Leonardo’s Mountain of Clams and the Diet of Worms (3 page)

4. “Promotion” to an essay may depend upon the coalescence of details into a general theme worthy of report, but sometimes those details, all by themselves, become arresting enough to merit treatment entirely for their own value (and then I will confess to using the emerging generality as an excuse for almost baroque
attention to the details). I do value the theme eventually addressed, but don’t you adore, entirely for their own sake as stories, the four tales of conventional prey that devour their predators (chapter 21), or the excruciatingly intricate and beautiful details of the bizarrely complex life cycle of the barnacle parasite, the “root-head”
Sacculina
(chapter 19)? And, as my personal favorite (and
here I do rest my case), how could anyone but a dolt not be moved by the fact that we know about the giant deer’s hump only because paleolithic cave painters left us a record—and that no other even potential source of evidence exists (chapter 9). I tell this story within a perfectly valid and sufficiently interesting context of discourse on biological adaptation as a general evolutionary principle,
but don’t you thrill to the notion of this kind of gift provided by such distant forebears; and aren’t you riveted by the details of these rare images, and the story of their discovery and recognition?

The foregoing discussion accounts for all individual bits in this eighth piece of my series. But just as the “two bits” of legend represented a cut from a totality called a “piece of eight,”
¹
my
bits have no coherence or valid generality without an overarching rationale or coordinating theme to make them whole. I pay my homage to evolution in the preface to every volume of this series, and will now do so again. Of all general themes in science, no other could be so rich, so deep, so fascinating in extension, or so troubling (to our deepest hopes and prejudices) in implication. Therefore,
for an essayist in need of a ligature for disparate thoughts and subjects, no binder could possibly be more appropriate—in fascination and legitimacy—than evolution, the concept that inspired the great biologist Theodosius Dobzhansky to remark, in one of the most widely quoted statements of twentieth-century science, that “nothing in biology makes sense except in the light of evolution.”

Moreover,
and finally, with this series’ emphasis on a humanistic natural history—an account of evolution that focuses as much on how we come to know and understand this great principle as on how such a process shapes the history of life—we encounter an endless recursion that provides even greater scope and interest to the subject. The wondrously peculiar human brain arose as a product of evolution, replete
with odd (and often misleading) modes of reasoning originally developed for other purposes, or for no explicit purpose at all. This brain then discovers the central truth of evolution, but also constructs human cultures and societies, replete with hopes and prejudices that predispose us toward rejecting many modes and implications of the very process that created us. And thus, in a kind of
almost cosmically wicked recursion, evolution builds the brain, and the brain invents both the culture that must face evolution and the modes of reasoning that might elucidate the process of its own creation. Round and round we go—into a whorl that may be endless and eternal, yet seems to feature some form of increasing understanding in all the gyrations that, at the very least, give us topics for
essays and, at best, provide some insight into the nature of our being.

I

A
R
T
AND
SCI
E
NCE

THE UPWARDLY MOBILE FOSSILS OF LEONARDO’S LIVING EARTH

M
ORGAN DESCRIBES HIS DESPAIR AS THEIR CAPTORS STRING UP
K
ING
Arthur for a hanging: “They were blindfolding him! I was paralysed; I couldn’t move, I was choking, my tongue was petrified . . . They led him under the rope.” But, in the best cliff-hanging traditions, and at the last conceivable instant, Sir Lancelot comes to the rescue with
five hundred knights—all riding bicycles. “Lord, how the plumes streamed, how the sun flamed and flashed from the endless procession of webby wheels! I waved my right arm as Lancelot swept in. I tore away noose and bandage, and shouted: ‘On your knees, every rascal of you, and salute the king! Who fails shall sup in hell to-night!’”

