light and how suggestions are made by bad angels. Joseph, too, won the rule of Egypt by his ability to predict.... But if this could have come from any science of human wisdom, I should think that some one of his ancestors before him would have merited it, or I should think that the saint, desirous of serving science and full of pious impulses, would have left the art as a legacy, if not to the human race at large, which would nevertheless have been just, at any rate to his brothers and sons. Besides, Moses, trained in all the wisdom of the Egyptians, either was ignorant of or spurned this art, since, detesting the error of impiety, he took pains to exterminate it from among God’s people. Furthermore, St. Daniel learned the studies and wisdom of the Chaldeans, which, as a saint, he would not have done, had he thought it sinful to be instructed in their lore. And he had companions in his education whom he rejoiced to have as comrades in divine law and justice. For at the same time Ananias, Axarias, Misael learned whatever a Chaldean would learn.... But notice that the privilege which man could not confer was given to Daniel alone, to bring to light the riddles of dreams and to scatter the obscurities of figures....”

Pointing out that Daniel read the king’s thoughts and prophesied “the mystery of salvation” in addition to interpreting the dream, John then concludes sarcastically: “Are the interpreters of dreams thus wont to examine thoughts and remove obscurities, to explain what is involved and illuminate the darkness of figures? If there is any who enjoys a like portion of grace, let him join Daniel and Joseph and like them ascribe to God the glory. He whom the spirit of truth does not illume vainly puts his confidence in the art of dreams.”[478]

The witchcraft delusion.

John concludes that many dreams are the work of demons.[479] Especially as of this sort he classifies the illusions of those who think that they have taken part during the night in witches’ Sabbats. “What they suffer in spirit they most wretchedly and falsely believe to have occurred in the body.”[480] And such dreams come mainly to women, feeble-minded men, and those weak in the Christian faith. Too much stress must not, however, be laid upon this apparent opposition to the witchcraft delusion.[481] John admits that the demons send dreams, and if he denies their verity, he merely repeats a hesitation as to the extent and reality of the power of demons over the body of men and the world of nature which we have frequently met in patristic literature and which is due to a natural reluctance to admit that their magic is as real as God’s miracles.

Prevalence of astrology.

From divination by dreams and demons John passes to astrology. To start with he admits the attraction which the art has for men of intellect in his own time. “Would,” he exclaims, “that the error of the mathematici could be as readily removed from enlightened minds as the works of the demons fade before true faith and a sane consciousness of their illusions. But in it men go astray with the greater peril in that they seem to base their error upon nature’s firm foundation and reason’s strength.”[482] Beginning with mathematical and astronomical truths based on nature, reason and experience, they gradually slip into error, submitting human destiny to the stars and pretending to knowledge which belongs to God alone.

John’s attack upon it.

John ridicules the astrologers for attributing sex to the stars and stating the exact characteristics and influences of each planet, when they cannot agree among themselves whether the stars are composed of the four elements or some fifth essence, and when they are confounded by a schoolboy’s question whether the stars are hard or soft.[483] He grants that the sun’s heat and the moon’s control of humors as it waxes and wanes are potent forces, and that the other heavenly bodies are the causes of many utilities, and that from their position and signs the weather may be predicted. But he complains that the astrologers magnify the influence of the stars at the expense of God’s control of nature and of human free will. “They ascribe everything to their constellations.” Some have even reached such a degree of madness that they believe that “an image can be formed in accordance with the constellations so that it will receive the spirit of life at the nod of the stars and will reveal the secrets of hidden truth.”[484] Whether John has some magic automaton or merely an engraved astrological image in mind is not entirely clear.

Does astrology imply fatal necessity?

