There are so many good things about this book that I cannot cover them all in one post. So to start, I will discuss how this book treats the most famous issue involved in Galileo’s life: his confrontation with the Roman Catholic church. Obviously a lot of very detailed, very carefully-researched tomes have been written about this affair, and I have read many of them. However, I think this book deals with the issue better than any other book I have read.
Why is this book’s coverage of the struggle between Galileo and the Roman Catholic church so good? For one thing, it doesn’t try to take sides. I have read books about Galileo that portray him as the champion of science who was persecuted by the mighty Roman Catholic church, and I have read books that portray him as a egotistical man who tried to use the force of his personality to make the Roman Catholic church change its theology based on very little evidence. Neither of those portrayals is accurate. Instead, as is the case with most history, the confrontation between Galileo and the Roman Catholic church was very complex, with no pure villains and only one pure hero. That hero was neither Galileo nor the Roman Catholic church. Instead, it was Suor Maria Celeste Galilei.
Because this book is more of a chronological telling of the events in Galileo’s life, his troubles with the Roman Catholic church occupy only one small part of the book. However, if you know the story, hints of trouble appear early on. For example, the book discusses how Galileo developed a telescope based on what he had heard about a Danish “spyglass.” Galileo saw the potential in such a device right away, but he seriously improved on the design by using mathematics (something I will post about later) to calculate what the shapes and placements of the two lenses in a telescope should be to give optimum performance. As a result, while he didn’t really invent the idea of the telescope, he is often credited with inventing it, since he was the first to make something that was really useful in studying the heavens.
Once he developed his telescope and pointed it skywards, he started discovering all sorts of things that contradicted the conventional wisdom of the day. For example, most scientists of his day followed the teachings of Aristotle, who believed that all celestial objects were pure, immutable spheres. When he looked at the moon through his telescope, however, it was nothing like that. As the book quotes Galileo:
It is like the face of the Earth itself…which is marked here and there with chains of mountains and depths of valleys. (p. 31)
He also found that there were dark spots on the sun. He tracked those spots in a most ingenious way. Rather than looking through the telescope at the sun, he allowed the telescope’s image to fall on a piece of paper, which he (or an assistant) carefully traced. Of course, these sunspots were also a direct contradiction of Aristotle’s teaching regarding celestial objects.
One thing I learned from this book, which I didn’t really learn from any other book I have read on the subject, is how careful Galileo was in checking to see whether or not his writings and his investigations were consistent with Roman Catholic teaching. For example, he was quite shocked to see direct evidence against Aristotle’s teachings in the fact that there were dark spots on the sun, so he checked with Carlo Cardinal Conti, a Bishop in Italy. Since Galileo was Italian, Cardinal Conti was the man to speak with regarding whether or not something went against the teachings of the Roman Catholic church. According to the book:
Cardinal Conti had assured him that the Bible did not support Aristotle’s doctrine of immutability; in fact, he said, Scripture seemed to argue against it. (p. 60)
We will see later on another example of how meticulous Galileo was in making sure that what he was writing was not seen as an attack on the Roman Catholic church in any way.
While Galileo’s telescope contradicted the conventional wisdom of science at that time, it made him a celebrity. Indeed, the fact that he discovered the moons that orbit Jupiter (he actually called them “planets”) made him the first to discover something completely new about the contents of the heavens. He wrote a book about that and his other discoveries called The Starry Messenger, and it sold out so quickly that he could only secure six copies for himself (the printer had promised him thirty).
Of course, those who wanted to protect the science of Aristotle tried various ways to attack Galileo, and one of the ways was through the Roman Catholic church. As a result of Galielo’s work, many in the Roman Catholic church thought that people might start taking Copernicus’s view of a sun-centered universe too seriously. Although Copernicus’s book was written many years earlier (1543), it was very technical, and it had not sold well. Also, it did not present a lot of evidence to make the case that the sun was at the center of the universe, so it was seen as more hypothetical than anything else. Galileo’s discoveries were seen by some as providing the evidence that Copernicus lacked, so on March 5 of 1616 (73 years after Copernicus’s book was written), the Congregation of the Index (the official body devoted to prohibiting books that were deemed heretical) officially declared Copernican Astronomy to be “false and contrary to Holy Scripture.”
