Chapter LXX: Peter of Abano (1)

Plan of this chapter--Birth and family--Travels abroad--At Paris--His Latin version of Abraham Aben Ezra--Conversation with Marco Polo--Translations from the Greek--Did he teach at Bologna?--Return to Padua--Three works of astronomy and astrology--Publications in the year 1310--Undated and spurious works--Closing years of his life--Relations with the church--Great reputation--Not a miracle in a rude age--But completed the work of his period--No mere compiler--The _Conciliator_ his masterpiece--Its method--Specimens of its questions--Was Peter the founder of Averroism at Padua?--Reputation for magic--Summary of occult science in the _Conciliator_--Definition of astronomy and astrology--Nature controlled by the stars--Astrology a science--And not magic--Occult virtues from the stars--Astrological medicine--The stars and length of life--Nativities--Revolution of the eighth sphere--Conjunctions--The astrological interpretation of history--Chronology--Astrological images--The stars and invocations, incantations, and fascination--Stars and spirits--Were Peter’s views heretical?--Fascination--Incantations--Number mysticism--Poisoning and magic--The treatise _De venenis_--Specific form or valence--An allusion to alchemy--Mineral, vegetable, and animal poisons--How poison takes effect--Safeguards against poison--The Bezoar--Physiognomy--Astrology in his other works--Attitude to “magic”--Magic books ascribed to him--Geomancy--Conclusion.

Appendix I. Previous accounts of Peter of Abano.

Original sources--Michael Savonarola--Secondary accounts
since 1500.

Appendix II. A Bibliography of Peter Abano’s writings.

Arrangement--Translation of Abraham Aben Ezra,
1293--The _Physiognomy_, 1295--_Problems_ of
Alexander of Aphrodisias--Translations of Galen--The
_Conciliator_, 1303--_On the astrolabe_--_On
the motion of the eighth sphere_, 1310--The
_Lucidator_, 1310--Commentary on the _Problems_ of
Aristotle, 1310--_On poisons_, 1316(?)--_Addition to
Mesuë_--Dioscorides--Pseudo-Hippocrates--Geomancy--Prophecies--
_Heptameron_, or _Elements of magic_--_Elucidarium
necromanticum_--_Annulorum experimenta_--_Circulus
philosophicus_.

Appendix III. Peter of Abano, Abraham Aben Ezra, and Henry Bate.

French translation from the Hebrew--Peter’s Latin
version--Additional treatises in Peter’s version--A
Latin translation by Henry Bate--Other writings of Henry
Bate--Other works by Abraham.

Appendix IV. Was Peter called to Treviso in 1314?

Appendix V. Peter’s salary at Padua.

Amount exaggerated--Why was it so far in arrears?

Appendix VI. When did Peter die?

Appendix VII. Was the _De venenis_ addressed to Pope John XXII?

Survey of the editions and MSS--Inference from a citation of
Avenzoar--Popes and poisons.

Appendix VIII. Peter and the Inquisition.

His own statement in the Conciliator--His professions
of orthodoxy--Does his will show fear of the
Inquisition?--Gloria’s inference--Did Peter’s sons inherit
his property?--If so, how?--Burning of Peter’s bones for
heresy--The account of Michael Savonarola--Scardeone’s
account--Naudé’s statement.

“... _he reconciled conflicts, a wonderful warrior!_”
--_Tomasini (1630) p. 22._

[Sidenote: Plan of this chapter]

Peter of Abano, or Peter of Padua, as he was often called from the larger city near his birthplace where he did much of his teaching, was one of the most influential men of learning during the last years of the thirteenth and the opening years of the fourteenth century. Of his writings in medicine, philosophy, and astronomy many are extant, and most of these in printed editions. Yet he has never been adequately or accurately treated in English. In our language there have merely been brief notices of or incidental references to him in histories of science and medicine, or of the inquisition and of rationalism in Europe, or in general encyclopedias. Such passages and parallel ones in foreign languages[2757] often give dates of Peter’s life or death incorrectly, or do injustice to his opinions from an insufficient or very indirect knowledge of his works, or represent him as a victim of the Inquisition and an example of the hostility of the medieval church to science to an extent which the sources do not justify. There are, however, in European languages, especially Italian, some secondary studies of importance concerning Peter. It is upon these and a direct examination of his works that the present chapter will be based. To avoid prolixity of text and footnotes, details of bibliography[2758] and a number of problems concerning his life which require to be discussed at some length have been transferred to appendices at the close of the chapter. In the present text, since most of Peter’s works can be dated rather exactly and since they were among the chief events of his life, we may combine biography and bibliography in large measure. We shall then treat somewhat, although by no means adequately, of his place in the history of science, and finally of his propensities toward astrology and other varieties of magic.

[Sidenote: Birth and family.]

Peter’s own statements in his chief work, the _Conciliator_,[2759] show that he wrote it in the year 1303, after having worked it over in class-room lectures and discussions for ten years previously, and that he was fifty-three years of age at that time. In other words, he was born in 1250. On one point of his biography more precise and scientific detail is forthcoming than is customary in the lives of the great men of the past, for he confides exactly how long a time elapsed before his birth, nine months and fourteen days, as he had learned by astrological scrutiny and from his “most careful mother.”[2760] In his will Peter gives his father’s name as Constantius of Abano,[2761] and he was probably the notary of that name whose tombstone inscription has been preserved.[2762] Scardeone stated that Peter had one son named Benvenuto,[2763] whose name also appears in a list of inhabitants of Padua in 1320[2764] and who took part in a street fight there in 1325.[2765] Gloria was the first to call attention to two other sons, named Pietro and Zuffredo, whose names appear together with their brother’s in deeds of sale and of inheritance of November 19, 1318, and February 2, 1321. Gloria was of the opinion that these sons were illegitimate, and Peter’s failure to make them his heirs in his will may perhaps be so interpreted, but they are not called natural sons in the documents.

