Photo-Finish

The phenomenon of simultaneous discovery is an old chestnut, roasted in turn by historians, sociologists and philosophers of science. No matter how frequently the phenomenon occurs, wrote Pierre Duhem, the historian can never suppress his astonishment. But the sociologist could and did. Robert Merton argued that independent simultaneous discoveries should be pereceived as the rule, not the exception. It was the singletons, not the ultiples, that required explanation. Among the more plausible arguments in defence of his inversion, Merton observed that the behaviour of research scientists, especially their concern for priority, testified to the fact that singletons were merely forestalled multiples. If Darwin had not got there first, someone else would. And we all know that, in a photo-finish, Wallace almost did; or, if we are to believe John Langdon Brooks, really did. If philosophers have been attracted to these historical sites, it is partly because the pattern of simultaneous discovery might seem to substantiate a relatively uncomplicated, inductivist account of scientific innovation. Once the data-base has reached a certain level, the crucial innovation becomes an irresistible inference. The simultaneous articulation of the tetrahedral carbon atom (by Le Bel and van’t Hoff in 1874) has been exploited by one philosopher of science to argue precisely that case.1 The complication is that such instances of simultaneity have lent themselves to an alternative style of explanation, showing less respect for the sufficiency of inductive logic. Might not the high incidence of simultaneous discovery simply confirm the primacy of the socio-economic base? It is conceivably no accident that the first island known to Darwin and Wallace was riven with industrial competition, that each remembered Malthus at a critical moment, and that evolution (to judge from the anonymous Vestiges, 1844) was patently in the air. Whether one embraces the inductivist models, or the stronger programmes in the sociology of knowledge, the conclusion might be much the same: simultaneous discovery eliminates the scientific genius. That would be the popular deduction – not surprisingly when the doyen of inductivism, Francis Bacon, could refer even to his own contribution as a ‘birth of time rather than wit’.

To his credit, Merton had the wit to see the danger of a false disjunction. ‘For more than three centuries,’ he complained, ‘there has been an intermittent mock battle between the advocates of the heroic theory and the theory of the social determination of discovery in science. In this conflict, truth has often been the major casualty.’ In his attempt to enlarge the sociology of science, Merton protected the genius, who merely suffered redescription as the ‘functional equivalent of a considerable array of other scientists of varying degrees of talent’. But if Merton expanded the sociology of science in one direction, he shrank it in another. His vision of singletons as forestalled multiples informed his very definition of genius: ‘scientists of genius are precisely those whose work in the end would be eventually rediscovered.’ All very well, but what is it that is ‘discovered’ and ‘rediscovered’? On closer inspection, the notion of independent simultaneous discovery turns out to be deeply problematic. In order to emphasise the frequency of multiples, Merton was driven to reducing subtly different discoveries to a common core, achievable by later reconstruction but only by conflating the often disparate theoretical matrices of the discoverers. It is precisely these divergences between discoverers of what Merton blithely described as ‘essentially’ the same doctrine which invite further sociological analysis. But this is to place a foot in a door which Merton effectively slammed. A critical question ought to be whether Darwin and Wallace did discover the same doctrine, and, if not, how we account for the differences.

