The Duhemian Argument

Abstract

This paper offers a refutation of P. Duhem's thesis that thefalsifiabilityof an isolated empirical hypothesis H as anexplanansisunavoidably inconclusive.Its central contentions are the following: 1.No general features of the logic of falsifiability can assure, for every isolated empirical hypothesis H and independently of the domain to which it pertains, that H can always be preserved as anexplanansof any empirical findings O whatever by some modification of the auxiliary assumptions A in conjunction with which H functions as anexplanans.For Duhemcannotguarantee on any general logical grounds the deducibility of O from anexplanansconstituted by the conjunction of H and some revised non-trivial version R of A: the existence of the required set R of collateral assumptions must be demonstrated for each particular case. 2.The categorical form of the Duhemian thesis is not only anon-sequiturbut actually false. This is shown by adducing the testing of physical geometry as a counterexample to Duhem in the form of a rebuttal to A. Einstein's geometrical articulation of Duhem's thesis. 3.The possibility of a quasia priorichoice of a physical geometry in the sense of Duhem must be clearlydistinguishedfrom the feasibility of a conventional adoption of such a geometry in the sense of H. Poincaré. And the legitimacy of the latter cannot be invoked to save the Duhemian thesis from refutation by the foregoing considerations.