I am not citing either Monty Python or
Saturday Night Live
,
and I didn’t mix up my genders in the first sentence. The speaker is not Morgan le Fay (who, no doubt, would have devised a magical, rather than a technological, solution to the same predicament), but Hank Morgan, the Connecticut Yankee in King Arthur’s court, and the hero in Mark Twain’s satirical novel of the same name. Morgan, transported from nineteenth-century Hartford, wreaks mayhem in sixth-century
Camelot by introducing all manner of “modern” conveniences, including tobacco, telephones, baseball—and bicycles.

As a literary or artistic device, anachronism exerts a powerful hold upon us, and has been a staple of all genres from the highest philosophy to the lowest comedy—as Jesus is crucified in a corporate board room by Dali, condemned at his Second Coming by Dostoyevsky’s Grand Inquisitor,
but only offered a half-price discount (as he changes to modern dress) by the Italian barber or the Jewish tailor of various ethnic, jokes, now deemed tasteless and untellable.

Anachronism works this eerie and potent effect, I suppose, because we use the known temporal sequence of our history as a primary device for imposing order upon a confusing world. And when “the time is out of joint. O
cursèd spite,” we really do get discombobulated. We also know that correction of a perceived time warp cannot be achieved so easily in real life as in magical fiction (where Merlin can put Hank Morgan to sleep for 1,300 years, or Dracula can be dispatched with a wooden stake driven into the right spot). We regard Hamlet’s blithe confidence as a mark of his madness when he completes his rhyming couplet
with the Shakespearean equivalent of “no sweat” or “hakuna matata”: “. . . That ever I was born to set it right!”

Science, for reasons partly mythical, but also partly accurate and honorable, presents itself as the most linear and chronologically well ordered of all disciplines. If science, working by fruitful and largely unchanging methods of reason, observation, and experimentation, develops
progressively more accurate accounts of the natural world, then history provides a time line defined by ever-expanding success. In such a simple linear ordering, mediated by a single principle of advancing knowledge, any pronounced anachronism must strike us as especially peculiar—and subject to diametrically opposite judgment depending upon the direction of warp. An ancient view maintained in the
present strikes us as risible and absurd—the creationist who wants to compress the history of life into the few thousand years of a literal biblical chronology, or the few serious members of the Flat Earth Society. But a “modern” truth, espoused out of time by a scholar in the distant past, fills us with awe, and may even seem close to miraculous.

A person consistently ahead of his time—a real-life
Hank Morgan who could present a six-shooter to Julius Caesar, or explain the theory of natural selection to Saint Thomas Aquinas—can only evoke a metaphorical comparison with a spaceman from a more advanced universe, or a genuine angel from the realms of glory. In the entire history of science, no man seems so well qualified for such a designation as Leonardo da Vinci, who died in 1519, but
filled his private notebooks with the principles of aeronautics, the mental invention of flying machines and submarines, and a correct explanation for the nature of fossils that professional science would not develop until the end of the eighteenth century. Did he have a private line across the centuries to Einstein, or even to God Himself?

I must confess that I share, with so many others, a
lifelong fascination for this man. I was not a particularly intellectual child; I played stickball every afternoon and read little beyond comic books and school assignments. But Leonardo captured my imagination. I asked, at age ten or so, for a book about his life and work, probably the only intellectual gift that I ever overtly requested from my parents. As an undergraduate geology major, I bought
the two-volume Dover paperback edition of Leonardo’s notebooks (a reprint of the 1883 compilation by Jean Paul Richter) because I had read some of his observations on fossils in the Leicester Codex,
¹
and had been stunned not only by their accuracy, but also by their clear statement of paleoecological principles not clearly codified before our century, and still serving as a basis for modern studies.

Leonardo remains, in many ways, a frustrating and shadowy figure. He painted only about a dozen authenticated works, but these include two of the most famous images in our culture, the Mona Lisa (in the Louvre) and the
Last Supper
(a crumbling fresco in Milan). He published nothing in his lifetime, despite numerous and exuberant plans, though several thousand fascinating pages of manuscript have
survived, probably representing only about a quarter of his total output. He did not hide his light under a bushel and was, in life, probably the most celebrated intellectual in Europe. Dukes and kings reveled in his conversation and his plans for war machines and irrigation projects. He served under the generous patronage of Europe’s most powerful rulers, including Ludovico il Moro of Milan, the
infamous Cesare Borgia, and King Francis I of France.

