The Book Nobody Read

by Owen Gingerich

  In Wittenberg, even before De revolutionibus was printed, Martin Luther had cited the Joshua passage in the course of a dinner conversation. Apparently, Luther had heard about the new cosmology from Rheti­cus or Reinhold at the university. Despite the informality of the mealtime setting, an eager student named Anton Lauterbach copied down the critique: "There was mention of a certain new astrologer who wanted to prove that the Earth moves and not the sky, the Sun and the Moon. This would be as if somebody were riding on a cart or in a ship and imagined that he was standing still while the Earth and trees were moving. Luther remarked, 'So it goes now. Whoever wants to be clever . . . must do something of his own. This is what that fellow does who wishes to turn the whole of astronomy upside down. . . . I believe the Holy Scriptures, for Joshua commanded the Sun to stand still, and not the Earth."

  Or maybe that's not exactly what he said, because another student, Johannes Aurifaber, later reported it a little differently. "That fool would upset the whole art of astronomy," Luther supposedly said, in what is one of his most widely quoted lines, though the experts generally believe this version is apocryphal if for no other reason than that Aurifaber wasn't actually present at the dinner.

  These off-the-cuff remarks might have been forgotten, though they were printed along with numerous other of Luther's conversational views in the Tischreden, or "Table Talk," series, first published in Wittenberg in 1566, long after Luther's death. But his opinion was given a popular press when Andrew Dickson White, the first president of Cornell University, publicized the reformer's Copernican remarks in 1896 as part of his A History of the Warfare of Science with Theology in Christendom. A liberal Christian, White announced that his goal was to let "the light of historical truth into that decaying mass of outworn thought which attaches the modern world to medieval conceptions of Christianity—a most serious barrier to religion and morals." He was eager to discredit what he believed was religion's antipathy toward the march of science, so he got his graduate students to dig up as many cases as they could find. The so-called Galileo affair played a central role in his account, introduced by the following wholly fictitious episode.

  Herein was fulfilled one of the most touching of prophecies. Years before, the opponents of Copernicus had said to him, "If your doctrines were true, Venus would show phases like the moon." Copernicus answered: "You are right; I know not what to say; but God is good, and will in time find an answer to this objection." The God-given answer came when, in 1611, the rude telescope of Galileo showed the phases of Venus.

  It is true that Galileo's telescope revealed for the first time that Venus went around the Sun, contrary to the Ptolemaic arrangement, but neither Copernicus nor his opponents ever considered such a test. The seeds for this myth were planted, perhaps inadvertently, by the English astronomer John Keill in a Latin textbook he published in 1718. With each retelling the story was more richly embroidered, reaching its apotheosis with White's well-embellished vignette.

  In any event, since the infamous Galileo affair played out in a Catholic setting, White was eager to give Protestants a role, too, in religion's presumed resistance to the advances in scientific knowledge. This is why he dusted off a version of Luther's comment. But the former Cornell president was not about to stop with Luther. Despite the fact that Copernicus' book was essentially published under Lutheran auspices, as was the first volume of tables based on De revolutionibus, White continued, "While Lutheranism was thus condemning the theory of the earth's movement, other branches of the Protestant Church did not remain behind. John Calvin took the lead, in his Commentary of Genesis, by condemning all who asserted that the earth is not at the centre of the universe. He clinched the matter by the usual reference to the first verse of the ninety-third Psalm,* and asked, 'Who will venture to place the authority of Copernicus above that of the Holy Spirit?'"

