John Hedley Brooke

The serene face of Michael Faraday radiates from all directions: first in disguised profile on a postage stamp, then more handsomely on the £20 note. Illuminating the dark warrens of the London Underground, he now advertises an exhibition at the Science Museum to commemorate the bicentenary of his birth. Visitors to this intimate and thoughtful display are reminded of how much the modern world owes to the gentle giant of experimental science, whose insights into electro-magnetism were eventually to find application in motors and machines which transformed human life even as they transformed electrical currents. Observing the video reconstruction of one of his Royal Institution lectures one begins to think of him as a latterday magus, informing an incredulous audience that his great object had been to get electricity from a magnet.

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. 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’.

In the concluding essay of an adventurous collection, Stephen Jay Gould observes that most ‘classic stories’ in science are wrong. There are good reasons why he is right. In their reconstruction of the past, practising scientists have been apt to celebrate the insight of those who anticipated their own ideas, tacitly dismissing those who were blind to where the future would lie. The result has often been sterile histories, distorted by a preoccupation with confirming the present. The apocalyptic aspects of science, with the next breakthrough just around the corner, may add to the distortion by a more general undervaluation of the past. And the distortion is often sealed by an appeal to history for corroboration of fashionable stereotypes of scientific method, the classic discoveries having been made by ‘prepared minds’ whose interrogation of nature was conducted according to the canons of inductivism, hypothetico-deductivism or some transcendent hybrid. Consequently, science carries along a false history which, like a recessive gene, can pass undetected from one generation to the next. Not one of the least justifications for serious scholarship in the history of science is that it can rectify the distorted vision which the textbook traditions enshrine. It is a justification which Gould happily accepts. Whilst the majority of the 30 essays which compose Hen’s Teeth and Horse’s Toes divulge the latest news in natural history, at least a third have the additional merit of bringing a critical history of science to a larger audience. Gould’s iconoclastic remark occurs in a discussion of a 19th-century ‘fact’, the history of which raises interesting questions indeed. This ‘fact’ was the ability of sires to influence subsequent progeny not fathered by them. One example was familiar and acceptable to Charles Darwin: the successive offspring of Lord Morton’s mare. Crossed with a quagga (a now extinct zebra with stripes confined to neck and forequarters), the Arab mare delivered a hybrid with stripes in evidence. Subsequently mated with a black Arab stallion, the mare again produced an offspring resembling the quagga. This curious form of action at a distance was given a name (telegony) and even inspired a major programme of experimental breeding. As a ‘fact’ it was comfortably embedded in most of the genetic theories of the time (including Darwin’s own) and was only rejected when August Weismann made it impossible in theory – the theory he erected on the continuity of the germ plasm and its protection from extraneous influence. Now for the moral. By contrast with the adage that an unquestioned theory may be overthrown by one novel fact, we have the illuminating case of an unquestioned fact being overthrown by one novel theory.–

The Darwin scholar, John Greene, once summarised the Darwinian revolution as the triumph of a dynamic and non-teleological structuring of nature over static, teological systems: the triumph of chance and change over design and permanence, the triumph of objectivity in the life sciences, of secularism and naturalism over clericalism and the supernatural. The form of such a characterisation is familiar enough – perhaps too familiar in the sense that we are apt to take for granted the structuring of historical material through dichotomies and antitheses. Such has been the stuff of scientific as well as historical exposition. When Galileo launched his controversial defence of Copernican cosmology, he insisted on a dialogue between two chief world systems. When Darwin published his Origin of Species, he fortified his argument by contrasting the strengths of his own theory with the inadequacies of ‘separate creation’. Within the subsequent history of evolutionary mechanics other dichotomies have become part of the folklore of science: ‘In effect, only two theories of evolution have ever been put forward,’ writes John Maynard Smith, ‘one, originating with Lamarck … the other originating with Darwin.’ Such reduction of the scientific corpus to patterns of mutual exclusivity doubtless tells us something about the strategy, if not the logic, of scientific corroboration. It is a form of reductionism which popular works on the historiography of science have done little to discourage. Thomas Kuhn’s The Structure of Scientific Revolutions envisaged competition between two rival and incommensurable ‘paradigms’ as the hallmark of a revolutionary period. A greater theoretical diversity and the science had to be regarded as immature and consigned to a pre-paradigm era. The discontinuity theses of Michel Foucault have lent themselves to a similar dualistic rigidity. Witness the use made of his ‘epistemes’ by N.C. Gillespie, who, in his recent study of Charles Darwin and the Problem of Creation (1979), implied that there were only two epistemes worth talking about: the ‘positivist’, with its exclusion of metaphysics and natural theology, and the ‘creationist’, which was ultimately, if not immediately, grounded in the supernatural.–