The Lying Stones of Marrakech

by Stephen Jay Gould

  The plan followed by nature in producing animals clearly comprises a predominant prime cause. This endows animal life with the power to make organization gradually more complex…. Occasionally a foreign, accidental, and therefore variable cause has interfered with the execution of the plan … [producing] branches that depart from the series in several points and alter its simplicity.

  But Lamarck, five years later in his final book of 1820, now abandons this controlling concept of his career, and embraces the opposite conclusion. The influence of circumstances (leading to a branching model of animal taxonomy) rules the paths of evolution. All general laws, of progress or anything else, must be regarded as subservient to the immediate singularities of environments and histories. The influence of circumstances has risen from a disturbing and peripheral joker to the true lord of all (with an empire to boot):

  Let us consider the most influential cause for everything done by nature, the only cause that can lead to an understanding of everything that nature produces…. This is, in effect, a cause whose power is absolute, superior even to nature, since it regulates all nature’s acts, a cause whose empire embraces all parts of nature’s domain…. This cause resides in the power that circumstances have to modify all operations of nature, to force nature to change continually the laws that she would have followed without [the intervention of] these circumstances, and to determine the character of each of her products. The extreme diversity of nature’s productions must also be attributed to this cause.

  Lamarck’s great intellectual journey began with a public address about evolution, delivered in 1800 during a month that the revolutionary government had auspiciously named Floréal, or flowering. He then developed the first comprehensive theory of evolution in modern science—an achievement that won him a secure place in any scientific hall of fame or list of immortals—despite the vicissitudes of his reputation during his own lifetime and immediately thereafter.

  But Lamarck’s original system failed—and not for the reasons that we usually specify today in false hindsight (the triumph of Mendelism over Lamarck’s erroneous belief in inheritance of acquired characters), but by inconsistencies that new information imposed upon the central logic of Lamarck’s system during his own lifetime. We can identify a fulcrum, a key moment, in the unraveling of Lamarck’s original theory—when he attended a lecture by Cuvier on the anatomy of annelids, and recognized that he would have to split his taxonomie class of worms into two distinct groups. This recognition—which Lamarck recorded with excitement (and original art) as a handwritten insertion into his first published book on evolution—unleashed a growing cascade of consequences that, by Lamarck’s last book of 1820, had destroyed his original theory of primary ladders of progress versus subsidiary lateral deviations, and led him to embrace the opposite model (in both geometry of animal classification, and basic philosophy of nature) of a branching tree of life.

  A conventional interpretation would view this tale as fundamentally sad, if not tragic, and would surely note a remarkable symbol and irony for a literary conclusion. Lamarck began his adventure in the springtime month of flowering. But he heard Cuvier’s lecture, and his system began to crumble, on the eleventh day of Nivôse—the winter month of snow. How fitting—to begin with springtime joy and promise, and to end in the cold and darkness of winter.

  How fitting in one distorted sense—but how very, very wrong. I do not deny or belittle Lamarck’s personal distress, but how can we view his slow acknowledgment of logical error, and his willingness to construct an entirely new and contrary explanation, as anything other than a heroic act, worthy of our greatest admiration and identifying Lamarck as one of the finest intellects in the history of biology (the name that he invented for his discipline). Two major reasons lead me to view Lamarck’s intellectual odyssey in this eminendy positive light. First, what can be more salutary in science than the flexibility that allows a person to change his mind—and to do so not for a minor point under the compulsion of irrefutable data, but to rethink and reverse the most fundamental concept underlying a basic philosophy of nature?

  I would argue, secondly, that Lamarck’s journey teaches us something vitally important about the interaction between nature and our attempts to understand her ways. The fallacies and foibles of human thinking generate systematic and predictable trouble when we try to grasp the complexities of external reality. Among these foibles, our persistent attempts to build abstractly beautiful, logically impeccable, and comprehensively simplified systems always lead us astray. Lamarck far exceeded most colleagues in his attraction to this perilous style of theorizing—this esprit de système—and he therefore fell further and harder because he also possessed the honesty and intellectual power to probe his mistakes.

