The Ghost of Galileo

by J. L. Heilbron

  JB. Does that mean that there is less fiction in physics than in astronomy? And, consequently, that, in trying to mathematize physics, Galileo labored under greater constraints than Ptolemy?

  MW. Exactly. Galileo tried to escape the problem by avoiding forces and causes whenever he could. He wanted to reduce the amount of physics required by letting geometry do most of the work. That is the modern spirit, according to Galileo’s great admirer Hobbes, who says somewhere that “most of what distinguishes today’s world from primitive times is owing to geometry.” On this reckoning, Galileo’s theory of the tides is postmodern. He has the oceans respond to the two Copernican motions of the earth, the daily spin and the annual circuit, without any physical connection between the earth and the moon. I doubt that that is the way to success. What does Virgil say? Felix qui potuit rerum cognoscere causas, which might be rendered for present purposes “whoever would succeed in physics should ascertain the causes of things.”42

  JB. Galileo’s famous account of the ballistic trajectory, the path described by a cannon ball, suffers from, or profits by, the same trick. He again obtains his answer by combining motions—the constant straight-line velocity of the ball along its original direction of flight and its accelerated fall to the ground—without discussing causes. That allows him to omit the cause that makes the real path very different from the perfect parabola he calculated. This is the resistance of the air to objects moving rapidly through it.

  FC. To get persuasive results, Galileo had to abstract the object of study, say the flight of a cannon ball, from the confusing details that obscure it. Just so the portrait painter must ignore the humdrum and ordinary circumstances of his sitters to bring out their characters.

  JB. The artist and the mathematician have to solve a similar problem. They both deal in caricature, and a good caricature can reveal much more than an image full of detail that is hard to grasp.

  FC. Perhaps Van Dyck’s projections of King Charles as a mighty man among his people and as a wise governor and faithful husband parallel Galileo’s cannon balls that fly without hindrance. Both representations contain some truth, but not all of it. I would place Van Dyck’s portrait of Bentivoglio (see Figure 9), perhaps his best, certainly one of his most famous, in the same class: we see the heart and soul of the man, and his gentleness, but not the bodily strength that enabled him to sustain long marches during the wars in the Low Countries.

  JB. We see what we are looking for and disregard the rest of the world. Your double portrait, Mr Cleyn, is a compelling depiction of a listless melancholy young man and a sympathetic doctor.

  FC. You were a compelling model, Mr Bankes. You were very melancholy, in both the Galenic and the Aristotelian senses. Your appearance confirmed the medical diagnosis and your interest in astronomy, represented by Galileo’s book, was in line with the pastimes of the children of Saturn. I painted you as I saw you and as Sir Maurice seemed to see you. You were sick and suffering, as was the monarchy; despite the sage advice of Greaves’s brother the doctor, melancholy stalked Oxford. We were horrified to think that neither you nor the monarchy had long to live. But while there’s life there’s hope. The globe and chart-like telescope in the picture referred to this hope; doctors of melancholy prescribed travel as a preeminent cure.

  JB. Your portrayal satisfies all of Sir Henry Wotton’s tests of a good rendition—“the Story…rightly represented, the Figures in true action, the Persons suited to their severall qualities, the affections proper and strong.”43 And your rendition of the frontispiece is a perfect example of expressive caricature, for with a few strokes you recover its essence and leave the knowledgeable viewer the task of supplying the details. That is just where Galileo’s parabolic trajectory left artillerymen.

  MW. As long as we are flying high on the wings of analogy, I submit that the masques that delighted our sovereigns and their courtiers have something of the same nature. Certainly they were caricatures! They are stocked with ideal types that everyone recognized as Platonic and hoped might prompt great persons to emulation. Just as the abstractions of mathematical physics may allow some control of nature, the abstractions of character in a masque may modify behavior of individuals. It may be a great discovery that masques and mathematics have something in common, but I will not press it.

  JB. Sir Henry’s little book on architecture teaches that too great accuracy in rendering a scene or person can be as bad as poor drawing. He says that there are some “Artificers so prodigiously exquisite” they are just too good. In trying for truth they privilege naturalness over gracefulness.44 Exactness can diminish that "free disposition…which doth animate Beautie where it is, and supplie it where it is not.”45 Galileo says the same thing in the Saggiatore.

