Duhem-Quine Thesis

The Duhem-Quine thesis, a position within the philosophy of science also known as confirmation holism or the underdetermination of theory by data, holds that no single scientific hypothesis can be conclusively tested, and therefore falsified, in isolation by a single experiment, because any real empirical test necessarily also relies on a number of additional background assumptions, including auxiliary theories, the correct functioning of measuring instruments, and stated initial conditions. When a predicted result fails to occur, the thesis holds, the failed experiment shows only that something within the entire combined set of the hypothesis plus its supporting assumptions must be false, without by itself indicating which particular part is at fault. French physicist and philosopher of science Pierre Duhem first articulated a version of the idea specifically concerning physics in his 1906 book La Theorie physique, and American philosopher Willard Van Orman Quine substantially extended and generalized the underdetermination argument to apply to empirical knowledge as a whole in his influential 1951 essay Two Dogmas of Empiricism. The thesis is widely discussed as posing a significant challenge to simple falsificationist accounts of scientific method, such as the one proposed by philosopher Karl Popper, since it suggests that a scientist facing a failed prediction always retains some latitude to instead reject one of the auxiliary assumptions rather than the hypothesis actually under test.