I have become somewhat infamous for writing #histSTM blog posts that are a predominately negative take on the scientific achievements of Galileo Galilei. In fact I think I probably made my breakthrough as a #histsci blogger with my notorious Extracting the Stopper post, deflating Galileo’s popular reputation. I actually got commissioned to write a toned down version of that post for AEON several years later. In my opinion Galileo was an important figure in the evolution of science during the early seventeenth century but his reputation has been blown up out of all proportion, well beyond his actual contributions. To make a simple comparison, in the same period of time the contributions of Johannes Kepler were immensely greater and more significant than those made by Galileo but whereas Galileo is regarded as one of the giants of modern science and is probably one of the three most well known historical practitioners of the mathematical sciences, alongside Newton and Einstein, Kepler is at best an also ran, whose popular image is not even a fraction of that of Galileo’s. This of course raises the question, why? What does/did Galileo have that Kepler didn’t? I think the answer lies in Galileo’s undeniable talents as a writer.
Galileo was a master stylist, a brilliant polemicist and science communicator, whose major works are still a stimulating pleasure to read. If you ask people about Galileo they will more often than not quote one of his well-known turns of phrase rather than his scientific achievements. The two books trope with its ‘mathematics is the language of nature’, which in the original actually reads: Philosophy is written in this grand book, which stands continually open before our eyes (I say the ‘Universe’), but can not be understood without first learning to comprehend the language and know the characters as it is written. It is written in mathematical language, and its characters are triangles, circles and other geometric figures, without which it is impossible to humanly understand a word; without these one is wandering in a dark labyrinth. Or the much-loved, the Bible shows the way to go to heaven, not the way the heavens go, which again in the original reads: The intention of the Holy Ghost is to teach us how one goes to heaven, not how heaven goes. It is a trivial truth that Galileo had a way with words.
This cannot be said of Johannes Kepler. I shall probably bring the wrath of a horde of Kepler scholars on my head for saying this but even in translation, Johannes Kepler is anything but an easy read. Galileo even commented on this. When confronted with Kepler’s Dioptrice (1611), one of the most important books on optics ever written, Galileo complained that it was turgid and unreadable. Having ploughed my way through it in German translation, I sympathise with Galileo’s negative judgement. However, in his rejection Galileo failed to realise just how scientifically important the Dioptrice actually was. Nobody in their right mind would describe Kepler as a master stylist or a brilliant polemicist.
I think this contrast in literary abilities goes a long way to explaining the very different popular conceptions of the two men. People read Galileo’s major works or selections from them and are stimulated and impressed by his literary mastery, whereas Kepler’s major works are not even presented, as something to be read by anyone, who is not a historian of science. One just gets his three laws of planetary motion served up in modern guise, as a horribly mathematical side product of heliocentricity.
Of course, a serious factor in their respective notorieties is Galileo’s infamous trial by the Roman Inquisition. This was used to style him as a martyr for science, a process that only really began at the end of the eighteenth and beginning of the nineteenth centuries. Kepler’s life, which in many ways was far more spectacular and far more tragic than Galileo’s doesn’t have such a singular defining moment in it.
Returning to the literary theme I think that what has happened is that non-scientists and non-historians of science have read Galileo and impressed by his literary abilities, his skill at turning a phrase, his adroit, and oft deceitful, presentation of pro and contra arguments often fail to notice that they are being sold a pup. As I tried to make clear in the last episode of my continuing ‘the emergence of modern astronomy’ series although Galileo’s Dialogo has an awesome reputation in Early Modern history, its scientific value is, to put it mildly, negligible. To say this appears to most people as some form of sacrilege, “but the Dialogo is an important defence of science against the forces of religious ignorance” or some such they would splutter. But in reality it isn’t, as I hope I made clear the work contributed nothing new to the on going debate and all that Galileo succeeded in doing was getting up the Pope’s nose.
The same can be said of Il Saggiatore, another highly praised work of literature. As I commented in another post the, oft quoted line on mathematics, which had led to Galileo being praised as the man, who, apparently single handed, mathematized the physical science was actually, when he wrote it, old hat and others had been writing the book of nature in the language of mathematics for at least one hundred years before Galileo put pen to paper but none of them had taken the time to express what they were doing poetically. In fact it took historians of science a long time to correct this mistaken perception, as they also tended to suffer from a serious dose of Galileo adoration. The core of Il Saggiatore is as I have explained elsewhere is total rubbish, as Galileo is arguing against the scientific knowledge of his time with very spurious assertions merely so that he doesn’t have to acknowledge that Grassi is right and he is wrong. An admission that very few Galileo scholars are prepared to make in public, it might tarnish his reputation.
Interestingly one work that deserves its historical reputation Galileo’s Sidereus Nuncius, also suffers from serious scientific deficits that tend to get overlooked. Written and published in haste to avoid getting beaten to the punch by a potential, unknown rival the book actually reads more like an extended press release that a work of science. It might well be that Galileo intended to write a more scientific evaluation of his telescopic observations and discoveries once he had established his priority but somehow, having become something of a scientific superstar overnight, he never quite got round to it. This is once again a failing that most readers tend to overlook, over awed by the very impressive literary presentation.
Much of Galileo’s written work is actually more appearance than substance, or as the Germans say Mehr Schein als Sein, but ironically, there is one major work of Galileo’s that is both literarily brilliant and scientifically solid but which tends to get mostly overlooked, his Discorsi. The experiments on which part of it is based get described by the book itself remains for most people largely unknown. I shall be taking a closer look at it in a later post.