Book review

American Intransigency: the Rejection of Continental Drift in the Great Debates of the 1920s Robert Newman, Earth Science History, 1995, 14, 62–83 The Rejection of Continental Drift: Theory and Method in American Earth Science Naomi Oreskes, Oxford University Press, USA, 1999, 420 pp, ISBN 0195117336, Paperback, £21.50 Early 20th century American geophysicists and geologists accepted James Dana's theory of the permanency of continents and oceans. To explained the disjunct distribution of terrestrial life, trans-oceanic land bridges were invoked. Around 1920, this was challenged by the displacement theory of Alfred Wegener. By moving continents laterally, he satisfied palaeontological, palaeoclimatic and stratigraphic homologies, and dispensed with land bridges, which were incompatible with isostacy. Arthur Holmes proposed a mechanism, that is, that continents were carried on the upper surface of laterally moving convection currents. Wegener's continental reconstructions and Holme's mechanism, although perhaps not fully acceptable, were certainly reasonable in terms of what was known at the time. Why, then, were they so vehemently rejected in the USA? Because, Naomi Oreskes tells us, Wegener violated the way American's did science. Robert Newman writes ‘the final contemptuous rejection was sparked by a concerted effort of a few mandarins of the geological community who were deaf to the judgements of foreigners’. Theirs are stories of American chauvinism. Oreskes relates how pluralism, so central to the social and political life of Americans, became embedded in their science. Americans rejected theory-driven science and subscribed to an ‘anti-authoritarian logic of discovery’ embodied in T. C. Chamberlain's canon of multiple working hypotheses. All ideas must be considered and treated equally. Wegener was dogmatic, neglectful of alternative solutions and too cocksure. His idea came quickly and ‘by accident’. But great ideas must not be conceived in this cavalier way; they are the reward of hard work, painfully executed. Wegener landed hard on the American way of doing science. According to Newman, the initial reception of drift in the USA was mixed, but hardened quickly. Charles Schuchert called drift a ‘trap’, ‘acceptable only to deranged minds’, and an affront to American-style uniformitarianism. The polemics of Schuchert and Bailey Willis, the latter's isthmian links (land-bridges, relieved he thought, of the isostasy difficulty) and the lazy argument that Wegener's reconstructions were wrong because his dynamic model would not work, together with loose applications of Chamberlain's canon, had, by the mid-1930s, curtailed reasonable discussion of drift. American earth science became locked in the dead-end of fixism, its mandarins just as dogmatic as they accused Wegener of being. Often in very laboured prose, mandarins heaped praise on one another. Newman relates how Willis, in his memorial in the Bulletin of the Geological Society of America, compared Chamberlain to Aristotle, Galileo and Darwin. These were depressing times for the Englishman, Holmes, for the Canadian, Reginald Daly, the sole mobilist among the American mandarinate, and particularly for the South African, Alex du Toit, who saw his compelling stratigraphic evidence for the juxtaposition of South America and Africa virtually ignored. As the 20th century advanced, instrument-based studies resulted in accordant measurements of continental displacements by several methods. Drift, in the guise of plate tectonics, became accepted in the late 1960s. Earlier 20th century workers were downgraded—they were ‘unimaginative empiricists’, not deeply concerned with theory, even though they theorized mightily. For example, as Oreskes describes, J. T. Wilson asked us to believe that plate tectonics ‘transformed the earth sciences from a group of rather unimaginative studies based on pedestrian interpretations of natural phenomena into a unified science that is exciting and dynamic and holds out the promise of great practical advances for the future’. Alan Cox told us that ‘prior to the mid-1960s, research in tectonics could scarcely be regarded as being in a state of scientific health. Experimentation and observation, not having a firm theoretical basis, were poorly focused and lacked specific objectives’. How, then, Oreskes pointedly asks, did such primitive studies produce such an advanced theory as plate tectonics? As she very commendably illustrates, earlier work was often neither unimaginative nor poorly focused. The above are, I think, best regarded as the rhetoric of the newly converted. Disapproval of drift was rife elsewhere, but, as I remember in the 1950s, far less extreme than in America. In Britain, Harold Jeffreys continued to believe that drift was impossible. In France, the palaeogeographic maps of Henri and Genevieve Termier were as fixist as Schuchert's. Few Australian geologists of influence, other than Warren Carey, supported drift. There had to be broader human reasons for its wider rejection, in addition to those proposed for the USA by Newman and Oreskes. Mandarins everywhere had too little doubt in their own opinions; Willis, Schuchert and Jeffreys knew a lot, but not about some matters on which they wrote. For Wegener to have create such an all-embracing theory, he must have possessed a special sort of energy and an uncommon desire to seek broad understanding. Secretly, many may have been jealous or even fearful of this imaginative and learned man. It was unconscionable that an atmospheric physicist should so confidently propose a radical overhaul of their ideas about their solid Earth. It is sad but not surprising, therefore, that mandarins, almost everywhere, tended to respond to this outsider with ridicule, with weakly reasoned alternatives, or by all but ignoring him in their lectures and writings. Newman's thesis of ‘American intransigency’, as extensively augmented by Oreskes, is, I think, essentially correct. Oreskes is to be commended especially for her attempt to reclaim older, reasonable voices from behind the noisy rhetoric of 20th century tectonics. She has not, I think, always read Wegener accurately—on the history of Gondwana, for instance. She repeats errors from unreliable secondary sources; for example, she says that Keith Runcorn was a student of Teddy Bullard's and that Bullard worked on palaeomagnetism. Neither is correct. Newman's essay is well written, a wonderful text for student essays, and a cautionary tale for aspiring mandarins.

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