Ever Since Darwin: Reflections in Natural History

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Ever Since Darwin: Reflections in Natural History Page 13

by Stephen Jay Gould


  Utterly fantastic? Sure, for 1975; but not for 1681. In fact, for his own time, Burnet was a rationalist, upholding the primacy of Newton’s world in an age of faith. For Burnet’s primary concern was to render earth history not by miracles or divine caprice, but by natural, physical processes. Burnet’s tale may be fanciful, but his actors are the ordinary physical forces of desiccation, evaporation, precipitation, and combustion. To be sure, he believed that the facts of earth history were given unambiguously in scripture, yet they must be consistent with science, lest God’s words be opposed to his works. Reason and revelation are two infallible guides to truth, but

  ’tis a dangerous thing to ingage the authority of Scripture in disputes about the Natural World, in opposition to Reason; lest Time, which brings all things to light, should discover that to be evidently false which we had made Scripture to assert.

  Moreover, Burnet’s God is not the continuous and miraculous actor of a prescientific age, but Newton’s imperial clock-winder who, having created matter and ordained its laws, let nature run its own course:

  We think him a better Artist that makes a Clock that strikes regularly at every hour from the Springs and Wheels which he puts in the work, than he that hath so made his Clock that he must put his finger to it every hour to make it strike; And if one should contrive a piece of Clock-work so that it should beat all the hours and make all its motions regularly for such a time, and that time being come, upon a signal given, or a Spring toucht, it should of its own accord fall all to pieces; would not this be look’d upon as a piece of greater Art, than if the Workman came to that time prefixt, and with a great Hammer beat it into pieces?

  I do not, of course, argue that Burnet was a scientist in any modern sense of the term. He performed no experiments and he made no observations of rocks and fossils (although several of his contemporaries did). He used a method of “pure” (we would say armchair) reason, and he wrote with as much confidence about an unobservable future as about a verifiable past. Likewise, his procedure is followed by no modern scientist that I know, with the exception of Immanuel Velikovsky (see essay 19)—for Burnet assumed the truth of scripture and fashioned a physical mechanism to make it happen, just as Velikovsky invented a new planetary physics to preserve the literal account of ancient records.

  Yet Burnet was no pillar of the theistic establishment. In fact, he got himself into considerable trouble over the sacred theory. In the best tones of the Inquisition, the bishop of Hereford attacked Burnet’s reliance on reason: “Either his Brain is crakt with overlove of his own Invention, or his Heart is rotten with some evil design”—that is, the subversion of the church. In a classic statement of antiscience, another clerical critic remarked: “Though we have Moses, yet I believe we must stay [wait] for Elias, to make out to us, the true Philosophical modus of the Creation and Deluge.” (The biblical reference is to Elijah, who will return to herald the Messiah’s advent—that is, science cannot discuss these questions and we must await some future revelation for their solution.) John Keill, an Oxford mathematician, argued that Burnet’s natural explanations were dangerous because they encouraged a belief that God is superfluous.

  Nonetheless, Burnet prospered for a time. He became Clerk of the Closet at the court of William III. (That title is not a fancy name for latrine cleaners but a designation for the royal confessor—the closet being a chapel for the king’s private devotions.) Rumor has it that he was even considered as a possible successor to the Archbishop of Canterbury. But Burnet finally went too far. In 1692, he published a work advocating an allegorical interpretation of the six days of Genesis—and he promptly lost his job, despite his profuse apologies for any unintended offense.

  It was the dogmatists and antirationalists who got Burnet in the end, not the theists (there were no reputable atheists outside the closet in seventeenth-century England). One hundred years later, the same men made Buffon retract his theory of the earth’s antiquity. One hundred fifty years after that, they unleashed a pompous, three-time loser against John Scopes. Today, using the liberal rhetoric of equal time, they are trying to drive evolutionary theory from the nation’s textbooks.

