Confirmation holism

In philosophy of science, confirmation holism, also called epistemological holism, is the view that no individual statement can be confirmed or disconfirmed by an empirical test, but rather that only a set of statements (a whole theory) can be so. It is attributed to Willard Van Orman Quine who motivated his holism through extending Pierre Duhem's problem of underdetermination in physical theory to all knowledge claims.^[1][2]

Duhem's idea was, roughly, that no theory of any type can be tested in isolation but only when embedded in a background of other hypotheses, e.g. hypotheses about initial conditions. Quine thought that this background involved not only such hypotheses but also our whole web of belief, which, among other things, includes our mathematical and logical theories and our scientific theories. This last claim is sometimes known as the Duhem–Quine thesis.^[3]

A related claim made by Quine, though contested by some (see Adolf Grünbaum 1962),^[4] is that one can always protect one's theory against refutation by attributing failure to some other part of our web of belief. In his own words, "Any statement can be held true come what may, if we make drastic enough adjustments elsewhere in the system."^[1]