Chapter XII: Introduction (7)

“Dante formerly had been used to spend his time
over his precious studies whenever he was inclined,
and would converse with kings and princes, dispute
with philosophers, and frequent the company of
poets.... Now, whenever it pleased his new mistress
he must at her bidding quit this distinguished
company, and bear with the talk of women, and to
avoid a worse vexation must not only assent to
their opinions, but against his inclination must
even approve them. He who, whenever the presence of
the vulgar herd annoyed him, had been accustomed
to retire to some solitary spot, and there to
speculate on the motions of the heavens, or the
source of animal life, or the beginnings of created
things, or may be to indulge some strange fancy, or
to compose somewhat which after his death should
make his name live into future ages, he now, as
often as the whim took his new mistress, must
abandon all such sweet contemplation, and go in
company with those who had little mind for such
things.”[80]

------------------------------------------------------------------------ [80] Boccaccio’s _Vita di Dante_; Translation from Toynbee’s _Dante Alighieri_ (Oxford Biographies), pp. 92, 93. ------------------------------------------------------------------------

However, after a long tirade against wives, Boccaccio owns that as far as concerns Dante the picture is entirely imaginary. He believes the marriage was an unhappy one, because after his exile Dante and his wife never met again, but we have no evidence whatever that while they were together their life was as Boccaccio depicts it. Doubtless family life and the care of four children interfered to some extent with Dante’s studies, but the one detail Boccaccio affirms as fact among his fancies, namely that the poet refused for nineteen years to see his wife, seems rather to imply that one thing poor Gemma did know how to do was to leave her husband in peace when he did not desire her company.

When and where Dante began to study astronomy seriously it is not easy to say. His favourite study in his youth was poetry, but his parents (says Bruni) gave him a good general education, engaging such teachers as could be found in Florence, where as yet there was no university. But seeing how clever the boy was, his relatives and friends helped and encouraged him, and among the latter Bruni mentions Brunetto Latini.

This famous Florentine was a very learned lawyer, who during Dante’s infancy and boyhood held high offices of state in the city. It is not possible, therefore, that he should have had pupils at this time, and he cannot have been Dante’s master in any strict sense of the word, as Vasari affirms, and as many commentators have assumed on the strength of the moving interview between these two in the _Inferno_.[81] Dante’s affectionate greeting mingled with reverence, and the fatherly solicitude of Brunetto, suggest just such a connection as Bruni indicates. The elderly man had taken an interest in the budding genius of the boy, and had held inspiring conversations with him from time to time on serious subjects, and by his own example had encouraged the youth to win fame through his pen. For Dante was no doubt well acquainted with Brunetto’s _Tesoretto_, and his more ambitious and voluminous _Trésor_, which Brunetto specially commends to his care.[82] This was a compendium of knowledge, a small part of which was devoted to the elements of astronomy, and it may well be that this short epitome was Dante’s first introduction to the science.

------------------------------------------------------------------------ [81] _Inf._ xv. 23 _et seq._

[82] _Inf._ xv. 119. ------------------------------------------------------------------------

Some have thought that Brunetto’s advice to Dante to follow his star “Se tu segui tua stella ...,”[83] indicates that he had cast the poet’s horoscope; but there is no evidence that Brunetto had ever practised astrology, or even that he took special interest in it above other branches of learning.

------------------------------------------------------------------------ [83] “If thou follow thy star,” _Inf._ xv. 55. ------------------------------------------------------------------------

Villani and other biographers tell us that after his banishment from Florence, therefore in middle age, Dante went to the University at Bologna, but they seem to have made this statement rather because of its probability than because they knew it for fact. It is, however, quite possible that he spent a couple of years there, between 1304 and 1306. He probably left his “primo rifugio”[84] at Verona when Bartolommeo della Scala[85] died in March 1304, and we know nothing of his whereabouts till August 1306, when he was in Padua, as is proved by a fifteenth century document.[86] Now in 1306 a number of Ghibelline students and professors left Bologna for Padua; and we know that Dante had friends among the Bolognese professors, for later on he seems to have corresponded with Cecco d’ Ascoli,[87] and Del Virgilio entreated him to come and receive the laurel crown, an invitation which the poet refused in one of his Latin Eclogues. Bologna and the Bolognese are referred to several times in Dante’s works, and the friar Catalano is no doubt alluding to the school of theology at the University when he says in _Inf._ xxiii. 142-144 that he used to hear at Bologna much about the wickedness and the lies of the Devil. One vivid passage can hardly be anything but a personal reminiscence of the Carisenda, the leaning tower at Bologna. The poet compares his fear when he saw the giant Antæus stooping over Virgil and himself to the sensation of looking up at the Carisenda from beneath the leaning side, when a cloud is passing over it, and the spectator feels that the tower is about to fall upon him.[88] (The tower was much higher in Dante’s day than it is now, part having been pulled down in the middle of the fourteenth century).

------------------------------------------------------------------------ [84] “First refuge,” _Par._ xvii. 70.

[85] _Par._ xvii. 71, 72.

[86] Imbriani, _Dante a Padova_.

[87] “_Torno a Ravenna e de lì non mi parto_ (I am going back to Ravenna, and shall not leave it again), is a line in the _Acerba_ which Cecco d’ Ascoli puts into the mouth of Dante, as though from a letter written to himself from the divine poet at the time” (about the year 1319). _Dante and Giovanni del Virgilio_, by Wicksteed and Gardner, p. 84.

[88] _Inf._ xxxi. 136-141. ------------------------------------------------------------------------

The University at Padua was also famous, and as it was originally an offshoot from Bologna and modelled on the same plan, it is sure to have included astronomy in its curriculum. But Dante does not seem to have stayed here more than a few months.

There is also a tradition that he went to Paris, the greatest intellectual centre of his times, and that he himself heard those lectures of Sigieri, the philosopher, in the Street of Straw, of which he makes mention in _Par._ x. 137. This is possible, but quite uncertain; the allusion to Sigieri is no proof, since it has lately been discovered that he died in Italy, and his story was well known there.

After sifting all the evidence available, we can only echo Boccaccio, and say of Dante that “As it was at divers ages that he studied and learned the divers sciences, so likewise it was at divers places of study that he mastered them under divers teachers.”

