This paper criticizes the attempt to found the epistemological doctrine that all theories are evidentially underdetermined on the thesis that all theories have empirically equivalent rivals. The criticisms focus on the role of auxiliary hypotheses in prediction. It is argued, in particular, that if auxiliaries are underdetermined, then the thesis of empirical equivalence is undecidable. The inference from empirical equivalence to the underdetermination of total theories would seem to survive the criticisms, because total theories do not require auxiliaries to yield (...) observational consequences. It is shown that, nevertheless, underdetermination cannot be established for total theories. (shrink)

, Peter Achinstein argues against the long-standing claim that ‘evidence’ is ambiguous in possessing a sense of confirming evidence and a sense of supporting evidence. He argues that explications of supporting evidence will necessarily violate his contentions that evidence is a discontinuous ‘threshold concept’ and that any philosophical account of supporting evidence will be too weak to be useful to working scientists. But an account of supporting evidence may be formulated which includes Achinstein's notion of epistemic thresholds that finds examples (...) in Achinstein's own historical case studies. Thresholds and the denial of ambiguity Achinstein's new account of confirming evidence Achinstein's argument against the ‘ambiguity response’ A threshold-based approach for restoring the ambiguity Maxwell and ‘a subject of rational curiosity’ Bohr and ‘future development of our understanding’ Perrin and the edge of reasonable belief Restoring ambiguity. (shrink)

Duhem is often described as an anti-realist or instrumentalist. A contrary view has recently been expressed by Martin (1991) (Pierre Duhem: Philosophy and History in the Work of a Believing Physicist (La Salle, IL: Open Court)), who suggests that this interpretation makes it difficult to understand the vantage point from which Duhem argues in La science allemande (1915) that deduction, however impeccable, cannot establish truths unless it begins with truths. In the same spirit, the present paper seeks to establish that (...) Duhem is at any rate not the kind of anti-realist he is often presented as being, and that his views are like those Quine sees fit to call realist. An interpretation of Duhem's views on explanation and precision in science, and their bearing on the epistemological status of theory, is advanced which leads naturally into his critique of conventionalism. His attitude towards atomism, which should not be judged from a post-1925 perspective, is considered part of the unified view he strove after and appropriately called Duhem's physicalism, standing in contrast to the kind of reductionist conception usually associated with atomism. (shrink)