The notion of simultaneous discovery is surely ripe for demythologising. Even the innocent reference to simultaneity bristles. If one asks when Darwin and Wallace had their first insight into the mechanism of natural selection, the answer is probably October 1838 and February 1858 respectively. If one then asks when each first produced a publishable essay on the mechanism of evolution, the answer is probably 1844 and 1858 respectively. When did each first perceive that natural selection would automatically favour the most divergent lines from a common ancestor? The answer is September 1857 at the latest for Darwin, and unclear for Wallace. If one asks who was nearer completing a book-length exposition of the theory in spring 1858, the answer has to be Darwin. Moreover, the problems attached to simultaneity are as nothing compared with those attending the notion of ‘discovery’. It must be simplistic to speak of the ‘discovery’ of such a meta-principle of scientific reasoning as the conservation of energy. And the same may be said of natural selection. The degree of abstraction in the formulation of highly theoretical constructs makes any parallel with buried treasure inappropriate. Even where we habitually speak, for example, of the ‘discovery’ of oxygen, there are immediate complications. Lavoisier’s name for the gas (literally ‘acid-producer’) was no less theory-laden than Priestley’s (‘de-phlogisticated air’). As T.S. Kuhn insisted, there was a degree of invention in the discovery. If a more elementary case were possible, it might be protested that in a descriptive science such as observational astronomy one must be allowed to ‘discover’ celestial objects. Astronomers, to be sure, have cultivated the image of heroic discovery. But a classic case of simultaneity, the discovery of Neptune by J.C. Adams and U.J.J. Le Verrier, shows how the public image may conceal events of considerable complexity. A preliminary point is that the optical discovery of Neptune in 1846 was a direct consequence of theoretical prediction, the existence of the planet having been postulated to explain the idiosyncrasies of Uranus. Sophisticated mathematical techniques were required to locate the position of the new planet, and these were developed independently by Adams in Cambridge (1845) and Le Verrier in France (1846), the former failing to publish, the latter bemoaning the reluctance of astronomers to test his prediction. If the hypothetical planet was only perfunctorily chased in England, it seems (according to a recent study by Robert W. Smith) that this was partly due to an assumption among the élite that the optical discovery ought to be the property of Cambridge, the director of whose observatory, James Challis, however, trailed his feet rather than trained his eyes. Because Le Verrier had published and because the sighting was first made in Berlin, there were inevitable complications over any claim for Adams’s priority. Neptune, in John Herschel’s opinion, ‘ought to have been born an Englishman and a Cambridge Man every inch of him’. Any such suggestion, however, and ‘these Frenchmen fly at one like wild cats.’ Because scientific ‘discoveries’ are pieces of property, there lies behind every case of apparent simultaneity a story with a political dimension. It was largely to assuage French fury at claims made on Adams’s behalf that Le Verrier was given the Copley Medal – two years before Adams was so honoured.

References to simultaneous discovery cannot be taken on trust because they often reflect a smoothing operation on the part of contemporaries who found contending claims even more difficult to handle than would later historians. If there could be cattiness over so remote an object as the eighth planet, how much more might there not have been over the evolution of life on this? When an Englishman (and a Cambridge man) recognised in a draft paper from Wallace an almost perfect summary of his own long-gestating theory, he panicked, or stage-managed a panic, on procedural as well as proprietorial grounds. In a well-known letter to Lyell, Darwin sobbed: ‘your words have come true with a vengeance – that I should be forestalled... Please return me the MS which [Wallace] does not say he wishes me to publish, but I shall, of course, at once write and offer to send to any journal. So all my originality... will be smashed.’ The Darwin/Wallace affair has been the classic case of simultaneous discovery, for at least two reasons. First, the theoretical convergence is remarkable, at least to a first approximation. ‘I never saw a more striking coincidence’, Darwin declared. ‘If Wallace had my MS sketch written out in 1842, he could not have made a better short abstract.’ Secondly, the resolution of Darwin’s dilemma has been incorporated into the mythology of science as the shining example, not only of a gentlemen’s agreement but of the existence within a scientific community of the resources to cope with just such a predicament. Responding to the emergency, Lyell and Hooker arranged that, at a meeting of the Linnean Society in July 1858, extracts from Darwin’s unpublished writings were presented simultaneously with the new essay from Wallace, thereby protecting Darwin’s priority and sharing the honours in a manner which Wallace never considered as other than generous.