_III. BOOKS ON ASTRONOMY USED BY DANTE._

BOOKS ON ASTRONOMY USED BY DANTE.

We shall probably be right if we conclude that Dante’s knowledge of astronomy was principally gained from independent reading, and from conversation and discussion with learned men. Like a true scholar, he was learning all his life, for in the _Paradiso_ he corrects the opinion expressed earlier in the _Convivio_ about the origin of the markings in the moon.

Boccaccio’s description of his planning out a course of study and attacking some subjects alone in his youth agrees with his own account of his lonely struggles with Latin authors;[89] and it is quite credible that he suffered heat and cold, and went without food and sleep in his eagerness to learn, since he himself mentions quite casually that at one time he injured his sight by constant reading, so that the stars appeared blurred to him, until by rest and bathing with cold water it became strong again.[90]

------------------------------------------------------------------------ [89] _Conv._ II. xiii. 22-26.

[90] _Conv._ III. ix. 146-157. ------------------------------------------------------------------------

His diligence must have been great, and his memory wonderful, judging from the numerous quotations from classical and contemporary authors to be found in his writings. They seem to be chiefly from memory, and it is not likely that he can often have had many books by him when writing. If he gives a reference it is often a vague one, and occasionally wrong: his authorities on astronomical questions are sometimes “the mathematicians,” “the astrologers,” or “the sages of Egypt,” by whom he means the Alexandrian astronomers.

One does not, of course, expect mediæval writers to verify their references, or to have our modern scruples about quoting other authors without acknowledgement: in those days they were only too glad to get their information wherever they could, often at second or third hand, and to make it their own by storing it in their memories. Nevertheless, from a careful study of Dante’s direct quotations, and his allusions and reminiscences, which are sometimes unconscious, a good idea may be gained of his range of reading, and of the books and authors on whom he chiefly relied for his astronomical data.

His supreme authority was of course Ptolemy. But it would only be by a rare chance that he could see the _Almagest_, even in a translation, and all the evidence that we can find in his own writings points to its being entirely unknown to him. On each of the three occasions that he quotes Ptolemy’s opinion on subjects dealt with in the _Almagest_ he is wrong: once it is Ptolemy’s view on the physical nature of the Galaxy,[91] as to which none had been expressed, although its appearance was carefully described; in another case he implies that Ptolemy discovered precession, and says that he added a ninth heaven to account for it,[92] and this double mistake was apparently copied from Albertus Magnus or Averroës.[93] As we know, it was Hipparchus who discovered precession, and Ptolemy gives him the credit for in the _Almagest_; it was the Arabian astronomers who added the ninth sphere.

------------------------------------------------------------------------ [91] _Conv._ II. xv. 73-77.

[92] _Conv._ II. iii. 36-52, _V. N._ xxx.

[93] Averroës, in his commentary on Aristotle’s _De Cœlo_, says that the ancients believed the eighth, or starry, heaven, to be the outermost, but that Ptolemy assumed a ninth, “because he said that he had discovered a slow motion along the signs of the zodiac in the fixed stars.” Albertus Magnus, in his _De Cœlo et Mundo_, Book II., says also that the ancients, including Aristotle, believed that there were only eight heavens, but that Ptolemy, so far as he can understand, believed in ten, on philosophical not mathematical grounds (compare _Conv._ II. iii. 40, 41). Albertus accepted the theory of “trepidation,” and thought this was the only movement which ought to be assigned to the star sphere; there remained, therefore, two motions, which affect all the planetary spheres and the star sphere, for which two more spheres must be assumed, a ninth sphere for precession, and a tenth, the primum mobile, for the diurnal motion. Outside all was the Empyrean. Dante never mentions trepidation, and evidently did not believe in it: he needed only nine moving spheres, therefore, but counts the Empyrean as a tenth heaven. ------------------------------------------------------------------------

On the other hand Dante quotes twice quite correctly from the _Tetrabiblios_, which was more widely known.[94] He may, therefore, possibly have read it, and he alludes to it in the _Convivio_, though by a curious slip he does not give its name, thinking he has done so already: “Tolommeo dice nello allegato libro....”[95] This is in the fourteenth chapter of the second treatise, but so far from having just quoted any special work by Ptolemy he has said nothing at all about him since the third chapter, and then it was only his opinion and name that were mentioned. I have not been able to trace the quotation given in the _Quæstio de Aqua et Terra_ (xxi. 29-31), where Ptolemy is said to have asserted that things on earth resemble things in heaven, but this probably comes also (or was supposed to come), from the “judicial astronomy” of the _Tetrabiblios_. It is not taken from the _Almagest_.

------------------------------------------------------------------------ [94] _Conv._ II. xiv. 198-202. _Ibid._ 249-253.

[95] “Ptolemy says in the book above cited.” ------------------------------------------------------------------------

The elements of Ptolemy’s system, however, could be learned indirectly, and it seems that Dante had recourse to the excellent epitome of the Arab astronomer Alfraganus. It is true that his name is only mentioned once, and his book once; but nearly all Dante’s astronomical data appear to have been taken from him, and his very expressions are sometimes repeated.

One of the most striking examples of borrowing from the _Elementa Astronomica_ of Alfraganus occurs in the _Paradiso_, where Dante likens twenty-four spirits to as many brilliant stars.[96] He makes up the number by taking fifteen specially bright stars from different parts of the sky, and adding to them the stars of Ursa Major and two stars of Ursa Minor. The seven chief stars of Ursa Major are well known, but Beta and Gamma Ursæ Minoris are not conspicuous nor specially familiar; and why, if he takes fifteen unnamed, should he name any of the twenty-four? Turning to chapter 19 of Alfraganus’ book, we find that he follows Ptolemy in enumerating fifteen first-magnitude stars in different parts of the sky, and then he gives as examples of the second magnitude (_i.e._ next in brightness) Benet Naax and Alfarcatein, Arab constellations which correspond with the tail of Ursa Major, and Beta and Gamma of Ursa Minor.