  No doubt White's quotation from Calvin increased the readership of Calvin's works, for it set historians of science off on a frustrated search to find where the Genevan reformer mentioned Copernicus. In 1960 Edward Rosen, a master of minutiae, not only tracked down a flock of authors who simply parroted White's account, but traced the comment itself back to the Reverend F. W Farrar, an Anglican canon who was at one time chaplain to Queen Victoria and who overconfidently relied on his capacious memory of quotations to generate out of whole cloth Calvin's comment on Psalm 93. In a sweeping generalization Rosen concluded that Calvin had never heard of Copernicus and therefore had no attitude toward him.†

  Given the relatively wide distribution of De revolutionibus, I think it highly likely that John Calvin saw the book, but he probably assumed from the notice on the back of its title page, addressed "To the Readers Concerning the Hypotheses in this Book," that Copernicus' book was intended as a mathematical device for calculation and not a real description of nature. This Ad lectorem declared that "it is the duty of an astronomer to record the motion of the heavens with diligent and skillful observations, and then he has to propose their causes or, rather, hypotheses, since he cannot hope to attain the true reasons. . . . Our author has done both of these very well, for these hypotheses need not be true nor even probable; it is sufficient if the calculations agree with the observations." It was added by Andreas Osiander, the learned theologian-minister of the Sankt Lorentz Kirche in Nuremberg who proofread most of its pages. When Copernicus' friend Bishop Tiedemann Giese saw this unauthorized addition, he was greatly exercised and wrote a letter to the Nuremberg City Council demanding that the front matter be revised and reprinted. To Copernicus' first and only disciple, Georg Joachim Rheti­cus, he expressed the wish that in the copies not yet sold, there should be inserted the little treatise "by which you have skillfully defended the idea that the motion of the Earth is not contrary to the Holy Scriptures." Such a replacement would have been relatively easy at a time when books were sold unbound, as loose stacks of folded signatures.

  Because of Bishop Giese's letter, Copernican scholars had long known that Rheticus, in addition to writing the Narratio prima, or "First Report," that served as a trial balloon for the radical heliocentric cosmology, had also written another tract discussing how to understand those scriptural citations that seemed at odds with a moving Earth. But none of his contemporaries, nor, for that matter, Andrew Dickson White and his students, ever knew what Rheticus, a staunch Lutheran, had written on heliocentrism and Holy Scripture. For many years it was assumed that Rheticus' report had been lost in the dustbin of history. Then, almost miraculously, it was rediscovered in the flurry of Copernican researches associated with the 1973 quinquecentennial year.

  It turned out that Rheticus' reconciliation of Copernicus' science and Scripture had actually been printed, but anonymously, in a little booklet published in Utrecht in 1651. This long-overlooked tract, now apparently existing in only two copies,* was identified and described by the Dutch historian of science Reijer Hooykaas. Thus we now know that Rheticus quoted Augustine as saying that Scripture borrows a style of discourse from popular usage "so that it may also fully accommodate itself to the people's understanding and not conform to the wisdom of this world." Rheti­cus emphasized this point repeatedly. He cited a series of passages commonly used to condemn the reality of the heliocentric plan, including Joshua and the battle of Gibeon, and noted that things appear to move either because of the motion of the object itself, or because of the movement of one's vision, but that common speech mostly follows the judgment of the senses, that is, the appearance that the motion is in the object itself. "As persons who seek the truth about things," he wrote, "we distinguish in our minds between appearance and reality."

  Yet, decades later, the same scriptural passages were still being used in their literal sense. And, long before Rheticus' little tract was printed (over a century after it was written), his arguments had been independently discovered and advocated by two of the leading Copernicans, Kepler and Galileo. Both Kepler's and Galileo's copies of De revolutionibus survive, preserved in European libraries, and in bo
th cases their annotations tell part of the story of the religious reception of this epoch-making book.

  I FIRST SAW, and photographed, Kepler's copy in the Leipzig University Library in the summer of 1972, a year before the quinquecentennial celebrations. In those days one needed a sponsor to enter East Germany, and Miriam and I found one in the publisher Edition Leipzig. It provided the entree into that fenced-off police state and enabled me to see rare books in several libraries. But the most memorable, and spookiest, part came as we were driving out of the country. We had easily cleared the potentially troublesome East German customs—worrisome because I was carrying out undeveloped film—but the young officer had been more interested in practicing English than in searching our luggage. As darkness fell, a large truck blocked the view of the actual exit, and we unwittingly headed off onto a stretch of abandoned Autobahn that meandered through the no-man's-land between East and West Germany. Some distance along this dim and suspiciously untrafficked route we realized that grass was growing down the middle of the highway. In stark terror we did a U-turn, hoping no border guards were taking aim at us. Nowadays it's hard to recapture the sense of relief that always came during those cold war times when one finally transited back into the free world.

