Careful Readers

Owen Gingerich’s The Book Nobody Read is an engaging account of a harmless obsession. For thirty years he has been ferreting out every copy of Nicholas Copernicus’s De revolutionibus orbium coelestium to which library catalogues, booksellers’ lists, auction records, informed tips and plain luck led him. The exceptional importance of Copernicus’s work in the history of science was only indirectly the cause of this monomania. The direct inspiration was a common sort of academic discomfort: being scheduled to speak at a large international meeting and having nothing particular to say.

The meeting was part of the worldwide celebration of the 500th anniversary of Copernicus’s birth in Torun, on the Vistula, in 1473. It was a much grander occasion than the 400th anniversary in 1873, which was primarily seen as an occasion for the new German state to claim Copernicus for the German cultural sphere by initiating the publication of his collected works. On the 400th anniversary of his death, in May 1943, the Nazis seized the opportunity to reassert German ownership of Nicolaus Koppernick and to assert that the Poles were intellectually too weak to have produced so great a genius. The Allies claimed Mikulaj Kopernik for Occupied Poland, and as an icon of the international character of scientific ideas and the transcendental importance of unfettered freedom of inquiry. The United States commemorated Nicholas Copernicus in schools and universities across the country, and in a ceremony at Carnegie Hall. There were co-ordinated radio broadcasts in the United States, Canada and Great Britain, and coverage of the British observances was beamed into Occupied Europe.

Neither nationality nor national culture made any sense in the place and time of Copernicus’s birth, however. Italy has as fair a claim to have created Copernicus as Poland or Germany, since he spent a decade studying in and around the universities of Bologna, Padua and Ferrara. But Germany and Italy lost the war and Nicholas Copernicus, Mikulaj Kopernik, Nicolò Copernico, Nicolaus Koppernick, Copernich or Coppernick, has been Polish since 1945.

De revolutionibus started a revolution in cosmology by placing the Sun motionless near the centre of the Earth’s orbit, making the Earth a planet and the planets so many Earths, violating common sense and sound physics, and conflicting with biblical passages that spoke plainly of the Sun’s motion and the Earth’s rest. Copernicus admitted all this to make sense of certain qualitative features of the behaviour of the planets: in particular, the limited elongations (angular distances from the Sun as seen from the Earth) of Mercury and Venus, and the stations and retrogradations of Mars, Jupiter and Saturn. These phenomena followed as direct consequences of placing the Earth’s orbit between those of Venus and Mars. Copernicus showed how to determine not only the order of the planets, but also the relative sizes of their orbits, which the traditional Earth-centred scheme could not accomplish without special hypotheses. Even astronomers and astrologers who rejected Copernicus’s system used it to determine planetary distances. They justified their paradoxical position by claiming that Copernicus’s masterpiece was not a revolution in cosmology, but merely a convenient calculating device.

De revolutionibus divides into three very unequal parts. The third and by far the largest, more than 90 per cent of the whole, is a severely technical reworking of the quantitative machinery of the traditional picture. (As Gingerich has established with the help of computers, Copernicus’s devices and parameters were, in fact, no better than those they replaced for predicting the positions of the planets.) The second part sets forth qualitative reasons, mainly concerning the harmony of things, for preferring a Sun-centred universe. The front matter contains a dedication to Pope Paul III and a preface ‘on the hypotheses of this work’.

The dedication to the pope recalls the genesis of the work, the support it received from bishops and other prominent men, and the need for techies like Copernicus and the pope, a competent astronomer/astrologer, to stick together. People such as the Church Father Lactantius, who had taught that the world was flat, inevitably object to novelties they do not understand. Ignore them, Copernicus goes on: ‘Astronomy is written for astronomers.’ The preface to De revolutionibus embroiders this dictum with Aristotelian philosophy, according to which mathematics applied to natural phenomena could go no deeper than exact description: astronomy is mathematics. Anyone who used the new system just for calculation would find it as good as, and perhaps better than, the old one. ‘As far as hypotheses are concerned, however, let no one expect anything certain from astronomy, which cannot furnish it, lest he accept as truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it.’

Readers who accept the preface as Copernicus’s view of his work might consider him either a ‘timid canon’ (as Arthur Koestler did, referring to Copernicus’s position at the Cathedral of Frauenburg) or a profound epistemologist (as did Pierre Duhem, a 19th-century physicist, philosopher, historian and Catholic apologist, who praised Copernicus’s grasp of the instrumental character of scientific theories). Both were wrong. The preface to De revolutionibus was written not by Copernicus but by Andreas Osiander, a Protestant minister, mathematician and fierce controversialist, who saw the book through the press. Osiander probably believed that his preface would ease the acceptance of Copernicus’s guiding idea, and that omitting his own name would improve the book’s chances with readers who had been offended by his polemics. The first generation of post-Copernican astronomers discovered that the preface had been written by Osiander. How they circulated news about De revolutionibus is the main subject of The Book Nobody Read.

Gingerich’s title refers to a discussion he had with his colleague Jerry Ravetz concerning Koestler’s conjecture that, because of its demanding technical content, De revolutionibus could not have found many readers. After totting up all the capable early modern astronomers they knew, Gingerich and Ravetz were inclined to accept his conjecture. Feeling obliged to contribute something worthwhile to the upcoming quincentennial, however, Gingerich thought he would consult the copy of De revolutionibus closest to him, in Edinburgh: had it been read? It had been, very carefully, and was full of comments on technical matters in an easy-to-read 16th-century hand. The annotator turned out to be Erasmus Reinhold, professor of astronomy at the University of Wittenberg, whose Prutenic Tables, published in 1551, were the first to be computed for the Copernican system. Reinhold’s marginalia corrected some of Copernicus’s calculations and re-derived some of his results: a lot of work for a non-believer in a Sun-centred universe.