------------------------------------------------------------------------ [96] _Par._ xiii. 1-13. ------------------------------------------------------------------------

There is no reason to suppose that Dante knew Arabic, but there were several versions of Alfraganus in Latin, and it is even possible to determine with some certainty which of them he used. Speaking of the movements of the planet Venus, he says that they may be found, summarized from the best demonstrations of the astrologers, in the _Book of the Collection of the Stars_:—

“Li quali, secondochè nel _Libro dell’ Aggregazione
delle Stelle_ epilogato si trova, dalla migliore dimostrazione
degli astrologi ....”
(_Conv._ II. vi. 133-136).

Although the usual name for the book of Alfraganus in Latin was _Elementa Astronomica_, the version for which mediæval students were indebted to the indefatigable translator Gerard of Cremona bears in the MSS. the title _Alfragani liber de aggregationibus Scientiæ Stellarum et de principiis cœlestium motuum_. It is this book, therefore, that Dante means, though he has translated the title somewhat inaccurately.[97]

------------------------------------------------------------------------ [97] See Schiaparelli’s letter in Lubin’s _Dante e gli Astronomi Italiani_. The name is, however, also used as a sub-title in the printed edition of Christmann, Frankfort, 1590, which was based not on the translation of Gerard but of Johannes Hispalensis of Seville; and Toynbee thinks that this Frankfort edition represents most nearly the version of Alfraganus used by Dante. It is the only one of the five printed editions which gives the same figure for the diameter of Mercury as that quoted by Dante. See Toynbee, “Dante’s Obligations to Alfraganus” in _Romania_ xxiv. 95, and Moore, _Studies in Dante_ iii. p. 3, _note_. ------------------------------------------------------------------------

There were several other books known to Dante from which he must have gleaned information about Ptolemy’s system, but Alfraganus we may regard as his standard reference book. Many versions of Alfraganus are still extant, and it is pleasant to feel that we can hold in our own hands Dante’s text-book on astronomy. The best known is the printed edition of Golius, published in Amsterdam in 1669: it is in both Latin and Arabic, and opening in the middle we may turn the pages backwards to see the beautiful Arabic letters of Alfraganus’ own language, which is written from right to left, or forwards to look at the Latin in which he became known to Dante.

Next in importance to Alfraganus among Dante’s authorities on astronomy was Aristotle. We have seen how overwhelming his authority became in natural science in the second half of the thirteenth century, and how for some time scholars failed to distinguish between the system of spheres devised by Eudoxus, which was the scheme upheld by Aristotle, and the epicycles and eccentrics of Ptolemy. Among all Aristotle’s admirers none was more devoted than Dante: for him Aristotle is not only “Il Filosofo,” the Philosopher _par excellence_, as he was generally called in that age; he is “quello glorioso filosofo al quale la Natura più aperse li suoi segreti,” his intellect was “quasi divino,” and his words are of “somma e altissima autoritade.”[98] Throughout Dante’s own writings his references to Aristotle are so frequent that Dr. Moore observes: “The amount and variety of Dante’s knowledge of the contents of the various works of Aristotle is nothing less than astonishing.”[99]

------------------------------------------------------------------------ [98] “That glorious philosopher to whom Nature most fully revealed her secrets,” _Conv._ III. v. 54-56; “almost divine,” _Conv._ IV. vi. 133; “supreme and highest authority,” _Ibid._ 52.

[99] Moore, _Studies in Dante_ I. (Scripture and Classical Authors in Dante), from which much of the information in this chapter has been taken. ------------------------------------------------------------------------

He does not, however, consider Aristotle infallible as regards the details of astronomy, for in these the philosopher was only following the observers and mathematicians;[100] but in all matters which depend upon first principles, in which Dante would include the form of the earth, Aristotle’s authority may not be called in question.[101] In cosmical physics, such as the doctrine of the four elements, and in meteorology, Dante follows “il mio Maestro”[102] implicitly, and it is also largely from the _De Cælo_ that he gained his knowledge of early Greek speculations regarding the universe.

------------------------------------------------------------------------ [100] _Conv._ II. iii. 19-21.

[101] _Conv._ III. v. 62-65.

[102] “My master.” ------------------------------------------------------------------------

Dante knew little more of Greek than of Arabic. His occasional use of Greek words is enough to prove this—for example when he discusses the Pythagorean theory of “Antictona,” using the accusative as if it were a nominative.[103] In several passages he implies that the language was not known to him, and he distinctly states that he used translations of Aristotle’s works. Here again we are able to identify the versions he used. In _Conv._ II. xv. 59-73 he complains that it is impossible to know what Aristotle believed about the Milky Way, because in the “old translation” he is made to say one thing, and in the “new translation” quite another. From his quotations of these two conflicting opinions, we are able to deduce that the “old translation” was that which Michael Scot made from the Arabic, and the “new translation” that of Aquinas, which was made direct from the Greek.

------------------------------------------------------------------------ [103] _Conv._ III. v. 32. ------------------------------------------------------------------------

He had access, therefore, to more than one Latin translation of Aristotle; and beside this, his quotations seem to have been often taken from commentators and compilers of his own times, especially Aquinas and Albertus Magnus. This was frequently the case with the _Meteorologica_ of Aristotle, for the _De Meteoris_ of Albertus Magnus seems to have been much used by Dante in place of Aristotle’s own work. Dante quotes it by name as _Meteora_ in _Conv._ II. xiv. 169, and also in _Conv._ IV. xxiii. 125-126, where he mentions “Alberto” as the author.

These two, then, the Arab Alfraganus and the Greek Aristotle, were Dante’s chief authorities in astronomy, both in Latin translations.

Besides these, there is evidence in his writings that he was familiar with several classical authors who treated of astronomy. He quotes frequently from many of Cicero’s works, and we find echoes, in two passages, of the _Dream of Scipio_,[104] which he is almost certain to have read, since it was a favourite book in his time. There are several references to Seneca, but the only time that an astronomical phenomenon recorded by him is mentioned[105] Dante is evidently quoting at second-hand from Albertus Magnus. With all the works of Virgil, and with the _Metamorphoses_ of Ovid (from which he took his astronomical myths)[106] he was evidently very familiar; and Lucan is one of his authorities for the position of the earth’s equator. In this case the name of the author and the number of the book are precisely stated.[107]

------------------------------------------------------------------------ [104] _Inf._ ii. 76-78; _Par._ xxii. 134-138.

