To begin the second act of Gilbert and Sullivan’s Patience, Lady Jane enters a bare set, seats herself before her cello, and in two verses bemoans the changes of increasing age. In the first, or conventional, account, she laments what she has lost with the years, but in the second (speaking mostly of weight) she reports a steady increase: “There will be too much of me in the coming by and by!” The humor of this song plays upon our onesided notion that anything old must become battered, worn, and increasingly bereft of information.

Scholars often make the same false assumption that contemporary cases must provide optimal data, while the records of scientific work steadily decrease in depth and reliability as they grow older and older. We might therefore suppose that, to understand science, a historian or sociologist should study debates and discoveries now in the making. Yet a moment’s thought about our technological age should expose the fallacy in such a position. Our machines have generally made data more ephemeral, or left it simply unrecorded. The telephone is the greatest single enemy of scholarship; for what our intellectual forebears used to inscribe in ink now goes once over a wire into permanent oblivion.

Moreover, in losing the art of writing letters, many scientists have abandoned the written word in a great many previous applications, from diaries (now passed from fashion) to lab notebooks (now punched directly in “machine-readable” format). The present can be a verbal wasteland. Paradoxically, then, our most copious data should, like Lady Jane, occupy a comfortable middle age—old enough to avoid our modern technological debasement, and young enough to forestall the inevitable losses of time’s destruction.

“The great Devonian controversy” occurred during the 1830s, an optimal decade probably unmatched for density of recorded detail. The controversy began with an apparently minor problem in dating the strata in Devonshire; it ended with a new view of the history of the earth. Martin Rudwick can usually trace the course of its enormously varied and complex changes on a daily basis; little more than conversations over ale and coffee, or bedtime thoughts before candle snuffing, seems to be missing. But density of data makes no case for significance on the fallacious premise that “bigger is better.” The subject must also be important and expansive. After a superficial first glance, most readers of good will and broad knowledge might dismiss The Great Devonian Controversy as being too much about too little. They would be making one of the biggest mistakes in their intellectual lives.

I want to state right away how much I respect and admire Martin Rudwick’s book for its rigor, its insights, and its uncompromising intellectual integrity. It is, in a phrase I rarely use, a masterpiece of scholarship. I make this clear because I disagree with its central interpretation of the controversy, and reach a conclusion opposite to Rudwick’s for what. I regard as an interesting (not merely ornery) reason. Only the best books can be praised so highly in the face of basic disagreement.

The geological time scale is a layer cake of odd names, learned by generations of grumbling students by way of mnemonics either too insipid or too salacious for publication: Cambrian, Ordovician, Silurian, Devonian…. Their ubiquity in all geological writing has led students to suspect that these names, like the rocks they represent, have been present from time immemorial (et nunc, et semper, et in saecula saeculorum, amen). In fact, the geological time scale was established in an amazingly fruitful burst of research during the first half of the nineteenth century. In 1800, scientists knew that the earth was ancient, but had no frame for ordering events into an actual history. The primary criterion for unraveling that history—the sequence of unique events forming the complex history of life as recorded by fossils—had not been developed. Indeed, many fine scientists still denied that species could become extinct at all on an earth made properly by a benevolent deity. Geologists of 1800 confronted a situation not unlike the hypothetical, almost unthinkable dilemma that historians would face if they knew that modern cultures had antecedents recorded by artifacts, but did not know whether Cheops preceded Chartres or, indeed, whether any culture, however old and different, might not still survive in some uncharted region.

By 1850, history had been ordered in a consistent, worldwide sequence of recognizable, unrepeated events, defined by the ever-changing history of life, and recorded by a set of names accepted and used in the same way from New York to Moscow. This “establishment of history” was a great event in the annals of human thought, surely equal in importance to the more theoretical, and much lauded “discovery of time” by geologists of generations just preceding. Yet while we celebrate Galileo, Darwin, and Einstein, who beyond a coterie of professionals has ever heard of William Smith, Adam Sedgwick, and Roderick Impey Murchison, the architects of our geological time scale and, therefore, the builders of history? Why has their achievement—surely as important an accomplishment as any ever made in science—been so invisible?


