INTRODUCTION.
In a beautiful passage of the Convivio Dante describes how he first began to devote himself diligently to science and philosophy. When the gentle soul of Beatrice had passed to heaven, a great darkness fell upon him: the streets of Florence were to him as a deserted city, and his life empty and purposeless. It was long before he could find any comfort, but at last he bethought himself of studying a book by Boëthius, who when exiled, imprisoned, and unjustly condemned to death, had strengthened his soul with the “Consolations of Philosophy.” This led him on to Cicero’s book “On Friendship,” in which Lælius explains how he is consoled for the death of Scipio.
Books in those days could only be had in manuscript, full of abbreviations, and often also of errors, and at first the young student found the Latin hard to master; but as he struggled on, half deciphering and half divining the meaning, the mists cleared a little, and the weight was lifted from brain and heart. With elation he discovered that obscure passages were becoming luminous, and to the exhilarating sense of conquest was added the joy of finding, beautifully expressed, thoughts which had already floated in his own mind, but dimly, as in a dream. He compares himself to one who, seeking silver, should light (not without Divine guidance) on a treasure of gold; for he found not only relief from his tears, but a door into a new world of literature, philosophy, and science. Henceforth, he tells us, he eagerly frequented the schools of the religious orders and the discussions of the philosophers; and how extensive and thorough was his learning we can see in his writings. In them we find a reflection of thirteenth-century thought in every field of intellectual research.
Among all his studies was one which evidently had a great attraction for him, even in the early days of the Vita Nuova, before learning had become a passion. Astronomy appealed to many sides of his nature. The beauty of the skies stirred his imagination; their suggestive symbolism touched his religious sense; the harmony of the celestial movements and the accuracy with which they can be foretold delighted his instinct for order and precision. He must have read, and perhaps possessed, some of the best text-books then available, and he grasped with singular clearness the phenomena observed and the theories taught in his day. His works are full of allusions to astronomy. In the Vita Nuova he finds pleasure in connecting the story of his lady with the revolutions of the spheres; in the Convivio he teaches the elements of the science; in the Vision of the Divine Comedy he journeys through the universe as it was depicted by mediæval astronomers; and throughout his works are scattered similes drawn from celestial phenomena and descriptions of “le belle cose che porta il ciel.”[1]
Therefore, for full enjoyment and understanding of Dante’s works it is necessary to have a rudimentary knowledge of astronomy.
Many of his readers think that Dante’s astronomy is very complicated and difficult to understand. What makes it seem difficult is that in this age we are generally unfamiliar with the skies. We do not eat our breakfast or go to our office by the sun, nor do we watch the stars to see when grouse-shooting begins or the summer holidays end. If it is important for us to know at what hour the sun sets and lamps must be lighted, or if we wish to see a view by moonlight, we consult an almanac. When we think at all of the movements of the heavenly bodies, our notions are usually taken from diagrams and tables, not from what is actually seen in the skies. We only think, for instance, of the seasons as caused by the earth’s journey round the sun, and the tilt of her axis: therefore, when Dante speaks of Venus as a Morning Star veiling the Fishes with her rays, or the horn of the Celestial Goat touching the sun, it conveys little, although the seasons of spring and of winter are as clearly indicated as if he had spoken of the blossoming of primroses or the fall of snow. When Cacciaguida, in the heaven of Mars, tells the date of his birth by counting how many times the planet had since then returned to his Lion, those who only think of Mars as circling round the Sun, and have never traced his path among the stars, are at a loss, and think the method very far-fetched. A short description, and especially a little individual watching, of the apparent movements of the heavenly bodies, would put us in a position to realize the meaning of a large number of Dante’s astronomical descriptions and allusions, without any knowledge of any theory.
Others complain that the subject is dull. Dante’s astronomy, when interpreted only by means of notes on single passages, is undoubtedly dull—as dull as the history of his own times learned in the same way. But when either subject is studied as a whole these passages acquire a special interest; and they in their turn give new life to the subject they illustrate.
Other readers say that Dante’s astronomy is so entirely false and obsolete that it is not worth study. This is hardly true. Where Dante speaks of appearances he is remarkably accurate, far more so than most modern artists and writers of fiction. Where he speaks of the heavens as he supposes them actually to exist, he is interpreting the appearances according to the astronomical theories of his day, with which he was very well acquainted. This interpretation was not correct, but it was an ingenious and beautiful system, and very successful in so far as it enabled astronomers to calculate the positions of sun, moon, stars, and planets for any date. Its main outlines can be explained in a few pages, with the help of a couple of diagrams, but when presented thus, especially to those unfamiliar with the skies, it seems very strange and artificial. To appreciate it at its true worth, we must know just what are the phenomena it was intended to explain, and trace its gradual development out of man’s first clear perception that the movements of sun, moon, and stars follow unchanging laws.
The story of this development is of enthralling interest, and after the system had been completed by one of the greatest mathematicians the world has seen, its later history reads like a romance. Though of classical Greek origin, it was almost wholly lost to Europe for many centuries, it returned at last in Oriental dress, and its final form was given by a devout and learned Dominican friar.
It was at this time that Dante was born, and the scholar-poet immortalized the Ptolemaic system of astronomy in his verse, adding to its popularity in his own day, and making it known to thousands of readers since, who might otherwise scarcely have heard of it.
Dante’s astronomy, therefore, is of wide and deep significance. To study its history is to learn a chapter in the development of the human intellect; to see the universe with his eyes is to know how it appeared, not only to his contemporaries but to men in many lands and many centuries. The system of Ptolemy was already a thousand years old when Dante studied it, and it continued to be taught long after Copernicus had introduced a truer one; nor has it ever been completely swept away, for much that it taught was accurate. The new astronomy has developed from the old, and bears traces to this day, in its phraseology, its written symbols, and its methods, of the many races and ages which have contributed to its progress.
This book, therefore, is divided into two parts. In the first, I put before my readers the elementary facts which form the foundations upon which all astronomy is based, the movements of sun, moon, stars, and planets, so far as they can be easily observed by the naked eye; then follows a sketch of the attempts which were made to interpret these observations from very early days until Dante’s time. Unnecessary technicalities are avoided, but we shall try to enter into the thoughts of past generations concerning the stars, to see why they were interested, how they worked, what hindered and what helped them in their search for truth.
In the second part, we shall examine Dante’s works, and see how familiar he was with the movements of the skies, and how well he understood the theories which in his time were held to explain them. We shall see how astronomy was generally regarded in his day, what books he read, and which authors influenced him most. We shall see how false is the assertion often made that in the Middle Ages men studied astronomy only for the sake of astrology, and how closely the science of the stars was connected with religion and the loftiest speculations of philosophy.
We shall also examine in particular some difficult passages connected with astronomy which occur in Dante’s works, but my aim is not so much to explain all the astronomical references as to put the reader in a position to attempt an explanation himself.
My greatest ambition is to share with others the pleasure I have had in learning what Dante knew and thought about the stars, and who were the master builders who had erected through the ages the system so vividly pictured in his immortal poem.