[105] _Conv._ ii. xiv. 174-176.

[106] Phaëthon, _Conv._ II. xv. 53-55, _Purg._ xxix. 118-120; Latona, _Purg._ xx. 130-132; the Horses of the Sun, _Conv._ IV. xxiii. 134-139, etc., etc.

[107] _Conv._ III. v. 115-117. ------------------------------------------------------------------------

Dante had a great reverence for Plato, whom he calls “uomo eccellentissimo,”[108] and of whom he repeats the mediæval legend that he was a prince who gave up all for the sake of acquiring wisdom.[109] Of his writings he only knew the _Timaeus_, probably the Latin translation and commentary of Chalcidius, which was widely known. Or he may have been acquainted with Aquinas’ commentary, which has since been lost. He also knew something of Plato’s teachings through Aristotle and Cicero, Albertus Magnus, and Aquinas, and perhaps St. Augustine. When he feels obliged to dissent from the great philosopher’s doctrine that the souls of men come from the stars, he does so with reluctance and great gentleness.[110]

------------------------------------------------------------------------ [108] “A man of supreme excellence.” _Conv._ II. v. 21, 22.

[109] _Conv._ III. xiv. 76-79.

[110] _Par._ iv. 22-24, 49-60. ------------------------------------------------------------------------

Among other Greek philosophers who speculated on astronomy, Dante mentions Thales[111] and Pythagoras. The date when the latter flourished he takes (he tells us) from Livy, and his theory that the Universe is governed by the principle of number from Aristotle’s first book of Metaphysics. The astronomical theories of his school are also doubtless taken from Aristotle. Dante tells the story of Pythagoras that he was the first man to be called “philosopher,” because when asked if he considered himself a wise man, he replied, “No, but only a lover of wisdom.”[112] Dionysius the Academician and Socrates are referred to for their opinions on the influence of the stars upon human souls;[113] and Anaxagoras and Democritus for their galactic theories,[114] which Dante obtained from Albertus Magnus.

------------------------------------------------------------------------ [111] _Conv._ III. xi. 39; _Inf._ iv. 137.

[112] _Conv._ III. xi. 22-33; II. xiv. 144-147; III. v. 29-44; III. xi. 41-47.

[113] _Conv._ II. xiv. 34, 35.

[114] _Conv._ II. xv. 56. ------------------------------------------------------------------------

Except for Alfraganus, Dante refers but seldom to Arab astronomers. He does not seem to have known Albategnius. The _De Substantia Orbis_ of Averroës is quoted in the _Quæstio de Aqua et Terra_,[115] and it is possible that from this book Dante derived a theory about the moon which he expounds in the _Convivio_. He quotes Alpetragius on circular existence (dependent on the spheres),[116] Avicenna on the Galaxy, and again with Algazel on the influence of the spheres,[117] and Albumassar on meteors.[118] The quotation from the latter, however, is second-hand from Albertus Magnus, and is a mistake, for the passage is not to be found in that astronomer’s works. He was born in Turkestan, in 805.

------------------------------------------------------------------------ [115] _Qu._ xviii. 38, 39.

[116] _Conv._ III. ii. 37.

[117] _Conv._ II. xv. 77, II. xiv. 32.

[118] _Conv._ II. xiv. 170-174. ------------------------------------------------------------------------

We may here remind our readers that the three Latin poets, Virgil, Ovid, and Lucan, were among the world’s five greatest poets met by Dante in Limbo; that next to Aristotle among the philosophers stood Socrates and Plato, and near these were Democritus, Anaxagoras, and Thales, Cicero and Seneca, Ptolemy, Avicenna and Averroës.[119]

------------------------------------------------------------------------ [119] _Inf._ iv. 80, 81, 90, 131-144. ------------------------------------------------------------------------

Among Christian writers, Dante may have gathered some information about ancient Greek speculations from St. Augustine and Peter Lombard; and Orosius, the Spanish friend of Augustine, was his chief authority for that geographical system which, in connection with astronomy, plays an important part in the time-indications of the _Divina Commedia_. Orosius had a great reputation among geographers and map-makers. He had travelled much between Spain, Africa, and Palestine, and he devotes a chapter to describing the different parts of the earth in his history _Adversus Paganos_, which he wrote to prove that Christianity had not injured but benefitted the countries in which it had been accepted. This fifth century geography seems to have been largely based on the first-century geography of Strabo, who quotes Eratosthenes, Posidonius, and Hipparchus among his authorities. Orosius states that the land is entirely surrounded by Ocean, and is divided into three continents—Asia, with the mouths of Ganges in the middle of its eastern coast, Europe stretching vaguely very far to the north-east, and Africa a narrow and long strip from east to west between the Mediterranean and the southern ocean. This chapter is quoted in _De Mon._ II. iii. 87-90 and _Qu._ xix. 43; and Orosius is almost certainly “quell’ avocato dei tempi cristiani,”[120] seen by Dante among the learned doctors in the Heaven of the Sun.

------------------------------------------------------------------------ [120] “The advocate of the Christian centuries.” (_Par._ x. 199). Orosius is also mentioned by name in _Conv._ III. xi. 27; _V. E._ II. vi. 84; and _De Mon._ II. ix. 26. ------------------------------------------------------------------------

The speaker who points him out in these words also mentions his own name and that of the spirit nearest to him:—

“Questi che m’è a destro più vicino
Frate e maestro fummi, ed esso Alberto
È di Cologna, ed io Thomas d’Aquino.”[121]

------------------------------------------------------------------------
[121]
“He who is nearest to me on the right
My brother and master was, and he Albertus
Is of Cologne, I Thomas of Aquinum.”
(_Par._ x. 97-99).
------------------------------------------------------------------------

These two, so near in heaven, had been close companions on earth. The youthful Thomas, son of Count d’Aquino in southern Italy, after six years’ study at the University of Naples joined the Dominican Order, and went to Cologne to learn from Albert, who was also of noble family but born in Suabia on the Danube. Together they went to Paris, together returned to Cologne, but after six more years there their paths separated: Albert rose to be Bishop of Ratisbon; Aquinas, after lecturing in Paris, Rome, and Bologna, became a professor at Naples, and died in Italy in 1274. His master survived him by six years, dying at Cologne at the advanced age of eighty-seven in 1280.[122]

------------------------------------------------------------------------ [122] Toynbee, _Dante Dictionary_; the source also of many other details given in this chapter. ------------------------------------------------------------------------

These two are in the foremost rank among authors of his own time who influenced Dante. He quotes both writers and several of their books by name,[123] and though he never mentions it he was very familiar with the _Summa Theologica_ of Aquinas. To the works of these famous authors he was frequently indebted for astronomical facts, theories, and history, as already noted. Besides this, his reverence for Aristotle, his belief in the essential harmony between religion and science, and his whole attitude towards knowledge, are greatly due to the influence of St. Thomas and his “brother and master,” Albert of Cologne.

