Samuel Butler, a master of acrimonious polemic, confronted Charles Darwin with the sorest of all scientific subjects—a dispute about priority. In Evolution Old and New (1879), Butler accused Darwin of slighting the evolutionary speculations of Buffon, Lamarck, and his own grandfather Erasmus. To this book, and to later, more specific taunts,1 Darwin reacted with the most effective ploy of all: silence. Darwin’s son Francis later wrote of this incident: “The affair gave my father much pain, but the warm sympathy of those whose opinions he respected soon helped him to let it pass into a wellmerited oblivion.”2

Yet since the currency of science is originality in ideas, the subject of priority never passes into oblivion. Historians and sociologists have demonstrated over and over again that no revolutionary idea arises without a pedigree and that most major discoveries are, in the sociologist Robert Merton’s term,3 “multiples.” (A.R. Wallace, of course, independently invented the principle of natural selection during a malarial fit on the island of Ternate eighteen years after Darwin had devised it, but before its publication.) The subject of Darwin’s predecessors had been aired long before Butler’s attacks. Most revolutionaries in science either ignore history or revise it for their own purposes. Darwin had not been generous toward previous evolutionists,4 and their claims had led him to add a historical introduction to later editions of the Origin of Species.

Nor did the subject die with Butler’s demise. In 1959, the centenary of the Origin inspired a flood of scholarship, much of it devoted to Darwin’s evolutionary predecessors.5 In the same year, Loren Eiseley, distinguished anthropologist and a notable prose stylist among scientists, published a long paper in the Proceedings of the American Philosophical Society: “Charles Darwin, Edward Blyth, and the Theory of Natural Selection.” In it, Eiseley charged that Blyth had developed a version of natural selection before Darwin in the 1830’s and that “Darwin made unacknowledged use of Blyth’s work.”

Edward Blyth (1810-1873), the “mysterious Mr. X” of this book’s title, was a gifted natural historian who, through misfortune and poverty, labored much of his life in relative obscurity as a curator in the museum of the Asiatic Society of Bengal. Eiseley, who died in 1977, did not pursue the subject much beyond his original paper, and this book is little more than a reprint of the 1959 essay, fleshed out with seven additional essays, none original, many of doubtful relevance, and only one written later than 1965.

Two standard misinterpretations, one fostered by Darwin himself, have plagued conventional commentary on the genesis of natural selection. In the story that ought to be true, Darwin entered the Beagle laden with the theological prejudices of his age. During the next five years, nature herself cut Darwin’s chains and he saw the truth in giant fossil bones from South America and in the tortoises and finches of the Galapagos. This heroic tale reinforces the false stereotypes that scientists often like to convey about their discipline—science as a dispassionate search for objective truth through untrammeled observations; great scientists as people who can free their minds of prejudice and hear nature’s own voice.

Darwin did begin to doubt aboard the Beagle. He did return with a prepared mind; and he did draw upon the resources of his voyage throughout his life’s work. But he did not simply see evolution in the field. In fact, Darwin originally identified the famous Galapagos finches as members of several bird families and did not even record the separate islands of their occurence. He put the story together only when a British Museum ornithologist later recognized the unity of ancestry behind a striking diversity of adaptation.

But Darwin never claimed conversion through the Beagle voyage. In his own account,6 source of the second misinterpretation, Darwin opened his notebooks on the transmutation of species shortly after the voyage and groped for a theory to explain how evolution had occurred. (Darwin’s demonstration of evolution as a fact must be distinguished from the theory he devised for its mechanism—natural selection. He accepted the fact before he developed his theory, and he never denied a long list of predecessors for the fact itself. He claimed originality only for the theory of natural selection.) Darwin did not underplay either his good preparation or the partial success of his first musings. But he does depict the genesis of natural selection as a “eureka” experience, a flood of insight after a lucky accident:

In October 1838, that is, fifteen months after I had begun my systematic inquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had at last got a theory by which to work.