  FC. I agree with him entirely. The artist cannot simultaneously render a scene or a person with complete accuracy, with every wart and speck of dust, and also portray true essences or characters. They are what you may call “complementary values.” You cannot express both perfectly at the same time and by maximizing one of them, you will ruin the other. You must smudge a bit to come close to evoking the desired emotional response. Again we meet the double blunt edge of fuzziness. Clarity is the enemy of truth; emotional response can be dangerous…I wonder what Sir Henry would have thought of my picture.

  MW. You will turn us into necromancers, Mr Cleyn! But perhaps we can work out an answer from common knowledge about the man and a few details I learned from Lord Strafford.46 Sir Henry would have given high marks to the handling of complementary values. You, John, are shown melancholic, but whether from illness of the body, as suggested by your pasty face, or of the soul, as suggested by your mathematical studies, or, most likely, both, or whether from being adolescent, is left to the viewer to resolve. I am depicted as a worried man; but whether as a tutor and doctor for both forms of your ailment, or as a distressed witness to the collapse of government and the judicial murder of Strafford, or as both, may be debated. The compass, globe, telescope, and book are each rendered with the degree of exactness appropriate to its function: thus the compass is presented in the greatest detail, to suggest costly mathematical instruments and a knowledge of their use; the globe only generically, to suggest travel in general; the telescope, with sufficient features to suggest an up-to-date model; and the book—that Sir Henry would have liked particularly—evoked with only the brushstrokes needed to identify it.

  FC. Very brilliant Sir Maurice. But perhaps the painting is so impressionistic because I never finished it. There was a great rush, as you remember. It was a difficult time. And then, how do you know when a painting is finished? Leonardo worked on some of his for a lifetime, while Rubens and Van Dyck knocked theirs off like suits of clothes. But you did not finish with Sir Henry’s evaluation of the painting. What would he have made of the reference to Galileo?

  MW. He would have understood it as he and his friend Donne did Sidereus nuncius, as a threat and a promise, an ambiguous comet, a herald of a great upheaval.

  JB. It appears from some stray remarks in the Elements that Sir Henry did not live in Galileo’s world. He takes as a theorem that heavy bodies fall to the center of the universe and praises Aristotle, from whom he learned it, as “our greatest Master among the sonnes of nature.” Sir Henry worked a curious reference to Tycho into his epitome of architecture. It should amuse you, Mr Cleyn. Sir Henry allowed a limited use of grotesques but had no time for grottoes. If you have one on your grounds, he advised, convert it into an underground observatory, “whereof mention is made among the curious provisions of Tycho Braghe the Danish Ptolemie.” Sir Henry took Tycho, not Copernicus or Galileo, as the prince of modern astronomy.47 To finish with Sir Henry, I suppose, given his attachment to Sarpi and the Venetians, he also would have understood the reference to Galileo as an indictment of the Roman Catholic Church, which showed its true colors by insisting that the world system must conform with a few obscure or metaphorical passages in a text written two millennia before the invention of th
e telescope.

  FC. My good sitters, I have learned much that surprises me, and used as I am to thinking in symbols, I cannot absorb any more today. Also, it is getting dark, and I must be going. The law might be observed in Gray’s Inn, but not invariably between it and Covent Garden.

  MW. And we—I think that I can speak for Mr Bankes too—have learned many things from you. But before we part, please bring our conversation to a conclusion by telling us what you had in mind when designing the painting.

  FC. My designs usually tell a story. So, Mr Bankes, when Sir Maurice asked me to put Galileo’s book in the painting, I thought how it might be done so as to indicate the esoteric nature of the studies you were then pursuing so avidly. That meant avoiding anything so trivial as presenting the book spine forward with its title and author clearly inscribed on it; and anyway I wanted it open, as a closed book suggests a closed mind or finished subject. A good example of what I wanted to avoid is Zubarán’s stupendous portrait of Diego Deza, Archbishop of Seville and Grand Inquisitor of Spain. Deza, looking very severe and elegant, sits at a table on which rest four closed volumes of theology (Figure 62). A marvelous depiction of a refined bigot! The uninformed viewer would have no idea that Deza had been the main champion of Columbus at the court of Ferdinand and Isabella. I wanted to tell a more complete story of my sitters.

