To print: Select File and then Print from your browser's menu.
The sharp-eyed lynx, outfoxed by nature: Galileo and friends taught us that there is more to observing than meets the eye.(Column)
Author/s: Stephen Jay Gould
Galileo and friends taught us that there is more to observing than meets the eye.
Part One: Galileo Galilei and the Three Globes of Saturn
In 1603, Federico Cesi, the duke of Aquasparta, founded an organization that grew from uncertain beginnings to become the first scientific society in modern European history. Cesi (1585-1630), then a teenage nobleman, invited three slightly older friends (all in their midtwenties) to establish l'Accademia dei Lincei (the Academy of the Lynxes), dedicated to scientific investigation ("reading this great, true, and universal book of the world," to cite Cesi's own words) and named for a sleek and wily carnivore, then still living in the forests of Italy and renowned in song and story for unparalleled sight among mammals.
The legend of the sharp-eyed lynx had arisen in ancient times and persisted to Cesi's day. Pliny's canonical compendium of natural history had called the lynx "the most clear sighted of all quadrupeds." Plutarch had embellished the legend by speaking of "the lynx, who can penetrate through trees and rocks with its sharp sight." And Galen, ever the comparative anatomist, had written: "We would seem absurdly weak in our powers of vision if we compared our sight to the acuity of the lynx or the eagle." (I have translated these aphorisms directly from Konrad Gesner's 1551 compendium on mammals, the standard source for information on natural history in Cesi's day.)
Still, despite Cesi's ambitious name and aims, the academy of four young men faltered at first. Cesi's own father made a vigorous attempt to stop his son's foolishness, and the four Lynxes all dispersed to their native cities, keeping their organization alive only by the uncertain media of post and messages. But Cesi persevered and triumphed (for a time), thanks to several skills and circumstances. He acquired more power and prestige, both by growing up and by inheriting substantial wealth. Most importantly, he became a consummate diplomat and facilitator within the maximally suspicious and labyrinthine world of civil and ecclesiastical politics in Rome during the Counter-Reformation. The Lynxes flourished largely because Cesi managed to keep the suspicions of popes and cardinals at bay while science prepared to fracture old views of the cosmos and develop radically new theories about the nature of matter and causation.
As a brilliant administrator, Cesi knew that he needed more clout among the membership of the Lynxes. He therefore recruited, as the fifth and sixth members of an organization that would eventually reach a roster of about thirty, two of the most prestigious thinkers and doers of early-seventeenth-century life. In 1610 he journeyed to Naples, where he persuaded the senior spokesman of the fading Neoplatonic school-the seventy-five-year-old Giambattista della Porta--to join a group of men young enough to be his grandsons. Then in 1611, Cesi made his preeminent catch when he recruited the hottest intellectual property in the Western world, Galileo Galilei (1564-1642), to become the sixth member of the Lynxes.
The year before, Galileo had provided an ultimate proof for the cliche that good things come in small packages by publishing Sidereus nuncius (Starry messenger)--little more than a pamphlet really, but containing more oomph per paragraph than anything else ever achieved in the history of science or printing. Galileo shook the earth by turning his newly invented telescope upon the cosmos and reporting that the moon is a planet with mountains and valleys, not the perfect sphere required by older science and theology; that thousands of previously invisible stars build the Milky Way, thus extending the cosmos beyond any previously conceivable limit; and that four moons orbit Jupiter, forming a miniature world analogous to the motion of planets around a central body. Moreover, Galileo pointed out, the crystalline sphere supposedly encompassing Jupiter (and each of the other planets) could not exist, for the revolution of moons would shatter this mystical structure of a geometrically perfect, unsullied, and unchanging cosmos--God's empyrean realm.
But Galileo also made some errors in his initial survey, and I have always been struck that standard books on the history of astronomy, written as they are in the heroic or hagiographical mode, almost never mention (or only relegate to an awkward footnote) the most prominent of Galileo's mistakes--for the story strikes me as so fascinating and so much more informative about the nature of science, and of creativity in general, than any of his valid observations.
Galileo also turned his telescope to Saturn, the most distant of the visible planets, and he saw the famous rings. But he could not properly visualize or interpret what he had observed, presumably because his conceptual world lacked the requisite "space" for such a peculiar object (while his telescope remained too crude to render the rings with enough clarity to force his mind, already benumbed by so many surprises, to the most peculiar and unanticipated conclusion of all).