The extent of the marginalia was surprising, but their authorship wasn’t. Reinhold would have made even Koestler’s very short list of 16th-century readers of De revolutionibus. Encouraged by the quick success of his first probe, Gingerich sought out other copies of the first edition of 1543 and the second of 1566 (the very existence of which should have discredited Koestler’s conjecture), and produced a census (not included in The Book Nobody Read) of 601 copies, about half the original press runs.

Gingerich’s actions have had at least two notable consequences. For one, it is now very hard to get away with stealing a first or second edition of De revolutionibus. Gingerich notes in his census not only the usual bibliographical identifiers – size, collation, names and stamps of former owners, and missing or doctored pages – but also the content of marginalia and other notes, where present. He describes several thefts he helped to unravel. His first chapter is an account of the trial of a man who had made off with a De revolutionibus that Gingerich knew well. The thief didn’t have a chance.

The second, and for historians the major result of Gingerich’s census-taking was the discovery that the earliest students of Copernicus’s work learned by transcribing notes made by masters such as Reinhold into their own copies of De revolutionibus. One such copy, formerly in the library of Tycho Brahe, is now in Prague. It contains many annotations and analyses not in Reinhold, and it was formerly assumed that Tycho, who had spent his last years in Prague, had composed and written them. The attribution was supported by manuscript diagrams that appeared to represent early stages in the formulation of the Tychonic world system, in which all the traditional planets circle a Sun revolving about a stationary Earth. Gingerich turned up a second copy, annotated in the same hand, in the Vatican Library. Bound in the back of this second copy was a series of diagrams, dated 1578, that move from the Copernican to a geo-heliocentric system resembling Tycho’s. It seemed to be another preliminary draft of the system Tycho first published in 1588. The volume had been deposited in the Vatican by Pope Alexander VIII, who had inherited it from the apostate Queen Christina, who had found it in the Royal Library in Stockholm, where it had been brought as booty from Prague during the Thirty Years’ War.

‘In a state of euphoria’, Gingerich revealed the Vatican copy to some experts on early modern astronomy at a meeting of the US History of Science Society in 1974. One of them, Robert Westman, punctured the euphoria and astonished all present with the news that he had found a third Tychonic copy, in the Prague-Vatican hand, in Liège. Soon after this unsettling meeting, Gingerich found a fourth such copy in London. Why had Tycho annotated four copies of De revolutionibus? Gingerich teamed up with Westman to find out. The answer was surprising: Tycho had not annotated any of them. The notes were the handiwork of an itinerant mathematician called Paul Wittich. Apparently, he had used his copies as repositories for his own discoveries as well as for updating and correcting Copernicus’s text. Since Wittich’s annotations show up in other people’s copies of De revolutionibus, he probably used his books as teaching resources. Tycho evidently learned something from them during Wittich’s stay at Uraniborg, Tycho’s observatory on the island of Hven in the Baltic, in 1580. But the Lord of Hven was sufficiently worried about the direction of his guest’s subsequent research to have made every effort to buy Wittich’s library after his death in 1586. Eventually, Tycho acquired the copies now in Liège, Prague and the Vatican.

Another copy of very considerable interest belonged to Johannes Kepler. Its previous owner, a friend of the printer of De revolutionibus, had written Osiander’s name above the preface, which occupies the reverse of the title page. Kepler unmasked Osiander in an ‘advice to readers’ published on the verso of the title page of his Astronomia nova of 1609, which unveiled the elliptical, Sun-centred geometry in which he recast Copernicus’s ideas.

Among the copies that have not turned up, or have not been identified, are those used by the experts charged by the Holy Office (the Congregation of the Inquisition) in 1616 to judge the Copernican system. These careful readers – careful at least about the front matter and the first chapter of De revolutionibus – advised that the immobility of the Sun was contrary to Scripture and absurd in philosophy, whereas the motion of the Earth, though equally absurd philosophically, was only rash in faith. The inquisitors decided to ban the book donec corrigatur: that is, ‘until corrected’. They issued the necessary corrections in 1620. Apart from deleting the sentence in which Copernicus found Lactantius wanting, and passages appearing to recommend heliocentrism as true in nature, the inquisitors limited themselves to insisting that the Earth’s motion be discussed only hypothetically, in the manner recommended by Osiander.

The deletions and improvements required by the Holy Office resulted in new possibilities for Copernican markings. Very few owners obliterated the obnoxious passages in the thorough manner of modern security agencies. Some owners crossed them out with a single line, leaving them legible; more, including prelates and cardinals, who should have known better, and virtually all Catholics outside Italy, ignored the good work of the censors altogether. Princes of the Church liked to collect books not to deface them, even prohibited ones – and sometimes they had an eye to posterity. One instance was the acquisition by Cardinal Saint Gregorio Barbarigo, a frequent also-ran for pope, of a copy of Galileo’s condemned Dialogo, annotated by Galileo himself. For safekeeping, Barbarigo deposited it in the library of a seminary he had founded in Padua. It served in 1744 as the text for the first licit reprinting of the Dialogo in Italy.