  Figure 62 Francisco de Zubarán, Fray Diego Deza (1630).

  MW. And so you exhibited Galileo’s Systema as an open book to signify an ongoing inquiry, and omitted its title so as to suggest the esoteric nature of the subject, since only people who had had the book in their hands would have been able to recognize it in your sketchy figures.

  FC. Also, I thought that della Bella’s design, of which you know I am a great admirer, would stick in the mind of anyone who saw it. I posed you, Sir Maurice, with your right hand on the globe, which, together with your empathetic gaze, suggests Mr Bankes’s opportunity to explore the great world beyond Oxford; which Mr Bankes does not seem to want to do, as he gestures listlessly toward the globe and looks over the telescope toward the open book. I apologize for botching your left hand, Mr Bankes, I would have fixed it if I had had time to revise.

  JB. No apology needed, Mr Cleyn. It is true that I was more strongly drawn to astronomy and cosmology than probably was fitting for the heir of a great landed lawyer. I remember that telescope, which Professor Greaves showed me how to use. I suppose you put it under the globe, Mr Cleyn, to emphasize its application to travel. I took one with me when I went to Europe and found it very useful for seeing towns and travelers at a distance and paintings high up in churches.

  FC. You give me too much credit, Mr Bankes. I put the telescope there to draw attention to it and the book, which incorporates and interprets the great discoveries Galileo made with it.

  MW. Still, I suspect, we have not got to the essence of the painting. For example, what is the other book? I cannot believe that it is there just as a paperweight. You do not waste opportunities like that, Mr Cleyn.

  FC. Sir John handed me the book and asked me to put its title on the spine. Its omission was one of the casualties of haste. But I did scratch the title on it so that I would not forget it when I came to fix up Mr Bankes’s hand and other details. I think that you can just make out a few letters despite the need for cleaning.

  JB. Yes, I see an “H” and an “i” followed a little further on by what looks like a “t”. Is it “History”?

  FC. Yes. I took it as a clever opposition to the Galileo: the closed book of history holding open a dramatic portrayal of present discovery. Which also points to future improvement through reasoned dialogue among people of good will. The past is the necessary foundation of the advance of humankind, but not a dictator of direction or scope.

  JB. That is very likely, Mr Cleyn. But, as Sir John usually had more reasons than one for his actions and had too strong a sense of symmetry to pair a particular volume indicative of the future with an unidentified general history, the closed book must have been something special. I am morally certain that it is the Corfe Castle copy of Sarpi’s Trent. It certainly has the right girth! Nothing could have been more appropriate. Or more eloquent of my father’s last judgment on the affairs of church and state he had seen and suffered.

  MW. He suffered from trying to do his duty to both prerogative and privilege, from struggling to reconcile his deep loyalties to the king and the Common Law. The conflict could easily bring on a fatal attack of melancholy.

  JB. Galileo’s book might represent Sir John’s last thoughts about this enduring problem. He came to see that Galileo’s brave defiance of an unjust order of legitimate authority was a responsible, not a seditious act, and that peaceful dissent is compatible with stable government.

  MW. That seems a plausible explanation of the hieroglyph as far as Sir John was concerned with it. But he did not make the painting. What was on your mind, Mr Cleyn, when you joined us with your subtle evocation of Galileo?

  FC. Sir Maurice, for me Galileo represents the highest attainments possible for unaided human reason energized by curiosity and ambition; and you two melancholy gentlemen (please forgive me!) the perfect embodiment of doubt and lethargy. Will Mr Bankes continue stupefied by traditional teachings or wake up, seize the instruments, and add a few more pages to the open book of knowledge? Or will he shun the light and sink into that disabling melancholy that Mr Burton described so powerfully?

  JB. Am I right in thinking that you placed us so as to indicate a gap of merit between real melancholics and a virtual Galileo?

