duck – rabbit See FIGURE – GROUND. Duhem, Pierre-Maurice-Marie (1861–1916), French physicist who wrote extensively on the history and philosophy of science. Like Georg Helm, Wilhelm Ostwald, and others, he was an energeticist, believing generalized thermodynamics to be the foundation of all of physics and chemistry. Duhem spent his whole scientific life advancing energetics, from his failed dissertation in physics (a version of which was accepted as a dissertation in mathematics), published as Le potentiel thermodynamique (1886), to his mature treatise, Traité d’énergétique (1911). His scientific legacy includes the Gibbs-Duhem and Duhem- Margules equations. Possibly because his work was considered threatening by the Parisian scientific establishment or because of his right-wing politics and fervent Catholicism, he never obtained the position he merited in the intellectual world of Paris. He taught at the provincial universities of Lille, Rennes, and, finally, Bordeaux.
Duhem’s work in the history and philosophy of science can be viewed as a defense of the aims and methods of energetics; whatever Duhem’s initial motivation, his historical and philosophical work took on a life of its own. Topics of interest to him included the relation between history of science and philosophy of science, the nature of conceptual change, the historical structure of scientific knowledge, and the relation between science and religion. Duhem was an anti-atomist (or anti-Cartesian); in the contemporary debates about light and magnetism, Duhem’s anti-atomist stance was also directed against the work of Maxwell. According to Duhem, atomists resolve the bodies perceived by the senses into smaller, imperceptible bodies. The explanation of observable phenomena is then referred to these imperceptible bodies and their motions, suitably combined. Duhem’s rejection of atomism was based on his instrumentalism (or fictionalism): physical theories are not explanations but representations; they do not reveal the true nature of matter, but give general rules of which laws are particular cases; theoretical propositions are not true or false, but convenient or inconvenient. An important reason for treating physics as nonexplanatory was Duhem’s claim that there is general consensus in physics and none in metaphysics – thus his insistence on the autonomy of physics from metaphysics. But he also thought that scientific representations become more complete over time until they gain the status of a natural classification. Accordingly, Duhem attacked the use of models by some scientists, e.g. Faraday and Maxwell. Duhem’s rejection of atomism was coupled with a rejection of inductivism, the doctrine that the only physical principles are general laws known through induction, based on observation of facts. Duhem’s rejection forms a series of theses collectively known as the Duhem thesis: experiments in physics are observations of phenomena accompanied by interpretations; physicists therefore do not submit single hypotheses, but whole groups of them, to the control of experiment; thus, experimental evidence alone cannot conclusively falsify hypotheses. For similar reasons, Duhem rejected the possibility of a crucial experiment. In his historical studies, Duhem argued that there were no abrupt discontinuities between medieval and early modern science – the so-called continuity thesis; that religion played a positive role in the development of science in the Latin West; and that the history of physics could be seen as a cumulative whole, defining the direction in which progress could be expected. Duhem’s philosophical works were discussed by the founders of twentieth-century philosophy of science, including Mach, Poincaré, the members of the Vienna Circle, and Popper. A revival of interest in Duhem’s philosophy began with Quine’s reference in 1953 to the Duhem thesis (also known as the Duhem-Quine thesis). As a result, Duhem’s philosophical works were translated into English – as The Aim and Structure of Physical Theory (1954) and To Save the Phenomena (1969). By contrast, few of Duhem’s extensive historical works – Les origines de la statique (2 vols., 1906–08), Études sur Léonard de Vinci (3 vols., 1906–13), and Système du monde (10 vols., 1913–59), e.g. – have been translated, with five volumes of the Système du monde actually remaining in manuscript form until 1954–59. Unlike his philosophical work, Duhem’s historical work was not sympathetically received by his influential contemporaries, notably George Sarton. His supposed main conclusions were rejected by the next generation of historians of science, who presented modern science as discontinuous with that of the Middle Ages. This view was echoed by historically oriented philosophers of science who, from the early 1960s, emphasized discontinuities as a recurrent feature of change in science – e.g. Kuhn in The Structure of Scientific Revolutions (1962). See also CRUCIAL EXPERIMENT, MACH, PHI- LOSOPHY OF SCIENCE , QUINE , VIENNA CIRCL. R.Ar.