John is aware, however, that many astrologers will deny that their science detracts in any way from divine prerogative and power, and will “appear to themselves to excuse their error quite readily” by asserting with Plotinus that God foreknew and consequently foredisposed everything that is to occur, and that the stars are as much under his control as any part of nature.[485] But John will have none of this sort of argument. “These hypotheses of theirs are indeed plausible but nevertheless venom lies under the honey. For they impose on things a certain fatal necessity under the guise of humility and reverence to God, fearing lest his intent should perchance alter, if the outcome of things were not made necessary. Furthermore, they encroach upon the domain of divine majesty, when they lay claim to that science of foreseeing times and seasons, which by the Son’s testimony are reserved to the power of the Father, even to the degree that they were hid from the eyes of those to whom the Son of God revealed whatever He heard from the Father.”[486]

John furthermore contends that divine foreknowledge does not require fatal necessity. For instance, although God knew that Adam would sin, Adam was under no compulsion to do so. God knew that by his guilt Adam would bring death into the world, but no condition of nature impelled him to this; in the beginning man was immortal. At this point John wanders off into a joust at the Stoics and Epicureans, whom he censures as equally in error, since the one subjected all to chance, the other to necessity. It is true, John argues, that I know a stone will fall to earth if I hurl it skywards, but it “does not act under necessity, for it might fall or not.” But that it does fall, “though not necessary, is true.” John presently recognizes that he has given away his previous argument against astrology and that the devotee of the stars will say that he does not care whether his predictions are necessary or not provided they are true. “‘Nor does it make any difference to me,’ says the devotee of the stars, ‘whether the affair in question might be otherwise, provided I am not doubtful that it will be (as I think.)’”[487]

John’s lame conclusion.

John accordingly resorts to other arguments and to facetious sarcasm to cover his confusion. Then he recovers sufficiently to reiterate his belief that God frequently interferes in the operation of nature by special providences; and asserts that God has been known to change His mind, while the astrologers assert that the stars are constant in their influences. Expressing doubt, however, whether Thomas Becket will be convinced by his arguments, especially the one concerning fate and Providence, or whether he will not laugh up his sleeve at such a clumsy attempt to refute so formidable a doctrine, John lamely concludes by citing Augustine and Gregory against the art, and by affirming that every astrologer whom he has known has come to some bad end,[488] in which assertion he probably simply echoes Tertullian.

Other varieties of magic.

Resuming his discussion of the varieties of magic John briefly dismisses necromancers with the bon mot that those deserve death who try to acquire knowledge from the dead.[489] A number of other terms in Isidore’s list—auspices, augurs, salissatores, arioli, pythonici, aruspices—he says it is needless to discuss further since these arts are no longer practiced in his day, or at least not openly. Turning to more living superstitions of the present, he explains that chiromancy professes to discern truths which lie hidden in the wrinkles of the hands, but that since there is no apparent reason for this belief it is not necessary to contravert it.

Thomas Becket’s consultation of diviners.

John wishes to ask Thomas one thing, however, and that is what triflers of this sort say when they are interrogated concerning uncertain future matters. He knows that Becket is familiar with such men because on the occasion of a recent royal expedition against Brittany he consulted both an aruspex and a chiromancer. John notes that a few days afterwards Thomas “lost without warning the morning-star so to speak of your race,” and warns him that such men by their vanity deserve to be consulted no more. This gentle rebuke did not avail, however, to wean Thomas entirely from his practice of consulting diviners, which he continued to do even after he became Archbishop of Canterbury. In a letter written to the future martyr and saint in 1170 John again chides Thomas for having delayed certain important letters because he had been “deluded by soothsayings which were not of the Spirit” and exhorts him “So let us renounce soothsayings in the future.”[490]

Witch of Endor: exorcisms.

Despite his previous declaration that he need not discuss the pythonici, John now proceeds to do so, listing instances of ambiguous and deceptive Delphic oracles and discussing at length the well-worn subject of Saul and the witch of Endor. He concludes the chapter by a warning against abuse of the practice of exorcism: “For such is the slyness of evil spirits that what they do of their own accord and what men do at their suggestion, they with great pains disguise so that they appear to perform it unwillingly. They pretend to be coerced and simulate to be drawn out as it were by the power of exorcisms, and that they may be the less guarded against they compose exorcisms apparently expressed in the name of God or in the faith of the Trinity or in the power of the incarnation or passion; and they transmit the same to men and obey men who use these, until they finally involve them with themselves in the crime of sacrilege and penalty of damnation. Sometimes they even transform themselves into angels of light, they teach only things of good repute, forbid unlawful things, strive to imitate purity, make provision for needs, so that, as if good and favoring, they are received the more familiarly, are heard the more kindly, are loved the more closely, are the more readily obeyed. They also put on the guise of venerable persons....”[491]

Divination from polished surfaces.