We must resolve this vexatious question in order to appreciate The Great Devonian Controversy, for Rudwick’s seminal book tells the story of how one major period of the earth’s history was recognized and unraveled. That period, the Devonian, occupies the crucial time between 410 and 360 million years ago, when life flourished in the seas, and plants and vertebrate animals became abundant and diverse on land. We will not grasp the importance of this achievement if we follow a common impression and consider stratigraphic geology as “mere description,” to be dismissed as “narrative” in the primitive mode of unquantified storytelling. The Great Devonian Controversy challenges us to understand natural history as a worthy style of science, equal in rigor and importance to the more visible activities of measurement and experiment that set the stereotype of science in the public image. Its success might therefore prompt a broadscale reassessment of science itself as a human activity. The Great Devonian Controversy, in its unassuming and highly technical format, could become one of our century’s key documents in understanding science and its history.

Since the history of science is usually written by scholars who do not practice the art of doing science, they usually impose upon this greatest of human adventures a subtle emphasis on theories and ideas over practice. (I exempt Rudwick, who had a first career as a distinguished paleontologist before switching to the history of science.) The late eighteenth-century Scottish geologist James Hutton, for example, is usually praised as the instigator of modern geology because his rigidly cyclical theory of the earth established a basis for an immense span of time. But Hutton had precious little impact on the practice of geology; his name became an icon, but his theory remained on a periphery of speculation, and the doers of geology largely ignored his contribution and went about their work.

Theory, of course, necessarily permeates everything we do. But it may be pushed below consciousness by groups of scientists who choose to view themselves as ardent recorders of nature’s facts. Early in the nineteenth century, the founders of the Geological Society of London explicitly banned all theoretical discussion from their meetings, and dedicated themselves to what they called the “Baconian” (or purely factual) recording of history. They relegated Hutton and other theorists of past generations to the shelves of speculation, and pledged themselves to fieldwork—specifically to the inductive construction of a stratigraphic standard for history.

When I was younger, and understood science poorly, I bemoaned what I considered the paltry spirit of these men. How could they abandon the exciting ideas, the expansive vision, that motivated Buffon and Hutton, and dedicate themselves instead to finding out what lay on top of what in the rocks? I now appreciate the motives of these men who, after all, forged the geological time scale with their own eyes and hands. Of course they were too extreme (even disingenuous) in their impossible rejection of theory; of course they overreacted to what they interpreted as past excesses of speculation. But they understood the cardinal principle of all science—that the profession, as an art, dedicates itself above all to fruitful doing, not clever thinking; to claims that can be tested by actual research, not to exciting thoughts that inspire no activity.

The younger rocks of Britain and the Continent had yielded with relative ease to consistent stratigraphic ordering—for they are arranged nearly as an ideal layer cake, younger above older, with relatively little distortion by folding, or breakage by faulting, or inversion when older layers thrust over younger strata. But the older rocks, from the Paleozoic Era of our modern time scale (600 million to 225 million years ago), posed greater problems for three major reasons well known to all field geologists: rocks of this age are usually far more contorted by intense folding and faulting; alteration by heat and pressure has obliterated fossils from many units, thus removing the primary criterion of history; large stretches of time lie unrecorded in the rocks, because repeated episodes of mountain building and continental collision destroy evidence.x

The complexity of Paleozoic rocks seriously threatened the stratigraphical research program. If older strata could not be ordered by resolving structure through mapping and by sorting their sequence according to fossils then the science itself was doomed. This ordering, moreover, had great economic importance. The period of great fossil forests or “Coal Measures” (the Carboniferous Period of our modern time scale dating from about 360 to 280 million years ago) lay near the top of this older pile. If geologists couldn’t figure out what came before and after, vast sums of money would be wasted drilling through strata misinterpreted as young but actually older than Coal Measures, in the vain hope of finding coal beneath.


The rocks of Devonshire became a focus for resolving the stratigraphy of older times. Most strata were dark, dense, compacted, and highly contorted—composed of rock known as “greywacke” to quarrymen. Under the lingering tendency to infer age from rock type (an old hope that had failed the test in detail, but had not been abandoned as a rough guide), greywacke smelled old and seemed destined for a position at the bottom of the stratigraphic pile.