Presented simultaneously – but not quite. The Darwin extracts were read first. Against the long-standing amiable view, H.L. McKinney argued in Wallace and Natural Selection (1972) that the meeting at the Linnean was not quite the innocent affair it appeared. The selection of the Darwin extracts, and the selection of the order of presentation, were natural only on the assumption that Darwin’s friends were more concerned to protect him than to give Wallace a fair hearing. And in a most astonishing case of simultaneous discovery two later writers have taken McKinney’s suggestion to a new and tendentious extreme. The contention of Arnold Brackman in A Delicate Arrangement (1980) and now John Langdon Brooks in Just Before Darwin is that Darwin himself was the conspirator. On a crucial technicality – the principle of divergence – Darwin allegedly learned more from Wallace than he was willing to admit. In each case the argument hinges on the same negative evidence – uncertainty over the exact date on which Wallace’s paper landed at Down. On the straightforward interpretation of events, there should be no problem. From Darwin’s letter to Lyell (dated the 18th and usually supposed to be the 18 June 1858) it may be inferred that it was on that same day that the missive had arrived from Malaya. Brackman, however, followed McKinney in suggesting that it could have reached him a fortnight earlier – to judge from the fate of another Wallace letter, supposedly aboard the same ship. What difference would a few days make? Just enough, it is implied, for Darwin to have assimilated Wallace’s treatment of evolutionary divergence and incorporated it in Chapter Six of his magnum opus, of which the Origin of Species was to be the rushed and abbreviated version. In Brooks’s extravagant account, even more time is bought for Darwin’s deceit with the proposal that the letter to Lyell had been dated the 18th because it was on the 18 May that the blow had struck. Darwin thus had a month in which to poach Wallace’s paper, delaying his despatch of the Lyell letter until the finishing touch had been given to his own theory. For corroborative evidence, Brooks charts the progress of the Dutch mail steamer from Ternate to Batavia in Java, the time to reach Singapore, and thence by the P&O system to London. The dubitable conclusion is that a letter despatched from Ternate on 9 March could have hit Darwin by 17/18 May.

In such reconstructions there are unverifiable insinuations against Darwin’s integrity. Nor is it necessary to go to such devious lengths to dispel the myth of simultaneous discovery. Yet the nub of the issue is whether there were insights in Wallace’s treatment of divergence which Darwin could turn to advantage. As David Kohn observed in a cogent dismissal of Brackman2, it is first necessary to distinguish between divergence as a purely taxonomic conception and divergence as an explanatory principle, integral to the dynamics of natural selection. Both Darwin and Wallace found the simile of a branching tree helpful in expounding their principles of classification. In the comments which Darwin made on Wallace’s earlier (1855) paper, with its thesis that ‘every species has come into existence coincident in time and space with preexisting species,’ he noted that Wallace ‘uses my simile of tree’. I underline the ‘my’ because it is rather perverse of Brooks to suggest that the diagram of a branching tree, which eventually appeared in the Origin, was derived from Darwin’s reading and rereading that 1855 paper. Such branching lines as Darwin drew in the margin were barely different from those sketched in his transmutation notebooks almost twenty years before. A genealogical classification displaying bifurcation upon bifurcation was, however, as much the problem as the solution. As committed transformists, both Darwin and Wallace had to explain why evolution had chosen the path of divergence, or more strictly, how could one account for the dynamics of divergence using the principles of natural selection? Whereas Brackman and Brooks would have Darwin learn from Wallace on this critical question, I find myself more persuaded by Kohn’s riposte – that the solutions proposed by Darwin and Wallace were governed by such dissimilar assumptions that there was nothing Darwin could have gleaned. The gist of Darwin’s mature position was that evolution created new evolutionary possibilities, that natural selection would favour the most divergent developments from parental forms because the more specialised variants would be able to exploit different ecological niches. Darwin admitted that it had taken a long time for the penny to drop, partly because he had earlier clung to global and local limits for the number of species that could be sustained. His clarification of the principle of divergence required his departure from that assumption towards the view that there were many ecological opportunities in a given locality.

The crux is that Wallace, in 1858, was still glued to global and local limits, employing the very assumption from which Darwin was now emancipated. In the paper which came as such a bombshell to Darwin, he was operating with a more constrictive and ecologically static form of competition in which only one superior form could eventually displace its parent. His reference to divergence seems to mean little more than a single line of departure from the characteristics of the progenitor. Successive variations simply led to further departure. The most that can be said is that his remarks on the subject were ambiguous – too spare to have nourished Darwin with a seminal insight. Curiously, Brooks himself admits that ‘Darwin’s view of the significance of ecological diversity in causing divergence and then extinction is entirely his own; it has no counterpart in Wallace’s conceptions, either in 1855 or in 1858.’ But instead of developing that critical point, he allows his obsession with priority to submerge it. This same obsession also subverts his treatment of Wallace’s 1855 paper which, for all its portent, never propounded a mechanism for speciation. Indeed, Darwin had read it as the rubric of a creationist, encouraged no doubt by Wallace’s quasi-idealist references to species types and antitypes.

