Duhem was convinced that all physical phenomena, including mechanics, electromagnetism, and chemistry, could be derived from the principles of thermodynamics. Influenced by Macquorn Rankine's "Outlines of the Science of Energetics", Duhem carried out this intellectual project in his Traité de l'Énergétique (1911), but was ultimately unable to reduce electromagnetic phenomena to thermodynamic first principles.
With Ernst Mach, Duhem shared a skepticism about the reality and usefulness of the concept of atoms. He therefore did not follow the statistical mechanics of Maxwell, Boltzmann, and Gibbs, who explained the laws of thermodynamics in terms of the statistical properties of mechanical systems composed of many atoms.
History of science
Nicole Oresme, a prominent medieval scholar. Duhem came to regard the medieval scholastic tradition as the origin of modern science.
Duhem is well known for his work on the history of science, which resulted in the ten volume Le système du monde: histoire des doctrines cosmologiques de Platon à Copernic (The System of World: A History of Cosmological Doctrines from Plato to Copernicus). Unlike many former historians (e.g. Voltaire and Condorcet), who denigrated the Middle Ages, he endeavored to show that the Roman Catholic Church had helped foster Western science in one of its most fruitful periods. His work in this field was originally prompted by his research into the origins of statics, where he encountered the works of medieval mathematicians and philosophers such as John Buridan, Nicole Oresme and Roger Bacon, whose sophistication surprised him. He consequently came to regard them as the founders of modern science, having in his view anticipated many of the discoveries of Galileo Galilei and later thinkers. Duhem concluded that "the mechanics and physics of which modern times are justifiably proud to proceed, by an uninterrupted series of scarcely perceptible improvements, from doctrines professed in the heart of the medieval schools."
Reason may be employed in two ways to establish a point: firstly, for the purpose of furnishing sufficient proof of some principle. [...] Reason is employed in another way, not as furnishing a sufficient proof of a principle, but as confirming an already established principle, by showing the congruity of its results, as in astronomy the theory of eccentrics and epicycles is considered as established, because thereby the sensible appearances of the heavenly movements can be explained; not, however, as if this proof were sufficient, forasmuch as some other theory might explain them. [...]
Philosophy of science
"A theory of physics is not an explanation. It is a system of mathematical propositions, deduced from a small number of principles, which have for their aim to represent as simply, as completely and as exactly as possible, a group of experimental laws."
Duhem, The Aim and Structure of Physical Theory, vol 13, p. 19
Duhem's views on the philosophy of science are explicated in his 1906 work The Aim and Structure of Physical Theory. In this work, he opposed Newton's statement that the Principia'slaw of universal mutual gravitation was deduced from 'phenomena', including Kepler's second and third laws. Newton's claims in this regard had already been attacked by critical proof-analyses of the German logician Leibniz and then most famously by Immanuel Kant, following Hume's logical critique of induction. But the novelty of Duhem's work was his proposal that Newton's theory of universal mutual gravity flatly contradicted Kepler's Laws of planetary motion because the interplanetary mutual gravitational perturbations caused deviations from Keplerian orbits. Since no proposition can be validly logically deduced from any it contradicts, according to Duhem, Newton must not have logically deduced his law of gravitation directly from Kepler's Laws.
Duhem's name is given to the underdetermination or Duhem–Quine thesis, which holds that for any given set of observations there is an innumerably large number of explanations. It is, in essence, the same as Hume's critique of induction: all three variants point at the fact that empirical evidence cannot force the choice of a theory or its revision. Possible alternatives to induction are Duhem's instrumentalism and Popper's thesis that we learn from falsification.
As popular as the Duhem–Quine thesis may be in the philosophy of science, in reality Pierre Duhem and Willard Van Orman Quine stated very different theses. Pierre Duhem believed that experimental theory in physics is fundamentally different from fields like physiology and certain branches of chemistry. Also Duhem's conception of theoretical group has its limits, since not all concepts are connected to each other logically. He did not include at all a priori disciplines such as logic and mathematics within these theoretical groups in physics which can be tested experimentally. Quine, on the other hand, conceived this theoretical group as a unit of a whole human knowledge. To Quine, even mathematics and logic must be revised in light of recalcitrant experience, a thesis that Duhem never held.
Duhem's philosophy of science was criticized by one of his contemporaries, Abel Rey, in part because of what Rey perceived as influence on the part of Duhem's Catholic faith.
Opposition to the English inductivist tradition
Duhem argues that physics is subject to certain methodological limitations that do not affect other sciences. In his The Aim and Structure of Physical Theory (1914), Duhem critiqued the Baconian notion of "crucial experiments". According to this critique, an experiment in physics is not simply an observation, but rather an interpretation of observations by means of a theoretical framework. Furthermore, no matter how well one constructs one's experiment, it is impossible to subject an isolated single hypothesis to an experimental test. Instead, it is a whole interlocking group of hypotheses, background assumptions, and theories that is tested. This thesis has come to be known as confirmation holism. This inevitable holism, according to Duhem, renders crucial experiments impossible. More generally, Duhem was critical of Newton's description of the method of physics as a straightforward "deduction" from facts and observations.