The Devonian controversy began in 1834 with a paradoxical claim about fossils supposedly found within the greywacke sequence of Devonshire. Henry De la Beche, later director of the Geological Survey of Great Britain, claimed the discovery of fossil plants within the Devonshire greywackes. (Don’t let the Francophonic name fool you; De la Beche, né Beach, was a proper English gentleman, an important theme in Rudwick’s analysis.) Roderick Impey Murchison, the aristocratic and wealthy exsoldier who had parlayed a taste for outdoor adventure into a serious and fulltime professional commitment, responded in a manner that seemed shockingly inconsistent with the professed empiricism of the Geological Society.

Murchison had never seen the Devonshire rocks, but he proclaimed, with vigor and total assurance, that De la Beche had made a monumental mistake, a kind of fool’s error in basic mapping and observation. The greywackes were old, belonging to Murchison’s own Silurian system (or even earlier); but the plant fossils must hail from Coal Measure (much later) times, since terrestrial life had not yet made an appearance during the Silurian. The plant-bearing strata, Murchison proclaimed, must lie on top of the stratigraphic pile, not within as De la Beche claimed. And the sequence must contain a prominent “unconformity,” or temporal gap in deposition, if such young rocks (Coal Measures) actually lie directly atop the ancient greywackes.

(I present, with great regret and almost with a sense of shame, this simplified caricature of such a complex argument and its eventual resolution. As his primary theme, Rudwick emphasizes the multiplicity of forces and arguments leading to the resolution of such debates; and he urges us to view scientific change as a social process of complex interaction based on class, status, age, and place of residence. I have been forced, by limitations of reviewing space, to depict the debate largely as a struggle between two men and a pair of sharply contradictory interpretations later forged into unity. You simply must read the book to sample the true richness of the controversy.)

Murchison based his bold and cocky response on his confidence in fossils as an ultimate criterion for assessing the relative ages of rocks. No issue could be more important in developing a proper methodology for reconstructing history. Geologists had to find a reliable criterion—some feature of rocks or their contents that changed in an absolutely reliable way through time to produce a sequence of unique and unrepeated states for marking the measuring rod of history. Nature does not yield her secrets easily. Nowhere on earth can geologists find a complete pile of unaltered rocks—so that relative age can be assessed by simply observing what lies on top of what (a procedure called “superposition” in geological jargon). Rock outcrops are fragmentary and jumbled; only a tiny part of the sequence graces any particular road-cut or stream bed. We need a criterion for linking these isolated pieces one to the other (“correlation” in the jargon). Just as archaeologists might place a group of pueblos from widely scattered sites in New Mexico in order by tree rings of support beams, styles of pottery, or forms of axheads, geologists needed, above all else, a criterion of history.

Geologists had toyed with a variety of criteria and rejected them. Rock type itself had been a favorite hope, the basis of the so-called Wernerian theory so popular in the generation just preceding the Devonian debate. (In Werner’s system, all rocks precipitated from a universal ocean in order of density. Granite crystallized out first and more conventional sediments followed. The demonstration, by Hutton and others, that granitic cores of mountains had, in liquid form, intruded the overlying sediments from below, and did not form the base of a stratigraphic pile, turned Wernerian theory on its head—for the granite became younger than the overlying sediment, not the oldest rock of all. Moreover, and more importantly, granite could be intruded at any time, and the mineralogical composition of a rock could not therefore specify its age.)

We can now understand Murchison’s vehemence. William Smith in England (the surveyor and engineer adopted by the more patrician leaders of the Geological Society as their intellectual father) and Georges Cuvier in France had established fossils as a proper criterion of history. We now know, as Murchison and his colleagues did not, that evolution is the reason for the uniqueness of each fossil assemblage. Extinction is truly forever; once a group dies out, the hundred thousand unpredictable stages that led to its origin will never be repeated in precisely the same way. All genealogical systems of such complexity must share this property of generating unique sequences, and can therefore serve as criteria of history. But a scientist need not understand (or may incorrectly interpret) the causal basis of uniqueness. Its empirical demonstration will suffice.