------------------------------------------------------------------------ [123] Albert in _Conv._ III. v. 113-115, vii. 26-28; IV. xxiii. 125-6; Aquinas in _Conv._ II. xv. 125-6; IV. viii. 3-6, xv. 125-130, xxx. 26-30; _De Mon._ II. iv. 5-8; and see _Purg._ xx. 69. ------------------------------------------------------------------------

There are also three of Dante’s own fellow-countrymen and contemporaries whose books he is most likely to have read, although he does not mention them:—Brunetto Latini the Florentine, Cecco d’ Ascoli, professor at Bologna, and Ristoro the monk of Arezzo.

Brunetto Latini is only mentioned once in Dante’s works, besides the passage in the _Inferno_ already referred to. In the _De Vulgari Eloquentia_ Brunetus Florentinus is mentioned with admiration as a distinguished man of letters, but blamed with other Tuscans for writing in his own local dialect.[124] Brunetto, who was born in Florence about 1210, was sent on an embassy in 1260 to Alfonso X. of Castile, the learned king under whose guidance the famous astronomical Tables had been drawn up. But on his way back to Florence he was met by the news that the Florentine Guelphs had been defeated at the disastrous battle of Montaperti,[125] and expelled from Florence; and as he belonged to this party he took refuge in France, first at Montpellier and afterwards in Paris. When the Guelphs had regained the ascendancy through their victory at Benevento in 1266 (where Manfred lost his life),[126] Brunetto returned to Florence, and his name subsequently appears in no less than thirty-five public documents as having been consulted by the government of his native city on various important matters. For the most part, moreover, it is recorded that his advice was followed. He died at a venerable old age in Florence in 1294, and was buried in the church of Santa Maria Maggiore.

------------------------------------------------------------------------ [124] _V. E._, I. xiii. 1-11.

[125] _Inf._, xxxii. 81, and x. 85, 86.

[126] _Purg._, iii. 112-129. ------------------------------------------------------------------------

It was while exiled in France that Brunetto wrote the Italian poem _Il Tesoretto_, in which he represents himself as a pilgrim on an allegorical journey; and from this Dante perhaps derived some suggestions for his Vision. The poem is incomplete, and breaks off at a tantalizing point, for Brunetto has just met Ptolemy on Mount Olympus, and has put a question to him: Ptolemy “rispose in questa guisa”[127]—and here the poem ends!

------------------------------------------------------------------------ [127] “Replied after this fashion.” ------------------------------------------------------------------------

In France also he wrote _Li Louvres dou Trésor_, a great compendium of learning, in French prose. The first part treats of the Creation and Biblical history, and of the natural sciences; the second of ethics, rhetoric, and politics. In the section on astronomy which is included in the first part, Brunetto gives a very brief account of Ptolemy’s system, and the sizes and distances of the heavenly bodies as estimated by the Arabs: it seems to be based chiefly on Alfraganus. But beside the periods of the planets he adds in each case their astrological properties, as for instance:—

“Saturnus, qui est le souverain sor tous, est cruex
et felons et de froide nature ... Jupiter ... ast
dous et piteus et plains de biens.... Mars et chaus
et bataillereus, et mauvais, et est apelez Diex de
batailles.”[128]

------------------------------------------------------------------------ [128] _Li Louvres dou Trésor_, Chabaille, Paris 1863. ------------------------------------------------------------------------

When speaking of the two principal movements of the skies, he quotes a curious old idea which had been mentioned by Isidore of Seville, that they are in contrary directions because the tremendous speed of the diurnal motion would shake the whole universe to pieces if it were not that the seven planets go as it were to meet it, and soften its vehemence:—

“Li firmamenz court de orient en occident entre
jor et nuit une fois, si roidement et si fort
que sa pesanteur et so grandor la feroient tout
tressaillir, se ne fussent les VII. planetes qui
vont aussi comme a l’encontre dou firmament, et
atemprent son cours selonc son erre.”[129]

------------------------------------------------------------------------ [129] _Ibid._ ------------------------------------------------------------------------

The _Acerba_ of Cecco d’Ascoli was another encyclopædic work, but in Italian verse. It was very much the fashion in those days to undertake a compilation of all kinds of knowledge, and this was doubtless very useful when few books could be owned by any single reader. Cecco had a considerable knowledge of natural science, and astrology was of great importance in his eyes. Though Dante never mentions him or his work, he can hardly have been ignorant of it, especially as he himself is mentioned in it.

Nor does he mention Ristoro of Arezzo, yet we find many ideas and expressions in Dante’s writings which are also in the _Composizione del Mondo_. Even if he did not borrow from it, the book is worth study by anyone interested in the popular astronomy of the thirteenth century. We learn from the author that he wrote his book in Arezzo, finishing it in the year 1282, that is about thirty years before Dante’s _Convivio_ appeared. The opening words run:—

“Incominiciasi il libro della Composizione del
Mondo colle sue cagioni: composto da Ristoro di
Arezzo in quella nobilissima città ... etc.”[130]

------------------------------------------------------------------------ [130] “Here beginneth the book of the _Composition of the World together with its Causes_: written by Ristoro of Arezzo in that most noble city.” ------------------------------------------------------------------------

and the closing words are:—

“Compiuto e questo libro sotto li anni di Cristo
nel mille dugento ottantadue. Ridolfo imperadore
aletto. Martino quarto papa residente. Amen.”[131]

------------------------------------------------------------------------ [131] “Here endeth this book, in the year of our Lord one thousand two hundred and eighty-two. Rudolph Emperor at this date. Martin IV. resident Pope.” Amen. ------------------------------------------------------------------------

We learn further that he was a monk and a native of Arezzo in an interesting passage where he describes a total eclipse of the sun seen by himself from his monastery: the sky was very clear, and it must have been a specially dark eclipse, for besides Mercury he saw many stars; totality lasted for as long as a man could easily walk 250 steps; there was a feeling of chill, and birds and wild animals were so frightened that they allowed themselves to be caught. Fra Ristoro made a calculation and found that on that day sun and moon were in the same position in the sky. It was perhaps this event which induced him to study astronomy.