Shortly before the pronouncement made by the Congregation of the Index, Cardinal Bellarmino had a private meeting with Galileo, and this private meeting is, essentially, what was used by the Roman Catholic church years later to implicate Galileo. In the meeting, Galileo claimed that Cardinal Bellarmino told him the Copernican view could not be held or defended, but it could be taken and used hypothetically.
This caused Galileo to see that he should abandon any attempts to use his discoveries to support the idea of a sun-centered universe. Instead, he decided to try to make more “practical” applications of his discoveries. For example, he spent a considerable amount of time during this part of his life in attempting to use the moons of Jupiter to help in navigation.
A few years later (1623), a man with whom Galileo had many pleasant exchanges was chosen to be Pope, and he took the name Urban VIII. He was very interested in the sciences, and he held Galileo in high regard. On April 24, 1624, Galileo had a private audience with the new Pope, and he found that the Pope had a different view on the 1616 decree of the Congregation of the Index. According to the author:
Urban, now more than halfway through the first year of his pontificate, was proud to say he had never supported that decree, and that it would not have seen the light had he been pope in those days. As cardinal, he had successfully intervened, along with his colleague Bonifazio Cardinal Caetani, to keep “heresy” out of the edict’s final wording. Thus, although the consultors to the Holy Office had called the immobility of the sun “formally heretical” in their February 1616 report, the March 5 edict merely stated that the doctrine was “false” and “contrary to Holy Scripture.” (pp. 137, 138)
Indeed, Pope Urban truly felt that there was no harm in using the Copernican system as a tool in astronomy, and he told Galileo to proceed in applying his science to the consideration of the Copernican system. As a result, Galileo began writing his book, Dialogue Concerning the Two Chief World Systems, which ended up getting him in a lot of trouble.
Now all of these details are covered by most people who chronicle Galileo’s life and accomplishments. But once again, this author’s treatment is unique because he sprinkles in letters from Galileo’s daughter, giving you such intimate detail in Galileo’s life that you almost feel you are there experiencing things with him. In addition to these “homey” details, however, the author of this book mentions a couple of things I had never heard of before.
I knew that it had taken several years for Galileo to write his Dialogue, but I didn’t really know why. I thought he spent a lot of time analyzing and collecting data. That is true to some extent, but other issues such as Galileo’s poor health and the outbreak of plague in Europe also conspired against Galileo getting done with his book in a timely fashion. Indeed, while Galileo started on his book with gusto in 1624, it did not get published until 1632.
The other thing I didn’t even have a clue about was how many pains Galileo went through to make sure his book would not be an affront to the Roman Catholic church. I knew that he had sent his manuscript to the church’s censor in Rome, and it was read by the man in charge of the entire office, Father Riccardi. I also knew that father Riccardi approved the book with only a few minor changes. What I didn’t know was that Galileo went much further than that in securing the church’s favor when it came to the book.
After securing approval from the censor in Rome, the plague caused problems in getting the book printed in Rome. As a result, Galileo went back to Florence, and he decided to submit the book to the Roman Catholic censor in Florence as well. He did not need to do this. However, the thought it was the most prudent course of action. Once again, all went well. He secured permission from the inquisitor in Florence as well as the censor there, just to make sure that there were no problems. They approved the book with no changes, but Galileo went ahead and made the changes that the Roman censor had asked for.
If you wonder why in the world two Roman Catholic censors would approve his book, all you need to do is read it. While Galileo (through a character in the book named Salviati) gave many strong evidences for a sun-centered universe, he refused to endorse the idea. In the end, his character says:
“This invention” – meaning the heliocentric design-“may very easily turn out to be a most foolish hallucination and a majestic paradox.” (p. 177)
So in the end, even the character in the book who speaks for Galileo would not say that the Copernican view of the heavens was correct. He simply listed the objective evidence that existed for it.
However, even though the Copernican system was not formally endorsed by the book, and even though the book passed the Roman Catholic censors’ review not once but twice, there were many in the church who didn’t take kindly to anything that made favorable mention of a sun-centered universe, and so they complained to Pope Urban. This was unfortunate, since at the time, the Pope was involved in a very unpopular war (the Thirty Years’ War) and could not afford to become any more unpopular. As a result, he summoned Galileo to Rome to answer a charge of heresy.