The stymied Galileo looked and looked and focused and focused, night after night. He finally decided that Saturn must be a threefold body, with a central sphere flanked by two smaller spheres of equal size, each touching the main planet. Following a common custom of the day--established to preserve claims of priority while not revealing preliminary conclusions ripe for theft by others--Galileo encoded his interpretation as a Latin anagram, which he posted to his friend and leading compatriot in astronomical research, Johannes Kepler.
Kepler may have been as brilliant as Galileo, but he never resolved the anagram and he misinterpreted the message as a statement about the planet Mars. In frustration (and a bit of pique), he begged Galileo for the answer. His colleague replied with the intended solution: Altissimum planetam tergeminum observavi (I have observed that the farthest planet is threefold).
I regard the last word of Galileo's solution as especially revealing. He does not advocate his conclusion by stating "I conjecture," "I hypothesize," "I infer," or "it seems to me that the best interpretation is. . . " Instead, he boldly writes "observavi"--I have observed. No other word could capture with such terseness and accuracy the major change in concept and procedure (not to mention ethical valuation) marking the transition to what we call "modern" science. An older style (as found, for example, in Gesner's compendium on mammals) would not have dishonored a claim for direct observation but would have read such an argument as a corroborative afterthought, surely secondary in weight to such criteria as the testimony of classical authors and logical consistency with a conception of the universe "known" to be both true and just--in other words, to authority and fixed reasonableness."
But the new spirit of skepticism toward past certainty, coupled with respect for "pure" and personal observation--then being stressed by Francis Bacon in England, by Rene Descartes in France, and by the Lynxes in Italy--was sweeping through the intellectual world, upsetting all standard procedures of former times and giving birth to the modern form of an institution now called "science." Thus, Galileo supported his theory of Saturn with the strongest possible claim of the new order, the one argument that could sweep. Aside all opposition by claiming a direct, immediate, and unsullied message from nature. Galileo simply said: I have observed it; I have seen it with my own eyes. How could old Aristotle, or even the present pope himself, deny such evidence?
I do not intend, in this essay, to debunk the usual view that such a transition from old authority to direct observation marks a defining (and wonderfully salutary) event in the history of scientific methodology. But I do wish to note that all great mythologies include harmful simplicities amid their genuine reforms, and that these negative features often end up by saddling an originally revolutionary doctrine with its own form of restrictive and unquestioned authority. The idea that observation can be pure and unsullied (and therefore beyond dispute)--and that great scientists are, by implication, people who can free their minds from the constraints of surrounding culture and reach conclusions strictly by untrammeled experiment and observation joined with clear and universal logical reasoning--has often harmed science by turning the empiricist method into a shibboleth. The irony of this situation fills me with a mixture of pain for a derailed (if impossible) ideal and amusement for human foibles--as a method devised to undermine proof by authority becomes, in its turn, a species of dogma itself. Thus, if only to honor the truism that liberty requires eternal vigilance, we must also act as watchdogs to debunk the authoritarian form of the empiricist myth and to reassert the quintessentially human theme that scientists can only work within their social and psychological contexts. Such an assertion does not debase the institution of science but rather enriches our view of the greatest dialectic in human history: the transformation of society by scientific progress, which can only arise within a matrix set, constrained, and facilitated by society.
I know no better illustration of this central principle than the tale of Galileo's losing struggle with Saturn, for he insisted on validation by pure sight (observavi), and he was quite wrong--presumably because his intellectual domain included no option for rings around a planet. Galileo did not just "see" Saturn; he had to interpret an object in his lens by classifying an ambiguous shape within the structure of his mental space, and rings didn't inhabit this interior world.