The extent and depth of Ristoro’s reading evidently bore no comparison to Dante’s, but he was able to sit writing in his quiet cell, day after day, and had such books as he wanted at hand. The monastery seems to have been furnished with astronomical tables, a celestial globe, and the books of Alfraganus and other Arab writers. All these he had studied, and he was something of an observer too. Alfraganus must have been always at his elbow when writing, for he turns to it constantly, quoting (unlike Dante) the chapter referred to:—

“Alfragano pose nell’ ottavo capitolo;” “è
testimonio l’Alfragano nelli venti e due capitoli
del suo libro;”[132]

------------------------------------------------------------------------ [132] “Alfraganus said in the 8th chapter”; “Alfraganus bears witness in the 22nd chapter of his book.” ------------------------------------------------------------------------

one chapter is avowedly taken whole from Alfraganus, and where the opinions of “il grande Tolommeo”[133] are quoted they are evidently copied from the same source. Other Arab writers are quoted once or twice, for instance, Albumassar,

------------------------------------------------------------------------ [133] “The famous Ptolemy.”

“il quale fu altissimo maestro d’astrologia,”[134]

[134] “Who was a very great teacher of astrology.” ------------------------------------------------------------------------

and several lines are copied from a Latin translation of Algazel,[135] giving some astrological jargon about the twelve zodiacal signs.

------------------------------------------------------------------------ [135] “An Arabian philosopher of Baghdad, 1058-1111.” ------------------------------------------------------------------------

We have already quoted from Ristoro’s preface, showing the high opinion he held of astronomy. But it is disappointing to find that the greatest part of his book is devoted to the “cagioni,” that is, to purely fanciful “reasons,” for all the facts and fallacies concerning nature which he has here brought together.

He gravely argues about the constellation figures as if they were real pictures of animals and things pricked out by nature in stars on the vault of heaven, and not a human convention. He notes their paucity in the southern hemisphere, and that nearly all have their heads towards the north, and from this he draws the conclusion that the northern part of the sky is the nobler, for we can see it is the upper side, just as we know the top side of a book by the position of its letters.

It is for this reason, he thinks, that only the northern hemisphere of the earth contains land and is inhabited. Some, especially the great Averroës, had indeed held that there is inhabited land south of the equator, because the sun goes there. But this is because his movements of recession and approach are necessary to produce the seasons, and hence the growth of plant life, in the north. The constellations are upside down for the south, so they can have no effect there, therefore, there are no animals there (since every race of animals is under the protection of a constellation); therefore no plants, since they exist for animals, and therefore, Ristoro concludes his chain of argument triumphantly, there are no men, and no lands, for land without life would be useless.

Ristoro reproduces Alfraganus’ description of the sun’s movements as seen in different latitudes, quotes him as saying that the equatoral regions are inhabited, and Avicenna that the temperature there is equable because days and nights are always equal. The city Arym which is exactly on the equator has a perfect climate, and as it has two summers and two winters there are two harvests; moreover, all the stars in the sky are visible at the equator; therefore, the best astronomers, and the wisest and richest men, ought to live there, says Ristoro. When writing thus, he seems to have had before him one of the “climate maps” which were common in Europe in the eleventh and following centuries, having been introduced by Arab cartographers, who adopted the idea from Greek maps. For he goes on to point out that the first “climate” is much the longest, and that the others diminish gradually towards the pole, all the “terra scoperta”[136] being thus contained in one quarter of the earth, and having the shape of the moon when we see it half full.[137]

------------------------------------------------------------------------ [136] “The uncovered earth,” _i.e._ not hidden under the ocean.

[137] Bk. VI. cap. xi. ------------------------------------------------------------------------

There is nothing but sea south of the equator, and
the habitable earth lies wholly in one half of the
northern hemisphere, the other half being sea. The
habitable earth, therefore, is the same shape as
the half-moon, _i.e._ a quarter sphere.]

The accompanying climate map shows all these features, the famous city Arym—occupying nearly half the space, although it is supposed to be merely on the equator—the seven climates, and the region beyond the seventh, near the north pole, marked as uninhabitable through the cold. The half-moon shape of Earth’s habitable quarter is obvious. The map betrays Arab influence in the orientation, the south being at the top; and Arym, or Aren, was an Arab myth, perhaps derived from the Mount Meru of the Hindus, which is said in the Vedas to be “in the middle of the earth.”

According to Ristoro, the positions of the constellation figures do not only explain why one hemisphere of earth has land and the other none; they also explain the movements of the skies. For the figures of the zodiac face west (those that have faces), and this is why the diurnal movement of the whole heaven is towards the west, so that the constellations may move straightforward, in the natural way. On the other hand, the planets move in the opposite direction because it would not be seemly for them to pass each figure of the zodiac arriving first at the back and moving on to the head. This is the true reason of the contrary direction of the two principal celestial movements. Ristoro does not approve of the solution quoted by Brunetto Latini. He adds that the width of the zodiac was designed to contain the figures of the animals!

After this, we are not surprised to hear that the red colour of the planet Mars is the cause of its martial nature (not the reason for which such a nature is attributed to it). The markings on the moon Ristoro explains by saying that some body must exist in the World which is neither polished and shining all over, like the stars, nor altogether rugged and dark, as the earth was supposed to be, but partaking of both natures; and this body must be the moon, because of her intermediate position between the earth and the nearest of the other planets (Mercury).