  Science, to be sure, has transgressed as well. We have persecuted dissenters, resorted to catechism, and tried to extend our authority to a moral sphere where it has no force. Yet without a commitment to science and rationality in its proper domain, there can be no solution to the problems that engulf us. Still, the Yahoos never rest.

  18 | Uniformity and Catastrophe

  THE GIDEON SOCIETY—those purveyors of spiritual comfort to a mobile nation—persist in recording the date of creation as 4,004 B.C. in their marginal annotation to Genesis 1. Geologists believe that our planet is at least a million times more ancient—some 4 1/2 billion years old.

  Each of the major sciences has contributed an essential ingredient to our long retreat from an initial belief in our own cosmic importance. Astronomy defined our home as a small planet tucked away in one corner of an average galaxy among millions; biology took away our status as paragons created in the image of God; geology gave us the immensity of time and taught us how little of it our own species has occupied.

  In 1975, we celebrated the centenary of the death of Charles Lyell, conventional hero of the geologic revolution—“the mirror of all that really mattered in geologic thought,” according to one recent biographer. The standard account of Lyell’s accomplishment runs in the following way: in the early nineteenth century, geology was dominated by the catastrophists—theological apologists who sought to compress the geologic record into the strictures of biblical chronology. To do this, they imagined a profound discordance between past and present modes of change. The present may run slowly and gradually as waves and rivers do their work; the events of the past were abrupt and cataclysmic—for how else could they fit into a few thousand years? Mountains were raised in a day, and canyons opened at once. Thus, the Lord interposed his will to break the rule of natural law and place the past outside the sphere of scientific explanation. Loren Eiseley writes: “[Lyell] entered the geological domain when it was a weird, half-lit landscape of gigantic convulsions, floods and supernatural creations and extinctions of life. Distinguished men had lent the power of their names to these theological fantasies.”

  In 1830, Lyell published the first volume of his revolutionary Principles of Geology. He, so the standard story goes, boldly proclaimed that time had no limit. Having removed this fundamental constraint, he advocated a philosophy of “uniformitarianism”—the doctrine that made geology a science. Natural law is invariant. With so much time, we need invoke no more than the slow and steady operation of present causes to produce the entire panorama of past events. The present is the key to the past.

  This tale of Lyell’s role is no different from most standard accounts in the history of science: it is long on inspiration and rather short on accuracy.

  A few months ago, while browsing through the stacks of Harvard’s ancient library, I discovered Louis Agassiz’s annotated copy of Lyell’s Principles of Geology (more things are buried in libraries than this world dreams of). Agassiz was America’s leading biologist and also her staunchest catastrophist. Yet his marginalia include an impossible contradiction if we accept the standard account of Lyell’s achievement. Agassiz’s penciled annotations include all the standard critiques of the catastrophist school. They record, in particular, Agassiz’s conviction that the summation of present causes over geologic time cannot account for the magnitude of some past events; a notion of cataclysm, he believes, is still required. Nonetheless, he writes as his final assessment: “Mr. Lyell’s Principles of Geology is certainly the most important work that has appeared on the whole of this science since it has merited its name.” (It occurred to me that Agassiz might have been citing someone else’s assessment from a published review; but I have consulted with several historians and we have concluded that his annotation reflects his own opinion.)

  If catastrophists wore the black mo
ustaches, if uniformitarians sported silver stars and white hats, and if Lyell was the sharp-shooting sheriff who kicked all the baddies out of town—the Manichaean or western-movie version of the history of science—then Agassiz’s statements are absurd, for how could a wrongdoer at liberty praise the sheriff so obsequiously? Either the western script is wrong or Agassiz was crazy.

  Why, then, did Agassiz praise Lyell? To answer that question, I must analyze Lyell’s so-called uniformitarianism, in order to argue that modern geology is really a blend of concepts from both Lyell and the catastrophists.

  Charles Lyell was a lawyer by profession, and his book is one of the most brilliant briefs ever published by an advocate. It is a mélange of precise documentation, incisive argument, and a few of the “quiddities, quillets [quibbles] … and tricks” that Hamlet ascribed to the profession when he exhumed a lawyer’s skull from the graveyard. Lyell relied upon two bits of cunning to establish his uniformitarian view as the only true geology.

