'But still it moves'

One of the most overworked clichés in book publishing today is the quote, usually from some minor celebrity, "I couldn't put it down..." However, I have to admit that I recently had just that experience with Galileo's Daughter by Dava Sobel (Penguin Books, New York, NY. 2000). This enthralling biography of the great astronomer and mathematician Galileo Galilei is written with tremendous sympathy for him and his struggles with the hierarchy of the Catholic Church and the interrogators of the Roman Inquisition.

The book is subtitled "A Historical Memoir of Science, Faith, and Love," an unusual title for a scientific biography. Sobel weaves the historical narrative around excerpts from more than 100 letters written to Galileo by his eldest daughter, Virginia, who became a cloistered nun in her mid-teens. Virginia had been born out of wedlock to Marina Gamba when Galileo was teaching in Padua in the year 1600. Taking the name Suor Marie Celeste, his daughter wrote to him frequently and he, in turn, corresponded with her, although none of Galileo's letters to his daughter remain. It's thought that the abbess of the convent burned Galileo's letters on Suor Marie Celeste's death in 1634 for fear of their discovery by the ecclesiastical authorities following Galileo's condemnation for heresy.

The letters, beautifully translated from the Italian by Sobel, give not only an insight into the strong religious faith of both Galileo and his daughter but also a view into the everyday lives of these two very different people. Suor Marie Celeste never retreats from her love and support for her father even when he is called in front of the Inquisition for supporting the views of Nicolaus Copernicus in saying the Earth and the planets revolve around the Sun. When Galileo was found guilty of heresy by the Inquisition, he is reputed to have said, "But still it moves," a very unlikely utterance directly in the face of his accusers. As Sobel makes clear, Galileo accepted the verdict and punishment of the Inquisition, but he continued to hold the view that the Earth moves around the Sun.

The book that caused the Inquisition to summon Galileo to Rome from his home in Florence was entitled Dialogue on the Two Chief World Systems: Ptolemaic and Copernican, a work that took six years to complete and almost as long to publish. As Sobel describes, Galileo's book took the form of an animated encounter spread over four days, comparable to a play in four acts, with three principal characters who argue their respective theories. One character, called Salviati, spoke Galileo's own mind; a second, Sagredo, a perceptive man of means who generally took Galileo's side; and Simplicio, a pompous Aristotelian philosopher who argued for the geocentric view.

Well aware of the startling nature of his work, Galileo traveled from Florence to Rome to obtain permission to publish his book, a journey that was fraught with danger because of the plague that was widespread in Europe at that time. However, Galileo did obtain a provisional license to publish the work in exchange for the promise of a few corrections. In fact, partly due to the spread of the plague, Galileo then sought publication in Florence rather than Rome. The book was a huge success but when copies of the published work finally reached Rome, several leading Jesuit astronomers took violent exception to its opinions and the furor resulted in Galileo's summons and trial by the Roman Inquisition.

In 1633, the book was listed on the infamous Index of Prohibited Books where it was to remain until 1835. Amazingly, it was not until 1982 that Pope John Paul II issued a call for theologians to reexamine Galileo's case. The Pope finally publicly endorsed Galileo's philosophy in 1992!

The history of science is replete with stories of scientists who struggled to get their work published and accepted by both fellow researchers and the wider public. But no one faced greater obstacles of religious intransigence than Galileo. We can only speculate on the degree to which the constant love and support of his daughter played a vital role in Galileo's work. This book makes the reader realize how much we owe to others close to us.