Eiseley’s critique lies in this tradition of “eureka” interpretations. It accepts the idea of a watershed or Rubicon, a definite moment that propelled Darwin from groping uncertainty to satisfaction. But it transfers inspiration from Malthus to Blyth, and raises the favorite issue of all science gossip: did Darwin enhance the impression of his own originality by claiming tangential inspiration from Malthus rather than direct borrowing from Blyth? (Eiseley avoids the contentious issue of whether Darwin’s slight was deliberate or unconscious.)


Twenty years have passed since the Origin’s centenary and Eiseley’s paper, and no subject has been more diligently and fruitfully studied during this time than the source of natural selection. Through the work of Kohn, Limoges, Mayr, and, especially, Gruber and Schweber,7 we now know that Darwin achieved no sudden triumph, but experienced more of a creeping conviction. Darwin’s many notebooks have been reassembled and scrutinized minutely; his every coming and going during the weeks before he read Malthus have been reconstructed so far as the data allow. Gruber has proved that Darwin “groped” with far more purpose, direction, and success during the first year of his search. Schweber has traced the path of Darwin’s month before Malthus and followed a trail from Comte, to Adam Smith and the Scottish economists, to Quetelet and the early statisticians, and from Quetelet’s own citations, and not by serendipity, to Malthus. Darwin’s “amusement,” it seems, lay primarily in reading the Malthusian statement in its original formulation. He had previously studied the central claim that population must outrun supplies of food in a review of Quetelet’s work.

Moreover, Schweber shows that most of the pieces were in place before Darwin experienced his Malthusian insight. His debt to Malthus may not extend beyond the quantitative formulation of a principle he already understood (and, in retrospect, an invalid quantification at that). This sensible reconstruction also resolves a major anomaly of the traditional “eureka” interpretation—why, if Malthus had removed opaque scales from his eyes, did Darwin not pause to celebrate, exult, or even record the event in his notebooks at the time itself? (Darwin wrote his autobiography when an old man, and largely as a moral homily for his children, not for publication. The famous Malthusian illumination cited above does not represent the only hazy recollection that led historians astray. Darwin’s portrayal of himself as a dull, patient man, working on “strict Baconian principles,” in the right place at the right time, set an entire tradition of scholarship that denigrated Darwin until his intellectual resurrection of the last twenty years. Thus, we cannot view Darwin’s misrepresentations in the Autobiography as consciously self-serving.) Incidentally, neither Gruber nor Schweber even mentions Blyth, and no major historian of Darwin has found a place for him in any of this recent work. Moreover, if there was no eureka, Blyth could only have been a minor actor in any case.

Even if later scholarship has swept the rug from Eiseley’s style of explanation, I believe that his claim for Blyth falters on its own terms. In 1835 and 1837, Blyth published extensive articles in the Magazine of Natural History, a journal well known to Darwin. Blyth does indeed speak, in several passages, of nature removing individuals with disfavored traits. He admits that breeders employ a conscious version of this process to improve their stock, and he even wonders aloud whether nature might follow a similar course: “As man, by removing species from their appropriate haunts, superinduces changes on their physical constitution and adaptations, to what extent may not the same take place in wild nature, so that, in a few generations, distinctive characters may be acquired, such as are recognized as indicative of specific diversity?” Yet Blyth, as Eiseley admits of course, then quickly squelches his question with a resounding “no.” “I would briefly despatch this interrogatory,” he writes, primarily because intermediary forms cannot be found between most modern species.