[Sidenote: Travels abroad.]

At some time of unknown date Peter was in Sardinia, where he says he saw a case of poisoning from “Pharaoh’s fig,”[2766] and at Constantinople, where he discovered a volume of the _Problems_ of Aristotle, which he translated into Latin for the first time. It was probably there too that he saw a Greek version of Dioscorides arranged alphabetically--his own edition of Dioscorides follows another text, the medieval Latin version--and secured the works of Galen and other treatises which Michael Savonarola[2767] says that he translated from Greek into Latin. Peter is also said to have visited Spain, England, and Scotland, but I have found no proof of this, although allusions to such visits may possibly occur somewhere in his voluminous works.

[Sidenote: At Paris.]

A number of years of Peter’s life were spent at the University of Paris, where Michael Savonarola states that he was regarded as a second Aristotle and called “the great Lombard.” There he wrote his work on Physiognomy (_liber compilationis phisonomie_) which he dedicated to Bordelone Bonacossi who was captain-general of Mantua from 1292 to 1299. In the version which has reached us and which is dated 1295 Peter alludes to an earlier draft which had gone astray and had failed to reach its destination in Italy.

[Sidenote: His Latin version of Abraham Aben Ezra.]

In 1293 Peter found astrological writings of the Jew, Abraham Aben Ezra, who had flourished at Toledo in the twelfth century, defectively translated from Hebrew into French,[2768] and therefore published a Latin revision of his own, apparently also adding treatises which had not been included in the previous translation.[2769] This raises the question whether Peter was acquainted with Hebrew and Arabic,[2770] or whether he may have used a Greek version of Abraham’s treatises in correcting the French one. At any rate Peter’s Latin version of Abraham’s astrological works had a widespread influence, as it was retranslated into various European vernaculars and apparently even back again into Arabic.[2771]

[Sidenote: Conversation with Marco Polo.]

Peter talked with the famous oriental traveler, Marco Polo, at some time between the latter’s return to Venice in 1295 and the completion of the _Conciliator_, in which he cites Marco’s statements to him concerning tropical countries near the equator.[2772]

[Sidenote: Translations from the Greek.]

A translation of the Problems of _Alexander medicus_ is ascribed to Peter in the list of his works in a fifteenth century manuscript.[2773] This can hardly refer to Alexander of Tralles. Perhaps what is meant is a translation of the Problems of Alexander of Aphrodisias, of which I know only one manuscript where it is dated 1302. Savonarola, however, states that Peter translated the Aphorisms of Alexander and also the Rhetoric of Aristotle, but the latter translation does not seem to be extant. Some at least of Peter’s translations of Galen’s works would appear to have been executed before 1303, since they are referred to by him in the _Conciliator_. Also two of them are found in manuscripts dated as early as 1304 and 1305, the latter containing Peter’s completion of the translation of Galen’s _Therapeutic Method_ begun by Burgundio of Pisa.

[Sidenote: Did he teach at Bologna?]

This last manuscript was written at Bologna in 1305 and is about the only evidence we have to support the old tradition, which was already questioned by Mazzuchelli, that Peter taught at Bologna.[2774]

[Sidenote: Return to Padua.]

Savonarola seems correct in stating that Peter completed the _Conciliator_ and began the composition of his Commentary on the Problems of Aristotle at Paris, and the _Explicit_ of the latter work likewise states that Peter wrote part of it in Paris and finished it at Padua in 1310. He left Paris therefore at some time after 1303 and returned to Padua at some time before 1310. Apparently he might have been in Bologna in 1305 but in 1307 he is listed as a member of a gild in Padua.[2775] Grabmann in his recent researches concerning the thirteenth century translations of Aristotle has called attention to a translation of the History of Animals made from the Greek in 1260 and of which Peter of Abano purchased a copy in 1309 from Francesco of Mantua for the price of seven Venetian _soldi_.[2776]

[Sidenote: Three works of astronomy and astrology.]

In the _Conciliator_ Peter refers a number of times to three works of his in the fields of astronomy and astrology, namely, a treatise on the astrolabe, another on the motion of the eighth sphere, and a work entitled _Lucidator_, of which the preface and a few chapters are extant and which perhaps was never finished, since such allusions to the work in the _Conciliator_ as I have noted are to these few chapters, while from the nature of these same allusions to the _Lucidator_ and from its own preface one would expect it to be of somewhat the same length as the bulky _Conciliator_, since it was to discuss disputed points in the fields of astronomy and astrology in the same way that the _Conciliator_ discussed them in the field of medicine.

[Sidenote: Publications in the year 1310.]

But we now encounter the seeming difficulty that, while both the _Lucidator_ and work on the motion of the eighth sphere are cited in the _Conciliator_, which was finished in 1303, they both mention 1310 as the date of their composition. A further indication that the _Lucidator_ was published after the _Conciliator_ is that in its preface Peter states that its method and arrangement will be similar to those of the _Conciliator_, which is also cited later in the text itself.[2777] Apparently, therefore, Peter had written first drafts of the two astronomical works before he finished the _Conciliator_ in 1303, but did not complete or publish them until 1310. In that same year, as we have seen, he completed his Commentary on the Problems of Aristotle.

[Sidenote: Undated and spurious works.]