The great Dutch astronomer Christian Huygens finally recognized the rings of Saturn in 1656, more than a decade after Galileo's death. Galileo, who had wrestled mightily with Saturn, never moved beyond his trigeminal claim and finally gave up and turned to other pursuits. In his 1613 Letters on Sunspots, published by the Lynxes (with the author designated on the title page as Galileo Galilei Linceo), Galileo continued to insist that Saturn must be threefold because he had so observed the planet: I have resolved not to put anything around Saturn except what I have already observed and revealed--that is, two small stars which touch it, one to the east and one to the west." Against a colleague who interpreted the planet as oblong, Galileo simply asserted his superior vision. The colleague, Galileo wrote, had viewed Saturn less often and with a much poorer telescope, "where perfection is lacking, [and] the shape and distinction of the three stars imperfectly seen. I, who have observed it a thousand times at different periods with an excellent instrument, can assure you that no change whatever is to be seen in it."
Yet just as Galileo prepared his book on sunspots for publication, he observed Saturn again after a hiatus of two years, and the two side planets had disappeared (a situation produced, we now know, when the planet's orientation causes us to see the rings directly on edge). The stunned Galileo, reduced to a most uncharacteristic modesty, had just enough time to make an addition to the last chapter of his book. He abjured nothing about his previous observations, or about the righteousness of the empirical method in general. He merely confessed his puzzlement, making a lovely classical allusion to the primary myth about the planet's eponym:
I had discovered Saturn to be three-bodied.
... Men I first saw them they seemed
almost to touch, and they remained so for
almost two years without the least change.
It was reasonable to believe them to be
fixed.... Hence I stopped observing Saturn
for more than two years. But in the past
few days I returned to it and found it to be
solitary, without its customary supporting
stars, and as perfectly round and sharply
bounded as Jupiter. Now what can be said
of this strange metamorphosis?
That the two lesser stars have been
consumed? ... Has Saturn devoured his
children? Or was it indeed an illusion
and a fraud with which the lenses of my
telescope deceived me for so long--and not
only me, but many others who have
observed it with me? ... I need not say
anything definite upon so strange and
unexpected an event; it is too recent, too
unparalleled, and I am restrained by my
own inadequacy and the fear of error
After this lengthy preamble on the maximally celebrated Galileo, I now wish to present the main subject of this dual essay: the virtually unknown Francesco Stelluti, one of the original four Lynxes, a loyal friend and supporter of Galileo, and the man who tried to maintain--and eventually disbanded with dignity in 1652--the original Academy of the Lynxes, fatally weakened after Cesi's untimely death in 1630. The previously uncharted links between Stelluti and Galileo are rich and fascinating (I would have said "the links between these Lynxes," if the pun were not so horrific) and provide a poignant illustration of this essay's central theme: the power and poverty of pure empiricism and the need to scrutinize the social and intellectual contexts of research, both for practicing scientists (so they will not be beguiled) and for all people who wish to understand the role and history of knowledge (so they will grasp the necessary and complex interdigitation of science and society).
The original Lynxes began with all the bravado and secrecy of a typical boys' club (Cesi, remember, was only eighteen years old, while his three compatriots were all twenty-six). They wrote complex rules and enunciated lofty ideals. (I do not know whether or not they developed a secret handshake.) Each adopted a special role, received a Latin moniker, and took a planet for his emblem. The leader, Cesi, commanded the botanical sciences as Coelivagus (the heavenly wanderer); the Dutchman Johannes van Heeck would read and interpret classical philosophy as Illuminatus; Anastasio de Filiis became the group's historian and secretary as Eclipsatus. Poor Francesco Stelluti, who published little and evidently saw himself as a systematic plodder, took up mathematics and geometry under the name of Tardigradus (the slow stepper). For his planet, Stelluti received the most distant and most slowly revolving body--Saturn, the subject of Galileo's error.
In their maturity, the Lynxes would provide powerful intellectual and institutional support for the open and empirical approach to science, as promoted by their most prominent member Galileo. But at their beginnings, as a small club of young men, the Lynxes preferred the older tradition of science as an arcane and secret form of knowledge, vouchsafed only to initiates who learned the codes and formulas that could reveal the mysterious harmonies of universal order--the astrological links between planetary positions and human lives; the alchemical potions and philosophers' stones, heated in vats, that could transmute base metals to gold ("Double, double toil and trouble; Fire burn and cauldron bubble," to cite some famous witches); and the experiments in smoke, mirrors, and optical illusions that occupied an uncertain position between categories now labeled as magic and science, but then conflated. Giambattista della Porta, the fifth Lynx, had survived as a living legend of this fading philosophy. Della Porta had made his reputation in 1558, long before the birth of any original Lynx, with a book entitled Magia naturalis (Natural magic). As a young man in Naples, della Porta had founded his own arcane organization, the Accademia dei Segreti (the Academy of Secrets), dedicated to alchemical and astrological knowledge and later officially suppressed by the Inquisition. By initiating the aged della Porta into the Academy of the Lynxes, Cesi and his compatriots showed the strength of their earlier intellectual allegiances. By inducting Galileo the next year, they displayed their ambivalence and their growing attraction to a new view of knowledge and scientific procedure.