  First, he set up a straw man to demolish. By 1830, no serious scientific catastrophist believed that cataclysms had a supernatural cause or that the earth was 6,000 years old. Yet, these notions were held by many laymen, and they were advocated by some quasi-scientific theologians. A scientific geology required their defeat, but they had been routed within the profession by both catastrophists and uniformitarians. Agassiz praised Lyell because he brought a geologic consensus so forcefully to the public.

  It is not Lyell’s fault that later generations accepted his straw man as an accurate representation of the scientific opposition to uniformitarianism. Yet all of the great nineteenth-century catastrophists—Cuvier, Agassiz, Sedgwick, and Murchison in particular—accepted an earth of great antiquity, and they all sought a natural basis for the cataclysmic changes that occurred in the past. A 6,000-year-old earth does require a belief in catastrophes to compress the geologic record into so short a time. But the converse is decidedly not true: a belief in catastrophes does not dictate a 6,000-year-old earth. The earth might be 4.5 or, for that matter, 100 billion years old and still build its mountains with great rapidity.

  In fact, the catastrophists were much more empirically minded than Lyell. The geologic record does seem to record catastrophes: rocks are fractured and contorted; whole faunas are wiped out (see essay 16). To circumvent this literal appearance, Lyell imposed his imagination upon the evidence. The geologic record, he argued, is extremely imperfect and we must interpolate into it what we can reasonably infer but cannot see. The catastrophists were the hard-nosed empiricists of their day, not the blinded theological apologists.

  Secondly, Lyell’s “uniformity” is a hodgepodge of claims. One is a methodological statement that must be accepted by any scientist, catastrophist and uniformitarian alike. Others are substantive notions that have since been tested and abandoned. Lyell gave them a common name and pulled a consummate fast one: he tried to slip the substantive claim by with an argument that the methodological proposition had to be accepted, lest “we see the ancient spirit of speculation revived, and a desire manifested to cut, rather than patiently to untie, the Gordian knot.”

  Lyell’s concept of uniformity has four major, and very different, components:

  1.Natural laws are constant (uniform) in space and time. As John Stuart Mill showed, this is not a statement about the world; it is an a priori claim of method that scientists must make in order to proceed with any analysis of the past. If the past is capricious, if God violates natural law at will, then science cannot unravel history. Agassiz and the catastrophists agreed; they, too, sought a natural cause for cataclysms and praised Lyell’s basic defense of science against theological intrusion.

  2.Processes now operating to mold the earth’s surface should be invoked to explain the events of the past (uniformity of process through time). Only present processes can be directly observed. Therefore, we are better off if we can explain past events as a result of processes still acting. This again is not an argument about the world; it is a statement about scientific procedure. And again, no scientist disagreed. Agassiz and the catastrophists also preferred present processes, and they applauded Lyell’s exquisite documentation of how much these processes can accomplish. Their disagreement concerned another issue. Lyell believed that present processes were sufficient to explain the past; catastrophists held that present processes should always be preferred, but that some past events required the inference of causes no longer acting or acting now at markedly slower rates.

  3.Geologic change is slow, gradual, and steady, not cataclysmic or paroxysmal (uniformity of rate). Here we finally encounter a substantive claim that can be tested—and a point of real difference between Agassiz and Lyell. Modern geologists would argue that Lyell’s view has largely prevailed, although they would also point out that his original insistence on a near uniformity of rate was stifling to the imagination. (Lyell, for example, never accepted the glacial theory that Agassiz developed; he would not concede that amounts of ice and rates of flow had been so different in the past.)

