I’ve just finished reading Dava Sobel’s Galileo’s Daughter, mostly of course about the great scientist himself. It’s a fascinating read about his personal life (Those other kids of mine? Feh! They never call, they never write, I could be lying dead in a ditch for all they know if not for all the letters asking for money, but my wonderful Suor Maria Celeste is the light of my life!), and how the classic Fight Against Ignorance wore him down.
Anyway, I’m asking about his run-in with the Inquisition. It was disappointing to learn that Galileo wasn’t defiant at his hearing; he never said “Eppur si muove” and all of his answers were abjectly groveling. But I’m still left hanging with wondering why his old friend and supporter Pope Urban VIII turned against him so completely and even spitefully. From enthusiastically supporting his scientific endeavors, and almost approving the Dialogues for publication to banning not only that but all of Galileo’s works and keeping him under arrest for the rest of his life was a total reversal that Sobel leaves unclear. She does mention that some reactionary churchmen had Urban’s ear, but that’s it.
So what changed Galileo’s old friend’s mind about his support of Copernicus’ theory but about the man himself?
Partly, it was the Dialogue themselves. The character of Simplico, who supports the geocentric theory in the Dialogue, comes across as a total idiot and fool. Simplico is also a not very well disguised caricature of Urban VIII (In the dialogue, Simplico repeats a theory that Urban had developed regarding the origin of the tides). By all accounts, Urban took that very personally.
Also, Gallileo had been working with Niccolo Riccardi, the the head of the Vatican’s licensing department in getting the book ready for publication, and Riccardi suggested a bunch of rewrites to the Preface to make the book theologically acceptable. Gallileo rewrote the Preface, and Riccardi approved it and the book got published. However, the revisions to the Preface weren’t sufficient enough for the Vatican (Riccardi got lectured pretty harshly for approving it, because it still didn’t meet the guidelines.), and Urban became convinced that Gallileo and Urban’s private secretary (who was one of the strongest advocates for publication) had tried to pull one over on him, by assuring him that the book would comply with Vatican guidelines while it didn’t.
Thirdly, Gallileo, convinced that Urban was on his side, made what were some pretty provocative statements regarding the truth of the bible and the authority of the Catholic church to make scientific interpretations of the bible. That also rankled Urban and the people around him, especially because the Reformation was going full swing at the time, and the Catholic church was really concerned about Protestantism. As Urban himself said:
Also, just so you know, Urban never changed his mind about “his support of Copernicus’ theory”. Pope Urban never supported Copernicus’ theory. He had always believed in geocentricism. Astronomy wasn’t a subject that particularly interested him, though. He was more interested in the humanities than in science (he actually wrote some light verse and some hymns, and he was a big patron of the arts).
The story is, of course, long and complex - as well as being widely misrepresented.
Galileo lived at a time of great political and intellectual change. Early in his life, the Church positively encouraged free and open discussion of all topics that did not outrageously contradict doctrine - and that certainly included celestial mechanics. But times changed and the Church became much more conservative taking the view that no view was acceptable that was contary to scripture (however tenuous) unless that view could be proven which would in turn require scripture to be reinterpreted.
Galileo insisted on continuing to teach that the earth moved just as Copernicus had said. Trouble was, he really could not prove it. When he was ordered to keep quiet, he persisted in the promotion of his views. To make matters worse, in doing so he seemed to be insulting the intelligence of the Pope himself.
In troubled times, the Pope really just had to establish his authority and silence Galileo.
If Galileo did “grovell” in the end it was primarily because he was, when the chips were down, a good Catholic.
If you think Galileo had a hard time, spare a thought for Giordano Bruno.
For further reading, I cannot recommend highly enough The Sleepwalkers.
Even Johannes Kepler complained in his private letters that Galileo was taking what should be a nice, dry, scholarly debate between astronomers and turning into a very public and embarrassing debacle. Copernicus’ Revolutionibus circulated among academics for years, with the full knowledge of the Church. It wasn’t until Galileo started harping on it that the book was placed on the Index of Prohibited Books.
Geocentrism could not have survived the invention of the telescope. Galileo’s observations of the phases of Venus put the nail in the coffin—but they came pretty late in the debate. It may well be that Galileo’s advocacy of heliocentrism did science more harm than good.
Another great book on the topic is Coming of Age in the Milky Way by Timothy Ferris.
Of course, Bruno was, if anything, more irascible than Galileo, (he got thrown out of every school and country where he lodged, Catholic and Protestant), and was eventually executed for denying the Divinity of Jesus. The Church should never have ordered his execution, but his scientific inquiries had nothing to do with his condenation.
There is a first-hand contemporary account of what Urban said were the motives for his actions - as I’ll explain, I don’t think he saw it as a change of mind. Sobel briefly mentions the incident and quotes a couple of sentences from the document in question (on p234 of the UK edition), but otherwise skips over it.
The document is the letter that the Tuscan ambassador in Rome, Franceso Niccolini, wrote to Andrea Cioli in Florence on September 5th 1632 following a stormy audience he’d had with the Pope about Galileo. It’s transcribed in the original Italian in volume XIV of the Opere as item 2298, which can be found online here (warning - it’s a big file containing the whole volume). There’s an English translation of virtually the entire letter in The Crime of Galileo (Chicago, 1955, p191-2) by de Santillana.
Niccolini was a good friend of Galileo’s and for this reason, along with the nuances of Florentine diplomacy, was therefore acting as his voice in the Vatican. There’s much disagreement in the secondary sources about when this particular audience was: the split’s between the 4th and the 5th. Regardless of the exact date, this is the moment at which Urban made it clear that he was very pissed about the Dialogue and the more formal moves against it and its author then follow.
So why was Urban so angry? His immediate objection was that Galileo had “ventured to meddle with things that he ought not and with the most grave and dengerous subjects that can be stirred up in these days.” Allowing for some rhetorical overkill (either on Urban’s part or Niccolini’s), this was probably a fair enough assessment from Urban’s standpoint, though it doesn’t explain a lot. Much of Urban’s rant then centres on the idea that Galileo and his dupe Ciampoli had misled Riccardi and the Vatican. The key passage that people have tended to focus on, however, is the following:
The Pope sees this as a personal matter. The most obvious guess is that he’s previously explained to Galileo what he saw the limits were and now believes that they’ve been crossed. He’s sticking to his previous stance. Unfortunately, there’s otherwise nothing on paper about this earlier conversation, though it’s the sort of issue that they surely would have discussed between themselves in earlier years.
There are other interpretations of Niccolini’s account. For instance, de Santillana believes that Urban was simply “blustering” and couldn’t back any of this up. Stillman Drake on the other hand (in Galileo at Work, Chicago, 1978) believed that Urban’s anger was such that it was evidence he had changed his mind. Drake’s suggestion is that he’d just learnt about the compromise with Bellarmine in 1616 and that there was a signed document to back this up. In this version, far from blustering, Urban has just realised that he can - and must - nail Galileo for betraying an agreement with the Vatican.
“Nothing to do with” is too strong a statement. The final verdict (officially) was based on heresy, but Bruno’s advocacy of Copernicanism was priminent in his trial before the Inquisition.
A side note, Bruno’s heresy wasn’t actually a denial of the divinity of Jesus. It was adherence to the idea that Jesus didn’t actually have a material body (in that God would never put his divine self in something so base as matter.) Bruno believed that Jesus’ body was an illusion created for the benefit of us mortals - an idea that the Church opposed because it would take all the meaning out of the crucifixion.