No definite date can be assigned for some of Peter’s works, namely, his continuation of the _Grabadin_ of the Arabian physician, Yuhanna ibn Masawaih, to whose second book on remedies appropriate to diseases of particular parts of the body he added a discussion of remedies for complaints of the heart and digestive organs, and his edition of the medieval Latin version of the _Materia medica_ of Dioscorides, of which we have treated in an earlier chapter.[2778] Peter is also credited with a Latin edition of the little tract on astrological medicine, or prognostication of diseases according to the motion of the moon in the signs; but a Latin translation of the same work is also attributed to William of Moerbeke who lived a little earlier. Some other medical treatises that have been ascribed to Peter, like the Questions on Fevers, listed in Mazzuchelli’s bibliography, are really portions of the _Conciliator_. Works of geomancy and magic attributed to Peter and probably spurious will be described more fully later in connection with those subjects.

[Sidenote: Closing years of his life.]

It has been stated by more than one author that Peter went to Treviso to teach medicine in 1314, but it is doubtful if he even received a definite call from that city, although it had his name under consideration.[2779] His salary at Padua has repeatedly been stated at the high figure of five hundred pounds or lire a month but this amount really represents his annual stipend.[2780] He must, however, have been fairly well-to-do--we have hints that his practice was lucrative--for in 1315 when he made his will he had not been paid any salary for three or four years, and yet had considerable property. Peter was dead before the close of 1318,[2781] but the apparent attribution of his work on poisons to Pope John XXII[2782] makes it seem that he lived beyond August, 1316. One manuscript of that treatise speaks of Peter as acting dean of Montpellier at that time, but this is unlikely.[2783]

[Sidenote: Relations with the church.]

We have dubious stories and more reliable data to show both that Peter had intimate and friendly relations with popes, whom he seems to have served in a medical capacity and from whom he received patronage and protection, and on the other hand that he was in difficulties with the Inquisition.[2784] Besides the fact that his work on poisons was certainly written for some pope, if not for John XXII, we have the tale that he was physician to Pope Honorius IV (1285-1287) and charged him one hundred florins a day.[2785] On the other hand, we have the assertion of Thomas of Strasburg, Prior-General of the Augustinian Friars from 1345 to 1357 that he was present in Padua when the bones of Peter of Abano were burned for his heretical errors, and the statements of still later writers, which are perhaps after all merely unwarrantable inferences from Thomas’s assertion and from Peter’s own words in his will and the _Conciliator_, that Peter died while under trial a second time by the Inquisition, which had once before instituted proceedings against him unsuccessfully. But these matters require a longer discussion than seems advisable now and so will be treated of more fully in Appendix VIII to this chapter.

[Sidenote: Great reputation.]

The promptness with which Peter’s works appeared in book form after the invention of printing and the number of times that the _Conciliator_ and some others were reprinted attest his long continued reputation and popularity as a medical authority and man of broad general learning. Regiomontanus, the renowned mathematician of the fifteenth century, when lecturing on Alfraganus at Padua, delivered a public panegyric upon Peter of Abano.[2786] It was perhaps to be expected that Michael Savonarola, grandfather of the famous friar who tried to reform Florence and himself a physician and medical writer of some note, should belaud Peter in his work on the great citizens of Padua in the past, which he wrote about 1445; and that these eulogies should be repeated in such books as Scardeone’s _On the Antiquity of the City of Padua_, Naudé’s _Apology for Great Men who have been falsely suspected of Magic_, Tomasini’s _Eulogies of Illustrious Men adorned with pictures_, and Duchastel’s _Lives of Illustrious Physicians_. But Peter’s reputation at the close of the middle ages is also attested in a criticism of some of his views by Symphorien Champier which was written in 1514 and is found appended to the 1526 edition of the _Conciliator_. Champier’s object is to correct Abano’s errors, that is to say, those passages in the _Conciliator_ where he regards Peter’s views as bordering too closely upon magic or of too extreme an astrological character for a Christian. But he admits Peter’s great medical reputation, stating that the most learned physicians praise the medical and philosophical views of the _Conciliator_ and that Peter is believed to have surpassed all other Christian physicians in his study of medicine and advancement of truth. But, as Horace says, even Homer nods; hence Champier will correct Peter in a few points in order to enable lovers of Peter’s doctrines to get the benefit of them without falling into his occasional errors.

[Sidenote: Not a miracle in a rude age.]

The writers of the Renaissance and of early modern times became so enthusiastic over Peter of Abano, and at the same time so failed to appreciate the character and accomplishments of medieval learning in general, that they were wont to depict him as a miracle of learning in a rude age--just as more recent scholars have over-estimated Roger Bacon’s superiority to his time--and to regard the physician of Padua, like the author of the _Divine Comedy_, as a precursor of their own period rather than as a final representative and product of a rich earlier period of culture. Thus Scardeone in the sixteenth century spoke of him as the first medical translator from Greek into Latin since Roman days, forgetting earlier medieval translators of Greek medicine like Burgundio of Pisa and William of Moerbeke. And in the seventeenth century Tomasini called Peter “a man most illustrious, in genius, doctrine, and merits, in a rude and unhappy age,” while Naudé declared him “a man who appeared as a prodigy and a miracle in his age.” This depreciation of the times in which Peter had lived became accentuated, as in the similar case of Roger Bacon, by the report that he had been persecuted by the medieval church.

[Sidenote: But completed the work of his period.]

As a matter of fact, as Dante really closed the medieval period of the flourishing of vernacular literature and the age of romance, so Peter of Abano came in a sense at the close of a period or movement in the history of science. He thus not unnaturally occupied himself especially in supplementing, correcting, and reconciling the work of his predecessors. Some works that had been unsatisfactorily translated, he retranslated. Such important works of Aristotle, Galen, and others as he could find that had not yet been translated, he translated from Greek into Latin. He filled in the missing portion of the medical work of Yuhanna ibn Masawaih. And in his _Conciliator_, a tome of enormous bulk, he endeavored to reconcile and harmonize the conflicting opinions of the medical men and philosophers who had gone before him.

