De revolutionibus orbium coelestium, libri VI: in quibus stellarum et fixarum et erraticarum motus, ex veteribus atq[ue] recentibus observationibus, restituit hic autor : praeterea tabulas expeditas luculentasq[ue] addidit, ex quibus eosdem motus ad quodvis tempus mathematum studiosus facillime calculare poterit. Item, De libris revolutionum Nicolai Copernici narratio prima, per Georgium Ioachimum Rheticum ad Ioan. Schonerum scripta.

Basel: Heinrich Petri, 1566.

Second edition of the most important scientific publication of the sixteenth century and a “landmark in human thought” (PMM). De revolutionibus was the first work to propose a comprehensive heliocentric theory of the cosmos, according to which the sun stood still and the earth revolved around it. It thereby inaugurated one of the greatest ever paradigm shifts in the history of human thought. “Renaissance mathematicians, following Ptolemy, believed that the moon, sun and five planets were carried by complex systems of epicycles and deferents about the central earth, the fixed pivot of the whole system. In Copernicus’s day it was well known that conventional astronomy did not work accurately … Copernicus, stimulated by the free entertainment of various new ideas among the ancients, determined to abandon the fixity of the earth … With the sun placed at the center, and the earth daily spinning on its axis and circling the sun in common with other planets, the whole system of the heavens became clear, simple and harmonious. The revolutionary nature of his theory is evident in his famous diagram illustrating the concentric orbits of the planets [C1v]” (PMM). The text of the second edition of De revolutionibus follows the 1543 first edition almost exactly, including Andreas Osiander’s notorious unsigned preface, in which he attempted to placate potential critics of the work by stating that “these hypotheses need not be true nor even probable” – all that was necessary was that they should allow astronomers to correctly calculate the motions of the heavenly bodies. Petri added, at the end of the ‘Index capitulorum’, a five-line recommendation by “our leading mathematician” Erasmus Reinhold, extracted from his Tabulae Prutenicae, stating that “all posterity will gratefully remember the name of Copernicus, by whose labor and study the doctrine of celestial motions was again restored from near collapse” (translation from Gingerich, Eye of Heaven, p. 221). This second edition is the first to contain the Narratio prima of Copernicus’s disciple George Joachim Rheticus, which summarises and champions the Copernican heliocentric hypothesis, and records Rheticus’s indefatigable efforts to persuade Copernicus to publish. The first edition of the Narratio, published at Gdansk in 1540, is virtually unobtainable, and the second edition of 1541 is hardly more procurable. According to Gingerich (Census, p. XIV), about 500-600 copies of this second edition of De revolutionibus were printed, perhaps slightly more than the first edition.

“The first speculations about the possibility of the Sun being the center of the cosmos and the Earth being one of the planets going around it go back to the third century BCE. In his Sand-Reckoner, Archimedes (d. 212 BCE), discusses how to express very large numbers. As an example he chooses the question as to how many grains of sand there are in the cosmos. And in order to make the problem more difficult, he chooses not the geocentric cosmos generally accepted at the time, but the heliocentric cosmos proposed by Aristarchus of Samos (ca. 310-230 BCE), which would have to be many times larger because of the lack of observable stellar parallax. We know, therefore, that already in Hellenistic times thinkers were at least toying with this notion, and because of its mention in Archimedes’s book Aristarchus's speculation was well-known in Europe beginning in the High Middle Ages but not seriously entertained until Copernicus.

“European learning was based on the Greek sources that had been passed down, and cosmological and astronomical thought were based on Aristotle and Ptolemy. Aristotle’s cosmology of a central Earth surrounded by concentric spherical shells carrying the planets and fixed stars was the basis of European thought from the 12th century CE onward. Technical astronomy, also geocentric, was based on the constructions of eccentric circles and epicycles codified in Ptolemy’s Almagest (2d. century CE).

“In the fifteenth century, the reform of European astronomy was begun by the astronomer/humanist Georg Peurbach (1423-1461) and his student Johannes Regiomontanus (1436-1476). Their efforts were concentrated on ridding astronomical texts, especially Ptolemy’s, from errors by going back to the original Greek texts and providing deeper insight into the thoughts of the original authors. With their new textbook and a guide to the Almagest, Peurbach and Regiomontanus raised the level of theoretical astronomy in Europe.

