Abstract

Kuhn’s incommensurability-thesis is crucial for interpreting his views on the development of science and their consequences for the pursuit of epistemology. A commemoration of the 50th anniversary of the publication of the original version of Kuhn’s epoch-making book The Structure of Scientific Revolutions should thus provide a thorough reflection on this thesis. However, this thesis is not easy to interpret. It is not only complex in itself but has also undergone a historical development—in Kuhn’s own hands and in those of his interpreters. In this article, I sort out the different interpretations of it, in particular, in Part A. In Part B, I demonstrate their epistemological consequences. Under closer scrutiny, Kuhn’s incommensurability-thesis contains several sub-theses. Different senses of “incommensurability” thus need to be distinguished. However, the way in which those distinctions are drawn in Kuhn-scholarship differs. In paragraph I of Part A, I provide an overview of the reception of the incommensurability-thesis in Kuhn-scholarship. In Paragraph II, I trace its development in Kuhn’s later writings: given its importance and contested nature, Kuhn later clarifies his original thesis. Those later clarifications’ main function consists in domesticating the most radically relativistic aspects his original incommensurability-thesis had, at least, in the eyes of his interpreters. The upshot of Part A is to provide a coherent interpretation of Kuhn’s incommensurability-thesis. To that end, I distinguish in line with much of Kuhn-scholarship a semantic from a methodological sense of incommensurability. In part B, the question is raised: What sort of epistemological consequences follow from both senses of incommensurability? In particular, what consequences follow for the issues of reference, subjectivity, pluralism, and realism? The underlying question is to what extent Kuhnian incommensurability caters to a relativistic understanding of those issues. This question is answered in Paragraph III with the help of the analyses of a currently leading Kuhn-scholar, C. H. Sankey. His answers are taken as a vantage point for my concluding evaluation of the consequences of Kuhnian incommensurability in Paragraph IV.