  And so I carried out the latent images of Kepler's De revolutionibus. Some of the most distinctive features in the book are not the notes he wrote in it but what was already present when he acquired it. The copy had originally been given by the Nuremberg printer Petreius to a local scholar, one Jerome Schreiber. Schreiber was clearly an insider, and he learned who had written the anonymous Ad lectorem, the advice to the readers printed on the back of Copernicus' title page. One of the slides I made in Leipzig shows the name Osiander written by Schreiber above the Ad lectorem. That annotation tipped off Kepler to the unnamed author's identity.

  Kepler was particularly incensed by this anonymous introduction, because, unlike the great majority of sixteenth-century astronomers, he was a realist, and he believed that Copernicus, too, thought that the heliocentric system was a real description of the planetary system and not just a mathematical computing device. Hence he was pleased with himself when he could put his own advice to the reader on the back of the title page of his great Astronomia nova, which was published in 1609 and in which he presented the evidence that the orbit of Mars was not a perfect circle but an ellipse. With the notice on the back of his own title page, Kepler revealed in print for the first time that Osiander had authored the Ad lectorem. He made it clear that Copernicus would not have subscribed to it. Osiander's advice was that the cosmology in the book was merely hypothetical, that "perhaps a philosopher will seek after truth but an astronomer will just take what is simplest, and neither will know anything certain unless it has been divinely revealed to him." Because this advice had essentially protected the book from religious condemnation for many decades, Kepler's revelation that Copernicus had not written nor subscribed to that caveat was dynamite; it undermined the Church's position that heliocentrism was a strictly hypothetical scheme, useful for mathematicians but not to be confused with physical reality. Thus the littie notice behind the title page of the Astronomia nova helped set the stage for the prohibition that would soon follow.

  I first saw Galileo's copy, a second edition in the National Library in Florence, in July 1974.1 found myself disbelieving that the book had really belonged to the Italian astronomer, for this copy had no technical marginalia, in fact, no penned evidence that Galileo had actually read any substantial part of it. Yet, as I finally convinced myself, his handwriting was there. He had carefully censored the book according to the instructions issued from Rome in 1620—universal instructions that he had helped trigger.

  Galileo's censored Copernicus was just one highlight of an intense weeklong research expedition in north-central Italy. Another memorable moment came in Padua, where the local archives agreed to let me photograph the oldest dated autograph document in Copernicus' own hand. I had brought along my case of photoflood lamps and found a precarious place near an electrical outlet where I could both clamp the lamps and place the open book of documents.* Copernicus, while a medical student in Padua in 1503, had written out a statement to be notarized, and that was the manuscript I photographed.

  Copernicus' earliest dated signature, 10 January 1503, from the Padua State Archives.

  In twentieth-century Central Europe, bitter contention broke out concerning Copernicus' ethnic origins, which became particularly shrill during the Nazi period. The Germans argued that the astronomer's family name was a Germanic Coppernigk or Koppernig, whereas the Poles defended Copernik. On the Padua document his signature clearly reads Nicolaus Copernik, though he was rather indifferent about orthography and later would occasionally sign off as Coppernicus.†

  Besides more than a dozen Copernicus volumes recorded on the Italian field trip, Miriam and I listened to sonorous Armenian chorales in the mosaic-laden cathedral in Ravenna, saw Coppelia danced by the La Scala ballet company in Milan, and feasted our eyes on the Botticellis, Fra An-gelicos, and Michelangelos in Florence and the Giottos in Padua. And while we were in Padua I also photographed the Renaissance anatomical theater, one of only two original surviving examples, the other being in Uppsala. Here medical students in Copernicus' day—and probably Copernicus himself—crowded into the ranks of the small oval auditorium to observe human dissections. Typically, a barber-surgeon would do the cutting while the professor read the relevant text from Galen. Quite possibly, the Italian penchant for cutting up saints to serve as holy relics helped make the medical dissections socially acceptable. We got the flavor of this when we visited the library in Ferrara (which had a censored copy of De revolutionibus) and were there astonished to discover Ludovico Ar­iosto's heart in a large urn,‡ and we found Galileo's index finger in a reliquary in the Florence History of Science Museum (whose De revolutionibus was not censored).