Although Brooks, like Brackman, fails to establish Darwin’s hidden debt, there are compensating virtues. One enjoys a vivid travelogue which cleverly integrates Wallace’s experiences as collector of money-spinning specimens, his reflections as a student of ethnology and his development of a convincing theory of speciation. One learns of the vital clues he picked up as he pondered the relationship between the Malay and Papuan races. One admires the clarity of an exposition which reveals the many surprises he suffered. He was surprised by the islands of Lombock and Bali where Australian and Asian bird faunas were insulated from each other by a strait only ten miles wide. The central isle of the Malay archipelago, Celebes, surprised him again, for instead of finding inhabitants typifying the richness of the whole archipelago, he found it parsimonious of species and families. The central island of the Aru group played a converse trick. But for one distinctive butterfly, its rich fauna were exclusively akin to New Guinea species, a hundred miles away. This jigsaw of geographical distribution was an all-consuming puzzle and Brooks has reassembled the pieces with commendable skill.

Wallace’s effort to rationalise the Malay archipelago inevitably calls to mind Darwin’s encounter with the Galapagos. Fortunately, the fullness of the primary sources interspersed in Brooks’s narrative allows the general reader to spot many of those striking similarities between Wallace and Darwin on which the case for simultaneous discovery has rested. Each was an avid collector of beetles. Each broke that tight teleological bond between structure and habit which had given plausibility to arguments for design. Just as Darwin had his web-footed geese which deigned not to swim, so Wallace was struck by the diversity of beak in the ibis, spoonbill and heron – three birds which nevertheless imbibed the same food from the same shallows. Each found himself in critical dialogue with Lyell’s notion that new species somehow sprang into being when environmental conditions became propitious. For Wallace the more critical relationship was that between new and pre-existing species. Each became dissatisfied with conventional distinctions between species and varieties. Just as Darwin’s sojourn with barnacles helped him to see varieties as incipient species, so Wallace was confirmed in the same conclusion by the Aru bird-wing butterfly. Their direct perceptions of human struggle and differential success were in each case reinforced by their assimilation of Malthus.

Formidable though the parallels were, the contrasts must not be obscured. Prominent among them were their respective attitudes towards variation under domestication and the legitimacy of inferences drawn from it. Wallace knew that a favourite argument against species mutability derived from the notion that varieties induced by human selection were unstable, showing a tendency to revert to parental forms. On the assumption that a similar instability affected varieties in the wild, one could protest that nature herself defended the fixity of species. In a preemptive strike against such analogical argument, Wallace insisted that ‘no inferences as to varieties in a state of nature can be deduced from the observation of those occurring among domestic animals.’ Darwin, by contrast, was building the exposition of his theory around just such an analogy: his concept of natural selection was given substance by constant reference to what man had achieved by selective breeding. As we have seen, there was divergence again on their very treatment of divergence. But the most revealing differences are arguably those which surfaced in later decades, as the ‘co-founders’ of natural selection found themselves at variance over the derivation of consciousness and man’s more spiritual and aesthetic capacities. Wallace was to doubt, more strenuously than Darwin, that natural selection, working on individuals, could account for attributes such as moral sensibility, mathematical prowess or musical appreciation, which were not transparently useful in a struggle for survival.