Leonardo’s notebooks did not become generally known until the late eighteenth century, and were not published (and then only in fragmentary and occasional form) until the nineteenth century. Thus, he occupies the unique and peculiar role of a “private spaceman”—a thinker of preeminent originality, but whose unknown works exerted no influence
at all upon the developing history of science (for nearly all his great insights had been rediscovered independently before his notebooks came to light).
²

The overwhelmingly prevailing weight of public commentary about Leonardo continues to view him as Western culture’s primary example of a “spaceman,” that is, as a genius so transcendent that he could reach, in his own fifteenth century, conclusions
that the rest of science, plodding forward in its linear march to truth, would not ascertain for several hundred years. Leonardo stood alone and above, we are told over and over again, because he combined his unparalleled genius with a thoroughly modern methodology based on close observation and clever experiment. He could therefore overcome the ignorance and lingering sterile scholasticism
of his own times.

For example, the “Introductory Note” in the official catalog for a recent exhibition of the Leicester Codex in New York summarizes the basis of Leonardo’s success in these words: “In it [the codex] we can begin to see how he combined almost superhuman powers of observation with an understanding of the importance of experimentation. The results were inspired insights into the
workings of nature that match his artistic achievements.” When such conventional sources acknowledge the persisting medieval character of many Leonardian pronouncements, they almost always view this context as a pure impediment to be overcome by observation and experiment, not as a matrix that might have been useful to Leonardo, or might help us to understand his beliefs and conclusions. For example,
the closing passage of the long
Encyclopaedia Britannica
article on Leonardo states: “Leonardo approached this vast realm of nature to probe its secrets . . . The knowledge thus won was still bound up with medieval Scholastic conceptions, but the results of his research were among the first great achievements of the thinking of the new age because they were based on the principle of experience.”

I think that this conventional view could not be more wrong in its general approach to the history of knowledge, or more stultifying for our quest to understand this most fascinating man of our intellectual past. Leonardo did make wonderful observations. He did often anticipate conclusions that public science would not reach for another two or three centuries. But he was neither a spaceman nor
an angel—and we will never understand him if we insist on reading him as Hank Morgan, a man truly out of time, a modernist among the Medici, a futurist in the court of Francis the First.

Leonardo operated in the context of his time. He used his basically medieval and Renaissance concept of the universe to pose the great questions, and to organize the subjects and phenomena, that would generate
his phenomenal originality. If we do not chronicle,
and respect
, the medieval sources and character of Leonardo’s thought, we will never understand him or truly appreciate his transforming ideas. All great science, indeed all fruitful thinking, must occur in a social and intellectual context—and contexts are just as likely to promote insight as to constrain thought. History does not unfold along
a line of progress, and the past was not just a bad old time to be superseded and rejected for its inevitable antiquity.

In this essay, I will try to illustrate the centrality of Leonardo’s largely medieval context by analyzing his remarkable paleontological observations in the Leicester Codex. I will begin by acknowledging their truly prescient character, but will then raise two questions that
expose the early-sixteenth-century context of Leonardo’s inquiry: first, “What alternative account of fossils was Leonardo trying to disprove by making his observations?” and, second, “What theory of the earth was Leonardo trying to support with his findings?” Leonardo did not make his observations to win the praises of future generations; he studied fossils to probe these two questions of his
own time—and his answers could not be more deeply embedded in a “hot topic” of his own century that we would now mock and dismiss as hopelessly antiquated. Thus, we cannot understand Leonardo’s paleontology when we only marvel at his empirical accuracy and ignore the reasons for his inquiry.