  Nature, to cite a modern cliché, always bats last. She will not succumb to the simplicities of our hopes or mental foibles, but she remains eminendy comprehensible. Evolution follows the syncopated drumbeats of complex and contingent histories, shaped by the vagaries and uniquenesses of time, place, and environment. Simple laws with predictable outcomes cannot fully describe the pageant and pathways of life. A linear march of progress must fail as a model for evolution, but a luxuriandy branching tree does express the basic geometry of history.

  When Lamarck snatched victory from the jaws of his defeat (by abandoning his beloved ladder of life and embracing the tree), he stood in proper humility before nature’s complexity—a lesson for us all. But he also continued to wresde with nature, to struggle to understand and even to tame her ways, not simply to bow down and acknowledge sovereignty. Only the most heroic people can follow Job’s great example in owning error while continuing to hurl defiance and to shout “I am here.” Lamarck greeted nature (traditionally construed as female) with Job’s ultimate challenge to God (construed as male, in equally dubious tradition): “Though he slay me, yet will I trust in him; but I will maintain mine own ways before him” (Job 13:15).

  I therefore propose that we reinterpret the symbolic meaning of Lamarck’s undoing in the month of Nivôse. Cuvier’s challenge elicited a cascade of discovery and reform, not the battering of bitter defeat. And snow also suggests metaphors of softness, whiteness, and purification—not only of frost, darkness, and destruction. God, in a much kinder mood than he showed to poor Job, promised his people in the first chapter of Isaiah: “though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool.” We should also remember that this biblical verse begins with an even more famous statement—a watchword for an intellectual life, and a testimony to Lamarck’s brilliance and flexibility: “Come now, and let us reason together.”

  3 The standard English literature on this subject always translates Lamarck’s phrase incorrectly as “intestinal worms.” These parasites dwell in several organs and places of vertebrate (and other) bodies, not only in the intestines. In French, the word intestin conveys the more general meaning of “internal” or “inside.”

  III

  Darwin’s Century

  — and Ours

  Lessons from

  Britain’s

  Four Greatest

  Victorian Naturalists

  7

  Lyell’s Pillars of

  Wisdom

  I. CONTROLLING THE FIRES OF VESUVIUS

  THE TWO CLASSICAL SCENARIOS FOR A CATASTROPHIC end of all things—destruction by heat and flames or by cold and darkness—offer little fodder for extended discussion about preferences, a point embedded, with all the beauty of brevity, in Robert Frost’s poem “Fire and Ice,” written in 1923:

  Some say the world will end in fire,

  Some say in ice.

  From what I’ve tasted of desire

  I hold with those who favor fire.

  But if it had to perish twice,

  I think I know enough of hate

  To say that for destruction ice

  Is about great

  And would suffice.

  Among nat
ural phenomena that poets and scholars have regarded as heralds or harbingers of the final consummation, volcanic eruptions hold pride of place. Mount Vesuvius may represent a mere pimple of activity compared with the Indonesian explosion of Tambora in 1815 or Kratakau in 1883, but a prime location on the Bay of Naples, combined with numerous eruptions at interesting times, has promoted this relatively small volcano into a primary symbol of natural terror.

  Given our traditional dichotomy for unpleasant finality, I note with some amusement that the two most famous encounters of celebrated scientists with this archetypal volcano—one in each millennium of modern history—have elicited contrasting comparisons of Vesuvian eruptions with the end of time: “lights out” for the first, “up in flames” for the second.

  Pliny the Elder (A.D. 23–79) wrote a massive compendium, Natural History, divided into thirty-seven libri (books) treating all aspects, both factual and folk-loric, of subjects now gathered under the rubric of science. Pliny’s encyclopedia exerted enormous influence upon the history of Western thought, particularly during the Renaissance (literally “rebirth”), when rediscovery of classical knowledge became the primary goal of scholarship (see chapter 3). Several editions of Pliny’s great work appeared during the first few decades of printing, following the publication of Gutenberg’s Bible in 1455.