In the appendix to The Aim and Structure, entitled "Physics of a Believer," Duhem draws out the implications that he sees his philosophy of science as having for those who argue that there is a conflict between physics and religion. He writes, "metaphysical and religious doctrines are judgments touching on objective reality, whereas the principles of physical theory are propositions relative to certain mathematical signs stripped of all objective existence. Since they do not have any common term, these two sorts of judgments can neither contradict nor agree with each other" (p. 285). Nonetheless, Duhem argues that it is important for the theologian or metaphysician to have detailed knowledge of physical theory in order not to make illegitimate use of it in speculations.
^See Hentschel (1988) on these and other parallels between Duhem and Mach, and on their correspondence.
^"Pierre Duhem, himself a distinguished physicist, initiated in heroic fashion, almost singlehandedly, the modern study of the history of medieval science by the simple but effective expedient of reading and analyzing as many medieval scientific manuscripts as possible." — Palter, Robert M. (1961). Preface to Toward Modern Science, Vol. I. New York: The Noonday Press, p. ix.
^Paul, Harry W. (1972). "Pierre Duhem: Science and the Historian's Craft," Journal of the History of Ideas, 33, pp. 497–512.
^Murdoch, John E. (1991). "Pierre Duhem and the History of Late Medieval Science and Philosophy in the Latin West," in R. Imbach & A. Maierù, eds., Gli Studi di Filosofia Medievale fra Otto e Novecento. Rome: Edizioni di Estoria e Letteratura, pp. 253–302.
^"By his numerous publications, Duhem made medieval science a respectable research field and placed the late Middle Ages in the mainstream of scientific development. He thus filled the hiatus that had existed between Greek and Arabic science, on the one extreme, and early modern science in the seventeenth-century Europe, on the other. For the first time, the history of science was provided with a genuine sense of continuity." — Grant, Edward (1996). The Foundations of Modern Science in the Middle Ages. Cambridge University Press, p. xi.
^Duhem, Pierre (1914). Le système du monde: histoire des doctrines cosmologiques de Platon à Copernic (The System of World: A History Cosmological Doctrines from Plato to Copernicus).
^Wallace, William A. (1984). Prelude, Galileo and his Sources. The Heritage of the Collegio Romano in Galileo's Science. N.J.: Princeton University Press.
^Lindberg, David C.; Westman, Robert S., eds. (27 Jul 1990) [Duhem, Pierre (1905). "Preface". Les Origines de la statique1. Paris: A. Hermman. p. iv.]. "Conceptions of the Scientific Revolution from Bacon to Butterfield". Reappraisals of the Scientific Revolution (1st ed.). Cambridge: Cambridge University Press. p. 14. ISBN978-0-521-34804-1.
^Pierre Duhem thinks "Kepler is, unquestionably, the strongest and most illustrious representative of that tradition," i.e., the tradition of realism, that physical theories offer explanations in addition to just "saving the phenomena."
^Cady, Walter G. (1946). Piezoelectricity. New York, NY, USA: McGraw-Hill. p. 245.
^ abcDuhem, Pierre; Philip P. Wiener (1954). La Théorie Physique: son Objet et sa Structure [The Aim and Structure of Physical Theory]. Jules Vuillemin. Princeton University Press. ISBN978-0-691-02524-7.
^Lakatos, Imre; Paul Feyerabend; Matteo Motterlini (1999). For and Against Method: Including Lakatos's Lectures on Scientific Method and the Lakatos-Feyerabend Correspondence. University of Chicago Press. pp. 45–49. ISBN978-0-226-46774-0.
^Lakatos, Imre; John Worrall; Gregory Currie (1980). "5: Newton's Effect on Scientific Standards". The Methodology of Scientific Research Programmes. Cambridge University Press. ISBN978-0-521-28031-0.
^Lakatos, Imre; John Worrall; Gregory Currie (1978). "5: The Method of Analysis-Synthesis". Mathematics, Science, and Epistemology. Cambridge University Press. ISBN978-0-521-21769-9.
Stoffel, Jean-François; Stanley L. Jaki (1996). Pierre Duhem et ses Doctorands: Bibliographie de la Littérature Primaire et Secondaire. Centre Interfacultaire d'Étude en Histoire des Sciences. p. 325. ISBN978-2-930175-00-3.
Stoffel, Jean-François; Jean Ladrière (2002). Le Phénoménalisme Problématique de Pierre Duhem. Brussels: Classe des Lettres, Académie Royale de Belgique. p. 391. ISBN978-2-8031-0190-0.
Alexander, Peter (1964). "The Philosophy of Science, 1850–1910," in D.J. O'Connor, ed., A Critical History of Western Philosophy. New York: The Free Press, pp. 402–425.
Jaki, Stanley L. (1992). Reluctant Heroine, The Life and Work of Helene Duhem. Scottish Academic Press.
Jaki, Stanley L. (1993). "Medieval Christianity: Its Inventiveness in Technology and Science," in Technology in the Western Political Tradition. Ed. M.R. Zinman. Cornell University Press, pp. 46–68.
Kahler, Erich (1943). "Reason and Science," in Man: The Measure. New York: Pantheon Books, Inc.
Quinn, Philip L. (1974). "What Duhem Really Meant," in Robert S. Cohen & Marx W. Wartofsky, eds., Methodological and Historical Essays in the Natural and Social Sciences. Dordrecht: Reidel Publishing Company.
Schaffers, V. (1922). "Pierre Duhem et la Théorie Physique," Revue des Questions Scientifiques, pp. 42–73.