The Duhemian Argument

Abstract

This paper offers a refutation of P. Duhem’s thesis that the falsifiability of an isolated empirical hypothesis H as an explanans is unavoidably inconclusive. Its central contentions are the following:

• (1) No general features of the logic of falsifiability can assure, for every isolated empirical hypotheses H and independently of the domain to which it pertains, that H can always be preserved as an explanans of any emprical findings O whatever by some modification of the auxiliary assumptions A in conjunction with which H functions as an explanans. For Duhem cannot guarantee on any general logical grounds the deducibility of O from an explanans constituted 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 only a non-sequitur but 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 quasi a priori choice of a physical geometry in the sense of Duhem must be clearly distinguished from 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.

The author is indebted to the national Science Foundation for the support of research and wishes to acknowledge the benefit of discussions with Dr Grover Maxwell and other fellow-partipants in the 1959 summer sessions of the Minnesota Center for Philosophy of Science.

Reprinted from Philosophy of Science 27, No. 1, January, 1960.