A More Perfect Heaven: How Copernicus Revolutionized the Cosmos - Dava Sobel (2011)

Part I. Prelude

Chapter 5. The Letter Against Werner

Faultfinding is of little use and scant profit, for it is the mark of a shameless mind to prefer the role of the censorious critic to that of the creative poet.

—FROM COPERNICUS’S Letter Against Werner, JUNE 3, 1524

The great Conjunction of 1524 brought Jupiter and Saturn together in the sign of Pisces. Astrologers, who classified Pisces as a watery sign, predicted the dread disaster at conjunction would take the form of a mass drowning, indeed, a global inundation to rival Noah’s flood. Every Jupiter-Saturn union blew an ill wind, but this one’s evil potential drew added force from the number of other heavenly bodies convening with the main two. On February 19, Copernicus’s birthday, the planets Jupiter, Saturn, Mars, Venus, and Mercury would all cluster together with the Sun in a grand sextuple conjunction, followed by a full Moon that night. Further proof of apocalypse derived from Pisces’ rank order as the twelfth and final zodiac sign. Given that astrologers believed the world had begun under a multiplanetary conjunction in Aries, the first sign, surely it would end now under a repeat occurrence in Pisces, the last. The growth of both printing and literacy helped spread these dire prognostications so far and wide that people living in coastal regions took to the mountains. Some looked to their Bibles for instructions on how to build an ark.

February passed, and no floodwaters rose. Disbelievers scoffed at the astrologers, who held firm that waves—if not of water, then of religious dissent or political unrest—would yet wash over Europe. Had not the Great Conjunction of 1345 required two years to unleash the Black Plague?

Copernicus, who neither issued nor heeded astrological forecasts, chose this moment to pursue a bad debt. Canon Henryk Snellenberg, who had been his sole comrade in arms during the final defense of Allenstein Castle, went to Danzig and, as a favor, collected some money owed to Copernicus by his cousin on the city council there. But when Snellenberg returned to Varmia, he turned over to Copernicus only ninety of the hundred marks the astronomer’s cousin had paid. Snellenberg repeatedly put off the reimbursement of the remaining ten marks, making one excuse after another over a period of months. When Copernicus finally confronted him, Snellenberg demanded written proof of the debt, and then dared his creditor to file suit for the sum still owed. Sufficiently grieved, Copernicus complained to Bishop Ferber.

“I therefore see that I cannot act otherwise,” he wrote to his superior on February 29, “and that my reward for affection is to be hated, and to be mocked for my complacency. I am forced to follow his advice, the advice by which he plans to frustrate me or cheat me if he can. I have recourse to your Most Reverend Lordship, whom I ask and beseech to deign to order on my behalf the withholding of the income for his benefice until he satisfies me, or a kind provision in some other way for me to be able to obtain what is mine.”

In comparison to the petulant but principled tone of his complaint against Snellenberg, the content of another letter Copernicus wrote that same year, on June 3, 1524, contained an invited analysis of such interest to the mathematics community that multiple copies of it circulated among his peers. Although terse and informal, the Letter Against Werner stands alongside the Brief Sketch and On the Revolutions as the third pillar of Copernicus’s oeuvre in astronomy. He addressed it “To the Reverend Bernard Wapowski, Cantor and Canon of the Church of Krakow, and Secretary to His Majesty the King of Poland, from Nicolaus Copernicus.”


The combined presence of Jupiter and Saturn—along with several other celestial bodies—in the twelfth zodiac sign, Pisces (the fishes), struck dread in the hearts of astrologers, who forecast the floodwaters shown pouring from the exaggerated sky-fish in this image from Leonhard Reynmann’s Prognostication for 1524.

Wapowski and Copernicus had attended the Collegium Maius in Krakow together as undergraduates in the 1490s. Possibly they developed their shared interest in planetary theory at that time, perhaps even in each other’s company. Wapowski, who also went on to study law at Bologna, had later served several years in Rome with the Polish embassy, and now communicated with an international coterie of intellectuals. Copernicus alluded to the closeness of their long-standing friendship in his Letter’s first sentence.

