All of the layers of land we now see, Hutton argued, had once been loose materials, washing around at the bottom of oceans; heat had fused these materials together and pushed them up above the ocean’s surface, producing dry land. This dry land was, in turn, constantly worn away by the waters around it, in a repeating cycle. This process could still be observed in the oceans and continents of the present day.
In other words, the earth around us had been formed not by huge past catastrophic events, not by extraordinary interventions, but simply through the exact same ebbs and flows, waves and recesses, accumulations and erosions, that still continue.6
Whatever happened in the past could be explained simply by observing the present; or, as later thinkers would phrase it, “the present is the key to the past.” There was uniformity between the natural phenomena we now see and the natural phenomena of epochs past—and, by inference, the natural phenomena of the future. “We are to examine the construction of the present earth,” Hutton explained, “in order to understand the natural operations of time past; [and] to acquire principles, by which we may conclude with regard to the future course of things.”7
Accepting the principle of uniformity (there were no great past catastrophes; the earth has been formed by the natural processes we can still measure) led to another conclusion. Those processes, which produce change very, very slowly, must have been going on for a very long time. “To sum up the argument,” Hutton wrote, “we are certain that . . . this operation is so extremely slow, that we cannot find a measure of the quantity in order to form an estimate. . . . The production of our present continents must have required a time which is indefinite.”8
Indefinite: outside of our ability to define. At the end of the first chapter of his paper, Hutton put this in even stronger terms: “The result, therefore, of this physical inquiry,” he concluded, “is that we find no vestige of a beginning, no prospect of an end.” This was not the Greek version of an eternal and unchanging earth, but rather a vision of a physical world that changes on an entirely different timescale than the one we inhabit. Hutton’s paper put into words what Buffon had only implied: that geologic time, “deep time,” is so different from the time of human experience that we can barely even use the measure of years to express it.9
This was even more transgressive of the Genesis story than Buffon’s relatively mild epochs had been, which may account for Hutton’s attack of nervous vapors on his first scheduled appearance before the Royal Society. Oddly, though, his paper—published three years later under the title Theory of the Earth—attracted relatively little ire. His biographer Playfair blames intellectual exhaustion: “The world was tired out with unsuccessful attempts to form geological theories,” he complains, “by men often but ill informed of the phenomena which they proposed to explain.”10
Jean André Deluc published a rebuttal of Hutton’s chronology, as did the Irish chemist Richard Kirwan, who accused Hutton of theorizing “contrary to reason and the tenor of the Mosaic history.” But geology was still a brand-new field, its practitioners were widely dispersed, and ten years after the publication of Theory of the Earth, reaction to Hutton’s theories of uniformity and deep time were still scattered. “This Theory of the Earth,” Playfair complains, “[should] have produced a sudden and visible effect, and . . . men of science would have been everywhere eager to decide concerning its real value. Yet the truth is, that it drew their attention very slowly.”11
Part of the blame may lie with Hutton’s writing, which tends toward the serpentine. (As Dennis Dean puts it, Hutton was “almost entirely innocent of rhetorical accomplishments.”) And Hutton also failed to explain whether any sort of catastrophe could have taken place in the past—which was confusing, given that sediment deposits and fossil strata seemed to testify to some unusual events, sometime in the past. But the Theory of the Earth was as much philosophy as science; Hutton was attempting to establish a general principle for earth science (“We cannot know anything about the past except through the lens of the present”), not to interpret the history of particular geologic layers.12
James Hutton, who was suffering from chronic kidney failure, did not live to see his theory either fully embraced or decisively rejected. He spent the next ten years working, slowly and painfully, on a revision and expansion of Theory of the Earth; it was published in 1795 and turned out to be even more obscure than the original.
In March of 1797, after a long day of writing, he was seized with fits of shivering and cramps. He sent for his personal physician but died just as the doctor arrived.13
•
One year before Hutton’s death, a young French naturalist named Georges Cuvier presented his first major paper to the National Institute of Sciences and Arts in Paris.
Cuvier, twenty-seven years old, had recently been elected to membership in the National Institute (the French equivalent of the Royal Society). He had studied in both France and Germany, mastering both Aristotle’s History of Animals and Buffon’s thirty-five-volume Natural History, and he had recently been appointed to a position at the National Museum of Natural History in Paris, where his job was to organize and catalogue a massive collection of fossil bones that had never been properly sorted (a “charnel house,” he called it) and also to deliver public lectures on animal anatomy.
The 1796 paper Mémoires sur les espèces d’éléphants vivants et fossiles (“On the Species of Living and Fossil Elephants”) compared the skeletons of Indian and African elephants to fossilized bones found in Siberia. These bones were thought by many naturalists to belong to ancient elephants, but Cuvier argued that differences in the skull shape, tusks, and teeth proved that the fossil bones belonged to an entirely different species—a “mammoth” animal, not an elephant at all, that had been wiped out. The “mammoth,” he concluded, was extinct—a “lost species” that no longer lived on the earth.14
This was a highly controversial statement.
