The Ghost of Galileo

by J. L. Heilbron

  MW. I accept Galileo as a symbol of legitimate inquiry suppressed by improper exercise of authority. But, while I acknowledge the depth and importance of Galileo’s contributions to knowledge, I blame him for setting back the cause of science with his insistence that he was right and all who disagreed with him wrong. The arrogance that infuses his writings runs exactly counter to the more tentative and sounder approach Bacon advocated. Galileo’s bullishness made it impossible for Catholic astronomers to debate freely about world systems.

  JB. Sir Maurice, do you really question that the sun stands still in the center, and the planets, including the earth, circle around it?

  MW. Yes, I do question it, although I think Copernicus’ system in Kepler’s version is far better than Ptolemy’s or Tycho’s. Maybe the world is not the sort of thing that has a center, either because it is infinite or because it has many centers equivalent to our sun. The arguments about world systems with which Galileo entertained us miss the great question. His Dialogue is one of the greatest books to come from Italy, but it is as much Ariosto as Copernicus.

  JB. I see that in your deep way, Sir Maurice, you approach the position of suspended belief occupied by such odd bedfellows as skeptics and voluntarists.

  MW. With a big difference: I consider the rational investigation of the natural world to be an obligation of human beings. Skeptics and voluntarists shirk this duty as, I regret, almost everyone else does. And this is very odd. It takes far less intellectual effort to master the intricacies of modern astronomy than to explain away the discrepancies in the Bible.

  JB. Even astrologers, or some of them, do not care to decide whether the earth moves or the sun. I read in the reprint of Christopher Heydon’s defense of astrology that, since only the aspects count, it is not necessary to bother about the real layout of the planets. And I recall reading in Carpenter’s Geography that Sir Henry Saville once indicated his indifference to the question of world systems with the strange analogy that it was all the same to him whether, in sitting down to dinner, he went to his table or his table came to him. Nonetheless, his cook had roasted his dinner by rotating the meat over the fire, not by running with the fire around the meat.

  MW. That is almost as peculiar an analogy as Viscount Conway’s argument that to move the gross earth among the light stars is as reasonable as requiring old fat people at a feast to dance while the young and vigorous sit still.33 He had not given the question his full attention. Most people, even educated ones, do not care whether the earth spins or not; they would take an interest only if it spun fast enough to throw them off. If they penetrated far enough into the Dialogue, they would perhaps be reassured by Galileo’s faulty proof that this could never happen.

  FC. May I suggest, Sir Maurice, that people who manage to change things believe more strongly than they can demonstrate? They are the ones who make a difference, the Raphaels, Michelangelos, Sarpis, Galileos. People who withhold their assent, however correct their arguments, do not get their ideas into other people’s heads. Debilitating skepticism is as much a hazard of learning as debilitating omniscience. Both positions are frozen for fear of error.

  JB. The omniscient Selden did not miss your point, Mr Cleyn. He argues in one of his books, there are so many, I don’t know which, that error honestly admitted can be a mighty source of advance. Galileo might be as great a source of fruitful error as of demonstrated truth. Already the Jesuits are bettering his measurements, and Gassendi and Descartes are trying to improve and extend his physics to apply to a Copernican world.

  MW. By choosing the Dialogue as his text, Sir John separated himself from people who cry wolf at every suggestion of change and think that innovating is a prime qualification for a place in Hell. And yet, although we cannot admire those divines who rejected the Gregorian calendar on the ground that every alteration is for the worse, we cannot overlook that even improvements in the material conditions of our lives may have adverse unintended consequences.

  JB. My father promoted devices and practices that he deemed likely to “improve man’s estate,” as Bacon put it, like the prolific inventions of the Moravian van Berg. He certainly understood the hazards. He championed the drainage of the fens, knowing that it threatened the ruin of the fen-dwellers, and he received some blame for it. We must have innovations and we must guard against them. Galileo is an inspiration and a warning.