  FC. Yes, Mr Bankes, but I placed within the gap the means by which you and posterity could not only close it but advance far beyond the level of Galileo. These are the instruments of exploration and discovery, which I represented by those now essential to navigation. For, as Sir Francis Bacon assures us through his wonderful image of the ship passing through the Pillars of Hercules with its invocation of the prophet Daniel, “many will pass through, and knowledge will be increased.”

  JB. I suspect that there is much more that you might tell us about the picture. You are famous for telling several stories at once.

  FC. Well, there is a little something more about the way I portrayed Galileo’s Dialogue. Is the symbol or motto of your university not an open book?

  MW. It is indeed, Mr Cleyn, and what is written on it is Dominus illuminatio mea. Your artistry is uncannily subtle if you intended to suggest the profound association I now perceive between the Oxford slogan and Galileo’s book.

  FC. I am not very clever, Sir Maurice. Tell me what I have done.

  MW. Dominus illuminatio mea are the first words of Psalm 27. The first of its six verses express optimism, confidence in the future, full faith in God’s protection: “Though an host should camp against me, my heart shall not fear: though war should rise against me, in this I will be confident.” The next six verses are pessimistic. The psalmist no longer takes God’s protection for granted: “Hide not they face far from me…Deliver me not over unto the will of mine enemies.” The psalmist does not choose between these attitudes, but advises: “Wait on the Lord: be of good courage, and he shall strengthen thine heart; wait, I say, on the Lord.”

  JB. Wait not upon the Lord, but depend upon yourself, is not the message of the psalm, but the only reasonable reply that experience suggests to it. Despite all the recent persuasive evidence to the contrary, let us read our portrait as Mr Cleyn suggests. In a passage that scandalized bigots and naysayers, Galileo boldly proclaimed that we can understand some propositions as well as God Almighty and can apply their truths to improving our circumstances. To be sure, God knows many more propositions than we do, and, in our fallen state and current confusion, the few we can grasp with absolute certainty are mathematical. “But with regard to those few [propositions] which the human intellect does understand, I [Galileo] believe that its knowledge equals the Divine in objective certainty, for here it succeeds in understanding necessity, beyond which there can be no greate
r sureness.”48

  Our interlocutors did not have much reason for optimism. Cromwell and his Commonwealth were in the ascendant. Any journeyman stargazer could predict from the conjunction of seven planets in Pisces scheduled for September 1656 that much worse was in store. Just such an assembly had happened the year before the Universal Deluge. The astrologer John Gadbury, who was not always wrong, could therefore most confidently predict that “the Politician will plague us with subtle and treacherous devices; the men in power with hard Taxes; the Countryman with want of Grain, the Soldier with wars and strifes.”49

  John Bankes died of one of the maladies on offer in that dire year. Another two years and Cleyn and Williams too were gone. They missed the revival of fortune that came with the dispersal of the planets and the return, in 1660, of the Stuarts. Their picture did better. During the Restoration, Ralph Bankes reacquired many of the family’s assets, including knighthood, by which Charles II acknowledged the sacrifices of Chief Justice Bankes. Sir Ralph was able to commission a splendid villa at Kingston Lacy by Roger Pratt, who designed in the style of Inigo Jones, and a portrait of himself by Peter Lely, who depicted him as an aesthetic version of his melancholic brother John (Figure 63). Among the lavish furnishings of Kingston Lacy were many fine paintings appropriate for display above the main mantelpiece. Ralph chose the double portrait of his brother and Maurice Williams for this honor.

  Figure 63 Peter Lely, Ralph Bankes (c.1660).

  In the inventory that specifies the portrait’s location, the painter’s name is given as “Decline.” It was an ominous slip. As Galileo remarked when naming Jupiter’s moons the Medici stars, man-made monuments all perish in the end and glory has a short shelf life. “For such is the condition of the human mind that…all memories easily escape from it.”50 Remodeling and forgetfulness have removed Cleyn’s picture from its original conspicuous place. As it fell in fortune it rose in obscurity. It now occupies a remote spot in a dark corridor at the top of the house, where it can still be seen if staff are available to open the upper stories to visitors.