“Several problems were facing astronomers at the beginning of the sixteenth century. First, the tables (by means of which astronomical events such as eclipses and conjunctions were predicted) were deemed not to be sufficiently accurate. Second, Portuguese and Spanish expeditions to the Far East and America sailed out of sight of land for weeks on end, and only astronomical methods could help them in finding their locations on the high seas. Third, the calendar, instituted by Julius Caesar in 44 BCE was no longer accurate. The equinox, which at the time of the Council of Nicea (325 CE) had fallen on the 21st, had now slipped to the 11th. Since the date of Easter (the celebration of the defining event in Christianity) was determined with reference to the equinox, and since most of the other religious holidays through the year were counted forward or backward from Easter, the slippage of the calendar with regard to celestial events was a very serious problem. For the solution to all three problems, Europeans looked to the astronomers” (Galileo Project).

Nicolaus Copernicus was born on 19 February 1473 in Thorn (modern day Torun) in Poland. His father was a merchant and local official. When Copernicus was 10 his father died, and his uncle, a priest, ensured that Copernicus received a good education. In 1491, he went to Krakow Academy, now the Jagiellonian University, and in 1496 travelled to Italy to study law. While a student at the University of Bologna he stayed with a mathematics professor, Domenico Maria de Novara, who encouraged Copernicus' interests in geography and astronomy. During his time in Italy, Copernicus visited Rome and studied at the universities of Padua and Ferrara, before returning to Poland in 1503. For the next seven years he worked as a private secretary to his uncle, now the bishop of Ermland. The bishop died in 1512 and Copernicus moved to Frauenberg, where he had long held a position as a canon, an administrative appointment in the church. This gave him more time to devote to astronomy. Although he did not seek fame, it is clear that he was by now well known as an astronomer. In 1514, when the Catholic church was seeking to improve the calendar, one of the experts to whom the pope appealed was Copernicus.

“It is impossible to date when Copernicus first began to espouse the heliocentric theory … His first heliocentric writing was his Commentariolus. It was a small manuscript that was circulated but never printed. We do not know when he wrote this, but a professor in Cracow cataloged his books in 1514 and made reference to a ‘manuscript of six leaves expounding the theory of an author who asserts that the earth moves while the sun stands still’ (Rosen, Three Copernican Treatises (1971), p. 343). Thus, Copernicus probably adopted the heliocentric theory sometime between 1508 and 1514. Rosen (ibid., p. 345) suggested that Copernicus's ‘interest in determining planetary positions in 1512–1514 may reasonably be linked with his decisions to leave his uncle's episcopal palace in 1510 and to build his own outdoor observatory in 1513.’ In other words, it was the result of a period of intense concentration on cosmology that was facilitated by his leaving his uncle and the attendant focus on church politics and medicine …

“Most scholars believe that the reason Copernicus rejected Ptolemaic cosmology was because of Ptolemy’s equant. They assume this because of what Copernicus wrote in the Commentariolus:

‘Yet the widespread [planetary theories], advanced by Ptolemy and most other [astronomers], although consistent with the numerical [data], seemed likewise to present no small difficulty. For these theories were not adequate unless they also conceived certain equalizing circles, which made the planet appear to move at all times with uniform velocity neither on its deferent sphere nor about its own [epicycle's] center … Therefore, having become aware of these [defects], I often considered whether there could perhaps be found a more reasonable arrangement of circles, from which every apparent irregularity would be derived while everything in itself would move uniformly, as is required by the rule of perfect motion’ …

“Most importantly, we should bear in mind what Swerdlow and Neugebauer asserted:

‘Copernicus arrived at the heliocentric theory by a careful analysis of planetary models — and as far as is known, he was the only person of his age to do so — and if he chose to adopt it, he did so on the basis of an equally careful analysis.’