Having rejected this suggestion, Blyth persistently discusses selection in an opposite sense—as a device for the removal of unfit individuals, leading to the preservation of species as constant and immutable, created entities. By acting as executioner for the sick, the weak, the deformed, the aberrant, the merely too large or too small, nature works with God to maintain species, not to change them. No notion of “natural selection” could be more precisely contrary to Darwin’s own (and, again of course, Eiseley acknowledges the difference). Blyth writes: “The original form of a species is unquestionably better adapted to its natural habits than any modification of that form.” Selection, therefore, is a law “intended by Providence to keep up the typical qualities of a species.” Predators impose constancy on their prey “by removing all that deviate from their normal or healthy condition, or which occur away from their proper and suitable locality, rather than those engaged in performing the office for which Providence designed them…. So profoundly wise are even the minor workings of the grand system; and thus do we perceive one of an endless multiplicity of causes which alike tend to limit the geographical range of species, and to maintain their pristine characters without blemish or decay to their remotest posterity.” Not much solace for an evolutionist in that!


Eiseley’s charge is thus reduced sharply in scope. He cannot claim that Darwin simply pinched the idea of selection from Blyth, for he must admit that Darwin’s recasting of selection as an agent of change represents one of the great reformulations of thought in Western history. This creative topsy-turvy is the essence of Darwin’s revolution; I cannot regard the possibility that he first encountered selection as a negative force in someone else’s work as an issue of great import. But, even on this reduced charge, Eiseley cannot be sustained. For Eiseley was apparently unaware that selection, as a preserving force, had been a common concept of creationist biology. Blyth constructed nothing original; he was merely reporting general wisdom—selection as God’s refining fire. C. Zirkle once wrote a monograph on pre-Darwinian uses of natural selection as a guarantee that evolution could not occur.8

Since Darwin could have learned about selection as God’s agent for constancy from a number of sources, Eiseley must prove more directly that he imbibed it from Blyth. Eiseley does indeed demonstrate that Darwin read Blyth’s key papers (although the interesting chain of circumstantial evidence in the long essay of 1959 is rendered irrelevant by the discovery, reported in a 1965 essay also reprinted here, that Darwin annotated Blyth’s 1837 paper in his own hand!). So what? Darwin was a voracious reader. We know that he admired Blyth greatly and cited many of his specific observations in later work. (Blyth, by the way, returned both friendship and admiration, and never raised any intimation of unacknowledged “borrowing.”) Blyth’s articles were published in a major journal that Darwin read regularly.

Eiseley’s more specific claims for direct influence of Blyth’s articles upon Darwin founder upon indefiniteness and inaccuracy. Eiseley begins his case, for example, with the fact that both Blyth and Darwin used the peculiar word “inosculate,” meaning to pass into. Eiseley writes: “A rare and odd word not hitherto current in Darwin’s vocabulary suddenly appears coincidentally with its use in the papers of Edward Blyth…. The rare and mildly archaic character of this word suggests that Darwin acquired it from his reading of Blyth.” Yet, far from being archaic, the word “inosculate” was, at the time, a technical term in a very hot subject dear to the hearts of both Darwin and Blyth—the so-called “quinarian system” of taxonomy. The quinarians claimed that all organisms could be arranged into groups, depicted as five interpenetrating circles. They referred to the connections between circles as their inosculations (literally, their kissings). Blyth’s article is, in fact, an explicit attack upon the quinarian system. Darwin’s interest in barnacles (he wrote four volumes about them!) may be traced in part to their anomalous position within the quinary system, a scheme of classification that he liked no better than Blyth did.

Yet Blyth and Darwin could not have been more different in their general vision of nature—and Blyth represented the old as firmly as Darwin pioneered the new. Their variant readings of natural selection represent the most striking expression of two incompatible views. To Darwin, selection is the creative force in evolution. If I had to summarize the essence of Darwinism in a single concept, I would emphasize the directing power of selection. Genetic variation is raw material; it is “random” in the sense that mutations do not arise preferentially directed toward the production of advantageous traits. Adaptation is the result of natural selection, acting relentlessly across generations, to accumulate favored variation through the differential success of fitter individuals in producing more surviving offspring. Evolutionists have waxed poetic in their metaphorical depictions of selection—Ernst Mayr compared it to the work of a sculptor, George G. Simpson to a poet, Theodosius Dobzhansky to a composer, Julian Huxley to Shakespeare himself. The comparisons may be stretched, or even silly, but they do reflect the essence of Darwinism—the creative power of natural selection.