After Nicholas Steno, most naturalists had come to accept that fossils were remains of living creatures instead of oddly shaped rock formations. But the idea that whole species of animals might have died out, in the past, was problematic from three different directions. It posed a theological difficulty: how could God have created animals that weren’t designed well enough to survive? It contradicted Aristotelian principles of biology, still accepted by many students of animal anatomy: animals had developed their structure so that they could function well and survive in their environment. And it made no sense in terms of Hutton’s recently proposed theory of infinitesimally gradual change: this change was surely too slow to wipe out entire classes of creatures, so recently that their bones still existed.
Many students of animal life continued to insist that fossils (like the Siberian mammoth) were variations on still-existing species, or that (like the mollusk remnants known as ammonites) they still existed in the very deep ocean, or somewhere that couldn’t be easily investigated by humans. But Cuvier disagreed.
He had, so far, no explanation for why some species had died out. He had not started out with a grand, overarching theory of life and tried to fit the mammoth fossils into it. Instead, he had exercised the scientific, Baconian method: close and careful examination of specific natural phenomena. This examination had led him to a conclusion: The mammoth was not an elephant. It was something else, and it no longer existed.
As he attempted to put together a history of different animal species that had populated (or still roamed) the earth, Cuvier found himself, unexpectedly, constructing a history of the earth itself. “There is a science that does not appear at first sight to have such close affinities with anatomy,” he noted in his 1796 paper,
one that is concerned with the structure of the earth, that collects the monuments of the physical history of the globe, and tries with a bold hand to sketch a picture of the revolutions it has undergone; in a word, it is only with the help of anatomy that geology can establish in a sure manner several of the facts that can serve as its f
oundations.15
Revolutions: hardly an innocuous word in a country that had seen the storming of the Bastille only seven years earlier. Already germinating in Cuvier’s mind was a possible explanation—that the mammoth, not to mention other fossil species (such as an enormous skeleton found in Ohio, which he later labeled the “mastodon”), might have been wiped out by an extraordinary, globe-changing, onetime catastrophe.
To Cuvier, nothing seemed more likely than that the history of the globe might mirror the stormy transitions of human society. And so, at the very end of his careful analysis of skeletons, he detoured into speculation:
What has become of these two enormous animals of which one no longer finds any traces, and so many others of which the remains are found everywhere on earth, and of which perhaps none still exist? . . . All of these facts . . . seem to me to prove the existence of a world previous to ours, destroyed by some kind of catastrophe. But what was this primitive earth? What was this nature that was not subject to man’s dominion? And what revolution was able to wipe it out, to the point of leaving no trace of it except some half-decomposed bones?
Committed to Baconian science, Cuvier could merely pose these questions, not answer them with any kind of certainty:
It is not for us to involve ourselves in the vast field of conjectures that these questions open up. Only more daring philosophers undertake that. Modest anatomy, restricted to detailed study and to the scrupulous comparison of the objects submitted to its eyes and its scalpel, will be content with the honor of having opened up this new highway to the geniuses who will dare to follow it.16
For the next three or four years, Cuvier concentrated on “modest anatomy,” analyzing and categorizing the bones in his “charnel house.” By 1800 he had identified twenty-three new species, all of which appeared to be extinct. And increasingly, he found himself pushed toward that “vast field of conjectures”—a theory of the earth itself. In a series of public lectures given in 1804 and 1805, he proposed that fossil beds revealed the “strongest proofs that the globe has not always been as it is at present.” The rock layers in which fossils were found could be used to construct a time line of the earth’s development; the fossil strata were a book of the earth’s past that could be read by the perceptive. Among his suggestions:
The parts that contain no organized bodies at all are the most ancient. Thus [life] has not always existed.
There have been several successive changes in state, from sea into land, from land into sea.
There have been different ages, producing different kinds of fossils.
Several of the revolutions that have changed the state of the globe have been sudden.17
Cuvier had moved from “conjecture” to hypothesis: the book of the earth, he now believed, was peppered with catastrophes.
While preparing and delivering his public lectures, he had also been working with one of his colleagues at the National Museum, the mineralogist Alexandre Brongniart, on a project analyzing the rock strata around Paris. The city sits in a 7,000-square-mile basin of sedimentary rock; Cuvier and Brongniart had been carefully constructing a cross-sectional map of the basin’s layers. In 1808 they presented their findings to the National Institute, and in 1811 the findings were printed, in an expanded form, for the public to read.
The bassin de Paris, they explained, was made up of an ancient foundation of chalk, over which successive layers had been deposited, one by one. Each of these layers contained unique fossils. Including the chalk, there were six distinct layers in the Paris Basin; six different eras in the earth’s past, each with its own population of plants and animals, some now extinct.
This orderly reading of a sequential past into confused and often disturbed layers caused a minor sensation in the world of natural philosophy; in both Europe and Britain, other mineralogists and “geologists” (still a brand-new term) set themselves to analyzing local layers of rock in the same way. Cuvier himself took an even wider view. The six layers of the Paris Basin, he soon concluded, were a microcosm of the planet; and he was quick to extrapolate his discoveries into an earth-wide theory.
