Lew Rockwell:
The popular science writer John Gribbin has written a book entitled The Scientists: A History of Science Told Through the Lives of Its Greatest Inventors. In it, Gribbin (p. 95) describes the seventeenth-century dispute over the nature of comets, between Galileo and several prominent Jesuit astronomers, as follows:
"Three comets were seen in 1618, and when a group of Jesuits… published a rather fanciful account of their significance, Galileo replied in withering terms, sarcastically suggesting that they seemed to think that 'philosophy is a book of fiction by some author, like the Iliad…" (When Galileo says "philosophy," he means what we would call science, which was referred to as natural philosophy in his day.)
Gribbin continues: "He had a point, and [respect for observed facts] is indeed a distinguishing feature of real science. Unfortunately, on this occasion, Galileo's explanation of comets was also wrong, and there is no point relating the details of the argument here…"
Gribbin is certainly correct in asserting that science must pay careful attention to human observations of reality. But he leaves the reader with the impression that, in the dispute in question, the Jesuits had merely concocted a "fanciful account" of the nature of comets, while Galileo, although not arriving at what we today would regard as the correct theory – after all, even the greatest scientists sometimes make mistakes – had at least followed the spirit of scientific procedure in developing his ideas. But just what were the respective theories of the two sides, and why is there "no point" in examining them?
Pietro Redondi, unlike Gribbin, does not think it pointless to examine these theories in Galileo: Heretic. He finds that the Jesuit astronomers' report on the comets, issued in 1619, won the approval of the prestigious Collegio Romano "because it documents the scientific quality of observational astronomy cultivated by the order." Their report, relying on the recent advances in astronomy made by Tyco Brahe, is summarized by Redondi as follows: "The exiguous size of the parallax [i.e., comets did not change their position against background stars very much, even when observed from widely separated places in Europe, indicating that they were fairly distant from the earth], the constant motion of a planetary type, the lack of telescopic enlargement, led [the Jesuits] to place the comet in a position between the moon and the sun: a celestial body in motion along a great circle, brilliant with reflected solar light, unlike what Aristotle had maintained. Once again, Jesuit astronomy gives the Collegio Romano an example of its open-minded freedom of research, as when it had officially recognized the discoveries of the Starry Messenger [Galileo's book in which he had described the findings he made by employing a telescope to explore the heavens]" (p. 41). The seventeenth-century Jesuit astronomers, based on their careful observations, had arrived at a theory of comets somewhat like the one that astronomers hold today. I have no doubt that modern scientists would find their theory unsatisfactory in some respects – but are there any astronomical theories that were current during the seventeenth century that would be completely acceptable today?
And what of Galileo? Redondi (p. 41) notes that the only comet Galileo had seen was when he was thirteen. (He was plagued by arthritis attacks during the appearances of the three comets in 1618, and so was unable to venture out to observe them.) However, he was aware that "a celestial body endowed with noncircular motion… was a threat to the Copernican system. So, without observations and without calculations, Galileo… took a position in the debate…" (Redondi, p. 31).
Just what was that position? Well, in order to avoid any potential embarrassment to Copernicanism, Galileo decided "to deny the physical reality of comets. They were not celestial bodies, but luminous appearances like rainbows or the sun's reflection on the sea at sunset" (Redondi, p. 32, emphasis mine). Comets, Galileo contended, were merely a visual phenomenon that did not correspond to any actual entities.
The Jesuits were stunned by Galileo's theory. They responded that "it is sufficient to have seen a comet 'only once,' with the naked eye or a telescope, to understand that it is not a matter of the play of light." Father Orazio Grassi, "an expert in the field of optics" (which Galileo was not), and other Jesuit astronomers, offered "a whole range of [scientific] refutations of Galileo's interpretive model" (Redondi, p. 43).
So, once we actually examine the arguments put forth by the Jesuits and by Galileo, which Gribbin claimed there was no point in discussing, it turns out that it was the Jesuit astronomers, and not Galileo, who based their conclusions on careful observation. Galileo, without having engaged in any scientific observation of comets whatsoever, was willing to dismiss them from physical reality because they were inconvenient for another theory he held.[/i] It was the Jesuit astronomers, and not Galileo, who had the more accurate theory of comets. And it was Galileo who was spinning a mere fancy, based on his faith in Copernicanism, while his Jesuit opponents explicitly contradicted the Catholic Church's favorite natural philosopher, Aristotle, based on their scientific studies.[/i]
So what was Gribbin thinking when he penned the lines I quoted above? I can only imagine two possibilities: either he was so sloppy in his research that he never bothered to look into what the competing theories of comets were, or he was so committed to the myth of Galileo that he was willing to deliberately deceive his readers in order to promote it. Since he acknowledges that Galileo's theory of comets was incorrect, the evidence, unfortunately, seems to suggest the latter conclusion. No wonder that Gribbin decided that "there is no point relating the details of the argument here," since doing so would have plainly contradicted the conclusion towards which he was steering his readers! In the interest of defending scientific objectivity, Gribbin ignored the objective facts about the historical events in question, instead choosing to promote an ideologically inspired myth.
If Gribbin's misrepresentation were unique, it would not be worth commenting upon. However, I believe that it typifies the historical distortions that are often used in order to elevate science and denigrate religious belief. The fact that such tactics are sometimes employed in the name of science does not, of course, condemn science itself, which, ideally, stands apart from any ideology. Nor does the fact that Galileo occasionally used similar methods of argumentation demote him from the ranks of great scientists. And, as a last caveat, I herein declare that I do not believe that because Jesuit astronomers had a better theory of comets than Galileo, the Church was justified in prosecuting him.
But historical misrepresentations, such as Gribbin's, do expose the ideological nature of the program forwarded by those who desire science to have absolute hegemony over all of the other modes of experience through which humans attempt to understand their world.