“Some time ago, my dear Bernard, you sent me a little treatise on The Motion of the Eighth Sphere written by Johannes Werner of Nuremberg.” Wapowski had sought Copernicus’s opinion of this widely praised paper, which was published in 1522 along with several other recent essays by the same author. Copernicus hesitated before complying, however, because he found fault with Werner’s thesis and was not at all sure he should say so. Now he excused himself to his old friend for the long delay.

“Had it been really possible for me to praise it with any degree of sincerity, I should have replied with a corresponding degree of pleasure.” Unfortunately, the highest compliment he could offer—“I may commend the author’s zeal and effort”—took him “some time” to muster. At first, he admitted, he feared arousing anger by expressing censure in writing. Better, perhaps, to say nothing at all against Werner than risk a negative backlash that might ruin any chance of a favorable reception for his own work.

“However, I know that it is one thing to snap at a man and attack him, but another thing to set him right and redirect him when he strays, just as it is one thing to praise, and another to flatter and play the fawner.” In the best spirit of correcting a fellow astronomer’s misstep, then, he would share his thoughts. He did not know that Werner, a clergyman at a Nuremberg infirmary, had died of the plague in 1522 while his papers were still on press. “Perhaps my criticism may even contribute not a little to the formation of a better understanding of this subject.”

The “eighth sphere” of Werner’s title spun the stars. They were all embedded in it, like jewels in a crown. This placement accounted for the way the stars retained their fixed positions vis-à-vis one another, each in its own constellation niche, even as the heavens revolved around the Earth every day. While rolling rapidly westward, however, the eighth sphere also betrayed a slow, subtle drift in the opposite direction, which astronomers had long sought to explain. In Copernicus’s cosmos, in contrast, the eighth sphere remained stationary. It only appeared to move because of the Earth’s rotation. But rather than raise this fundamental difference in his critique, Copernicus focused on Werner’s technical mistakes.

“In the first place, he went wrong in his calculation of time.” Werner had bungled a conversion of Egyptian calendar dates to Julian chronology, so that he assigned certain observations by Ptolemy to the year A.D. 150, when in fact, Copernicus demonstrated, Ptolemy had made those observations eleven years earlier, in 139. Then Werner compounded his initial error by accusing Ptolemy and other ancient astronomers of sloppy observing technique. Here Copernicus lost his temper:

“We must follow in the footsteps of the ancient mathematicians and hold fast to their observations, bequeathed to us like an inheritance. And if anyone on the contrary thinks that the ancients are untrustworthy in this regard, surely the gates of this art are closed to him. Lying before the entrance, he will dream the dreams of the deranged about the motion of the eighth sphere, and will receive his deserts for supposing that he must support his own hallucination by defaming the ancients, who observed all these phenomena with great care and expert skill.” In fact, Ptolemy’s observations were not as unassailable as Copernicus so passionately insisted, but they were all he had to serve as a basis of comparison, and so he defended them.

Another of his revered ancient Greeks, Hipparchus of Rhodes, had pioneered the exploration of the eighth sphere. More than two hundred years before Ptolemy, around 130 b.c., Hipparchus mapped the positions and comparative brightness of nearly a thousand stars. He intended this work as a baseline for future studies, but tested it first against the few observations that had come down to him from astronomers of prior centuries. Just as he suspected, the constellations showed no change in shape over the course of human memory. However, they had systematically shifted their overall positions. For example, Hipparchus observed the bright star Spica, in the constellation Virgo, at 6° west of the Sun’s position at autumnal equinox, while his pre de ces sor Timocharis, on the first night of fall in the fourth century b.c., had seen Spica at 8° west. Every star Hipparchus tested had moved over the interim by the same two degrees—a distance four times the apparent width of the Moon.