Galileo was sick and couldn’t immediately come to Rome, and for a while, Urban waited. Eventually, he tired of waiting and told Galileo to come of his own free will or be drug to Rome in chains. Galileo reluctantly made the trip. Perhaps the only reason he survived the trip was that Grand Duke Ferdinando gave him a litter and servants to attend him during the arduous journey.
When the author recounts Galileo’s various hearings, he does an excellent job. Indeed, he provides extensive transcripts (translated into English, of course) of the hearings, so you can see exactly how the hearings were set up. The real issue in the hearings goes back to his 1616 meeting with Cardinal Bellarmino. According to Vatican records, the Cardinal told Galileo not to hold, defend, or teach the Copernican view, and that this order came from the Pope (who was not Urban at the time). Thus, publishing his Dialogue was in direct contradiction to a Papal order. There was no signed Papal order to that effect, however. There was just a document in the Vatican stating that this is what the Cardinal had told Galileo.
Many of the questions posed to Galileo in the trial were regarding what exactly the Cardinal had told him, and Galileo continued to stress that the Cardinal had never told him not to teach the Copernican system. He just couldn’t hold to it or defend it. Given that his Dialogue ends with the only person who provided evidence for the sun-centered universe saying that it was probably wrong, he clearly didn’t defend it. He also didn’t hold it. In Galileo’s own words:
I have neither maintained nor defended in that book the opinion that the Earth moves and that the Sun is stationary but have rather demonstrated the opposite of the Copernican opinion and shown the arguments of Copernicus are weak and inconclusive. (p. 253)
Now this statement, straight from Galileo’s mouth, might sound rather odd. After all, he is generally characterized as this champion of science who refused to obey the Roman Catholic church. However, that is just not true. My reading of the Galileo incident (from this book and many others) indicates that Galileo thought there was some evidence that Copernicus might have been correct, but he did not believe it himself, and he certainly did not try to make others believe it. He simply presented the best case for Copernicus, in hopes that others would read it, study the issue more, and advance both scientific and Scriptural knowledge until the real details of the heavens could be understood. He was not trying to challenge the Roman Catholic church with his book. Instead, he bent over backwards to make sure the church would not be offended by it. He simply wanted the data communicated.
Now please note that this is different from many of Galileo’s other scientific beliefs. He was adamant about some scientific concepts, and he routinely excoriated those who desperately clung to the ideas of Aristotle despite the evidence. However, his church had not made pronouncements about things like what causes an object to float and whether or not matter has a preferred state of motion. For those kinds of ideas, Galileo took strong stands and was quite rude to those who disagreed with him. On the matter of the heavens, however, his church had taken a stand, and he was loathe to disagree with it. Thus, while he saw some evidence that his church was wrong, he did not disagree with it. He simply thought of the whole thing as a mystery that needed to be resolved by both theologians and scientists.
In the end, however, Galileo was pronounced “vehemently suspected of heresy” and sentenced to formal imprisonment. Dressed a white robe (to signify penance), he knelt and publicly stated that he agreed with the Holy Office that he had published errors and heresies regarding the idea that the earth moved and the sun was stationary, and he swore he would never write such things again. The author quotes his statement in full, which is definitely worth reading. Then the author makes this very important point:
It is often said that as Galileo rose from his knees he muttered under his breath “Eppur si muove” (But it still moves). Or he shouted out these words, looking toward the sky and stamping his foot. Either way, for Galileo to voice such undaunted conviction in this hostile encounter would have been beyond foolhardy, not to mention that the comment suggests a defiant feistiness beyond his means to muster then and there. (pp. 277-278)
Indeed, the whole “But still it moves” story is almost certainly an urban legend that sprung up among Galileo’s defenders, many of whom are discussed in detail in the book.
I think the author’s refutation of the “But still it moves” story is indicative of his entire treatment of Galielo’s encounter with the Roman Catholic church. It attempts to paint a realistic picture of what happened, and it seems to me to do a very good job. The Roman Catholic church was not a hero in this story, but neither was Galileo. As I said at the beginning, the real hero of this story is Suor Maria Celeste Galilei. She stood by her father, supporting him, loving him, and praying for him, as a devoted daughter should. I think I know how thankful Galileo must have been, as I have a daughter like Suor Maria Celeste. Every father should be should be so blessed.