“In the Commentariolus Copernicus listed assumptions that he believed solved the problems of ancient astronomy. He stated that the earth is only the center of gravity and center of the moon's orbit; that all the spheres encircle the sun, which is close to the center of the universe; that the universe is much larger than previously assumed, and the earth's distance to the sun is a small fraction of the size of the universe; that the apparent motion of the heavens and the sun is created by the motion of the earth; and that the apparent retrograde motion of the planets is created by the earth's motion. Although the Copernican model maintained epicycles moving along the deferent, which explained retrograde motion in the Ptolemaic model, Copernicus correctly explained that the retrograde motion of the planets was only apparent not real, and its appearance was due to the fact that the observers were not at rest in the center. The work dealt very briefly with the order of the planets (Mercury, Venus, earth, Mars, Jupiter, and Saturn, the only planets that could be observed with the naked eye), the triple motion of the earth (the daily rotation, the annual revolution of its center, and the annual revolution of its inclination) that causes the sun to seem to be in motion, the motions of the equinoxes, the revolution of the moon around the earth, and the revolution of the five planets around the sun.

“The Commentariolus was only intended as an introduction to Copernicus’s ideas, and he wrote ‘the mathematical demonstrations intended for my larger work should be omitted for brevity's sake’. In a sense it was an announcement of the greater work that Copernicus had begun. The Commentariolus was never published during Copernicus’s lifetime, but he sent manuscript copies to various astronomers and philosophers. He received some discouragement because the heliocentric system seemed to disagree with the Bible, but mostly he was encouraged. Although Copernicus’s involvement with official attempts to reform the calendar was limited to a no longer extant letter, that endeavor made a new, serious astronomical theory welcome. Fear of the reaction of ecclesiastical authorities was probably the least of the reasons why he delayed publishing his book. The most important reasons for the delay was that the larger work required both astronomical observations and intricate mathematical proofs. His administrative duties certainly interfered with both the research and the writing. He was unable to make the regular observations that he needed and Frombork, which was often fogged in, was not a good place for those observations. Moreover, as Gingerich (ibid., p. 37) pointed out,

‘[Copernicus] was far from the major international centers of printing that could profitably handle a book as large and technical as De revolutionibus. On the other [hand], his manuscript was still full of numerical inconsistencies, and he knew very well that he had not taken complete advantage of the opportunities that the heliocentric viewpoint offered…Furthermore, Copernicus was far from academic centers, thereby lacking the stimulation of technically trained colleagues with whom he could discuss his work.’

“Although Copernicus received encouragement to publish his book from his close friend, the bishop of Chelmo Tiedemann Giese (1480–1550), and from the cardinal of Capua Nicholas Schönberg (1472–1537), it was the arrival of Georg Joachim Rheticus (1514-1574) in Frombork that solved his needs for a supportive and stimulating colleague in mathematics and astronomy and for access to an appropriate printer. Rheticus was a professor of mathematics at the University of Wittenberg, a major center for the student of mathematics as well as for Lutheran theology. In 1538 Rheticus took a leave of absence to visit several famous scholars in the fields of astronomy and mathematics. It is not known how Rheticus learned about Copernicus’s theory; he may have been convinced to visit Copernicus by one of the earlier scholars he had visited, Johann Schöner, though, as Swerdlow and Neugebauer noted, by ‘the early 1530’s knowledge of Copernicus’s new theory was circulating in Europe, even reaching the high and learned circles of the Vatican.’ Rheticus brought with him some mathematical and astronomical volumes, which both provided Copernicus with some important material and showed him the quality of the mathematical printing available in the German centers of publishing. Rheticus’s present of the 1533 edition of Regiomontanus's On all Kinds of Triangles (De triangulis omnimodis), for example, convinced Copernicus to revise his section on trigonometry. But Rheticus was particularly interested in showing Copernicus the work of the Nuremberg publisher Johann Petreius as a possible publisher of Copernicus’s volume. Swerdlow and Neugebauer plausibly suggested that ‘Petreius was offering to publish Copernicus's work, if not advertising by this notice that he was already committed to do so.’ Rheticus wrote the Narratio prima in 1540, an introduction to the theories of Copernicus, which was published and circulated. This further encouraged Copernicus to publish his Revolutions, which he had been working on since he published the Commentariolus