  FC. It is the human condition. Galileo can symbolize legitimate questioning necessary for science, as Mr Bankes observed, or, as Pope Urban thought, disobedient meddling subversive of religion; or, as we seem to agree, perpetual struggle between innovation and conservation.

  JB. I remember that the first Copernican book you had me read, Sir Maurice, Wilkins’s New Planet, has at its first proposition something like, “That the seeming Novelty and Singularity of this opinion, can be no sufficient reason to prove it erroneous.”34

  MW. If we are to believe what John Barclay wrote in his Mirrour of European minds, the English have the peculiarity of holding on to any law or custom, no matter how ridiculous, provided it is ancient, and yet in cosmology are willing to follow the strangest modern opinions, for which, of course, he takes the idea of a moving earth as exemplary.35

  FC. Who was Barclay?

  MW. A very popular French–Scottish writer trained by the Jesuits and pensioned by King James. According to his informed cosmopolitan opinion, it is almost impossible to make Englishmen accept anything new; and, in the rare cases that they do, they pick the craziest.

  Multivalence

  FC. What you say reminds me of what King Charles said when he came to see your portrait.

  JB. A royal review? You never told us that.

  FC. Well, I thought that he just came by to see whether I might be competent enough to paint his portrait. He considered many options after Van Dyck died. He was familiar with practical mathematics and emblems and even with my inventions on the borders of tapestries and recognized the Galilean frontispiece.36 Perhaps he was a closet Galilean. If I heard him correctly, he muttered, “Galileo could stand for me.” What do you suppose he meant?

  JB. I would have thought that the king would identify himself with the rightful ruler (the pope) and Galileo with the upstart Parliament. Galileo was guilty of something like sedition for having defended the Copernican theory after it was judged contrary to Scripture, and King Charles, not to mention Star Chamber and my father, punished even trivial acts or statements they deemed challenges to the royal prerogative. Remember the case of the royal fool?

  MW. Yes, and furthermore the late king and the late pope had many things in common through being sovereigns by divine right. That implied conflict, since the pope’s sovereignty extended in principle over all Christian kings. Still, there is a natural camaraderie among absolute rulers appointed by God when they are not at war with one another. It would seem unnatural for the king to see a reference to himself in the frontispiece to a book considered anathema by the pope.

  JB. How then do you explain the royal remark that Mr Cleyn says he heard?

  MW. Urban was then ruling absolutely in Rome and King Charles was fighting for the right to rule in any manner against a parliament led by people he condemned as traitors. They usurped his authority just as, in our Protestant teachings, the popes had usurped and corrupted the true Catholic Church. Parliament had become the pope and he, the king, a Galileo, trying desperately to persuade the usurpers to accept the naked truth he saw so clearly. In his days of power, Charles might well have seen parliament’s challenge to his right to rule as a parallel to Galileo’s challenge to scriptural authority over physics. With his subsequent change in fortune, Charles could see his and Galileo’s struggles as similar: Galileo trying to set the sun in the center, where it in fact belongs, and Charles striving to return to the center, where he thought he belonged.

  JB. Bravo, Sir Maurice! It makes sense. During the heyday of personal rule, when the king enjoyed good relations with his court, managed religious dissent at home, and
remained at peace abroad, he could identify with his fellow connoisseur and brother in divine right, the pope. When, however, his ill-advised war against the Scots forced him to face the reality that God unaccountably had given him the right to rule as he wished without the income to do so, he had a choice between conceding to the Scots or surrendering to parliament. He mismanaged things so badly as to be obliged to do both. When he muttered to Mr Cleyn about Galileo, he regarded himself as an embattled witness to the truth and perhaps foresaw his martyrdom.

