The Earth Moves: Galileo and the Roman Inquisition Book

Subtitle: Galileo and the Roman Inquisition

This is another title in the (excellent) Great Discoveries series. Like past volumes I've read, on figures like Darwin and Copernicus, this one is about a figure so iconic in the history of human thought that he is almost obscured, as a mortal man, by the legend that has grown around him. Thinking about Galileo as a human being is almost like thinking about George Washington as an American citizen; not impossible, but harder than for most of us. Hofstadter's job is to try to wipe the gauzy (dusty?) web away and show us what Galileo Galilei, Italian and Renaissance man and student of optics and telescope maker (and seller), was really like.

In fact, Hofstadter does this, but what is more impressive is what he is able to do with (for?) the villain of this tale, Pope Urban VIII, the former friend and patron of Galileo who ultimately is responsible for the trial for heresy which made Galileo a hero of science. There is not any plausible rendering of the tale which will rescue Urban from the villain's role, but Hofstadter allows us to see at least what Urban thought he was doing, and thought he was protecting. It was not simply (according to Hofstadter) the primacy of the Bible, or the papacy, but a vision he had of a European civilization brought out of the Dark Ages into the light of Renaissance art, Catholic morality, and papal-enforced peace. To us, it looks like an Orwellian vision of conformity, but in Urban's mind it was a world with more grace and beauty than the centuries before had given, and not primarily meant to glorify himself, but God and man.

Unfortunately for Urban, and especially for Galileo, it was a doomed vision. Hofstadter does a good job of explaining how the same advances in understanding of optics which had enabled Renaissance artwork, were also central to the advancing craft and science of making telescopes. Galileo (and others, it should be noted) made increasingly effective telescopes, and they made it impossible for all Europeans to maintain a number of pious mythical beliefs:

1) that the Moon, associated with Mother Mary, was not perfect. This is hard for modern minds to imagine as a plausible theory in any level of technology, but before the telescope many learned men said that the apparent blemishes on it were but reflections of Earth (and its many seas and forests), and the Moon itself was mirror-perfect. Galileo's telescope made it clear that the moon (small m) had mountains, valleys, craters, and all the imperfections of age
2) that the stars do not all move across the celestial sphere in unison; in other words, there is stellar parallax. This shows that the stars (even exempting the planets) are not all in a single sphere.
3) that there were moons orbiting Jupiter. In theory there is nothing about moons orbiting Jupiter that is incompatible with Jupiter orbiting the Earth, but once you have admitted into your imagination that things can orbit something other than the Earth, it's not far before the evidence will point to the sun rather than the earth as the most likely thing for the planets to orbit around.

Galileo's trial was a strange affair, to modern eyes, and most closely resembles what we would call a kangaroo court. The truth or falsity of Galileo's ideas or the evidence he had seen through the telescope was not only not examined, it was not considered relevant. The only issue at question was, not even whether or not he had endorsed Copernicanism, but whether or not he did so knowing that it was forbidden by the Church. In other words, the trial resolved around this issue: was Galileo trying to think for himself, contrary to the edicts of the Church on this particular issue?

This is a tough thing for a modern author to portray in any shades other than black and white. Hofstadter, while clearly in sympathy with Galileo rather than Urban, does his best to show Urban and the court around him as something other than leering villains. In fact, they were something far more tragic (and far more likely to be cruel and destructive): they were humans confronting a universe that does not work the way their mental model of it says it should. Eventually, the Earth-centered view of the universe would fall before the onslaught of telescopic (and other) evidence, but in Galileo's time it was (just) possible to cling to it. Even Pope Urban VIII, however, knew at some level that the geocentric theory's position was tenuous, and the Reformation in northern Europe (where individuals such as Johannes Kepler were using telescopes to convince local nobility of the Copernican model) added to the papal insecurity. This was the time of the counter-Reformation, and Rome was in no mood to tolerate dissent, even compared to previous centuries.

In the end, though, it was the papacy that was broken by Galileo's trial, not the heliocentric model. The Copernican Revolution, in fact, came to be seen not just as the idea that the earch revolves around the sun, but more generally as the idea that It's Not All About Us. Darwin's idea that we humans were created by the same process that created all other life, Hubble's idea that our Sun's own galaxy was not the only galaxy (and not a particularly important or impressive one), all fall in a chain of scientific discoveries that have gradually caused us to see the universe as being vaster, and less concerned with humans, than the model which the Vatican at the time was attached to. In essence, it was Galileo's trial more than anything else that gave learned Europeans the impression that the Catholic Church was opposed to science, when throughout the Middle Ages it was the Church that had seemed to preserve learning while kings and armies disregarded it. Galileo was forced to recant, and lived out the rest of his life under house arrest. But the Catholic Church lost the hearts and minds of Europe's greatest thinkers from that day until today; it was not until Pope John Paul II's papacy that the Catholic Church officially expressed regret. Galileo, who spoke the truth as he saw and was condemned by the Powers That Be, became part of the lore of science history.

But, before he was a myth or a hero, he was this guy, who noticed these things when he looked in his telescope. That Galileo is one that we don't hear (read) as much about. Hofstadter brings him back for us to look at. Check it out.