[Sidenote: No mere compiler.]

Pico della Mirandola at the close of the fifteenth century made a trenchant criticism of Peter’s erudition, when he characterized him as “a man fitted by nature to collect rather than to digest.” But this judgment was also too severe, for Peter was no mere compiler, but something of an experimental astronomer as well as a painstaking and critical translator, voluminous commentator upon Aristotle, and great medical authority. In the _Conciliator_ he makes several references to his personal astronomical observations and to other treatises which he has composed upon astronomical topics and which are at least in part extant. He did not hesitate to correct the astronomical calculations of Ptolemy, and appreciated the margin of error in astronomical observations caused by variations in the construction of instruments as well as in their employment by the human observer.[2787] His _Lucidator_, we have seen, was intended to parallel in the field of astronomy and astrology the achievement of the _Conciliator_ in that of medicine; but the portion completed or extant is not a great addition to Peter’s science, since it covers about the same ground already discussed in portions of the _Conciliator_ and more especially in the treatise on the motion of the eighth sphere.

[Sidenote: The _Conciliator_ his masterpiece.]

The _Conciliator_ therefore remains his chief work and the one for which he is most famous, his masterpiece and most influential writing. Like the _Opus Maius_ of Roger Bacon, it to a large extent covers his views as expressed elsewhere and is representative of his philosophy and learning as a whole. It is in many ways a valuable historical document, providing a good example of scholastic method, a broad picture of the state of medieval medicine, and much incidental illustration of the more general knowledge of Peter’s times, as when he alludes to the overland travelers and to the ocean voyages of the thirteenth century. He learned from Marco Polo that there was human life in the Antipodes, he cites a letter of John of Monte Corvino from India “in the coasts where lies the body of the Apostle Thomas,” he alludes to the attempt of two Genoese galleys to reach India by sea “almost thirty years ago”[2788]--two centuries before Vasco da Gama and Columbus. The _Conciliator_ does not, however, quite cover the entire field of medieval science. The subjects of “geometry and perspective,” for instance, Peter rather avoids, explaining, “The arguments taken from the books of geometricians and students of perspective, such as Euclid, Alhazen, and others, and marked out by letters of the alphabet, I omit because most of those for whom I am writing are unfamiliar with that sort of thing.”[2789]

[Sidenote: Its method.]

The _Conciliator_ is made up of over two hundred questions or “Differences” which Peter and his associates have been investigating publicly for the past ten years. Each problem is stated and any doubtful terminology is explained; the utterances of past authorities anent the question are reviewed; the true solution is then reached and the reasons for it given; fourth and finally, hostile objections are answered. This rigid scheme of argumentation does not, however, prevent Peter from indulging in a deal of rather rambling digression. This makes a very long volume, especially as supplementary questions or corollaries are added to some of the two hundred odd _Differentiae_. Also it is, like most works in scholastic form, hard and tiresome reading, as one has to keep in mind all the authorities and objections which Peter has cited and raised until he finally gets around to answering them. Many of the questions concern purely medical matters and admit little debate between philosophers and physicians. The first ten, however, deal with general questions such as whether medicine is a science, whether a doctor ought to be a logician, whether the human body is amenable to medicine, and whether the physician can help the sick by a knowledge of astronomy. Nearly a hundred distinctions are then concerned with medical theory concerning the elements, the physical constitution, generation, the members of the human body, fevers, and kindred questions. The last odd hundred distinctions deal with matters of medical practice and personal hygiene.

[Sidenote: Specimens of its questions.]

The mere list of these questions is interesting and illuminating, and a few of them may be reproduced here to show the kind of questions then debated by doctors--some of them are identical with the questions put by Petrus Hispanus in his _Commentary on the Diets of Isaac_--and to illustrate the broader scientific and philosophical interests of Peter’s volume and time.

11. Is the number of the elements four or otherwise?

14. Has air weight in its own sphere?

23. Is the brain of hot or moist complexion?

28. Is manhood hotter than childhood or youth?

30. Does blood alone nourish?

42. Is the flesh or the heart the organ of touch?[2790]

52. Does the marrow nourish the bones?

57. Is vital virtue something different from natural and
animal virtue?

66. Is spring temperate?

67. Is life possible below the equator?

69. Is the white of an egg hot and the yolk cold?

70. (Supplement). Is wine good for children?

72. Is there a mean between health and sickness?

77. Is pain felt?

79. Is a small head a better sign than a large one?

80. Are the arteries dilated when the heart is and
constricted also when it is?

81. Is there attraction exercised when the arteries dilate
and a loosening when they are constricted?

83. Is musical consonance found in the pulse?

101. Can a worm be generated in the belly?

103. (Supplement). Is death more likely to occur by day or
night?

110. (Supplement). Are eggs beneficial in fevers?

114. Does the air alter us more than food or drink does?

115. Is life shortened more in autumn than other seasons?

118. (Supplement). Should one take exercise before or after
meals?

119. Should heavy food be taken before light?

120. Should one eat once, twice, or several times a day?

121. Should dinner be at noon or night?[2791]

122. Should one drink on top of fruit?

123. Should one sleep on the right or left side?

135. Does confidence of the patient in the doctor assist the
cure?

153. Is every cure by contrary?

154. Should treatment begin with strong or weak medicine?

157. Does sleep help the cure?

171. Is cold water good in fevers?

182. (Supplement). Can fever coincide with apoplexy?

183. Is paralysis of the right side harder to cure than that
of the left?

193. Can consumption be cured?

194. Does milk agree with consumptives?

204. Is a narcotic good for colic?

206. Is blood-letting from the left hand a proper treatment
for gout in the right foot?

[Sidenote: Was Peter the founder of Averroism at Padua?]

