Galilei Galileo - The Earth moves : Galileo and the Roman Inquisition

T here are many books about Galileo, so the reader is entitled to ask how this one differs from any others that he or she might come across. It is, as the title suggests, an attempt to recount how the great physicist and astronomer Galileo Galilei was tried and convicted by the Roman Inquisition in 1633 for championing the Copernican hypothesis about the solar system, against which the Vatican had issued an edict. I have tried to tell this story succinctly for the general reader, and without inserting any but a few paragraphs of the simplest mathematics into the text.

In addition, I have chosen a very specific path through a thicket of information. Galileo had several reasons for embracing Copernicanism. Deductions in both mechanics and mathematical astronomy contributed to his growing conviction that the earth revolved around the sun, and I have touched upon these; I have devoted much more attention, however, to his sudden and vast improvement of the telescope in the autumn of 1609, which enabled him to actually see the surface of the moon, the phases of Venus, and the moons of Jupiter, and so to behold celestial mechanics at work. In time these telescopic sightings would put him at greater variance with the edicts of the Roman Catholic Church than his far greater discoveries in physics ever did. This was the first great clash of religion and science, and it still has much to teach us.

What Galileo did with the telescope is in itself an exciting story. But I have a special reason for retelling it. I am primarily interested in the arts, and Galileo loved music, literature, and painting. A musicians son, he played the lute well, wrote poetry and literary criticism, taught perspective, and drew with some verve; he corresponded at length with at least one major painter. He favored the classics, yet he belonged to a world no longer classical but Baroque in orientation. A system of thought may be described as Baroque when its parts cannot be understood or enjoyed unless they are constantly related to some larger, dynamic whole, and in that sense Galileo was a prime representative of the Baroque era, which began around 1600. Geometry, trigonometry, and perspective were then still the common property of mathematicians, painters, and architects, and the budding science of optics interested them all: indeed we find painters among the most enthusiastic supporters of Galileos discoveries with the telescope. Understandably, Galileos position within the general context of Baroque civilization has not much concerned historians of science, and I have tried to offer a brief picture of it here.

Most writing about Galileo and the Inquisition has to do with philosophy, and that is as it should be. But there are already a number of excellent books on this subject, and I found myself more drawn to the psychological complexities of the 1633 trial. I have always found it hard to control my bewilderment over the fact that Galileos persecutor, Pope Urban VIII, is known in art history as Berninis and Borrominis great patron, indeed as the most devoted supporter that the Baroque style ever found in Italy; during the 1620s he also befriended and encouraged Galileo. In this book I have tried to accord him more sympathy than he usually receives.

The man who really caught my attention, however, was the all-but-forgotten Tuscan ambassador to the Vatican, Francesco Niccolini, who is the virtual hero of many of the pages that follow. Since Galileo was mathematician to the court of the Grand Duke of Tuscany, both the duke and his emissary Niccolini wished to avert a trial by the Inquisition, or, failing that, to curtail an eventual trial by means of an extra-judicial solutionwhat we would call a plea-bargain. Unhappily Galileo, as one of Europes first professional intellectuals, did not fit into this scheme. Unlike earlier Italians who had taught largely by personal exampleunlike, say, Saint Francis, who kissed the leper, or Giordano Bruno, who chose to die rather than think as he was told toGalileo had faith in the transcendent value of a good argument, and he wanted to argue with the Vatican. He even wanted to argue with the Inquisition. Ambassador Niccolini, with his insight into the papal court, foresaw the danger of such a project and tried to induce Galileo to abandon it. Reading Niccolinis correspondence, I found myself touched by the abrasion between two friends representing such different ethical approaches to life.

Galileo has often been described as an inordinately suspicious man. There is some truth to this, but his friends letters suggest that he was also subjected to a great deal of envy and hostility. The literary background to the concept of envy, or invidia , was raised some years ago by Miles Chappell in relation to two graphic works by Ludovico Cigoli, one of them dedicated to his friend Galileo. I have returned to this idea, stressing its background in Dantes Divine Comedy .