The election of both newcomers virtually guaranteed a period of definitional struggle within the academy, for no love could be lost between della Porta, and Galileo, who not only differed so greatly in their basic philosophical approaches to science but who also nearly came to blows for a much more specific reason rooted in the eternally contentious issue of priority. Galileo never claimed that he had invented the telescope from scratch. He stated that he had heard reports about a crude version during a trip to Venice in 1609. He recognized the optical principles behind the device and then built a more powerful machine that could survey the heavens. But della Porta, who had used lenses and mirrors for many demonstrations and illusions in his Magia naturalis and who understood the theory of optics quite well, then claimed that he had formulated all the principles for building a telescope (although he had not constructed the device) and therefore deserved primary credit for the invention. Although tensions remained high, the festering issue never became an overt battle royal because Galileo and della Porta held each other in mutual respect, and della Porta died in 1615 before any growing bitterness could get out of hand.
Stelluti first encountered Galileo in the context of this struggle, and he initially took della Porta's side. In 1610, with della Porta inscribed as a Lynx but Galileo not yet a member, Stelluti wrote a gossipy letter to his brother about the furor generated by Sidereus nuncius and the dubious claims of the pamphlet's author:
I believe that by now you must have seen
Galileo, he of the Sidereus nuncius. . . .
Giambattista della Porta wrote about [the
telescope] more than thirty years ago in
his Magia naturalis . . . so poor Galileo
will be besmirched. But, nonetheless, the
Grand Duke has given him 800 piastres.(*)
But when Galileo joined the Lynxes, and as his fame and success solidified and spread, Stelluti and his compatriots became fervent Galileans. With della Porta, dead and the Starry Messenger riding a truly cosmic crest of triumph, the Academy of the Lynxes grew to become Galileo's strongest intellectual (and practical) base, the primary institutional supporters of the new, open, empirical, and experimental view of scientific knowledge. Making the link between Galileo's error and Stelluti's planet, Cesi wrote to Stelluti in 1611 about the wonders of the telescope, as revealed by Galileo himself, who was paying a long visit to the duke of Aquasparta:
Each evening we see new things in the
heavens, the true office of the Lynxes.
Jupiter and its four revolving satellites; the
moon with its mountains, caverns, and
rivers; the horns of Venus; and Saturn,
your own triple-star [il triplice suo
Such floods of reforming novelty tend to alienate reigning powers, to say the least--a generality greatly exacerbated in early-seventeenth-century Rome, where the papal government, besieged by wars and assaulted by successes of the Reformation, felt especially unfriendly to unorthodoxy of any sort. Galileo had written a first note of cautious support for the Copernican system at the end of his Letters on Sunspots, published by the Lynxes in 1613. Soon afterward, in 1616, the Church officially declared the Copernican doctrine false and forbade Galileo to teach heliocentrism as a physical reality (although he could continue to discuss the Copernican system as a "mathematical hypothesis"). Galileo kept his nose clean for a while and moved on to other subjects. But then in 1623, the Lynxes rejoiced in an unanticipated event that Galileo called a "great conjuncture" (mirabel congiuntura): the elevation of his friend and supporter Maffec, Barberini to the papacy as Urban VIII. (In an act of literal nepotism, Maffeo quickly named his nephew Francesco Barberini as his first new cardinal. In the same year, Francesco Barberini became the twenty-ninth member of the Lynxes.)
On August 12, 1623, Stelluti wrote from Rome to Galileo, then in Florence, expressing both his practical and intellectual joy in the outcome of local elections. Three members of the Lynxes would be serving in the new papal government, along with "many other friends." Stelluti then enthused about the new boss:
The creation of the new pope has filled us
all with rejoicing, for he is a man of such
valor and goodness, as you yourself
know so well. And he is a particular
supporter of learned men, so we shall
have a supreme patron. . . . We pray to the
Lord God to preserve the life of this pope
for a long time.