Peter has often been called a disciple of Averroes and the founder of Averroism in Italy at Padua,[2792] but I have noticed little in his works to substantiate this. Renan admits that Peter knew neither the _Colliget_ nor the medical works of Averroes, while the doctrine of religious change according to astrological conjunctions which he takes as a sign of Averroism[2793] in Peter came of course from much earlier Arabian astrologers. Indeed, it would seem that most of the points of view which are loosely designated by the word “Averroism” had been common enough among earlier Arabic writers and had even in considerable measure been taken from other sources than Averroes himself by the Latin world. Only if we accept the very dubious and loose assertion of Renan that “medicine, Arabism, Averroism, astrology, incredulity, became almost synonymous terms,”[2794] can we connect Peter of Abano with Averroism and even then we have the obstacles that Peter often makes profession of Christian faith and that Steinschneider asserts that he made no translations from the Arabic.[2795] And if astrological medicine be Averroistic, Peter was certainly not the first Averroist in Italy.

[Sidenote: Reputation for magic.]

Along with his reputation among the learned as a medical authority Peter acquired a popular reputation as a magician and nigromancer. This reputation had become established by the middle of the fifteenth century, when Michael Savonarola tells us that Peter’s great knowledge of astronomy enabled him to make such predictions that men thought he employed magic, and that the present tradition among his fellow townsmen is that Abano was most skilled in the magic art. Of Peter’s astrological skill Savonarola tells the story that, noting the approach of an unusually favorable constellation, he advised the immediate building of a new Padua in order to make her the queen of all cities. Similarly Scardeone ascribed to Peter the idea of the numerous astrological pictures illustrating the influence of the planets and signs upon terrestrial life with which the ceiling of the Palazzo della Ragione at Padua is adorned.[2796] A different story and on the whole perhaps the most incredible one is told by Benvenuto of Imola,[2797] perhaps seventy years after Peter’s death. About to die, Peter said that his life had been especially devoted to three noble sciences, of which one, philosophy, made him subtle; the second, medicine, made him rich; and the third, astrology, made him a liar.

But to return to Peter’s reputation as a magician. Savonarola, whom we were quoting and who evidently has a favorable opinion of magic, continues, “Moreover, this helps to round out his teaching, nor is it contrary to his other sciences, but makes the man the more illustrious.” Naudé,[2798] on the contrary, endeavored to exculpate Peter from the charge of magic and regarded “the common opinion of almost all authors” that he “was the greatest magician of his age and learned the seven liberal arts from seven familiar spirits whom he held captive in a crystal,” as a legend developed from Peter’s astrological predictions and from his own statements concerning incantations in the 156th _Differentia_ of the _Conciliator_. As for the story of seven familiar spirits, already before Naudé Giovan Francesco Pico[2799] had noted the incongruity between the universal reputation of Peter of Abano as a magician and the doctrine attributed to him that there are no demons. Among the authors whom Naudé had in mind was doubtless the learned Bodin who in the sixteenth century declared that Peter of Abano was proved to have been easily the chief of Italy’s magicians. Naudé admitted that Peter had left treatises in physiognomy, geomancy, and chiromancy, but held that he had then abandoned “the idle curiosity of his youth to devote himself wholly to philosophy, medicine, and astrology.”[2800] We have already stated that Champier’s criticisms of Peter’s teachings largely related to astrology and magic. Let us now turn to Peter’s own works and see what his attitude in regard to such matters really was.

[Sidenote: Summary of occult science in the _Conciliator_.]

In the _Conciliator_, as in most of his writings, Peter manifests a marked weakness for astrology and an extensive familiarity with that art. His penchant displays itself in the very prologue where he mentions “the power of genesis in the stars” (_vim geneseos sydeream_) in stating that most men are slaves not only in body but also in the nature of their minds. Peter also occasionally displays a credulous interest in dreams, fascination, incantations, and other varieties of magic. The sections of the _Conciliator_ in which he has most to say of such matters are as follows. In the ninth Difference, “Whether human nature is weakened from what it was of old?” he appeals to astronomy and astrology for support of his views and digresses to speak of his own astronomical researches and publications and of the influence of the stars. The tenth _Differentia_, “Whether a doctor to-day can help the sick by his knowledge of astronomy?” discusses at considerable length the arguments against the art of astrology and argues in favor of astrological medicine. Question one hundred and thirteen, “Whether natural death can be retarded by any benefit?” involves further astrological discussion. In Difference one hundred and fifty-six the efficacy of incantations in medicine is considered. We shall have occasion, however, to cite many other _Differentiae_ than these four.

[Sidenote: Definition of astronomy and astrology.]

By Peter’s time the words “astronomy” and “astrology” were beginning to be used in about their present meaning. He is at pains to explain that their derivation from the similar Greek words, _nomos_ and _logos_, does not justify this distinction. But he accepts the division of the science of the heavens into two parts, one descriptive and dealing with the measurement and motion of the stars, the other judicial and studying their effects. This latter is subdivided as usual into the branches of revolutions, nativities, interrogations, and elections, which last includes the science of images. Conjunctions go with revolutions.

[Sidenote: Nature controlled by the stars.]