By claiming that Coal Measure plant fossils could occur in Silurian or older rocks, De la Beche had made, in Murchison’s view, the most retrograde possible step. He had abandoned the hard-fought and newly won fossil criterion of history, and had reverted to discredited rock type (the “old” appearance of the greywacke). The plants, Murchison claimed, were conclusive; the strata containing them must date from the Coal Measures.

The Great Devonian Controversy traces the resolution of De la Beche’s and Murchison’s diametrically opposite views into “a significant new piece of reliable knowledge about the natural world.” Through four hundred pages of the most dense and complex documentation I have ever read, Rudwick shows that the eventual resolution was not one of those dull compromises that mix a bit of this with a little of that and end up squarely in a lifeless middle between extreme alternatives. The basic resolution introduced a new dimension to the argument, a type of solution that neither side could have foreseen, and that emerged from a swirling context of debate when both initial positions had reached impasses. As Rudwick concludes in an apt metaphor:

The battle lines defended by [the two initial interpretations] having initially faced each other in opposition, filtered silently through each other, as it were, until they faced outward, leaving at their rear a domain defended by them both…. The development of a successful interpretation…resulted in claimed knowledge that was unforeseen, unexpected, and above all novel.

De la Beche soon admitted that he had mismapped the structure of Devonshire. The strata with the disputed plants did lie on top of the stratigraphic pile, not within it. But De la Beche stuck to his central claim that the plants came from old Silurian rock. He insisted that the sequence contained no unconformities (temporal breaks in sedimentation); the plants lay atop the pile, but the entire pile was Silurian. With greater reluctance, Murchison finally dropped his a priori insistence that an unconformity must separate the old rocks from Coal Measure plants atop the stratigraphic pile. He admitted continuity of sedimentation, but continued to insist, by the fossil criterion, that the plants could not be Silurian. These modified positions were closer, but still irreconcilable, in a way even more so because agreement had been reached about basic data of structure and sequence.

The eventual resolution required a novel interpretation: the rocks containing the plants, indeed most of the strata of Devonshire, were neither old (Silurian) nor young (Coal Measures) but representatives of a previously unrecognized time in between (the Devonian Period). The fossil criterion had been vindicated—for Murchison could not know that plants of Coal Measure type had arisen in an earlier unknown age, while he had stated correctly and for certain that these plants could not have inhabited the known Silurian strata. The rock-type criterion had failed again—greywacke did not mean old. The Devonian concept proved enormously fruitful. It quickly achieved firm status as a distinct, worldwide fauna, recognizable in rocks from Russia to New York. By the early 1840s, Devonian had entered the geological lexicon.

As the subtitle of his book attests, Rudwick views scientific knowledge as a social construction, uninterpretable as nature speaking directly to us through bits of fact in a logic divorced from human context. It mattered intensely that the Devonian was codified in Britain by Anglican gentlemen who viewed the Geological Society of London as their intellectual home. Rudwick takes no sides in the silly and fruitless debate between realism and relativism. The study of social setting does not imply either the irrelevance or nonexistence of a factual world out there. A lot happened between 410 and 360 million years ago, and our geological record has entombed the events in copious strata. But a good deal of arbitrariness, or rather social play, must accompany the parsing of continuous time into a series of discrete, named periods. The rocks didn’t have to be called Devonian. And the boundaries are not naturally fixed at 410 and 360 million years; the strata contain no golden spikes. These are largely social decisions. (In fact, the boundaries of the Devonian are poorly defined by the general standard that major divisions of the time scale should be set by episodes of mass extinction to form more or less natural units—for one of the five major extinctions of life’s history occurs within the Devonian.)

They are also vitally important decisions. Scientists are apt to say—but don’t think for a moment that they believe it—“Who cares what we call it so long as we know what happened.” Anyone with the slightest understanding of reward in science knows in his bones that accepted names and terms define status and priority—for actual history is soon forgotten. (The greatest “fast one” in the history of science must be Charles Lyell’s subsumption of acceptable parts of both catastrophism—the doctrine of periodic destruction by cataclysms—and his own excessively gradualistic and ahistorical world view under his favored name “uniformitarianism,” with victory as the father of geology as his reward.) Murchison, a keen debater and a self-promoter if ever there was one, understood this reality acutely and campaigned assiduously for his cherished term, Devonian. “The perpetuity of a name affixed to any group of rocks through his original research,” he wrote, “is the highest distinction to which any working geologist can aspire.”