The Lynxes, suffused with hope that freedom of scientific inquiry would now be established, met for an extended convention and planning session at Cesi's estate in 1624. Galileo had just built the first usable microscope for scientific investigation after recognizing that lenses, properly arranged, could magnify truly tiny nearby objects, as well as enormous cosmic bodies rendered tiny in appearance by their great distance from human observers. Anticipating the forthcoming gathering of the Lynxes, Galileo sent one of his first microscopes to Cesi, along with a note describing his second great optical invention:
I have examined a great many tiny
animals with infinite admiration.
Mosquitoes are the most horrible among them. . . . I have
seen, with great contentment, how flies
and other tiny animals can walk across
mirrors, and even upside down. But you,
my lord, tall have a great opportunity to
view thousands and thousands of details. . . In
short, you will be able to enjoy infinite
contemplation of nature's grandness,
and how subtly, and with what
incredible diligence, she works.
Galileo's microscope entranced the Lynxes and became the hit of their meeting. Stelluti took a special interest and used the new device to observe and draw the anatomy of bees. In 1625, Stelluti published his results, including a large engraving of three bees drawn under Galileo's instrument. Historian of science Charles Singer cites these bees as "the earliest figures still extant drawn with the aid of the microscope," and if the name of the sadly underrated Francesco Stelluti, the tardigrade among the Lynxes, has survived at all in conventional annals of the history of science, he perseveres only as an entry in the "list of firsts" for his microscopical drawings.
The Lynxes, always savvy as well as smart, did not choose to draw bees for abstract amusement. Not coincidentally, the family crest of Maffeo Barberini, the new pope and the Lynxes' anticipated patron, featured three bees. Stelluti dedicated his work to Urban VIII, writing in a banner placed above the three bees: "To Urban VIII Pontifex Optimus Maximus . . . from the Academy of the Lynxes, and in perpetual devotion, we offer you this symbol."
The emboldened Galileo now decided to come out of intellectual hiding and to risk a discussion of the Copernican system. In 1632, he published his epochal masterpiece in the history of science and, from the resultant tragedy, in the history of society as well: Dialogo . . . sopra i due massimi sistemi del mondo tolemaico e copernicano (A dialogue . . . on the two great systems of the world, Ptolemaic and Copernican). Galileo hoped that he could avoid any ecclesiastical trouble by framing the work as a dialogue--an argument between a supporter of the earth-centered Ptolemaic system and a partisan of Copernicus's sun-centered view.
We all know the tragic outcome of this decision only too well. The pope, Galileo's erstwhile friend, became furious and ordered the scientist to appear at a trial before the Roman Inquisition. Galileo was convicted and forced to abjure, on his knees, his "false" and heretical Copernican beliefs. He was then placed under a form of house arrest on his small estate at Arcetri for the remainder of his life. His situation scarcely resembled solitary at Alcatraz, and Galileo remained fully active in scientific affairs by receiving visitors and engaging in voluminous correspondence up to the moment of his death (even though blindness afflicted his last four years). In 1638, he even managed to smuggle a copy of his second great book in dialogue form to a printer in the liberal Netherlands: Discourses and Mathematical Demonstrations Concerning Two New Sciences. But Galileo was not allowed to leave Arcetri either, as the vindictive pope, still feeling betrayed, refused Galileo's requests to attend Easter mass and to consult doctors in Florence when his sight began to fail.
The literature on the whys and wherefores of Galileo's ordeal is varied and voluminous, and I shall not attempt even the barest summary here (the most interesting and original of recent books include Mario Biagioli's Galileo, Courtier, University of Chicago Press, 1993; and Pietro Redondi's Galileo Heretic, Princeton University Press, 1987). All agree that Galileo might have avoided his fate if any one of a hundred circumstances had unfolded in a slightly different manner. He was, in other words, a victim of bad luck and bad judgment, not an inevitable sacrificial lamb in an eternal war between science and religion.