“The manuscript of On the Revolutions was basically complete when Rheticus came to visit him in 1539. The work comprised six books. The first book, the best known, discussed what came to be known as the Copernican theory and what is Copernicus's most important contribution to astronomy, the heliocentric universe (although in Copernicus's model, the sun is not truly in the center). Book 1 set out the order of the heavenly bodies about the sun: ‘[The sphere of the fixed stars] is followed by the first of the planets, Saturn, which completes its circuit in 30 years. After Saturn, Jupiter accomplishes its revolution in 12 years. The Mars revolves in 2 years. The annual revolution takes the series’ fourth place, which contains the earth … together with the lunar sphere as an epicycle. In the fifth place Venus returns in 9 months. Lastly, the sixth place is held by Mercury, which revolves in a period of 80 days’. This established a relationship between the order of the planets and their periods, and it made a unified system. This may be the most important argument in favor of the heliocentric model as Copernicus described it. It was far superior to Ptolemy’s model, which had the planets revolving around the earth so that the sun, Mercury, and Venus all had the same annual revolution. In book 1 Copernicus also insisted that the movements of all bodies must be circular and uniform, and noted that the reason they may appear non-uniform to us is ‘either that their circles have poles different [from the earth's] or that the earth is not at the center of the circles on which they revolve’. Particularly notable for Copernicus was that in Ptolemy’s model the sun, the moon, and the five planets seemed ironically to have different motions from the other heavenly bodies and it made more sense for the small earth to move than the immense heavens. But the fact that Copernicus turned the earth into a planet did not cause him to reject Aristotelian physics, for he maintained that ‘land and water together press upon a single center of gravity; that the earth has no other center of magnitude; that, since earth is heavier, its gaps are filled with water’. As Aristotle had asserted, the earth was the center toward which the physical elements gravitate. This was a problem for Copernicus's model, because if the earth was no longer the center, why should elements gravitate toward it?

“The second book of On the Revolutions elaborated the concepts in the first book; book 3 dealt with the precession of the equinoxes and solar theory; book 4 dealt with the moon's motions; book 5 dealt with the planetary longitude and book 6 with latitude. Copernicus depended very much on Ptolemy’s observations, and there was little new in his mathematics. He was most successful in his work on planetary longitude, which, as Swerdlow and Neugebauer commented, was ‘Copernicus’s most admirable, and most demanding, accomplishment … It was above all the decision to derive new elements for the planets that delayed for nearly half a lifetime Copernicus’s continuation of his work – nearly twenty years devoted to observation and then several more to the most tedious kind of computation – and the result was recognized by his contemporaries as the equal of Ptolemy’s accomplishment, which was surely the highest praise for an astronomer.’ Surprisingly, given that the elimination of the equant was so important in the Commentariolus, Copernicus did not mention it in book 1, but he sought to replace it with an epicyclet throughout On the Revolutions. Nevertheless, he did write in book 5 when describing the motion of Mercury,

‘the ancients allowed the epicycle to move uniformly only around the equant’s center. This procedure was in gross conflict with the true center [of the epicycle’s motion], its relative [distances], and the prior centers of both [other circles] … However, in order that this last planet too may be rescued from the affronts and pretenses of its detractors, and that its uniform motion, no less than that of the other aforementioned planets, may be revealed in relation to the earth’s motion, I shall attribute to it too, [as the circle mounted] on its eccentric, an eccentric instead of the epicycle accepted in antiquity’ …

“The Narratio prima was written in 1539 and took the form of a letter to Johann Schöner announcing Copernicus’s findings and describing the contents of the Revolutions. He dealt with such topics as the motions of the fixed stars, the tropical year, the obliquity of the ecliptic, the problems resulting from the motion of the sun, the motions of the earth and the other planets, librations, longitude in the other five planets, and the apparent deviation of the planets from the ecliptic. He asserted that the heliocentric universe should have been adopted because it better accounted for such phenomena as the precession of the equinoxes and the change in the obliquity of the ecliptic; it resulted in a diminution of the eccentricity of the sun; the sun was the center of the deferents of the planets; it allowed the circles in the universe to revolve uniformly and regularly; it satisfied appearances more readily with fewer explanations necessary; it united all the spheres into one system. Rheticus added astrological predictions and number mysticism, which were absent from Copernicus's work. The Narratio prima was printed in 1540 in Gdansk (then Danzig); thus, it was the first printed description of the Copernican thesis. Rheticus sent a copy to Achilles Pirmin Gasser of Feldkirch, his hometown in modern-day Austria, and Gasser wrote a foreword that was published with a second edition that was produced in 1541 in Basel …