I know from my own experience as a participant in major scientific debates that the explicit record of publication is utterly hopeless as a source of insight about shifts, forays, and resolutions. As Peter Medawar and others have argued, scientific papers are polite or self-serving fictions in their statements about doing science; they are, instead, logical reconstructions after the fact, written under the conceit that fact and argument shape conclusions by their own inexorable logic. Levels of interacting complexity, contradictory motives, thoughts that lie too deep for either tears or even self-recognition—all combine to shape this most complex style of human knowledge.

Just consider some—a pitifully small sample—of the levels that must be grasped in order to understand the Devonian controversy (note also that all but the first do not enter the public record). We might begin with the pressures of data, for nature does speak to us in muted tones. Second, consider the ideological setting, so often unmentioned in published papers that emphasize the fiction of empirical determination. Both Murchison’s allegiance to the fossil criterion and De la Beche’s reluctance to grant it pride of place set the outlines of the debate. Basic attitudes to history itself lie embedded in these differing commitments.

Third, the overall social setting of science: The chief participants in the Devonian controversy were not academic geologists (for the profession did not yet exist in this form), but gentlemen of private means (or genteel poverty that threatened their commitment and forced them to scramble in an age that had not devised the concept of federal grants). Their published papers were archival, for the arguments had long before been aired and modified in open, but semiprivate debate at the Geological Society and other venues. (Modern science, with its “invisible colleges,” proceeds no differently.) Although nearly one hundred men (yes, as another social reality, all men) participated, only a dozen or so really mattered, and they effectively excluded (or milked for their assessed value) all others who were not of the right class, degree of commitment or expertise, or simply couldn’t get to London for the meetings.

Fourth, consider practical utility. Murchison persuaded the Czar of Russia that he was wasting resources by drilling for coal in a basin of Silurian rocks. If De la Beche had been right about the Devonshire plants, his majesty might have excavated much warmth.

Fifth, the social and economic position of the individuals involved: Murchison was well-off and free to travel (he was also busy campaigning for a baronetcy, which he eventually obtained). De la Beche’s social status was high enough, but his family fortunes had fallen on hard times. He persuaded the government to set him up as head of a geological survey—with salary. Government commitments placed him at a great disadvantage to the peripatetic Murchison; often, he could not even attend meetings since survey work required his presence in the field. When Murchison attacked his interpretation of Devonshire stratigraphy, De la Beche reacted with a fierceness hard to understand until you realize that a charge of incompetence in mapping truly threatened his livelihood and his ability to continue any geological work at all.

Sixth, differences in personality: Murchison, an aristocratic old soldier, was self-assured and curt almost to the point of egomania. He described all his activities in military metaphor. In his own words, he never did fieldwork simply to find out what happened, or had a friendly discussion with an adversary over a pipe and glass of wine; he waged campaigns. De la Beche, on the other hand, tended to modesty and self-effacement in his letters and public statements. He swore up and down, over and over again, that he didn’t care who got the credit, so long as the truth became known. Taking them at face value, one could develop a strong fondness for De la Beche and an equally firm antipathy toward Murchison.

But here we must probe below the surface of private documents. In fact, both men behaved pretty much the same in their secretiveness and quest for status. De la Beche once privately sent some crucial rock samples to the British Museum, hoping to hide them from Murchison, for he could scarcely deny Murchison access once he knew about them. Murchison found out and forced De la Beche’s hand; De la Beche relented and swore (quite dishonestly) that he had meant no such thing. One ends up with a dubious feeling about De la Beche’s two-facedness, and with a grudging admiration for Murchison’s consistency, despite his brutal characterizations as in this note to Adam Sedgwick:

De la Beche is a dirty dog…. I knew him to be a thorough jobber & a great intriguer & we have proved him to be thoroughly incompetent to carry on the survey…. He writes in one style to you and in another to me.