  FC. Yes, that must be the point, I remember that he said something like, “man cannot be blamable to God or man who seriously endeavors to see the best reason of things and faithfully follows what he takes for reason.”37

  MW. Or, as Mr Quarles put it, the king’s opponents endeavored “To banish wisdom, that at last they may ǀ Make all the world, as ignorant as they.”38 That fits the Galileo case rather well. There is something else the king might have seen in the reference to Galileo: an unintended accusation against himself for his part in a process resembling the Inquisition’s proceeding against Galileo. I have in mind the mock trial of Lord Strafford, which ended in judicial murder. By signing the extra-legal bill of attainder, the king allowed the execution of a faithful servant. Similarly, Urban, by agreeing to or overlooking irregular procedures of the Inquisition, sentenced his old friend Galileo to perpetual house arrest. I suspect that history will judge the king and the pope harshly for these acts.

  JB. I think we must add another reason. Probably the main cause for the destruction of the Stuart monarchy was religious strife, particularly between Puritans and Catholics. As we all know, the king would not enforce the laws against recusants against the wishes of his queen and his Catholic peers and advisers, and perhaps also because he did not want to; he disliked the Puritans, as he made clear by allowing the barbaric mutilation of those pious crackpots, Bastwick, Burton, and Prynne. There is good reason to think that, if left to himself, he would have countenanced Catholics who acknowledged his supremacy in everything but spiritual matters. In two words, he had nothing against Catholics who opposed the temporal claims of the popes and were willing to say so by subscribing to the Oath of Allegiance.

  MW. And, of course, the very best examples of anti-Roman Catholics were the group around Paolo Sarpi. It makes sense to see Galileo as a distinguished representative of good Catholics, tolerable Catholics, able to make contributions to culture of the first order and acceptable within a Protestant state as fellow Christians once they foreswore allegiance to the pope. Would that have been your father’s view, John?

  JB. Indeed. He saw that accommodation along these lines would be possible if only the pope would allow English Catholics to take the Oath of Allegiance or if parliament would decide not to require it. But Urban again drew a hard line and remained as inflexible as Paul V had been. So, although my father thought that Catholicism is a valid Christian religion, as, I think, King Charles and Archbishop Laud did, he regarded Roman Catholicism as a dangerous foreign power.

  MW. Which returns us to our main question. Galileo’s Dialogue was condemned because the Roman Inquisition, following the advice of Roman theologians and philosophers, decided that it conflicted with passages in the Bible interpreted in their literal sense. Galileo had argued that the Bible has no authority over the matters of interest to him, which, he claimed, were to be decided solely by sensory experience and reasoned inference. Here you have a formal contradiction of authorities over questions that had not only not been resolved by the inspired writers of Scripture but had not even occurred to them; whereas anyone could look into them, and perhaps answer them, by the methods advocated by Galileo. These were the methods I put young John here to study in the book by Wilkins…

  FC. I know it, that book with the bumbling buffoonery of a title page …

  MW …at just the time that the brilliant Dr Harvey, the intrepid author of the unsettling theory of the circulation of the blood, was investigating the development of chick eggs. All sorts of other freethinking took place in wartime Oxford, some of which perhaps offended clear reason and good taste, but free and unmolested by irrelevant objections from slavish divines. Galileo is the pre-eminent example of the loss humankind would suffer from the suppression of unauthorized opinions. And I am sure that Oxford freethinkers, or anyway those whose freedom had not made them ignorant, would have recognized this symbolic meaning of the Dialogue in our picture.

  FC. I do not doubt that Galileo can stand as a symbol for any of these things, or for all of them, and also for himself, as a man most worthy of praise. But, with all respect, I must say that you may be missing the big picture by focusing on Galileo’s troubles. If we look on Galileo as the heir to the genius of Michelangelo, the Dialogue is a sublime product of the bravura, self-confidence, and profound culture of Renaissance Italy. Galileo knew art and poetry and could invent more cleverly than the devil. Already Sidereus nuncius showed him to be a new Columbus if not a new Michelangelo, and even better than Columbus, in the proportion that heaven excels earth, and peaceful exploration armed conquest.39 Sir Henry Wotton regarded Sidereus nuncius as the single most notable invention ever made anywhere, and, for its bravura, pure Florentine. Or so I remember his telling me.40 And the Dialogue is even richer in invention and arditezza. The book could stand for all good literature in all respectable subjects.