In the tenth _Differentia_ of the _Conciliator_ Peter lists and replies to a number of arguments against the art of astrology, such as that the distances involved are too great, the number of stars too numerous, their influences too diverse and conflicting, the instant of nativity too minute, to admit of accurate calculation and prediction. These objections remind us of those raised by Sextus Empiricus. Against such objections Peter adduces not only arguments of his own, but the opinions of philosophers, astrologers, and physicians. All wise men agree, he says, that aside from God, the celestial bodies are the first causes of happenings in this world. Aristotle and the Commentator,[2801] indeed, hold that God does not act directly upon our lower world, and that all operations here are through mediums and instruments; but the true Christian Faith contends that the Creator can, if He will, affect His creatures “immediately and without motion and alteration.”[2802] Of the general law, however, that the natural world is universally controlled by the heavenly bodies there can be no doubt in Peter’s opinion. In another chapter[2803] he cites in favor of this view the assertion of Hermes, Enoch, or Mercury that each sand of the sea has its star influencing it, and that of the _Centiloquium_ ascribed to Ptolemy that the face of this world is subject to the face of the heavens.

[Sidenote: Astrology a science.]

The only question is, how far are we able to follow the workings of this general law in individual cases? The perfect astrologer would require a thorough acquaintance with all the infinite detail of nature and the powers of mind and body. Often therefore astrologers can only approximately and not precisely predict what the stars signify. But the science of astrology should not be abused because certain men who call themselves astrologers or physicians but are really diviners and liars err in their judgments. But astrology proper is neither deceitful nor idle, and the astrologer “speaks the truth in most cases and very rarely fails of correct prognostication except in certain particulars.”[2804] Peter’s confidence in astrology despite the complexity of the problems involved reminds one a little of the confidence of the political or social scientist of the present in his methods compared to those of the mere politician or indiscriminate philanthropist.

[Sidenote: And not magic.]

Again in the first _Differentia_ of the _Lucidator_ Peter argues the question whether astronomy or astrology is a science and meets various arguments raised against the study of the stars.[2805] He holds that, while difficult and laborious, it is noble and honorable, a beautiful discipline adapted to the loftiest intellects, an entirely lawful and licit science. Like Michael Scot, Peter lists and defines various other arts of divination and magic in order to show that the science of the stars is in no way superstitious, as some of them are, and that it neither conjures spirits nor employs exorcisms and suffumigations, as do some arts of divination which try to justify themselves by claiming a connection with the highly reputable science of the stars. Like Guido Bonatti, Peter characterizes as “hypocrites” those who under pretense of defending God’s prerogatives attack judicial astrology as derogating from divine majesty and involving necessity and compulsion. Those who detest such a science should rather be detested themselves, he says, together with those vulgar deceivers and charlatans whom they mistake for astrologers.

[Sidenote: Occult virtues from the stars.]

Indeed, if the perfect astrologer should know nature and man thoroughly, it is also true in Peter’s opinion that astrology helps one to solve the problems of natural science. “We see,” he writes,[2806] “that precious stones and medicines have marvelous and occult virtues which cannot come from the qualities and natures of the elements (constituting them), since nothing acts beyond its species and every agent produces an effect in matter commensurate with itself.” It is useless to try to argue _a priori_ from the qualities of the constituent elements what these occult properties of particular objects will be; they can be investigated only by experience. And it seems evident to Peter that they can be accounted for only as products of the influence of the stars. Indeed, the same species of plant, grown under a different quarter of the heavens, may acquire new virtues. All inferior objects, he affirms in another chapter,[2807] are filled by the action of those superior bodies with demoniac functions and virtues, so that Aristotle in _De coelo et mundo_ says that some of the ancients held that all these objects are full of gods. An indeed suggestive passage from Aristotle, and more so than Peter of Abano or the Stagirite himself realized, tracing back the conception of occult virtue to its origin in fetishism and animism, whence too the gods sprang!

[Sidenote: Astrological medicine.]

Peter was convinced that a knowledge of astronomy and astrology was not only valuable but necessary in the practice of medicine. “Those who pursue medicine as they should and who industriously study the writings of their predecessors, these grant that this science of astronomy is not only useful but absolutely essential to medicine.”[2808] Peter cites Hippocrates and Haly in his support and advises the medical practitioner to look up the nativity of the patient, or, if this is impracticable, to address an interrogation on the case to an astrologer. By astronomy one can also foretell changes in the weather and regulate the treatment of the case accordingly. Diet and drink, purgatives and drugs, should all be administered with due regard to the constellations. Two _Differentiae_[2809] of the _Conciliator_ discuss at length the theme of critical days and their relation to the phases of the moon, which planet, as Peter more than once explains, is assumed to represent the influence of all the others, while to it is especially delegated the control of generation and corruption. The doctor should therefore keep his eye especially upon the moon, a point further emphasized in the pseudo-Hippocratic treatise of astrological medicine which Peter is said to have translated. In still another chapter of the _Conciliator_[2810] the question at issue is whether blood-letting is preferable in the first or some other quarter of the moon. Surgeons, too, should not operate when the stars are unpropitious and should note the apportionment of the members of the human body among the signs of the zodiac. When the patient’s symptoms are ambiguous, the perplexed doctor may bridge the gap in his medical prognostication by recourse to astrology. This will tend to increase his reputation with his patients who will marvel at his power of prognostication. While thus discussing his tenth question, whether a doctor should know astronomy, Peter adds that astrology is useful in metaphysics as well as in medicine, giving as an example the fact that Aristotle appeals to astrologers at one point of his _Metaphysics_.

[Sidenote: The stars and length of life.]

Peter more than once touches upon the influence of the stars upon the length of human life: in Difference 9, for example, where he is inquiring whether men lived longer in ancient times than in his own day; in Difference 21, where the point at issue is whether a temperate “complexion” is more conducive to longevity, and where he indulges in considerable detail about the control of the planets over the process of generation; and in Difference 113, where the question is whether there is any way of putting off natural death. According to the astrologers, one hundred and twenty years--the length of a greater solar year--was the natural term of life, a considerable reduction from the age of the patriarchs of the Old Testament, but much longer than most men lived in Peter’s time. He thinks that the people of India live longer because their climate is subject to Saturn. In Difference 26 Peter divides the life of man into seven ages under the seven planets.