Why did Wallace have these second thoughts, making Darwin groan? This question is of no concern to Brooks, who stops in 1859. Yet, for a rounded view of Wallace, these later developments require analysis. He was soon convinced that once the human mind had emerged, with its ability to take over the task of adaptation, man became as much an evolutionary participant as an evolutionary product. A desire to preserve something distinctive in man (compared with Darwin’s unyielding continuity) has been correlated with Wallace’s growing interest in spiritualism. That he was perceived to be somewhat gullible in that domain has been one of the reasons offered for a reputation almost totally eclipsed by Darwin’s. Recent scholarship has also exposed the possibility that in Wallace’s distinctive social and political beliefs lies the key to his apostasy. Was it possible for an incipient, and eventually ardent, socialist, with the nationalisation of land in his manifesto and a concern for the economic independence of women, to rest content with a derivation of man which was being invoked by all and sundry to justify their social Darwinisms? Building on foundations laid by Roger Smith,3 John Durant has explored an ‘enduring tension between Wallace’s philosophy of nature and his hopes for the future of man and society’.4 Lacking the social privileges of a Darwin, his commitment to social reform had been kindled in the reading rooms of Mechanics Institutes and working-men’s clubs. Whereas Darwin had read his Paley and Herschel, Wallace had fed on George Combe and Tom Paine. Though he also succumbed to Spencerian individualism, the mark made on him by Owenite socialism was to prove indelible. During the 1860s he shifted the struggle for existence in human evolution away from competition between individuals towards competition between groups. He could then underline the survival value of co-operation rather than individual might. Whereas Darwin had appealed to the division of labour as a metaphor for evolutionary divergence, Wallace appealed to the same as a means of contrasting the individualism of the animal world with the ‘mutual assistance’ beneficial in human society. In contrast with blatant forms of social Darwinism, Wallace sought to minimise competition within a community. Although he had earlier concurred in the view that other races were disappearing from the ‘inevitable effects of an unequal mental and physical struggle’ with superior whites, even that preconception had been dislodged by 1869. It was now ‘among people in a very low state of civilisation’ that some approach to a perfect social state could be seen, for among them, there were ‘none of those wide distinctions, of education and ignorance, of wealth and poverty, master and servant, which are the product of our civilisation’.

The intellectual career of Alfred Russel Wallace is illuminating because it shows how it was possible to swim against those pervasive currents which sought to legitimise capitalism, materialism (in both senses), racism, imperialism, colonialism and almost every other ‘ism’ (including Marxism) by appealing to the credentials of positive science. This versatility of Darwinism as a social and political resource is a familiar theme. Very far from familiar, however, is the history of the same, or comparable, versatility in an Oriental culture. In China and Charles Darwin, James Reeve Pusey has met the deficiency in a most authoritative and painstaking manner. His detailed study of the introduction and development of Darwinian motifs in Chinese political life is a distinguished work, impressive in its sensitivity to the richness and ambiguity of Darwinian metaphors, fastidious in its exposition of the social and political programmes into which they slotted. For Pusey it is no accident that the first murmurings of Darwinism were heard in the mid-1890s, following China’s defeat in the Sino-Japanese War. The humiliation of that defeat intensified fears of ultimate domination, even extinction, by the West – a prospect which conferred urgency on the question of how the West had secured its progress and how China’s own survival could be ensured. How easy it could have been, Pusey notes, for the Chinese to have invented social Darwinism without Darwin proper. Yet Darwin symbolised that very knowledge of nature’s laws in which the West’s supremacy appeared to lie. And once incorporated into programmes of moderate reform, how Chinese Darwin seemed: ‘continuing the work of his fathers (at least of his grandfather), he had the patience of a Confucian compiler. He spoke only after long and painstaking study. And how Chinese was his first conclusion, that the many are descended from one.’ The basic lesson was that China must herself evolve, but only ephemerally was Darwin enlisted exclusively on the side of reform. In the great argument between the Constitutional Monarchists and the Revolutionaries, Darwinian banners were to be unfurled by both sides. What of the impact of Darwin’s theory on traditional cultural and religious values? Pusey is once again a scrupulous guide whose comparisons between China and the West are a constant source of instruction. An a-moral struggle for self-preservation sounded as discordant a note for Confucianism as it had for much of Christendom. If only Wallace had entered China, with his transference of struggle from intra- to inter-specific competition, how even more Chinese would he have seemed.