Blyth, on the other hand, was a natural theologian of the old school. Immutable unity of intended design was his watchword, and his arguments for divine beneficence were a bit outmoded even in his own time. He actually argued, in the crudest version of the argument from design, that God made mountains high enough to be covered with snow, so that the white color would reflect heat and prevent them from becoming “an increased source of cold by radiation to all around”; and that the moisture, thus retained in winter, would “furnish, by the action of the summer sun, a due supply of water, when needed to the foundations and rills which irrigate and fertilize the more level country.”

Blyth’s world contained “one omnipotent and all-foreseeing Providence, under the beneficent dispensation of whom nought that ever exists or occurs stands isolated and alone, but all conduce and work admirably together for the benefit of the whole.” The essential difference between old and new, between Blyth and Darwin, lies in Blyth’s illustration of the divine unity: “It is the grand and beautiful, the sublime and comprehensive, system which pervades the universe…and which is so well exemplified in the adaptation of the ptarmigan to the mountain top, and the mountain top to the habits of the ptarmigan.” Darwin’s system permits us to speak of the ptarmigan adapting to the mountain top, for natural selection produces such apparent “order” in a world devoid of intrinsic purpose. But we can no longer speak of the mountain top adapting to the ptarmigan, and in this loss lies both the grandeur and the despair of “this view of life”—Darwin’s own designation for his reconstructed world.

Disputes about priority, in any case, tend to ring hollow, despite the vigor of their persecution. Ideas are cheap. The use of ideas, the systematic reconstruction of a world in their light, is the stuff of intellectual revolutions. Patrick Matthew developed the notion of natural selection in 1831—and in Darwin’s later sense of a creative force. And who among you has ever heard of Matthew? He presented his position in scattered comments of an appendix to a book on naval timber and arboriculture—not the most auspicious location for a reconstituted world. The chief joy in reading Darwin lies in sensing the excitement of a man, not yet thirty, who knows that he holds a key to the reinterpretation of all biological and anthropological knowledge—and who pursues the reconstruction systematically. Matthew never saw the forest for his trees. Darwin cut through 2,000 years of philosophy with his statement in an early notebook: “Plato says in Phaedo that our ‘imaginary ideas’ arise from the pre-existence of the soul, are not derivable from experience—read monkeys for pre-existence.”

Eiseley’s article on Blyth performed a service in 1959. Its errors and provocative suggestions helped to foster the close look at Darwin’s early notebooks that has led to a more accurate reconstruction of his mental saga. But its republication today, without any commentary on work done since, does not make a worthy or coherent book. More than half of the present book comes directly from the 1959 article—the long essay on Blyth; a turgid obituary notice, dealing more with Blyth’s troubled finances than with his science, and published by Arthur Grote in the Journal of the Asiatic Society of Bengal in 1875; and several papers by Blyth himself, highly technical, but without explanatory comments, and not written in the most felicitous style—Blyth had a lamentable tendency to write about “nidification of the feathered tribes” when he wanted to describe how birds build their nests.

Around this central material, two sets of essays have been added like the bread of a sandwich. The first three, all from Scientific American articles of the 1950s, discuss Darwin and his great contemporaries Lyell and Wallace. The last three, on human evolution, do not mesh well with the preceding material. All contain numerous errors that speak no ill of Eiseley, but merely record the fact that we have learned something during the past twenty years. Old essays deserve commentary, not sanctification. Even the title, we are told in the editor’s preface, represents one that Eiseley himself chose not to use for his work on Blyth. All in all, this book seems to be a poor way to honor the memory and accomplishments of a very fine man.

This Issue

August 16, 1979