_Reproduced by permission from Beazley’s “Dawn of Modern Geography.”_]

Of the influence of the heavens on the earth Ristoro has very much to say, from general statements such as that the spheres impress their influence on things of Earth, just as a seal impresses wax, down to details about the births of horses. If the moon is strong in Aries, and Aries is powerful, then, because the moon signifies white among the colours and Aries signifies the head, the horse will be born with a white mark on its head, and if the influence is very strong it will be a beautifully-shaped mark. Again and again he tells us about the various properties and “virtues” of the seven planets, but he does not omit to mention that the powers which move the planets and cause them to influence Earth are spirits, which we call Angels, and the philosophers call Intelligences. These have their several dwelling-places in the spheres, and the nobler their nature the higher is the sphere which they inhabit.

From these quotations the reader may judge of the general trend of the eight books comprised in _La Composizione del Mondo colle sue Cagioni_: we shall have occasion to refer to it again, by way of comparison and contrast, when dealing with Dante’s works in detail.

It is rather curious that there is no trace in Dante’s writings of acquaintance with the great Roger Bacon, or with Sacrobosco, especially as Brunetto Latini knew the former personally, and Cecco d’Ascoli wrote a commentary on the latter, but Dante may have known them, and also the works of Isidore and Bede, who are both mentioned in _Par._, x. 131, as well as other books which are now completely lost. Those we have described above would, however, be enough to supply him with all the astronomical data, except one, which we find in his writings. It is now time to examine these, and see what use he made in literature of the knowledge he possessed.

_IV. ASTRONOMY IN DANTE’S WRITINGS._

ASTRONOMY IN DANTE’S WRITINGS.

If we except the seven _Penitential Psalms_ and the _Profession of Faith_, which are only paraphrases, and are very doubtfully ascribed to Dante, no work of his can be mentioned which does not contain some reference to the heavenly bodies.

When writing the _Vita Nuova_, that story of his love for Beatrice which he calls the work of his boyhood,[138] he was haunted by the sublime idea of the rolling spheres. Beatrice at her first appearance as a little girl of eight, and Beatrice when she died, suggested thoughts of the nine heavens;[139] almost the first words of the book allude to the circling spheres of the sun and of the stars:[140] and the last sonnet soars beyond them all to the Empyrean.[141] Already he seems to have read Alfraganus, for he takes a suggestion which occurs in the first chapter of the _Elementa Astronomica et Chronologica_. Alfraganus there describes the different methods of reckoning days, months, and years, in use among different nations, and gives a special list of the Syrian months with their corresponding Roman months; and Dante, by using the Arabian system of days and the Syrian months, is able to prove to himself that the day and the month when Beatrice died were both at the sacred number of nine.[142] According to our method of reckoning, the time was sunset on the eighth of June, but this was the first hour of the ninth day according to Arabian usage, and our sixth month corresponds with the ninth of the Syrians.

------------------------------------------------------------------------ [138] _Conv._ I. i. 125, 126. Compare _Conv._ IV. xxiv. 1-13.

[139] _V. N._ ii. 9-12, xxx. 13-24.

[140] _V. N._ ii. 1-12.

[141] _V. N._ xlii. 47.

[142] _V. N._ xxx. 1-6. ------------------------------------------------------------------------

Dante had also read at this time Aristotle’s doctrines about the spheres and their Movers, for he quotes from the _Metaphysics_,[143] and this is the work in which they are found.

------------------------------------------------------------------------ [143] _V. N._ xlii. 30. ------------------------------------------------------------------------

Yet a familiarity with Alfraganus and Aristotle so early as this is hardly consistent with the difficulty he says he found in understanding Latin books of philosophy some time after the death of Beatrice.[144] Perhaps the latter part of the _Vita Nuova_ was written a good deal later; or it may be not altogether frivolous to suggest that in his youth Dante had read the first chapters of Alfraganus, which are easy, but did not master the rest of the book till later.

------------------------------------------------------------------------ [144] _Conv._ II. xiii. 22-26. ------------------------------------------------------------------------

Out of his fifty-three short poems (including all in Moore’s Oxford Edition, except those which form part of the _Vita Nuova_ or _Convivio_), twelve, or nearly a quarter, contain some reference to sun, moon, or stars, planets, or spheres; and from these alone we could form some idea of Dante’s acquaintance with astronomy. He speaks of the sun as measuring time,[145] and giving light to the stars[146] (according to the general belief); the moon[147] and each of the planets[148] is mentioned, some of the constellations also,[149] especially with reference to the seasons; the theory of the several heavens and their First Mover,[150] and the supposed influences of the stars and planets are alluded to.[151] These poems were written at different times, and some belong to a much later period than the _Vita Nuova_.

------------------------------------------------------------------------ [145] _Son._ xxxvi. 2; _Canz._ xx. 89.

[146] _Canz._ xix. 117; _Canz._ ix. 16, 17.

[147] _Canz._ xx. 89; _Son._ xxviii. 11.

[148] _Son._ xxviii.; _Canz._ xv. 4, 7.

[149] _Canz._ xv. 3, 29, 41.

[150] _Son._ xxviii. 2.

[151] _Son._ xxviii. _Canz._ xix. 77, _Ball._ vi. 11, 12, _Canz._ xv. 41., _Son._ xxvi. 14. ------------------------------------------------------------------------

It is when we come to examine the _Convivio_, the work of his manhood,[152] that we find the clearest evidence of Dante’s careful study of astronomy. This book was written with the professed intention (as one of its aims) of sharing with others the learning he had been happy enough to acquire—not indeed as one of the guests at the Table of Wisdom, but as one sitting at their feet and gathering up the crumbs.[153] The thread which connects his discourse is a collection of his own Odes, on each of which he had intended to write a treatise or commentary, but the book never advanced beyond the fourth treatise. These Odes were nearly all love-poems, but the poet explains that they are a figurative expression of his devotion to Philosophy, and the whole book is a glorification of the pursuit of knowledge. In the opening sentences, with the reference to Aristotle, the manner of reasoning, the assumptions of our innate desire for absolute knowledge and the bliss brought by its attainment, Dante is the spokesman of his period.

------------------------------------------------------------------------ [152] _Conv._ I. i. 111-113 and 125-127.