“The publication of Rheticus’s Narratio prima did not create a big stir against the heliocentric thesis, and so Copernicus decided to publish On the Revolutions. He added a dedication to Pope Paul III (r. 1534–1549), probably for political reasons, in which he expressed his hesitancy about publishing the work and the reasons he finally decided to publish it. He gave credit to Schönberg and Giese for encouraging him to publish and omitted mention of Rheticus, but it would have been insulting to the pope during the tense period of the Reformation to give credit to a Protestant minister. He dismissed critics who might have claimed that it was against the Bible by giving the example of the fourth-century Christian apologist Lactantius, who had rejected the spherical shape of the earth, and by asserting, ‘Astronomy is written for astronomers. In other words, theologians should not meddle with it. He pointed to the difficulty of calendar reform because the motions of the heavenly bodies were inadequately known. And he called attention to the fact that ‘if the motions of the other planets are correlated with the orbiting of the earth, and are computed for the revolution of each planet, not only do their phenomena follow therefrom but also the order and size of all the planets and spheres, and heaven itself is so linked together that in no portion of it can anything be shifted without disrupting the remaining parts and the universe as a whole’.

“Rheticus returned to Wittenberg in 1541 and the following year received another leave of absence, at which time he took the manuscript of the Revolutions to Petreius for publishing in Nuremberg. Rheticus oversaw the printing of most of the text. However, Rheticus was forced to leave Nuremberg later that year because he was appointed professor of mathematics at the University of Leipzig. He left the rest of the management of printing the Revolutions to Andreas Osiander (1498–1552), a Lutheran minister who was also interested in mathematics and astronomy. Though he saw the project through, Osiander appended an anonymous preface to the work. In it he claimed that Copernicus was offering a hypothesis, not a true account of the working of the heavens: ‘Since he [the astronomer] cannot in any way attain to the true causes, he will adopt whatever suppositions enable the motions to be computed correctly from the principles of geometry for the future as well as for the past …these hypotheses need not be true nor even probable’. This clearly contradicted the body of the work. Both Rheticus and Giese protested, and Rheticus crossed it out in his copy” (Stanford Encyclopedia of Philosophy).

“The reception of De Revolutionibus was mixed. The heliocentric hypothesis was rejected out of hand by virtually all, but the book was the most sophisticated astronomical treatise since the Almagest, and for this it was widely admired. Its mathematical constructions were easily transferred into geocentric ones, and many astronomers used them. In 1551 Erasmus Reinhold, no believer in the mobility of the Earth, published a new set of tables, the Prutenic Tables, based on Copernicus’s parameters. These tables came to be preferred for their accuracy. Further, De revolutionibus became the central work in a network of astronomers, who dissected it in great detail. Not until a generation after its appearance, however, can we begin point to a community of practicing astronomers who accepted heliocentric cosmology. Perhaps the most remarkable early follower of Copernicus was Thomas Digges (c. 1545 - c.1595), who in A Perfit Description of the Coelestiall Orbes (1576) translated a large part of Book I of De Revolutionibus into English and illustrated it with a diagram in which the Copernican arrangement of the planets is imbedded in an infinite universe of stars.

“The reason for this delay was that, on the face of it, the heliocentric cosmology was absurd from a common-sensical and a physical point of view. Thinkers had grown up on the Aristotelian division between the heavens and the earthly region, between perfection and corruption. In Aristotle's physics, bodies moved to their natural places. Stones fell because the natural place of heavy bodies was the center of the universe, and that was why the Earth was there. Accepting Copernicus's system meant abandoning Aristotelian physics. How would birds find their nest again after they had flown from them? Why does a stone thrown up come straight down if the Earth underneath it is rotating rapidly to the east? Since bodies can only have one sort of motion at a time, how can the Earth have several? And if the Earth is a planet, why should it be the only planet with a moon?