To account for this eastward drift of the eighth sphere, Hipparchus’s successors posited a ninth: The invisible, external ninth sphere impelled the eighth to turn. But the star-studded eighth, falling just shy of the ninth’s pace, lagged behind. The tiny difference between the two went unnoticed night to night, but worked a cumulative effect over decades, amounting to about one degree per century. It would take many ages—many millennia, in fact—for the cycle to come full circle. The extreme slowness and variable rate of the motion, which came to be called the precession of the equinoxes, guaranteed employment for astronomers far into the future. By the time of Werner and Copernicus, accounts of precession had introduced tenth and even eleventh spheres to fine-tune the orientation of the fixed stars.

In modern terms, precession results from the Earth’s daily rotation, which produces a planet-wide bulge at the equator. The Sun pulls preferentially on the bulging part, causing the Earth’s axis to gyrate slowly over time. It takes twenty-six thousand years for the axis to trace its lazy circle in the sky, at the pace of one degree every seventy-two years. The north pole of the Earth’s axis currently points to a star in Ursa Minor (the Little Bear, or Little Dipper) called Polaris, or the Pole Star, also known as the North Star. Precession has brought us to this point, and also warrants that in the next millennium, a different star—Alrai, in the constellation Cepheus, the King—will take over the title of pole star.

Continuing his Letter, Copernicus corrected “a second error no less important than the first” and untangled a third “childish blunder” before dismissing Werner.

“What finally is my own opinion concerning the motion of the sphere of the fixed stars?” he asked rhetorically. “Since I intend to set forth my views elsewhere, I have thought it unnecessary and improper to extend this communication further.” He wished his friend Bernard sound health and good fortune, and signed off.

In the sphere of sacred affairs, the new Bishop of Rome, Pope Clement VII, watched with horror as Martin Luther’s heresy spilled over the German borders into surrounding countries. In Poland, Bishop Ferber could attest that Prussia teemed with Lutherans—not new immigrants but resident Catholics, recently converted. In the diocese of Samland, just east of Varmia in the knights’ territory, Bishop Georg von Polenz had renounced his holy vows, publicly endorsed Luther’s teachings, and excoriated the Catholic Church. On Easter Sunday 1524, he led a Lutheran Mass in his cathedral. Following this lead, the Bishop of Pomesania, Varmia’s western neighbor, also forswore Catholicism for the new evangelism.

Despite Bishop Ferber’s angry denunciation of the “heretical wave,” certain canons in Varmia viewed the Reform developments differently. Tiedemann Giese responded to Bishop von Polenz’s action with a plea for moderation. Giese held that Christians of every stripe should work together to glorify Christ, not denounce one another. “While referring constantly to the spirit of God,” he said of the interfaith dispute, “we are estranging ourselves entirely from love.”

Copernicus read Giese’s letter and supported its sentiment so strongly that he convinced Giese to publish the content as a pamphlet. Printed in Krakow in February 1525, the Antilogikon advocated both tolerance toward Lutherans and defense of Catholic tradition. “Undeniably many things in the Church come close to superstition, and abuses have slipped in,” Giese conceded. “But the time of the harvest should be awaited, so that we do not destroy the wheat in order to eradicate the weeds.” Eager for his plea to fall on fertile soil, he sent the little book to Wittenberg, to the attention of the scholar and reformer Philip Melanchthon, Luther’s closest confederate.

Was the spread of Lutheranism the floodtide presaged by the Great Conjunction of 1524? Astrologers who thought so scrutinized the time and place of Luther’s birth to make the case, but even Luther could not say for sure in what year he had been born, whether 1483 or 1484. One practitioner configured Luther’s natal chart for October 22, 1484, during a Great Conjunction in the sign of Scorpio, at an hour that conjoined the planets in the ninth house, which was considered the mansion of religion. That fit together nicely, until Luther’s brother and mother confirmed an earlier date, November 10, 1483.