[153] _Conv._ I. i. 67-86.

“Siccome dice il Filosofo nel principio della
_Prima Filosofia_, Tutti gli uomini naturalmente
desideranno di sapere: La ragione di che puote
essere, che ciascuna cosa, da providenza di
propria natura impinta, è inclinabile alla sua
perfezione. Onde, acciochè la scienza è l’ultima
perfezione della nostra anima, nella quale sta la
nostra ultima felicità, tutti naturalmente al suo
desiderio siamo soggetti.”[154]

[154] “As the Philosopher says at the beginning of the _First Philosophy_, ‘All men naturally desire to have knowledge.’ The reason of this may be that everything, being impelled by foresight belonging to its own nature, tends to seek its own perfection. Wherefore inasmuch as knowledge is the final perfection of our soul in which our final happiness consists, all men are naturally subject to the desire for it.” _Conv._ I. i. 1-11. ------------------------------------------------------------------------

And from a study of the _Convivio_ we may learn much of the authors most esteemed, the methods of study pursued, and the results obtained, by thirteenth-century scholars seeking to gain the ultimate perfection of the soul.

Astronomy is frequently introduced, especially in the second and third treatises. The Ode which forms the text of the second treatise is that which is quoted by Charles of Hungary in _Par._ viii. 37—“Voi che intendendo il terzo ciel movete,”[155] and it gives Dante the occasion to speak first of the heaven of Venus, explaining Ptolemy’s system of epicycles, and later of all the heavens in their order, and the celestial bodies contained in them. The ode of the third treatise contains the line “Non vede il Sol, che tutto il mondo gira ...”[156] and upon this he hangs a complete little essay describing the movements of the sun, and how they appear from different parts of the earth, as well as a short dissertation on the question whether it is Sun or Earth which actually moves.

------------------------------------------------------------------------ [155] “Oh ye whose intellectual ministry Moves the third heaven.”—_Carey._

[156] “The sun sees not, though circling all the world.” ------------------------------------------------------------------------

The Latin works, _De Monarchia_, _De Vulgari Eloquentia_, the _Eclogues_, and the _Letters_, do not give much scope for astronomical references; yet there are many similes drawn especially from the sun and moon, and the thought of the spheres as instruments of God’s Will in bringing about events on earth is constantly recurring. In the curious work _Quæstio de Aqua et Terra_, Dante argues learnedly about the spheres, the orbit of the moon, and her effect on the tides, and the influences of the stars. The book purports to have been written at Verona in 1320 as the outcome of a discussion in which Dante had taken part as to the respective heights of land and ocean, a problem which had been dealt with by Ristoro d’ Arezzo some forty years earlier. Its authenticity has been questioned, partly under the mistaken idea that facts such as gravity, the spherical form of Earth, and the connection of tides with the moon were not known until much later; but as a matter of fact the discussion is quite in the manner of Dante’s day, and no facts or theories are put forward which he could not have learned from books with which we believe he was acquainted.[157] The internal evidence of his authorship is strong, and belief in it seems to be gaining ground among experts.[158]

------------------------------------------------------------------------ [157] The spherical form of Earth, and the action of gravity at the earth’s surface, were commonplaces with the Greeks, as we have seen in Part I. of this book. Posidonius, Strabo, and other classical writers speak of the tides as following the revolution of the heavens, and having periods similar to those of the moon; Albertus Magnus and Aquinas ascribe them to the influence of the moon, and so does Dante himself in _Par._ xvi. 83.

[158] See Moore, _Studies in Dante_, II. “The Genuineness of the _Quæstio de Aqua et Terra_,” for a complete discussion of the question. ------------------------------------------------------------------------

Finally, the _Divine Comedy_, the work of Dante’s maturity, which took him so many years to write, and for which he had studied ever since he closed the _Vita Nuova_ with the resolve to write more worthily one day of Beatrice,[159] focuses in one unique and finished work the thoughts and ideals, the knowledge and fancies, of the poet and his age. The subject of the poem, taken in its literal sense, is cosmical, for it describes a journey in which the author penetrates to the centre of the universe, and passes from planet to planet until he reaches the outermost sphere. Moreover, the journey is assumed to take a definite space of time, and the passing of the hours by day and by night is indicated by the successive positions of sun or stars, and the phases and movements of the moon. The _Divine Comedy_ contains more than twice as many allusions to the heavenly bodies as all the other works of Dante put together.

------------------------------------------------------------------------ [159] _V. N._ xliii. 3-7. ------------------------------------------------------------------------

But we must discriminate in drawing conclusions from these astronomical references so freely distributed in all Dante’s writings. If he wrote the _Quæstio_, it is his only professedly scientific work, written for scientific men, and astronomy is only brought in incidentally. The _Convivio_, in which astronomical facts and theories are set forth in much greater detail and fulness than elsewhere, was a popular work meant for those who had no inclination, or else no opportunity, for prolonged serious studies. We expect, therefore, that technical details will be avoided. Still more will they be omitted in the _Divine Comedy_ and other poetical works, where difficult problems and pedantical accuracy would be most unsuitable. We can _infer_ the knowledge which lay in Dante’s mind, behind his popular use of it in literature; and we can often find an explanation in the prose of the _Convivio_ for a slight allusion in the poetical works; but we must not deal with any as if they were text-books, and set forth precisely and completely all that Dante knew of his favourite science. It is the poet’s artistic use of the astronomy of his day which merits our admiration quite as much as the scholar’s proficiency.

This being premised, we may now proceed to quote from his works, showing how he has dealt with first the facts, and secondly the theories, of astronomy. Finally we shall be able to form a clear mental picture of the universe as it was believed to exist by Dante, and not only by his contemporaries but by his successors for many generations.

_V. OBSERVATIONAL ASTRONOMY._

“The heavens declare the glory of God; and the
firmament sheweth His handy-work. Day unto day
uttereth speech, and night unto night sheweth
knowledge. There is no speech nor language where
their voice is not heard. Their line is gone out
through all the earth, and their words to the end
of the world. In them hath he set a tabernacle for
the sun; which is as a bridegroom coming out of his
chamber, and rejoiceth as a strong man to run a
race.”

1. MOVEMENTS OF THE MOON.