“The specularii,” John continues, “flatter themselves that they immolate no victims, harm no one, often do good as when they detect thefts, purge the world of sorceries, and seek only useful or necessary truth.”[492] He insists that the success of their efforts is none the less due to demon aid. John tells how as a boy he was handed over for instruction in the Psalms to a priest who turned out to be a practitioner of this variety of magic, who after performing various adjurations and sorceries tried to have John and another boy look into polished basins or finger-nails smeared with holy oil or chrism and report what they saw. The other boy saw some ghostly shapes but John thanks God that he could see nothing and so was not employed henceforth in this manner. He adds that he has known many specularii and that they have all suffered loss of their sight or some other evil except the aforesaid priest and a deacon, and that they took refuge in monasteries and later suffered evils above their fellows in their respective congregations.

Natural science and medicine.

John closes his second book with a chapter on natural scientists and medical men, for he seems to apply the term physici in both senses, although towards the close of the chapter he also employs the word medici. He begins by saying that it is permissible to consult concerning the future anyone who has the spirit of prophecy or who from scientific training knows by natural signs what will happen in the bodies of animals, or who “has learned experimentally the nature of the time impending,” provided only that these latter men say and do nothing prejudicial to the Christian faith. But sometimes the physici attribute too much to nature,[493] and John has heard many of them disputing concerning the soul and its virtues and operations, the increase and diminution of the body, the resurrection, and the creation, in a way far from accord with the Christian faith. “Of God Himself too they sometimes so speak, ‘As if earth-born giants assailed the stars.’”[494] John recognizes, however, their knowledge of animals and medicine, although he finds their theories sometimes in conflict. As for practicing physicians, he dares not speak ill of them, for he too often falls into their hands, and he grants that no one is more necessary or useful than a good doctor. John makes considerable use of the Natural History of Pliny and of Solinus, and sometimes for occult or marvelous phenomena, as when he cites Pliny concerning men who have the power of fascination by voice and tongue or by their glances, and adds the testimony of the Physiognomists.[495]

Summary.

It may be well to review and further emphasize some of the chief features of John’s rather rambling discussion. Despite its frequent quotations from classic poets and moralists, it is theological in tone and content to a degree perhaps greater than I have succeeded in suggesting, for to repeat all its scriptural passages would be tedious. There is even some theological jealousy and suspicion of natural science shown. John perhaps more nearly duplicates the attitude of Augustine than that of any other writer. Magic is represented as inevitably associated with, and the work of, demons. John sometimes charges the magic arts with being irrational or injurious, but these charges are in a way but corollaries of his main thesis. The arts must be harmful since demons are concerned with them, while the influence of demons seems the only rational explanation for their existence. John repeats the old Isidorian definition of magic but he adds some current superstitions and shows that the magic arts are far from having fallen into disuse. Finally he shows us how vain must have been all the ecclesiastical thunders and warnings of demons and damnation, like his own, directed against magic, from the fact that not merely kings of the past like Saul and Pharaoh, but clergy of the present themselves—a priest and a deacon, a chancellor and an archbishop of England—practice or patronize such arts. Sometimes John’s own condemnation of them seems a bit perfunctory; he takes more relish, it seems at times, in describing them. Again, as in the case of astrology, he evidently feels that his opposition will be of little avail.

[461] Johannis Sarisberiensis Episcopi Carnotensis Policratici sive de nugis curialium et vestigiis philosophorum libri VIII. Recog. C. C. I. Webb. 2 vols. Oxford, 1909. The work is also contained in Migne, PL vol. 199. For John’s life see DNB. All references are to book and chapter of the Polycraticus unless otherwise stated.

[462] The most recent discussion of it is by R. L. Poole, “The Masters of the Schools at Paris and Chartres in John of Salisbury’s Time,” in EHR XXXV (1920), 321-42.

[463] Metalog. II, 10.

[464] I, 9.

