Abstract

The concept of a linguistic framework and the distinction between internal and external questions are the central ideas of Rudolf Carnap's "Empiricism, Semantics, and Ontology." It is not uncommon to encounter the suggestion that reflection on the theoretical and experimental investigations which led to the acceptance of the atomic hypothesis undermines Carnap's distinction between these two types of question and the utility of his notion of a linguistic framework. I believe this is a mistake. There is a natural development of the distinction and the notion of framework choice with which it is paired that is perfectly capable of accommodating this case. I show this by bringing out a subtlety that arises in the extension of the con ceptual apparatus of ESO to the realism/instrumentalism controversy. When this subtlety is taken into account, the question contested by the nineteenth- and early twentieth-century opponents and proponents of the atomic hypothesis, and successfully addressed by Einstein and Perrin, is readily seen to be internal. Moreover, this formulation of the distinction and the controversy are both independent of Carnap's views on cognitive significance and factual content. I conclude with a presentation and discussion of two formulations of the realism/instrumentalism controversy that are based on Carnap's explication of the factual content of a theory in terms of the notion of its Ramsey sentence.