He published this theory in 1812 as the first section of his collected papers on fossils (Recherches sur les ossemens fossiles de quadrupèdes, an anthology of all the different studies he had presented and published since 1804). The Recherches was a technical work for specialists, but the first section, which Cuvier titled “Preliminary Discourse,” was intended for the general public.18
The earth, Cuvier argued, had undergone six separate catastrophic changes. The fossil content of each Paris layer changed suddenly and distinctly, not gradually and by degrees (as Hutton’s theory of uniformity suggested); therefore, it seemed clear that a series of nearly worldwide disasters had wiped out various populations of flora and fauna, leaving only small unaffected areas from which surviving animals and plants could then migrate over the newly changed surface of the earth. The “Discourse” covers, carefully and methodically, the proofs of these six calamities in fossil beds, in soil strata, and in mountain rocks. “Thus, life on earth has often been disturbed by terrible events,” Cuvier concluded, “calamities which initially perhaps shook the entire crust of the earth to a great depth. . . . These great and terrible events are clearly imprinted everywhere, for the eye that knows how to read.” Cuvier was working on the same methodological path as Hutton, but the close examination of the earth had led the two men in opposite directions: one toward an earth history that rumbled along in a steady, unspectacular, single direction; the other, toward a past punctuated by multiple unexpected disasters.19
The “Preliminary Discourse” was translated and republished separately again and again, reaching an even wider audience than Cuvier had hoped. The theory of repeating catastrophes struck a chord in his readers—not just the French citizens who were living in the wake of the recent revolution, but also the British and European readers who had been raised with the biblical accounts. Cuvier’s six “eras” were easily reconciled with the six days of creation; his extraordinary events recollected creation ex nihilo, the Fall, the Great Deluge.
Which was, in all likelihood, not Cuvier’s intention. He was reading the layers of the Paris Basin, not the book of Genesis. At the very end of the “Discourse” he suggests that the biblical Flood, as well as flood accounts from China and India, might preserve the memory of the last of his six catastrophes: “All known traditions make the renewal of society reach back to a major catastrophe,” he writes, “[but] the date cannot reach back much more than five or six thousand years. . . . But these countries . . . had already been inhabited previously, if not by men, then at least by terrestrial animals.” He had come to his conclusion because of the physical evidence, not the biblical story.
In fact, although the Great Deluge might mark the beginning of human civilization, the era of human existence is only a small and recent one, compared with the entire history of the earth: “Man,” Cuvier concludes, “to whom has been accorded only an instant on earth, [may now have] the glory of reconstructing the history of the thousands of centuries that preceded his existence, and of the thousands of beings that have not been his contemporaries.”20
This, too, was a version of deep time, of thousands of centuries preceding the human race.
Cuvier’s catastrophism proposed a very different mechanism for change than Hutton’s long, slow uniformity of process. Over the next decades, uniformity and catastrophism would struggle for control over the interpretation of the earth’s raw data. But despite their differences, the two theories shared a common commitment: both would find Bishop Ussher’s date far, far too recent to make sense of the history of the earth.
To read relevant excerpts from the Theory of the Earth, visit http://susanwisebauer.com/story-of-science.
JAMES HUTTON
Theory of the Earth
(1785/1788)
James Hutton’s prose style does him no favors; even his biographer Playfair, one of his greatest fans, remarks delicate
ly that the reasoning is “sometimes embarrassed by the care taken to render it strictly logical,” and that the “transitions, from the author’s peculiar notions of arrangement, are often unexpected and abrupt.” But Hutton’s argument for a long and uniform history provided the foundation for modern geology. It isn’t necessary to plow through the entire, unnecessarily obscure Theory of the Earth, but be sure to read the first chapter, which outlines the basic method by which Hutton believes the continents took shape, and also presents Hutton’s version of deep time.
Although there are several versions of the original 1785 and 1788 English text archived online, they use unmodernized spelling, and the scans are often indistinct. A digital version with modern typesetting is available for Kindle.
James Hutton, Theory of the Earth, Amazon Digital Services (e-book, no date, ASIN B0071FII7O).
A paperback reprint is available from Kessinger Publishing.
James Hutton, Theory of the Earth, Kessinger Publishing (paperback, 2010, ISBN 978-1162713540).
To read relevant excerpts from “Preliminary Discourse,” visit http://susanwisebauer.com/story-of-science.
GEORGES CUVIER
“Preliminary Discourse”
(1812)
The best modern translation of Cuvier is found in an anthology of Cuvier’s works collected and translated by Martin J. S. Rudwick. It contains not only the “Preliminary Discourse,” but excerpts from Cuvier’s groundbreaking 1796 paper, the 1811 publication on the Paris Basin, and other works.
The “Preliminary Discourse,” or “The Revolutions of the Globe” (the title often given the discourse when published separately), is found in Chapter 15. There is no need to read all of Rudwick’s preface, which is almost as long as the “Discourse” but less elegantly written.
The Story of Western Science Page 13