[Sidenote: Nativities.]

It is clear from many passages in the _Conciliator_ that Peter believes that much of a man’s life and character can be inferred from his horoscope. The geniture of a prince may involve the slaughter of vast multitudes in war, although their own horoscopes may not have definitely indicated this fate for them but only a certain inclination in that direction.[2811] Peter devotes considerable space and pains to the process of generation and the problem of measuring the time of nativity. He gives physiological explanations why twins, even before birth, are not under the same astrological influence and approvingly quotes the lines of Lucan:[2812]

_Stant gemini fratres fecundae gloria matris_
_Quos eadem variis genuerunt viscera fatis._

[Sidenote: Revolution of the eighth sphere.]

In connection with the subdivision of judicial astrology known as revolutions Peter was especially interested in the motion of the eighth sphere of the fixed stars, concerning which we have seen he wrote a distinct treatise[2813] and of which he treats in both the _Lucidator_[2814] and _Conciliator_.[2815] Ptolemy had reckoned that the sphere of the fixed stars moved one degree in a hundred years and that consequently the eighth sphere made a complete revolution every 36,000 years. Albategni’s estimate was 23,760 years for a complete revolution or a motion of one degree in the course of sixty-six years. Peter’s own calculation was that one degree was accomplished in seventy years. He regarded this as a matter of great importance because of the vast changes which he believed the revolution of the eighth sphere brought about. Its influence could even change dry land into sea, as the story of the lost island of Atlantis showed. Peter mentions the doctrine of the _magnus annus_, held by “certain Stoics and Pythagoreans” that history would repeat itself as soon as the eighth sphere had accomplished a complete revolution. His own favorite theory, set forth three times in the aforesaid three works, was that when the heads of the equinoctial and tropical signs of the mobile zodiac come directly under the heads of the same signs of the immobile zodiac in the heaven of the fixed stars, then virtue from the First Cause passes in a more perfect manner through the mediate causes or heavens and men live longer and are stronger. For some five hundred years before and after the period of exact coincidence a golden age occurs, men of genius appear in large numbers, and the world tends to unite under one government. Such a period in Peter’s opinion was that of classical antiquity, when there were great rulers like Darius, Alexander, and Julius Caesar; great minds like Hippocrates, Plato, Aristotle, Stoics and Peripatetics, Euclid, Abrachys, Ptolemy, Galen, Cicero, and Vergil; and when both the Roman law and the Christian religion were promulgated. But then gradually, as the discrepancy between the mobile and immobile signs increases, all is changed to the contrary, human nature deteriorates, the span of life is shortened, monarchy is corrupted, faith and law are made light of, the people are oppressed, and true sages are rare indeed.

[Sidenote: Conjunctions.]

In a number of places in the _Conciliator_ Peter discusses the subject of the effects of conjunctions of the planets. He states[2816] that very rarely at long intervals of time, when a greatest conjunction of Saturn and Jupiter occurs in the beginning of the sign of the ram, a well-balanced type of constitution[2817] is produced, but never more than a single specimen at one time. Such a man becomes “a prophet, introducing a new law or religion, and teaching sages and men.” Such a man, according to Isaac Amaraan, Avicenna, and Algazetes, is midway between angels and sages, and some say that Moses and Christ were such men. Peter also hints at a coincidence between the length of time that astrology teaches that such a perfectly proportioned physical constitution will last and the duration of Christ’s life. Champier included this passage in his list of Peter’s errors. Champier further attacked the astrological doctrine of great conjunctions and censured Peter for connecting Noah’s flood and the advent of Mohammed with them. In another passage[2818] concerning this same conjunction of Saturn and Jupiter in the first degree of _Aries_[2819] Peter asserted that it not only altered the strength of human nature and affected the length of life but produced new kingdoms and religions, as in the case of the respective advents of Moses, Nebuchadnezzar, Alexander the Great, Christ, and Mohammed.

[Sidenote: The astrological interpretation of history.]

This astrological interpretation of history Peter carries out in further detail. As he had divided man’s life into seven ages, so he distributed periods of history among the seven planets. Each presides in turn over human affairs for a period of 354 years and four lunar months, a term analogous to the number of days in the lunar year. When Mars governed the world, the flood occurred because of a greatest conjunction of the planets in the sign _Pisces_. Under the Moon’s supremacy happened the dispersion of tongues, overthrow of Sodom and Gomorrah, and escape of the children of Israel from Egypt. Peter also alludes to the less significant minor conjunctions which happen every twenty years, to the moderate ones which take place every 240 or 260 years, and to the effects following eclipses. A solar eclipse seventy years ago, he says, was followed by sterility of the soil, movements of phantasms and of good demons and bad demons, intercourse of incubi and succubi, a weakening of human nature and increase of avarice and cupidity.

[Sidenote: Chronology.]

