Online research in philosophy

The thesis that certain competing scientific theories are incommensurable was introduced by Kuhn and Feyerabend in 1962 and has been a subject of widespread critique. Critics have generally taken incommensurable theories to be theories which cannot be compared in a rational manner, but both Kuhn and Feyerabend have explicitly rejected this interpretation, and Feyerabend has discussed ways in which such comparisons can be made in a number of his writings. This paper attempts to clarify the incommensurability thesis through the examination of a number of examples, both scientific and nonscientific, of cases in which incommensurable points of view compete. There follows a discussion of Kuhn's analogy between paradigm change and gestalt shifts, the ways in which incommensurable theories can be compared, and one key reason why the incommensurability thesis has been so often misinterpreted by its critics.

Kuhn's incommensurability thesis has generally been interpreted by friends and foes alike so as to preclude direct rational communication across revolutionary divides in science. In this paper, a weaker form of incommensurability is sketched which allows eventual comparison of incommensurable theories, but is consistent with Kuhn's model of science. Incommensurability occurs whenever the knowledge or ability to translate from the language of one theory to that of another is lacking. It can be resolved by acquiring the necessary knowledge or ability.

Relatively recent work on Carnap, based on his published papers and books as well as on his unpublished correspondence and other material, has suggested that Carnap and Kuhn might not have been miles apart when it comes to the issue of theory-change (cf. Earman 1993; Irzik & Grunberg 1995). Two prevailing thoughts are that a) Kuhnian ‘paradigms’ might be taken to be very similar to Carnapian ‘linguistic frameworks’ (cf. Irzik & Grunberg 1995, 286) and b) Kuhnian ‘incommensurability’ between competing paradigms is consonant with Carnap’s thesis that when a linguistic framework is replaced by another, there is a change of language and the analytic-synthetic distinction (which is supposed to separate the meaning-fixing from the fact-stating component of a language) needs to be redrawn within the new framework (cf. Irzik & Grunberg 1995, 300-1). Irzik and Grunberg have gone on to note that Carnap endorsed “semantic incommensurability” (op.cit., 286). They base their claim on the theses that a) Carnap endorsed meaning holism; b) Carnap endorsed the thesis of ‘theory-ladenness of observation’. They are certainly right in saying that “without semantic holism semantic incommensurability would be groundless; without theory-ladenness it would be severely restricted to the theoretical terms” (op.cit., 293). But, I think, they are wrong in claiming that Carnap endorsed either meaning holism or the theory-ladenness of observation. The aim of this paper is to show how Carnap avoided the alleged problem of incommensurability. Better put, Carnap’s view about the language of science (the linguistic framework in which theories are cast) is such that this problem does not arise. Drawing on his published and unpublished material, I highlight some connections between his work on semantics (and in particular his method of intension and extension in his Meaning and Necessity) and his mature work on the structure of scientific theories, which was based on his re-invention of the Ramsey-sentences..

Summary The incommensurability of scientific theories is not the only famous incommensurability issue in the history of western philosophy. The commensurability of all magnitudes (things) by means of ratios of integers (arithmetical ratios) wasthe thesis of Pythagoreanism. The diagonal and side of a square, however, are not commensurable, thus the Pythagorean thesis is refuted. Most philosophers ancient and contemporary would agree that Pythagoreanism was refuted by the counter-example and the concommitant argument or proof. The incommensurabilists were victorious. The present paper examines the prospects of the contemporary thesis of the incommensurability of scientific theories in the light of the history of the Pythagorean thesis. What factors were responsible for the rather clear-cut victory of theincommensurability side? How were they able to carry through a refutation? How likely is it that the contemporary dispute over the commensurability of scientific theories will be resolved in such a sharp manner? The paper concludes that it is not at all likely.

In a shift of position that has gone largely unnoticed by the great majority of commentators, Thomas Kuhn's version of the incommensurability thesis underwent a major transformation over the last decade and a half of his life. In his later work, Kuhn argued that incommensurability is a relation of translation failure between local subsets of interdefined theoretical terms, which encapsulate the taxonomic structure of a theory. Incommensurability arises because it is impossible to transfer the natural categories employed within one taxonomic structure into the categorial system of another such structure. Apparently on the basis of such taxonomic incommensurability, Kuhn asserted a number of antirealist theses about truth, reference and reality. In this paper, it will be argued, however, that, far from leading to antirealist consequences about the relationship between theory and reality, the taxonomic incommensurability thesis may be incorporated unproblematically within a reasonably robust scientific realist framework.

The incommensurability thesis is the thesis that the content of some alternative scientific theories is incomparable due to translation failure between the vocabulary the theories employ. This paper presents an overview of the main issues which have arisen in the debate about incommensurability. It also briefly outlines a response to the thesis based on a modified causal theory of reference which allows change of reference subsequent to initial baptism, as well as a role to description in the determination of reference. On such a view. the content of theories may be compared on the basis of shared reference, despite failure of translation. Two recent developments involving the incomnensurability thesis are also examined: (i) the taxonomic version of the incomensurability thesis found in Kuhn’s later writings. (ii) Hoyningen-Huenc’s neo-Kantian interpretation of Kuhn’s metaphysics.

The incommensurability thesis is the thesis that the content of some alternative scientific theories is incomparable due to translation failure between the vocabulary the theories employ. This paper presents an overview of the main issues which have arisen in the debate about incommensurability. It also briefly outlines a response to the thesis based on a modified causal theory of reference which allows change of reference subsequent to initial baptism, as well as a role to description in the determination of reference. On such a view, the content of theories may be compared on the basis of shared reference, despite failure of translation. Two recent developments involving the incommensurability thesis are also examined: (i) the taxonomic version of the incommensurability thesis found in Kuhn's later writings, (ii) Hoyningen-Huene's neo-Kantian interpretation of Kuhn's metaphysics.

The paper considers the two main challenges to scientific realism, stemming from confirmation holism and the underdetermination thesis as well as from semantic holism and the incommensurability thesis. Against the first challenge, it is argued that there are other criteria besides agreement with experience that enable a rational evaluation of competing theories. Against the second challenge, it is argued that at most a thesis of local incommensurability can be defended that is compatible with a minimal version of scientific realism, namely conjectural realism. However, in order to establish a fully-fledged scientific realism, one has to refute the local incommensurability thesis as well, showing how a comparison is possible on the level of the proper concepts of the theories in question. The paper examines the prospects for such a comparison, distinguishing three cases.

This paper reviews the situation with respect to the referential approach to the problem of semantic incommensurability. It argues that the thesis of semantic incommensurability does not pose a significant threat to scientific realism. However, there exists a "non-realist" defence of incommensurability, according to which the referential approach begs the question against advocates of the incommensurability thesis. This defence is criticized, and the basis for a realist response to incommensurability is presented.

It is widely recognized that Kuhn and Feyerabend did not mean the same thing when they originally spoke of the incommensurability of competing theories. Feyerabend employed the term ‘incommensurability’ to refer to the absence of logical relations between theories due to semantic variance of the terms employed by theories. Kuhn employed the term to describe the obstacles to communication between advocates of rival paradigms which result from perceptual, methodological and semantic differences between paradigms. While Feyerabend’s use of the term remained constant throughout much of his writing on the topic, in his later work Kuhn developed a refined version of the notion of incommensurability which involved the inability to translate between holistically interdefined subsets of terms within the vocabulary of alternative theories.