  MW. Galileo not only gave the measure of human capacity by his example, but also, by his method, showed how greater heights might be attained. For this he makes a better emblem than my Lord Bacon, who preached the possibility of progress but did not recognize that Galileo was in its van.

  Abstractions

  MW. The problem for Bacon was that Galileo dealt in mathematical abstractions from physical phenomena. For Bacon, a successful physics had to be fuzzy: the mathematician’s compulsion to order everything by number fatally collides with all the “Idols” as Bacon called the obstacles that block our way to reliable knowledge.41

  JB. If I remember correctly, the obstacles derive from general human traits, like lusting after simplicity (Idol of the Tribe); from individual idiosyncracies, like requiring exactness in all things (Idol of the Cave); for love of grand theories (Idol of the Theater); and for want of apt words (Idol of the Market Place). Did I get that right, Sir Maurice?

  MW. Yes, indeed. And, to break the hold of those Idols, he recommended fitting philosophers with lead boots, to prevent speculative flights. Galileo plumped for the opposite extreme: true philosophers are like eagles, and every effort should be made to abet their flight. There were not many. Galileo could think of only one eagle beside himself: Kepler. Most other philosophers flock together like starlings and foul the ground beneath them.

  JB. And yet Galileo insisted when criticizing Aristotelian physics that the only reliable natural knowledge comes from “sensory experience and necessary deduction,” not from mathematical abstractions. How, good doctor, are we to heal the fracture between these views?

  MW. You must begin with the assumption that nature is inherently mathematical, or, as Galileo put it, that the book of nature is written in geometrical language. I suppose he meant that the goal of physics is a mathematical description of observed phenomena, as in planetary astronomy. This was a very bold program, indeed, his boldest. There was (and still is!) no convincing reason to think that a mathematical physics is possible or even desirable, no matter what Descartes says.

  FC. Why should a mathematical physics have been a bold idea if a mathematical astronomy had existed since the Greeks, and maybe earlier?

  MW. A good question, Mr Cleyn! It is because the astronomer is at liberty to invent geometrical constructions, like circles moving perpetually on circles, or around empty points, that have no real existence: all that is required is that the fictitious geometrical motions describe the choreography of the planets closely enough that you know where to look for them. It is clear that such a mathematical astronomy is possible, since we have one, or rather several, Tycho’s a
nd Copernicus’ being the best. Experience shows their utility. We use our knowledge of the motions of the stars for navigation and, if you believe in astrology by aspect alone, to forecast using a false system, as Sir Christopher Heydon allowed, and as Mr Lilly does, sometimes successfully.

  FC. So why can we not be confident that a mathematical physics is possible and practical?

  MW. For two reasons. Experience does not suggest that motions that occur beneath the moon are regular enough to be describable mathematically: you need only to consider the weather to be persuaded of the impossibility of any such description. It does not seem likely that we will ever prognosticate it reliably. Do you think that mathematicians will be able to predict the occurrence of volcanic eruptions, earthquakes, thunder and lightning, as they now do eclipses?

  JB. I remember reading in Aristotle’s Physics that its subject is not events that take place by strict rule, but those that happen “for the most part.” That implies that a mathematical physics is impossible. And Aristotle may well be right: Galileo’s arguments to the contrary cover a very limited domain and in fact do not agree perfectly with his own experiments.

  MW. The second reason to doubt the possibility is that we are not free to invent every fiction we find convenient to account for the behavior of objects around us. We have ideas about matter, cause, time, space, and so on that mathematical fictions should not violate. One of the most important consequences of the sun-centered system is to force people who believe in it to develop a physics that allows the earth—“the heavy sluggish earth,” as anti-Copernicans put it—to move around the sun. A theory adequate to the job would join the earth and the heavens, and physics and astronomy, in new ways. The only such theory that existed before our time is astrology.