PETER OF ABANO

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.

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.

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.

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.

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]

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]

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.

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]

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]

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.

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.

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.

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]

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.

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.

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.

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.

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.

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]

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.

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.

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.

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.

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.

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.

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.

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.

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.

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!