Despite the title, this is very much a book about the life and times of the great Renaissance thinker
By sending her to the convent, Galileo was in no way punishing the young girl. Born out of wedlock and before Galileo's fame had brought him limited financial security, this was one way that the young girls could have a more secure future. Though to modern eyes, their life remained one of poverty and difficulties, brought about by the convent's reliance on the generosity of others.
However the meat of the biography is Galileo himself. His trials and tribulations are illuminated by the collection of letters that were sent to him by Suor Maria Celeste. Her letters are filled with the support of a young woman for her aged father, discussing his financial (and spiritural) needs and returning mended clothes and foodstuffs that she had prepared for him. Galileo's own letters haven't survived, perhaps having been destroyed after his death by someone fearful that a keeping the letters of a victim of the inquisition might bring ill fortune upon themselves. But from Celeste's responses we can see that Galileo himself responded in kind. Sending money to alleviate temporary hardships in the convent, discussing his work and theories and ultimately the problems he faced with the church hierarchy.
Dava Sobel is excellent however and drawing out the dynamics of Galileo's arguments with senior figures in the Church. Few who select this book would not know that Galileo had faced criticism for defending the work of Copernicus, whose books, arguing that the Earth was not the centre of the universe and instead circled the Sun, had been banned by the Catholic Church. In an earlier brush with the Church's inquisition in 1616, Galileo had been instructed that he could not believe Copernicus' ideas, only hold them as a theory. At his later trial Galileo had emphasised this, saying "I do not hold this opinion of Copernicus, and I have not held it after being ordered by injunction to abandon it".
Some have argued that Galileo was an early example of someone who fought against the irrationality of Catholic Doctrine, fighting it with science and reason. The truth, as Sobel explains, is much more complex. Galileo was a convinced Christian, but he understood that the problem was with those who argued the literal interpretation of the Bible as opposed to those who thought that God's word was more complex.
Sobel points out, that Galileo had once heard the Vatican librarian Cesare Cardinal Baronio say that "the Bible was a book about how one goes to Heaven - not how Heaven goes." The problem for the Church, and indeed Galileo was that the Bible itself was mostly silent on the issues of the day. Galileo had seen the four major satellites of Jupiter with his telescope, but the Bible never mentioned them, as he wrote:
"Surely if the intention of the sacred scribes had been to teach the people astronomy, they would not have passed over the subject so completely."
Indeed, one of the problems for Galileo was that his Church, in dismissing the arguments of Copernicus and those beginning to follow him, was in danger of embarrassing itself in the face of wider revelations. As Sobel notes, Galileo sought more evidence to support Copernicus, not to damage the Church, but to correct it - "For if the Holy Fathers banned Copernicus as rumour predicted they might do at any moment, then the Church would endure ridicule when a new generation of telescopes, probably manned by infidels, eventually uncovered the conclusive evidence of the Sun-centred system."
As Galileo publishes the greatest of his books on the nature of the universe he works hard to ensure it is acceptable to the Church. It is checked by a number of senior figures and he tries hard to avoid further damage. The book is in the form of a dialogue, so Galileo avoids having himself argue the Copernican position, though he cleverly frames the debate in a way that encourages the reader to a particular conclusion. When the storm of criticism hits, Sobel makes it clear that Galileo himself was stunned by the allegations against him, and clearly thought that it was an enormous misunderstanding that would be clarified when he was able to explain himself. After all, Galileo was a new type of philosopher. His writings were based on observational evidence and experimental data. They were linked to God's reality, even if they ran counter to doctrine.
Sadly for Galileo and his daughter, despite the former close friendship of Pope Urban, the Church needed to be seen to defend doctrine firmly and Galileo was a sad victim of the reassertion of the Aristotelian view of the universe. Galileo died an old man, blinded and housebound, forbidden to discuss matters pertaining to his book (though he clearly flouted these rules and continued his scientific work). His daughter deceased him by several years, a victim of disease in a period when Medicine had barely escaped its links with mystical understandings of human health. To the end she remained a loyal daughter and despite her religious position her support for her father never wavered Her end was eased when Galileo was finally allowed to return to his home near her, and their mutual company was clearly a great help to both of them.
Sobel's book then is more than a biography, as it demonstrates the way that as the scientific revolution was beginning, new ideas, even those dealing with outer space, challenged the political status quo. By refusing to accept Copernicus and banning Galileo's book, the Church wasn't simply dismissing theories that ran contrary to the Bible, it was also reasserting the ideology that gave it so much power and wealth. For Pope Urban, this was far more important than old ties of friendship, or experimental evidence.
Johnson - The Ten Most Beautiful Experiments