The Man Who Flattened the Earth: Maupertuis and the Sciences in the Enlightenment (review)

For some time, historians of early modern science have evinced less interest in the content of scientific work than in its social context. Terrall's intellectual biography of Pierre-Louis Moreau de Maupertuis continues this pattern, demonstrating in the process the historiographical riches still to be mined with this approach. Terrall distinguishes her study from previous works on Maupertuis by arguing that earlier investigations failed to illuminate "what it meant to do science and be a man of science in the eighteenth century" (7).¹ To that end, she focuses on the contributions that Maupertuis made to diverse fields of inquiry—mathematics, geodesy, cosmology, mechanics, natural history, and the study of generation—in the context of a lifelong struggle to gain honor, fame, and reward in the related worlds of science and letters. Terrall's central claim is that Maupertuis' career illustrates with special clarity the ways in which scientific achievement in Enlightenment France was bound up with thequest for renown among overlapping elites of "the learned and the fashionable" (2).

Terrall's study opens by examining Maupertuis' origins in the wealthy merchant class of his native Saint-Malo in Brittany. After a brief look at his education and years in military service, she turns to Maupertuis' early work in mathematics, which earned him membership in the Paris Academy of Sciences. A delightful chapter on Maupertuis' leadership of the famed expedition to Lapland—intended to resolve the question of whether the earth was elongated or flattened at the poles—demonstrates both Maupertuis' physical intrepidity and his readiness to challenge powerful figures in French science. Discarding the older view of a straightforward collision between "Newtonians" and "Cartesians," Terrall expertly interweaves themes of national rivalry, personal animosity, and competing conceptions of scientific authority. While crediting Maupertuis' scientific acumen, Terrall emphasizes his adroitness in appealing to diverse readers with a carefully constructed tale of scientific heroism.

The second half of Terrall's study is devoted to the unfolding of Maupertuis' career in Berlin, where he enjoyed the favor of Frederick the Great. Avid for glory, Maupertuis accepted Frederick's invitation to head the Berlin Academy of Sciences and Belle-Lettres. However, after early success, he became disappointed by the lack of material resources and the mediocrity of local academicians. Functioning in an alien environment (he never learned German), Maupertuis faced hostility in Berlin and, when France and Prussia faced off in the Seven Years' War, accusations of treason by erstwhile admirers at home.

Maupertuis' labors of the later 1740s and the 1750s, including his championing of the principle of least action and his investigations into problems of generation, proved him eager as always to gain acclaim from an "ideal readership" (281) of assorted elites. Although intently focused on public approbation, Maupertuis remained intellectually alive. A lifetime of self-promotion did not dull his excitement in discovery. He became "dizzy" encountering the profusion of life revealed by John Turberville Needham's microscopic investigations. Maupertuis devoted his last years to breeding experiments intended to illuminate the mysterious processes of heredity, and, under cover of another authorial identity ("Dr. Baumann of Erlangen"), he speculated about whether matter could think and feel. Denis Diderot's response, in his famous Pensées sur l'interprétation de la nature (1754), proved that Maupertuis had seduced yet another influential reader.

This stylish and beautifully written study adds much to our knowledge of Enlightenment science. Terrall writes cogently about the sometimes recondite problems that Maupertuis addressed, and she is entirely convincing in her claim that he succeeded as a man of science because he was equally adept as a man of letters.