However, until doing the research for this essay, I had never appreciated the strength of one particularly relevant factor along the string of contingencies. From the vantage point of the Lynxes, Galileo would almost surely have been able to navigate a subtle path around potential trouble, if the most final of all events had not intervened. In 1630, at age forty-five and at the height of his influence, Federico Cesi, founder and perpetual leader of the Lynxes, died. Galileo learned the sad news in a letter from Stelluti: "My dear signor Galileo, with a trembling hand, and with eyes full of tears [con man tremante, e con occhi pieni di lacrime--it sounds so much better in Italian!], I must tell you the unhappy news of the loss of our leader, the duke of Aquasparta, as the result of an acute fever."
I feel confident that Cesi could have interceded to spare Galileo for two reasons. First, his caution and diplomacy, combined with his uncanny sense of the practical, would have suppressed Galileo's famous and fatal impetuosity. Galileo, ever testing the limits, ever pushing beyond into a realm of danger, did cast his work in the form of a dialogue between a Copernican and a supporter of Ptolemy's earth-centered universe, but he had scarcely devised a fair fight. Ptolemy's champion bore the name Simplicio, and the quality of his arguments matched his moniker. Moreover, Urban VIII developed a sneaking suspicion that Simplicio might be a caricature of his own imperial self--hence his angry feeling that Galileo had betrayed an agreement to discuss Copernicanism, as one coherent theory among equally valid alternatives. If Cesi had lived, he would, no doubt, have insisted that Galileo write his dialogue in a less partisan, or at least a more subtly veiled, form. And Cesi would have prevailed, both because Galileo respected his judgment so highly and because the Lynxes intended to publish his book at Cesi's expense.
Second, Cesi was the most consummate of politicians on the Roman scene. As a nobleman and diplomat (contrasted with Galileo as a commoner and something of a hothead), Cesi would have greased all the wheels and prepared a smooth way. Galileo recognized the dimensions of his personal misfortune only too well. He wrote to his friend G. B. Baliani in 1630, just before Cesi's death:
I was in Rome last month to obtain a
license to print the Dialogue that I am
writing to examine the two great systems,
Ptolemaic and Copernican. . . . Truly, I
would have left A this in the hands of
our most excellent prince Cesi, who
would have accomplished it with much care, as
he has done fro my other works. But he
is feeling indisposed, and now I hear that he
is worse, and may be in danger.
Cesi's death produced two complex and intertwined results lying at the heart of this essay: the subsequent--and preventable--condemnation of Galileo and the attrition and inevitable death of the Academy of the Lynxes. Stelluti tried valiantly to keep the Lynxes alive. He importuned Francesco Barberini--the cardinal and nephew of the pope and the only member of the Lynxes with enough clout to fill Cesi's shoes--to become the new leader. Barberini's refusal sealed the Lynxes' fate, for no other rich and noble patron could be found. Stelluti soldiered on for a while and, in a noble last hurrah, finally published, in 1651, the volume on the natural history of the New World that the Lynxes had been planning for decades: Nova plantarum et meniralium mexicanorum historia. In a final loving tribute, Stelluti included Cesi's unpublished work on botanical classification in an appendix. In 1652, Stelluti, the last original Lynx, died--and the organization that he had nourished for a lifetime, in his own slow and steady manner, ceased to exist.
(*) The quotations from Galileo's Letters on Sunspots come from Stillman Drake's 1957 English translation, published by Anchor Books. I have translated all other quotes from the Italian of Stelluti's 1637 monograph on fossil wood, letters from several volumes of the Edizione nazionale of Galileo's complete works, and three standard sources on the history of the Academy of the Lynxes: Breve storia della Accademia dei Lincei, by D. Carutti (Rome: Salviucci, 1883); Contributi alla storia della Accademia dei Lencei, by G. Gabrieli (Rome: Classe di scienze morali, 1989); and L'Accademia dei Lincei e la cultura europea nel XVII secolo, a catalog for a traveling exhibit about the Lynxes by A. M. Capecchi and several other authors, published in 1991.
Stephen Jay Gould teaches biology, geology, and the history of science at Harvard University. He is also the Frederick P. Rose Honorary Curator in Invertebrates at the American Museum of Natural History.
|COPYRIGHT 1998 American Museum of Natural History|
in association with The Gale Group and LookSmart. COPYRIGHT 2000 Gale Group