Soon another candidate for the destruction prophecy’s fulfillment reared up in the form of the Peasant Rebellion, which shed the blood of thousands all over Germany between 1524 and 1525. Ragged peasant militias attacked nobles and armored knights for such things as the right to fish in favorite streams or hunt in forests deemed the private property of the upper class. Although their fight did not concern religion, those peasants who had heard of Martin Luther expected him to support their cause. He disappointed them by failing to intervene: No war of flesh and blood could deter him from his campaign against spiritual wickedness. Soon he turned against them, saying that a peasant in open rebellion stood outside the law of God.

In Varmia, peace finally ended the years of strife between prelates and knights in the spring of 1525, when Albrecht knelt in homage before King Sigismund at Krakow. On April 10, Albrecht ceded his territory to the kingdom, and Sigismund gave it back to him in a new guise, as the Duchy of Prussia, Albrecht’s own hereditary fief. As the first Duke of Prussia, he relinquished the title of grand master and, upon his return to Königsberg in May, dissolved the Order of Teutonic Knights. He not only converted, as he had promised Luther he would, but also made Ducal Prussia a fully Protestant state—a new entity on the map of Eu rope.

Sigismund’s agreement with Albrecht stipulated that the duchy would issue no new coins for at least one year, at which time the king would convene an official session to coordinate the ducal currency with the royal. Copernicus dutifully updated his treatise on coinage one last time, in Latin, to accommodate the creation of Ducal Prussia. He added so many specific references to the minting abuses of past grand masters and so many prescriptions for remedy that the essay doubled in length. “What kind of money it will become hereafter, and what its condition is now,” Copernicus regretted, “it is shameful and painful to say.”

Although Albrecht, as a Catholic, had been the scourge of Varmia, Duke Albrecht the Lutheran behaved more cordially in his dealings with the chapter. He faced different enemies now, among the knights and nobles he had betrayed. Although some members of the old order converted with him, most moved to Germany, where they plotted against him, slandered him, and summoned him to appear before the Holy Roman Emperor’s court of justice. When he refused, they proscribed him. Meanwhile Albrecht devoted his energies to the development of his new homeland. He set about establishing schools in every town of Ducal Prussia. On February 12, 1526, he married Princess Dorothea of Denmark, then sired six children in rapid succession.

The King of Poland, who endured the presence of large communities of Jews driven into his realm by intolerance in other countries, gradually hardened his stance toward Lutherans. In the spring of 1526, Sigismund ordered the homes of the few Protestants in Krakow to be set on fire. There followed a Lutheran uprising that summer in the Varmian city of Braunsberg. A majority of the citizens had converted to the new religion, including Mayor Philip Teschner, the bastard son of former bishop Lukasz Watzenrode. After the king’s forces suppressed the unrest, Bishop Ferber banished all non-Catholics from the diocese. He gave them one month from the date of his edict, September 22, to pack up and go—and on their way elsewhere he insisted they surrender their pro-Lutheran books for burning. Luther himself had published several books and hundreds of pamphlets by this time, as well as his German translation of the New Testament.


Like the Brief Sketch, Copernicus’s Letter Against Werner was repeatedly hand-copied and forwarded from one interested astronomer to another. This particular copy dates from 1569 and covers ten pages.

Copernicus and Giese could not defend their tolerant attitudes against the objections of the majority of the canons, the bishop, the king, and the pope. They were compelled to vote in favor of the edict that expelled the Lutherans from Varmia. Nevertheless, Giese continued to write in defense of love and ac cep tance as the Reformation gained ever more new adherents. Several letters allude to these later tracts by Giese, but unfortunately, none was printed or preserved even in manuscript. In one of them, he endeavored to demonstrate the compatibility of Copernicus’s theory with the Bible.

One can only guess how Giese squared the Psalmist’s praise for a fixed Earth, “immovable and firm,” with his friend’s contention that the Earth rotated and revolved. Or how he accounted for Joshua’s commandment that the Sun stand still, given that Copernicus’s Sun never moved. Perhaps Giese did not address each scriptural reference individually, but focused on depicting Copernicus as a godly man, divinely inspired, and blessed with insight into the true workings of the universe. However he constructed his defense, he must have sensed that defense was necessary.