The chronology of some of Peter’s astrological periods of history has been sharply criticized. Thus Lea remarks, “Even worse was his Averrhoistic indifference to religion manifested in the statement that the conjunction of Saturn and Jupiter in the head of Aries, which occurs every 960 years, causes change in the monarchies and religions of the world as appears in the advent of Moses, Nebuchadnezzar, Alexander the Great, Christ, and Mahomet--a speculation whose infidelity was even worse than its chronology.”[2820] The printed editions of the _Conciliator_ which I have consulted also give the time as 960 years, but it would seem as if the figure must have been wrongly copied in or from the manuscripts, since in the _Lucidator_,[2821] which I have examined in manuscript, Peter shows acquaintance with different systems of chronology, stating, for example, that Ptolemy and Galen flourished under Antoninus Pius in the year 886 of the era of Nebuchadnezzar or in 141 A. D. Peter therefore would appear to have known perfectly well that no such period as 960 years had elapsed between the time of Nebuchadnezzar and Christ, to say nothing of Alexander and Christ. In another passage of the _Conciliator_,[2822] moreover, Peter explains that conjunctions may precede by many years the events which they signify and produce but which are long in the making. Thus the conjunction for the flood preceded it by 287 years and the conjunction connected with Mohammed came fifty years before him, as Albumasar and Alchabitius state. In his treatise on the eighth sphere Peter stated that his theory of its motion and influence holds good independently of the question whether the world is eternal, as all the philosophers except Plato held, or had a beginning and when that beginning was. He gives, however, a list of various estimates of the number of years since creation, such as Bede’s estimate of 5259; Abraham Judaeus’ of 5071; the Septuagint, 7270; Josephus, 5262; and so on up to the enormous figure of 1,474,346,290 years given by the Indians and Persians.[2823]

[Sidenote: Astrological images.]

Peter believed not only that astrologers could predict the future with considerable assurance of success, but also that they could influence the future to suit themselves and perhaps change threatening misfortune into good fortune by applying to earthly objects the occult virtue of the heavenly bodies. The way to capture and store up such celestial influence is by means of images made by human art with due reference to the constellations. Of such astrological images Peter speaks frequently in the _Conciliator_.[2824] Physicians are advised to construct such images at the proper time when “the vivifying and health-exciting celestial light” will flow freely into them, as is illustrated by the astronomical images of Ptolemy, Thebith ben Chorat, and others. The figure of a scorpion made as the moon is leaving the sign of the scorpion cures that reptile’s bite.[2825] Human life can be prolonged by such images which add to the influx of astral force received at birth.[2826] On the other hand, Peter elsewhere states the theory that the impulse to construct an image was received at birth from the stars,[2827] and so does not really alter their influence. He usually, however, speaks as if the employment of images was a matter of choice. They are more often made by night than by day, so that the rays of the sun may not obscure and dissolve those of the other heavenly bodies.[2828] The astronomers of India employ allegorical images.[2829] Peter himself “has tested to remove pain in the intestines the figure of a lion impressed on gold when the sun was in mid-sky, with the heart of a lion, when Jupiter or Venus was in aspect and the evil unfortunate stars were declining.” He bound this amulet “on the bare flesh with a string made of sea calf’s hide and a clasp from the bone of a male whale.”[2830] What could be more magical? In another passage Peter notes that theologians attribute the efficacy of such images to demons, but he sets aside this suggestion as not in accord with his present method, which apparently takes into account only natural and not spiritual forces, although he suggests that the celestial light and force may be regarded as the instruments of intelligences.[2831] In the _Lucidator_ Peter makes much the same distinction between astronomical and necromantic images as Albertus Magnus had made in the _Speculum astronomiae_. Notes by Peter on astrological images are contained in the _Astrolabium planum_, published in 1488.[2832]

[Sidenote: The stars and invocations, incantations, and fascination.]

Peter refers twice in the _Conciliator_[2833] to his success with an invocation to God to acquire knowledge, when the head of the dragon and Jupiter were together in mid-sky and the moon was approaching them. He also cites _Albumasar in Sadam_ for a similar practice by “the kings of the Greeks,” when they wished to ask God for anything. Elsewhere[2834] he states that the defenders of fascination and incantations aver that their potency consists in the virtue which the soul of the operator receives from the stars, just as an image receives their motion and light. The horoscope of the person uttering the invocation is a factor of some importance, but not the preponderating influence.[2835] Not a few of the Magi invoke Jupiter, Saturn, or another heavenly body by the name of the intelligence which guides it.[2836]

[Sidenote: Stars and spirits.]

This last passage and one or two others already cited show that Peter was inclined to associate spirits and intelligences with the heavenly bodies. Once he describes a celestial body as “perpetual and incorruptible, leading through all eternity a life most sufficient unto itself, nor ever growing old.” In the same chapter[2837] he tells us that when Aristotle wished to investigate the number of Intelligences, he betook himself to two famous astrologers and according to the number of spheres as stated by them calculated the number of Intelligences. In the preceding chapter[2838] he had repeated from Averroes the following association of seven intelligences or angels with the planets: Saturn and Cassiel, Jupiter and Sachiel, Mars and Samael, the Sun and Michael, Venus and Anael, Mercury and Raphael, the Moon and Gabriel.

[Sidenote: Were Peter’s views heretical?]

This passage and Peter’s invocation are a dangerously close approach to astrological necromancy. Enough so perhaps to justify the reproach which Champier repeated from some “recent authority” that Peter borrowed a great deal from Picatrix, “a very idle book full of superstitious prayers to planets and evil spirits.” Champier, however, cited no specific passages to substantiate this charge, and I doubt if it can be shown that the _Conciliator_ either cites or makes unacknowledged quotation from Picatrix. It will also be observed that Peter does not assert that the stars themselves are spirits or intelligences or gods, and that both Aquinas and Albert were inclined to agree that angels or heavenly intelligences moved the stars. That Peter’s views were objectionable to some persons, however, is indicated by the closing passage of this ninth _Differentia_, in which he has associated seven spirits with the planets, the rise of prophets and new religions with great conjunctions, and activity of demons with solar eclipses. Some malicious persons have long troubled him, he says, but his utterances in nothing derogate from divine wisdom but rather confirm it, and at last an apostolic mandate has snatched him and his truth from the hands of his detractors. In other words, the pope has protected him. Peter’s astrology sometimes seems to show scant regard for human free will, but he recognized it as an essential Christian doctrine.[2839]

[Sidenote: Fascination.]