  Although Galileo made his most significant astronomical discoveries in Padua—the mountains on the Moon, the myriad stars composing the Milky Way, the satellites of Jupiter—his years of fame and confrontation with the Church took place in Florence. Like Kepler, Galileo endorsed a realist stance, and to this end he wrote a privately circulated letter in which he argued (as Rheticus had done, though he didn't know this) that the Bible spoke in idiomatic terms so that everyone could understand it, but it was not a scientific textbook. His punch line was that "the Bible teaches how to go to heaven, not how the heavens go." It was one thing for Kepler, who had been trained as a Lutheran theologian, to argue this way in a Lutheran context in the introduction to his Astronomia nova, but quite another for Galileo, who was at best an amateur theologian, to argue the same way in a Catholic context.

  In 1545 Pope Paul III had convened the Council of Trent to discuss both Church reform and a hardened line against heretics, and following Pope Pius IV's publication of the council's decrees in 1564, the Protestant protest was no longer seen as an in-house debate. Catholic scriptural interpretation was reserved for the trained hierarchy, and Rome did not like the idea of an amateur theologian rocking the boat when they had their hands full with the heretical dissidents north of the Alps. If Galileo was invading its interpretive turf, the Vatican determined to remind everyone just who had authority by banning Copernicus' book. But it was not that easy. The Vatican claimed the power to establish the calendar, as it had done with the Gregorian reform in 1582. A fundamental part of calendar reform was specifying how to determine Easter, and this required astronomical knowledge of the Sun and Moon. De revolutionibus included observations of the Sun and Moon, of potential value to the Church, so it was inadvisable to ban the book outright. Nor could the heliocentrism simply be excised, for it was too firmly embedded in the text. The only path was to change a few places to make it patently obvious that the book was to be considered strictly hypothetical.

  Thus it happened that in 1616 De revolutionibus was placed on the Roman Index of Prohibited Books "until corrected," and in 1620 t
en specific corrections were announced. Two examples will show what the Vatican was up to. The heading of Book I, chapter 11, "The Explication of the Three-Fold Motion of the Earth," was changed to "The Hypothesis of the Three-Fold Motion of the Earth and Its Explication." At the end of the preceding chapter, where Copernicus had declared that the great extent of the starry universe made it impossible to detect any annual oscillation in the positions of the stars owing to the Earth's annual motion, he had exclaimed, "So vast, without any question, is the divine handiwork of the Almighty Creator!" This, too, met with the censors' condemnation. Why was such a pious statement forbidden by Rome? Simply because it made it appear that God had created the universe from a heliocentric perspective. All of these corrections were dutifully recorded by Galileo in his copy of the book, though he took care to cross out the original text only lightly so that he could still read it.

  Because the Vatican Congregation of the Index was so explicit about its instructions, it is almost immediately obvious whether or a not a copy was censored, something I took note of as I examined and reexamined several hundred copies of the book. In addition, I systematically recorded provenances, that is, where the books had been. For about half of the copies it was possible to determine where they had been in 1620 when the instructions for censoring the book were announced. Then a very interesting result emerged, something the Inquisitors never knew. Roughly two-thirds of the copies in Italy were censored, but virtually none in other countries, including Catholic lands such as Spain and France. It became apparent that the rest of the world looked on the exercise as a local Italian imbroglio, and they were having none of it. In fact, the Spanish version of the Index explic-idy permitted the book!