  4.The earth has been fundamentally the same since its formation (uniformity of configuration). This last component of Lyell’s uniformity is rarely discussed. After all, it is an empirical claim, and largely an incorrect one at that—and who wants to expose the false steps of a hero? Yet I believe that this uniformity was closest to Lyell’s heart and most central to his concept of the earth. Newton’s earth revolves endlessly about its star with no direction to its history. One moment is like all moments. Could not such a grand vision apply to the geological record of our planet as well? Land and sea might change their positions, but land and sea exist through time in roughly the same proportion; species come and go, but the mean complexity of life remains forever constant. Endless change in detail, ceaseless constancy in aspect—a dynamic steady state, to use today’s jargon of information theory.

  Lyell’s vision led him to propose, contrary to all evidence, that mammals would be found in the earliest fossiliferous beds. To reconcile the appearance of direction with dynamic constancy in the history of life, he supposed that the entire fossil record represents but one part of a “great year”—a grand cycle that will occur again when “the huge iguanodon might reappear in the woods, and the ichthyosaur in the sea, while the pterodactyle [sic] might flit again through umbrageous groves of tree ferns.”

  The catastrophists took the literal view. They saw direction in the history of life, and they believed it. In retrospect, they were right.

  Most geologists would tell you that their science represents the total triumph of Lyell’s uniformity over unscientific catastrophism. Lyell’s brief won the victory for his name, but modern geology is really an even mixture of two scientific schools—Lyell’s original, rigid uniformitarianism and the scientific catastrophism of Cuvier and Agassiz. We accept Lyell’s first two uniformities, but so did the catastrophists. Lyell’s third uniformity, appropriately derigidified, is his great substantive contribution; his fourth (and most important) uniformity has been graciously forgotten.

  Yet there is much to be said for Lyell’s vision of steady state. A dynamic constancy may seem fundamentally at odds with clearly directional aspects of the history of life and the earth. But medieval Christianity could encompass both views in its concept of history. In the stained glass of Chartres, human history is displayed as a linear sequence beginning in the north transept and running around the nave to the south transept—a directional process: one creation, one coming of Christ, one resurrection of the dead. But correspondence also pervades the system, giving a timelessness to apparent direction. The New Testament is a replay of the Old. Mary is like the burning bush because both held within themselves the fire of God, yet were not consumed. Christ is like Jonah because both arose again after three days in extremis. The two visions—directionalism and dynamic constancy—are not irreconcilable. Geology, too, might seek their creative synthesis.

  19 | Velikovsky in Collision

  NOT LONG AGO, Venus e
merged from Jupiter, like Athena from the brow of Zeus—literally! It then assumed the form and orbit of a comet. In 1500 B.C., at the time of the Jewish exodus from Egypt, the earth passed twice through Venus’s tail, bringing both blessings and chaos; manna from heaven (or rather from hydrocarbons of a cometary tail) and the bloody rivers of the Mosaic plagues (iron from the same tail). Continuing its erratic course. Venus collided with (or nearly brushed) Mars, lost its tail, and hurtled to its present orbit. Mars then left its regular position and almost collided with the earth in about 700 B.C. So great were the terrors of these times, and so ardent our collective desire to forget them, that they have been erased from our conscious minds. Yet they lurk in our inherited and unconscious memory, causing fear, neurosis, aggression, and their social manifestations as war.

  This may sound like the script of a very poor, late-late movie on TV; nonetheless, it represents the serious theory of Immanuel Velikovsky’s Worlds in Collision. And Velikovsky is neither crank nor charlatan—although to state my opinion and to quote one of my colleagues, he is at least gloriously wrong.

  Worlds in Collision, published twenty-five years ago, continues to engender intense debate. It also has spawned a series of issues peripheral to the purely scientific arguments. Velikovsky was surely ill treated by certain academics who sought to suppress the publication of his work. But a man does not attain the status of Galileo merely because he is persecuted; he must also be right. The scientific and sociological issues are separate. And then, times and the treatment of heretics have changed. Bruno was burned to death; Galileo, after viewing the instruments of torture, languished under house arrest. Velikovsky won both publicity and royalties. Torquemada was evil; Velikovsky’s academic enemies, merely foolish.

 

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