“For astronomical purposes, astronomers always assumed that the Earth is as a point with respect to the heavens. Only in the case of the Moon could one notice a parallactic displacement (about 1°) with respect to the fixed stars during its (i.e., the Earth’s) diurnal motion. In Copernican astronomy one now had to assume that the orbit of the Earth was as a point with respect to the fixed stars, and because the fixed stars did not reflect the Earth's annual motion by showing an annual parallax, the sphere of the fixed stars had to be immense. What was the purpose of such a large space between the region of Saturn and that of the fixed stars? …

“There was another problem. A stationary Sun and moving Earth also clashed with many biblical passages. Protestants and Catholics alike often dismissed heliocentrism on these grounds. Martin Luther did so in one of his ‘table talks’ in 1539, before De Revolutionibus had appeared. (Preliminary sketches had circulated in manuscript form.) In the long run, Protestants, who had some freedom to interpret the bible personally, accepted heliocentrism somewhat more quickly. Catholics, especially in Spain and Italy, had to be more cautious in the religious climate of the Counter Reformation, as the case of Galileo clearly demonstrates. Christoph Clavius, the leading Jesuit mathematician from about 1570 to his death in 1612, used biblical arguments against heliocentrism in his astronomical textbook.

“The situation was never simple, however. For one thing, late in the sixteenth century Tycho Brahe devised a hybrid geostatic heliocentric system in which the Moon and Sun went around the Earth but the planets went around the Sun. In this system the elegance and harmony of the Copernican system were married to the solidity of a central and stable Earth so that Aristotelian physics could be maintained. Especially after Galileo's telescopic discoveries, many astronomers switched from the traditional to the Tychonic cosmology. For another thing, by 1600 there were still very few astronomers who accepted Copernicus's cosmology … Finally, we must not forget that Copernicus had dedicated De Revolutionibus to the Pope. During the sixteenth century the Copernican issue was not considered important by the Church and no official pronouncements were made.

“Galileo's discoveries changed all that. Beginning with Sidereus Nuncius in 1610, Galileo brought the issue before a wide audience. He continued his efforts, ever more boldly, in his letters on sunspots, and in his letter to the Grand Duchess Christina (circulated in manuscript only) he actually interpreted the problematical biblical passage in the book of Joshua to conform to a heliocentric cosmology. More importantly, he argued that the Bible is written in the language of the common person who is not an expert in astronomy. Scripture, he argued, teaches us how to go to heaven, not how the heavens go … It was at this point that Church officials took notice of the Copernican theory and placed De Revolutionibus on the Index of Forbidden Books until corrected.

“Galileo's Dialogue Concerning the Two Chief World Systems of 1632 was a watershed in what had shaped up to be the ‘Great Debate.’ Galileo's arguments undermined the physics and cosmology of Aristotle for an increasingly receptive audience. His telescopic discoveries, although they did not prove that the Earth moved around the Sun, added greatly to his argument. In the meantime, Johannes Kepler (who had died in 1630) had introduced physical considerations into the heavens and had published his Rudolphine Tables, based on his own elliptical theory and Tycho Brahe’s accurate observations, and these tables were more accurate by far than any previous ones. The tide now ran in favor of the heliocentric theory, and from the middle of the seventeenth century there were few important astronomers who were not Copernicans” (Galileo Project).

Adams C2603; Cinti 3; Wightman 172; Zinner 2390. For the first edition see Dibner 3, Horblit 18a and 18b and PMM 70. Gingerich, An Annotated Census of Copernicus’ De Revolutionibus (Nuremberg, 1543 and Basel, 1566), 2002. Swerdlow & Neugebauer, Mathematical Astronomy in Copernicus’s De Revolutionibus, 1984.



Folio (269 x 184 mm), ff. vi, 213, [1], with printer’s device on title and verso of last leaf and woodcut diagrams in text. Contemporary vellum, manuscript lettering on spine, end-papers renewed, faint damp stain to first seven leaves, early inscription to upper margin of title washed out leaving a brown stain and a few tears which have been carefully repaired with Japanese paper.

Item #4704

Price: $265,000.00

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