Posted by Pastoral Musings on August 23rd, 2011
Sixteenth Century Reactions to On the Revolutions
Copernicus’s fame and book made its way across Europe over the next fifty years, and a second edition was brought out in 1566. As Gingerich’s census of the extant copies showed, the book was read and commented on by astronomers. Gingerich (2004, 55) noted “the majority of sixteenth-century astronomers thought eliminating the equant was Copernicus’ big achievement.”
While Martin Luther may have made negative comments about Copernicus because the idea of the heliocentric universe seemed to contradict the Bible, Philip Melanchthon (1497–1560), who presided over the curriculum at the University of Wittenberg, eventually accepted the importance of teaching Copernicus’s ideas, perhaps because Osiander’s preface made the work more palatable. His son-in-law Caspar Peucer (1525-1602) taught astronomy there and began teaching Copernicus’s work. As a result, the University of Wittenberg became a center where Copernicus’s work was studied. But Rheticus was the only Wittenberg scholar who accepted the heliocentric idea. Robert Westman (1975a, 166–67) suggested that there was a ‘Wittenberg Interpretation’: astronomers appreciated and adopted some of Copernicus’s mathematical models but rejected his cosmology, and some were pleased with his replacement of the equant by epicyclets. One of these was Erasmus Reinhold (1511–1553), a leading astronomer at Wittenberg who became dean and rector. He produced a new set of planetary tables from Copernicus’s work, the Prutenic Tables. Although, as Gingerich (1993, 232) pointed out, “there was relatively little to distinguish between the accuracy of the Alfonsine Tables and the Prutenic Tables,” the latter were more widely adopted; Gingerich plausibly suggested that the fact that the Prutenic Tables more accurately predicted a conjunction between Jupiter and Saturn in 1563 made the difference. Reinhold did not accept the heliocentric theory, but he admired the elimination of the equant. The Prutenic Tables excited interest in Copernicus’s work.
Tycho Brahe (1546–1601) was the greatest astronomical observer before the invention of the telescope. He called Copernicus a ‘second Ptolemy’ (quoted in Westman 1975, 307) and appreciated both the elimination of the equant and the creation of a planetary system. But Tycho could not adopt the Copernican system, partly for the religious reason that it went against what the Bible seemed to preach. He, therefore, adopted a compromise, the ‘geoheliostatic’ system in which the two inner planets revolved around the sun and that system along with the rest of the planets revolved around the earth.
Among Catholics, Christoph Clavius (1537–1612) was the leading astronomer in the sixteenth century. A Jesuit himself, he incorporated astronomy into the Jesuit curriculum and was the principal scholar behind the creation of the Gregorian calendar. Like the Wittenberg astronomers, Clavius adopted Copernican mathematical models when he felt them superior, but he believed that Ptolemy’s cosmology — both his ordering of the planets and his use of the equant — was correct.
Pope Clement VII (r. 1523–1534) had reacted favorably to a talk about Copernicus’s theories, rewarding the speaker with a rare manuscript. There is no indication of how Pope Paul III, to whom On the Revolutions was dedicated reacted; however, a trusted advisor, Bartolomeo Spina of Pisa (1474–1546) intended to condemn it but fell ill and died before his plan was carried out (see Rosen, 1975). Thus, in 1600 there was no official Catholic position on the Copernican system, and it was certainly not a heresy. When Giordano Bruno (1548–1600) was burned at the stake as a heretic, it had nothing to do with his writings in support of Copernican cosmology, and this is clearly shown in Finocchiaro’s reconstruction of the accusations against Bruno (see also Blumenberg’s part 3, chapter 5, titled “Not a Martyr for Copernicanism: Giordano Bruno”).
Michael Maestlin (1550–1631) of the University of Tübingen was the earliest astronomer after Rheticus to adopt Copernicus’s heliocentricism. Although he wrote a popular textbook that was geocentric, he taught his students that the heliocentric system was superior. He also rejected Osiander’s preface. Maestlin’s pupil Johannes Kepler wrote the first book since the publication of On the Revolutions that was openly heliocentric in its orientation, the Mysterium cosmographicum (Secret of the Universe). And, of course, Kepler eventually built on Copernicus’s work to create a much more accurate description of the solar system.
And what of Galileo?
What was really going on in the background was that enemies of Galileo convinced Pope Urban VIII that a character in the Dialoguenamed Simplicio who ineptly defended the Ptolemaic system was a thinly veiled caricature of the Pope himself. This provided a pretext for making an example of Galileo, albeit on trumped up charges. Galileo was his own worst enemy in this situation, as he vastly overestimated his influence in Rome, and the degree to which his well-deserved fame would protect him.
Publicly humiliated and threatened with torture, Galileo had no choice but to admit guilt, and “abjure, curse and detest the aforesaid errors and heresies…”
That’s right. Galileo’s problem was more a problem of politics than it was of his views. His views were rejected for personal and political reasons.
Let’s get rid of this idea that the church was anti-science. The church was anti-Galileo.