[465] At II, 18 he makes the same distinction.

[466] For Isidore’s account see PL 82, 310-14.

[467] Polycrat. II, prologus. “Alacres itaque exeant nugae nostrae quas serenitas tua prodire iubet in publicum, ut conjectores, mathematicos, cum quibusdam aliis nugatoribus introducant; quia quibus dedisti egrediendi audaciam, securitatis quoque fiduciam praestabis.” The following words, “Connectantur ergo inferiora superioribus” seem to mean that the second book goes on where the first left off, but perhaps the suggestion of astrological doctrine is an intentional play upon words on John’s part.

[468] II, 12.

[469] De doctrina Christiana, II, 20 in Migne, PL vol. 34.

[470] Thus, it will be recalled, Marcellus Empiricus and Alexander of Tralles labelled their superstitious recipes.

[471] “Capitula Evangelii.”

[472] II, 11.

[473] II, 12.

[474] II, 14-17.

[475] II, 14. Quis nescit somniorum varias esse significationes, quas et usus approbat et maiorum confirmat auctoritas.

[476] II, 15. Somnium ... gerit imagines, in quibus coniectorum praecipue disciplina versatur, et nunc suum cuiusque est, nunc alienum, modo commune, interdum publice aut generale est. Ut enim ait Nestor, de statu publico regis credatur somnio.

[477] II, 17. Sed dum has coniectorum traditiones ex(s)equimur, vereor ne merito non tam coniectoriam ex(s)equi, quae aut nulla aut inania ars est, quam dormitare videamur ... Verum quisquis credulitatem suam significationibus alligat somniorum, planum est quia tam a sinceritate fidei quam a tramite rationis exorbitat.

[478] Polycrat. II, 17. Gratian appears to refer to the same book on oneiromancy in his Decretum, Secunda pars, Causa XXVI, Quaest. vii, cap. 16, “somnialia scripta et falso in Danielis nomine intitulata.”

[479] II, 17 (Webb I, 100). Quis huius facti explicet rationem nisi quod boni spiritus vel maligni exigentibus hominum meritis eos erudiunt vel illudunt?... Quod si materiam vitiis afferat, libidinem forte accendens aut avaritiam aut dominandi ingerens appetitum aut quidquid huiusmodi est ad subversionem animae, procul dubio aut caro aut spiritus malignus immittit.

[480] II, 17 (Migne, col. 436), Webb I, 100-1.

[481] John is perhaps influenced by a similar passage in the Canon, Ut episcopi (Burchard, Decreta, X, 1).

[482] II, 18. Possit utinam tam facile mathematicorum error a praestantioribus animis amoveri quam leviter in conspectu verae fidei et sanae conscientiae istarum illusionum demonia conquiescunt. Verumtamen eo periculosius errant quo in soliditate naturae et vigore rationis suum fundare videntur errorem.

[483] II, 19.

[484] II, 19 (Migne, col. 442). Webb, I, 112. ... stellarum nutu recipiet spiritum vitae et consulentibus occultae veritatis manifestabit arcana.

[485] II, 19.

[486] II, 20.

[487] Cap. 24, nec mea, inquit astrorum secretarius, interest an aliter esse possit, dum id de quo agitur ita futurum esse non dubitem.

[488] John’s argument against astrology extends from the 18th to the 26th chapter of the second book of the Polycraticus.

[489] II, 27.

[490] Epistola 297 (Migne, cols. 345-46).

[491] II, 27; Webb, I, 155-56.

[492] II, 28.

[493] II, 29 (Migne, col. 475). Licet tamen ut de futuris aliquis consulatur, ita quidem si aut spiritu polleat prophetiae, aut ex naturalibus signis quid in corporibus animalium eveniat physica docente cognovit, aut si qualitatem temporis imminentis experimentorum indiciis colligit. Dum tamen his posterioribus nequaquam quis ita aurem accommodet ut fidei aut religioni praejudicet.... At physici, dum naturae nimium auctoritatis attribuunt, in auctorem naturae adversando fidei plerumque impingunt.

[494] Webb, I, xxxiii and xxxv.

[495] V, 15 (Webb, I, 345).