King Sigismund Augustus I, shown here in a miniature by Lucas Cranach the Elder.

Copernicus also became defensive. By his own admission, he did not feel so confident of his own work as to care nothing for others’ opinions of it. He agreed with Giese that readers ignorant of astronomy might easily attack his ideas by twisting chapter and verse to their purposes. Others might laugh at the absurdity of the basic premise. A joke at his expense held that he mistook the Earth for a side of beef, so he put it on a spit and roasted it in the Sun’s fire.

The difficulty of the work, coupled with the press of his other duties, may have held Copernicus’s anxieties at bay while he was writing his book about the heavenly revolutions. Since he kept no log of his progress, and no one witnessed his isolated toil, it is difficult to say which sections he wrote when, or how long he labored over each. The last observation mentioned in its pages is the one he made on March 12, 1529, when the Moon passed in front of the planet Venus and hid it from view.

“I saw Venus beginning to be occulted by the Moon’s dark side midway between both horns at one hour after sunset—the start of the eighth hour after noon,” he reported. “This occultation lasted until the end of that hour or a little longer, when I observed the planet emerging westward on the other side. Therefore, at or about the middle of this hour, clearly there was a central conjunction of the Moon and Venus, a spectacle that I witnessed at Frauenburg.” He used that observation, paired with others from antiquity, to describe the revolutions and mean motions of Venus, in several pages’ worth of diagrams and geometrical proofs spelled out in his small, neat handwriting.3

With his book virtually complete by 1535, Copernicus lost courage. He worried that his labored calculations and tables would not yield the perfect match with planetary positions that he had aimed to achieve. He feared the public reaction. He empathized with the ancient sage Pythagoras, who had communicated his most beautiful ideas only to kinsmen and friends, and only by word of mouth, never in writing.

Despite the decades of effort invested in the text, Copernicus eschewed publication. If his theory appeared in print, he said, he would be laughed off the stage. No argument from Giese could change his mind.

Other supporters also tried to sway him. In the summer of 1533, for example, the distinguished linguist and diplomat Johann Albrecht Widmanstetter, then secretary to Pope Clement VII, delivered a lecture on Copernicus’s astronomy in the Vatican gardens. Widmanstetter went on, after Clement’s death the following year, to serve Nicholas Schönberg, the Cardinal of Capua, and to awaken in him a profound desire to see Copernicus’s book published.

On November 1, 1536, the cardinal wrote from Rome: “Some years ago word reached me concerning your proficiency, of which everybody constantly spoke.” Cardinal Schönberg had traveled to Poland in 1518 on a peacekeeping mission. Although Albrecht and the Teutonic Order rebuffed his gestures, Bishop Fabian Luzjanski had entertained him in Varmia. “At that time I began to have a very high regard for you, and also to congratulate our contemporaries among whom you enjoyed such great prestige. For I had learned that you had not merely mastered the discoveries of the ancient astronomers uncommonly well, but had also formulated a new cosmology. In it you maintain that the Earth moves; that the Sun occupies the lowest, and thus the central, place in the universe; that the eighth heaven remains perpetually motionless and fixed; and that the Earth, together with the elements included in its sphere, and the Moon, situated between the heavens of Mars and Venus, revolves around the Sun in the period of a year. I have also learned that you have written an exposition of this whole system of astronomy, and have computed the planetary motions and set them down in tables, to the greatest admiration of all. Therefore with the utmost earnestness I entreat you, most learned Sir, unless I inconvenience you, to communicate this discovery of yours to scholars, together with the tables and what ever else you have that is relevant to this subject. Moreover, I have instructed Theodoric of Reden4 to have everything copied in your quarters at my expense and dispatched to me. If you gratify my desire in this matter, you will see that you are dealing with a man who is zealous for your reputation and eager to do justice to so fine a talent. Farewell.”

Copernicus received this letter, read it perhaps several times over, and then, without responding, filed it away for future use.