Rudwick somehow manages to encompass in his narrative all these influences, and all the swirling, sallying, trenching and retrenching of opinion in the debate itself. The book is organized as a very thick sandwich—60 pages on context and methods, 340 pages of documented narrative, and 60 pages of interpretation and conclusions. Bowing to the reality of harried lives, Rudwick recognizes that not everyone will read every word of the meaty second section; he even explicitly gives us permission to skip if we get “bogged down in the narrative.” Readers absolutely must not do such a thing, it should be illegal. The publisher should lock up the last 60 pages, and deny access to anyone who doesn’t pass a multiple-choice exam inserted into the book between parts two and three. The value of this book lies precisely in its detailed narrative.

I read this book, particularly its dense narrative, with great joy, but not without criticism. In my view, The Great Devonian Controversy suffers from two kinds of problems linked to its greatest strength—the enormous complexity of its tale. This is not easy to say without sounding flip or even anti-intellectual, but the brain, like the eye, cannot focus on all depths simultaneously. One can lose important aspects of the general pattern by concentrating too strictly upon intricate details. The old cliché about trees and forests is hackneyed because it has merit. I cherish what Rudwick has done; it is a monument to scholarship in an age of mediocrity. But I do think that the years immersed in detail, indeed the love one develops for each tiny facet, have led Rudwick to weigh some of the nuances wrongly, and to miss a major message that the Devonian resolution offered to the history of geology.

My first criticism is structural. Rudwick faced a monumental problem in deciding how to convey his unprecedented detail, so brilliantly worked out, in comprehensible form. He chose, unfortunately I think, a procedure that virtually forecloses full understanding of his book to all but probably a few hundred people in the world. He decided, in short, to follow with uncompromising strictness the historian’s proviso that past events should not be read in the light of later knowledge, perforce unavailable to participants at the time. I would never dispute this credo as a general statement; I have fulminated against “Whiggish” history with as much gusto as any man. But one can make almost a fetish of a good principle and find that it has turned against you.

Rudwick has chosen to organize his story by strict chronology, and absolutely never to mention, never even to drop the slightest hint about, any development that occurred later in time. I do appreciate the rationale. In 1835, no one knew that, a few years hence, a new block of ancient time would resolve the controversy. The injection of foreshadowing can only distort our understanding of people’s positions as they developed. Thus Rudwick never breathes a word about the Devonian solution until Buckland, Sedgwick, and Murchison think of it themselves.

The result is faithful to narrative, but deeply confusing. And why not? The participants themselves were incredibly confused; tell it from their point of view, and what else can you derive? Is this style of presentation best for modern readers? I could make head or tail of Rudwick’s narrative only because, as a professional geologist, I knew the eventual resolution. I don’t think that this knowledge (which I couldn’t expunge in any case) distorted my perspective; rather, it gave me an anchor to mesh the disparate threads into a coherent tale.

To cite just one example where modern information would clarify rather than distort. Devonian rocks had not been unknown in Britain before the controversy. One of the most famous and prominent of British formations, the Old Red Sandstone (another of those lovely quarry-men’s terms), contains a rich fauna of Devonian fishes. The Old Red had not been resolved for an interesting reason: fossils of marine organisms form the standard stratigraphic sequence, but the Old Red rocks are freshwater in origin. Thus, the Old Red cannot easily be correlated with the standard sequence. A simple point, easily made in a sentence—and so enormously helpful in understanding the difficulties that the Old Red presented to geologists of the 1830s (who assumed that the fishes had lived in the sea). The Old Red and its problems circulate through nearly every page of Rudwick’s narrative, but he never tells us about the freshwater solution because it wasn’t devised until after the 1840s—and we are left confused about the Old Red even after Rudwick’s story ends. Only in a short appendix, “The Devonian Modernized,” do we finally learn the solution (but how many people will read the appendices?). Again, as a professional geologist, I knew the answer from the start—and could spare myself the frustration of repeating the contemporary confusion in my own mind. Mystery writers don’t tell the end at the beginning, but even their most complex stories are orders of magnitude simpler than the Devonian controversy. You do need a scorecard, at least partially filled in, to tell the players of Rudwick’s drama.