  In August of A.D. 79, while serving as commander of the fleet in the Bay of Naples, Pliny noted a great cloud arising from Mount Vesuvius. Following the unbeatable combination of a scientist’s curiosity and a commander’s duty, Pliny sailed toward the volcano, both to observe more closely and to render aid. He went ashore at a friend’s villa, made a fateful decision to abandon the shaking houses for the open fields, and died by asphyxiation in the same eruption that buried the cities of Pompeii and Herculaneum.

  Pliny the Younger, his nephew and adopted son, remained at their villa, a few miles farther west of the volcano, to continue (as he stated) his studies of Livy’s historical texts. After the dust had settled—sorry, but I couldn’t resist this opportunity to use a cliché literally—he wrote two famous letters to the historian Tacitus, describing what he had heard of his uncle’s fate and what he had experienced on his own. Pliny the Younger recounted all the horrors of shaking houses, falling rocks, and noxious fumes, but he emphasized the intense darkness produced by the spreading volcanic cloud, a pall that he could compare only with one scenario for the end of time.*

  A darkness overspread us, not like that of a cloudy night, or when there is no moon, but of a room when it is shut up and all the lights are extinguished. Nothing then was to be heard but the shrieks of women, the screams of children, and the cries of men … some wishing to die from the very fear of dying, some lifting up their hands to the gods; but the greater part imagining that the last and eternal night had come, which was to destroy both the gods and the world together.

  Athanasius Kircher (1602–80), a German Jesuit who lived in Rome, where he served as an unofficial “chief scientist” for the Vatican, cannot be regarded as a household name today (although he served as a primary character and inspiration for Umberto Eco’s novel The Island of the Day Before). Nonetheless, Kircher ranked among the most formidable intellects of the seventeenth century. He wrote, for example, the most famous works of his time on magnetism, music, China (where the Jesuit order had already established a major presence), and the interpretation of Egyptian hieroglyphics (his system ultimately failed, but did offer important clues and inspiration for later scholars). Kircher tumbled into intellectual limbo largely because his Neoplatonic worldview became so completely eclipsed by an alternative concept of causality that we call modern science—a reform that Galileo (whom Kircher had more or less replaced as a leading scientist in Vatican eyes) had espoused in the generation just before, and that Newton would carry to triumph in the generation to follow.

  Kircher published his masterpiece in 1664, an immense and amazing work entitled Mundus subterraneus (Underground world), and covering all aspects of anything that dwelled or occurred within the earth’s interior— from lizards in caves, to fossils in rocks, to mountain springs, earthquakes, and volcanoes. Kircher had been inspired to write this work in 1637–38 when he witnessed the major eruptions of Etna and Stromboli. Mount Vesuvius, after centuries of quiescence, had also erupted in 1631, and Kircher eagerly awaited the opportunity to visit this most famous volcano on his return route to Rome.

  He climbed the mountain at night, guided by flames still issuing from the active crater, and then lowered himself as far as he dared into the fuming and bubbling vent the next morning. When he published his great treatise twenty-five years later, the memories of his fear and wonder remained so strong that he prefaced his entire volume with a vivid personal tale of his encounter with a primary symbol for the end of time. But Kircher favored the alternative scenario of fire:

  In the middle of the night, I climbed the mount with great difficulty, moving upward along steep and rugged paths, toward the crater, which, horrible to say, I saw before me, lit entirely by fire and flowing pitch, and enveloped by noxious fumes of sulphur…. Oh, the immensity of divine power and God’s wisdom! How incomprehensible are thy ways! If, in thy power, such fearful portents of nature now punish the duplicity and maliciousness of men, how shall it be in that last day when the earth, subjected to thy divine anger, is dissolved by heat into its elements. (My translation from Kircher’s Latin)

  I like to imagine that, as he wrote these lines, this greatest of priestly scientists hummed, sotto voce, the haunting Gregorian tune of the Dies irae, the most famous prayer about the last judgment:

  Dies irae, dies ilia

  Solvet saeclum in favilla

  [On this day of anger,

  the world will dissolve into ashes]

  Vesuvius looms over modern Naples even more ominously than Mount Rainier over Seattle, for Vesuvius lies much closer to the city center and sports a record of much more recent and frequent activity—though neither city could ever claim a medal from the global commission on safe geological siting. (My father, as a GI in World War II, observed the aftermath of the last eruption of Vesuvius in 1944.) In the light of this historical testimony, combined with a continuing and pervasive presence for any modern visitor (from a majestic mountain standing tall on the horizon, to the petrified bread and bathroom graffiti of ordinary life suddenly extinguished one fine day in Pompeii), how could anyone fail to draw from Vesuvius the same geological lesson that led Pliny and Kircher to extrapolate from a raging local volcano to a globally catastrophic end of time: the history of our planet must be ruled by sudden cataclysms that rupture episodes of quiescence and mark the dawn of a new order.

  And yet the most famous geological invocation of volcanism in the Bay of Naples, bolstered by the most celebrated visual image in the profession’s entire history, led scientific views of the earth in the opposite direction—toward a theory that currently observable processes, operating at characteristically gradual rates, could explain the full pageant of planetary history without any invocation of episodic global paroxysms or early periods of tumultuous planetary change, superseded later by staid global maturity.

  Charles Lyell (1797–1875), the primary architect of this “uniformitarian” view, and the most famous name in the history of anglophonic geology, visited Naples on the “grand tour” of European cultural centers that nearly all Britons of good breeding undertook as an essential part of a gentleman’s education. He made all the customary stops, from the steaming vents and bubbling pools of the Phlegraean Fields, to the early excavations of Pompeii, to the obligatory ascent of Vesuvius (still putting on a good show after erupting throughout the late eighteenth century, during the long tenure in Naples of British diplomat, and aficionado of volcanoes, Sir William Hamilton—a level of ardent activity matched only by the torrid, and rather public, affair between Hamilton’s wife Emma and Lord Nelson himself).

  How, then, could Lyell redefine Naples as a source of support for a theory so contrary bot
h to traditional interpretations and to the plain meaning of the grandest local sights? This question occupied the forefront of my mind as I prepared for my first trip to Naples. In contemplating this geological mecca, I could hardly wait to visit the palpable signs of Pliny’s misfortune (the excavations of Pompeii and Herculaneum), and to follow Kircher’s path to their immediate source. But most of all, I wanted to stand upon the site of Lyell’s visual epiphany, the source of his frontispiece for Principles of Geology (1830–33)—perhaps the most important scientific textbook ever written—and the primary icon for transforming the Vesuvian landscape from a poster for catastrophism into a paradoxical proof of triumphant gradualism: the three Roman columns of the so-called Temple of Serapis (actually a marketplace) at Pozzuoli. (I shall document, in the second part of this essay, how Lyell used these three pillars as a “tide gauge” to record extensive and gradual changes of land and sea levels during the past two thousand years—a uniformitarian antidote to the image of fiery Vesuvius as a symbol for catastrophic global endings.)

  The clichés of travel literature require an arduous journey sparked with tales of adventure and danger. But I have never managed to strike up a friendship with this stylistic convention, and I remain a city boy at heart (and therefore quite unafraid of rather different kinds of dangers). In truth, I never got to the top of Vesuvius. My rented car carried no tire chains, and a sheet of January ice had closed the road. As for Pozzuoli, I can’t claim any more adventure than a trip to South Ferry or Ozone Park would provide. Pozzuoli is the last stop on the Neapolitan subway.

  But then, why should intellectual content correlate with difficulty of physical access—a common supposition that must rank among the silliest of romantic myths? Some of the greatest discoveries in the history of science have occurred in libraries or resided, unsuspected for decades, in museum drawers. By all means, take that dogsled across the frozen wastes if no alternative exists, but if the A train also goes to the same destination, why not join Duke Ellington for a smoother ride?