Yet I strongly defend Rudwick’s narrative style, storytelling in the grandest mode. Narrative has fallen from fashion; even historians are supposed to ape the stereotype of physics and be quantitative, or cliometric. Fine in its place, but not as a fetish. Narrative remains an art and science of the highest order, but of different form. How fitting that a book defending the importance of those scientists who established geological history should also defend so ably the narrative style of historical writing itself. (Rudwick’s last chapter contains several wondrously complex diagrams, outlining the changing views and their resolution, and the roles of varous actors in the drama. Some will read these charts as a cliometric excursion. They will misunderstand Rudwick’s intent. The charts are not a quantification; they have no scale except the chronology of years. One cannot quantify the magnitude of a changed opinion. The charts are pictorial models of narrative arguments, brilliantly conceived as epitomes.)

My second criticism is conceptual, for I disagree fundamentally with Rudwick’s interpretation of the controversy’s resolution. Rudwick’s analysis is so fine-grained, his interest in every item so intense, that he does not provide criteria for ranking the theoretical importance of various issues that the controversy resolved. Rudwick sees, because he knows the details so well, that nobody “won” in the narrow sense of getting all the marbles. But how could it be otherwise for issues of truly great scope? No one can possibly be right about everything the first time. When controversies pit first-rate scientists against one another, any resolution will take bits and pieces of all views. Who could be so misguided as to get everything absolutely wrong?

From this knowledge of intimate detail, Rudwick depicts the resolution as a grand compromise (with a novel solution, not a melding of original views). He even implies that social construction of anything this complex could scarcely, in principle, be judged by victories. He writes, for example: “The finally consensual Devonian interpretation could be regarded as the analogue of a successfully negotiated treaty, precisely because it incorporated the nonnegotiable positions of both sides and found a reconciliation between them.”

I disagree. I read the Devonian resolution as a clear victory for Roderick Impey Murchison—as sweet and unalloyed as any I know in science. Rudwick’s own data reinforce this claim. De la Beche largely drops out of his story about half way through. Murchison moves on to honor and recognition. He is hailed as the “King of Siluria”; he receives medals from the Czar of all the Russias; his Devonian (name and concept) becomes a significant period of the earth’s history. He views his own “campaign” as victorious. His triumph, moreover, is no cynical result of his assiduous self-promotion. He wins because his concepts have succeeded as the foundation of historical reconstruction.

Murchison had begun with an outrageously audacious claim; he identified De la Beche’s errors before he had seen any of the rocks. Of course Murchison was wrong about the Coal Measure age of the plants. But how could he have known that plants also lived just before, in a time previously unrecognized? He did know that such plants, by the fossil criterion of history, could not be Silurian—and he was right.

When we step back far enough, we can view the Devonian debate as part of a larger struggle about proper criteria for the reconstruction of history. From this perspective, we can rank the relative importance of issues. The defense of the fossil criterion was paramount. Murchison said so again and again and directed his choicest invective at De la Beche’s willingness to abandon it for the convenience of resolving some rocks in Devonshire. Murchison was right, and his rightness remains the cornerstone of stratigraphic geology. It also permits us to understand better the meaning of history.

Of course, the fossil criterion did not survive in the simplistic form that Murchison had advocated at the beginning—as I said, you never get everything right the first time. The correlation of Old Red fish with marine Devonian proved that different environments could sport different faunas at the same time—a point that De la Beche had urged. But this is a refinement of the criterion, not a retreat. What you cannot have—or the criterion fails—is a wholesale extension, as De la Beche sought, of the same fauna through time; that is, you can find different faunas at the same time, but not the same fauna through greatly different times. History is a series of irreversible changes yielding a series of unique states.

I am not happy in the role of Miniver Cheevy. I have lived through the revolution of plate tectonics and know how excitement in geological theory feels. But some victories of knowledge are so central, so sweet, that once attained, we can never experience their like again. Could any intellectual thrill be greater than the codification of a proper criterion for history itself, and the subsequent discovery of a great chunk of distinctive time, valid and recognizable on a worldwide basis?

We must recover this commitment to history from the conventional and prejudicial ordering of sciences by status that dismisses the sequencing of events in time as mere narrative or description. What better way than Rudwick’s elegant double achievement—an explicit defense of the wisdom and modernity of historical inquiry (narrative as a term of pride) applied to the codification of geological history as one of the greatest triumphs in human understanding.

This Issue

February 27, 1986