One of the central notions in Thomas Kuhn’s thought is the notion of incommensurability. Generally, we can distinguish two kinds of incommensurability: methodological and semantic incommensurability. The methodological incommensurability is the thesis that the standards of theory appraisal are themselves theory-dependent. So, some kind of standard variance can be recognized at the level of theory appraisal. On the other hand, semantic incommensurability seems to imply semantic variation between theories or paradigms, regarding the terms occurring in them. These two kinds of dependencies have been employed in support of two forms of relativism: truth relativism and epistemic relativism. The main focus of this paper is on the possible relations that one can depict between incommensurability and these two kinds of relativism. First, I outline possible connections articulated by sufficient and necessary conditions. After that, I attempt to assess the viability of the resulting propositions.

The incommensurability thesis, in philosophy of science, says that competing scientific paradigms/theories, although using the same terms, do not talk about the same matter and so, the scientists who work in competing scientific paradigms or defend competing scientific theories cannot understand each other. This paper aims to examine and criticize the incommensurability thesis. I first try to elucidate the thesis in its historical context. For doing so, I focus on its two main proponents: Thomas Kohn and Paul Fayerabend. Then, I bring out the premises of their argument for the thesis. Finally, I use the theory of semantic externalism to reject a main premise of their argument. To explain the theory of semantic externalism, I focus on its tow most important defenders: Saul Kripke and Hillary Putnam. I believe that “semantic externalism is a way of refuting the incommensurability thesis”.

Comparative studies scholars believe that the most difficult challenge facing researchers in this field, first and foremost, is the possibility or impossibility of comparability between different traditions, cultures, and schools of thought. This difficulty manifests itself most notably in the field of comparative research in philosophy and theology. Philosophers engaged in comparative explorations of texts and cultures of ancient philosophical traditions have found themselves confronted with a plethora of terms and vocabulary for which finding equivalents has been very difficult. In this essay, with reference to three types of incommensurability—fundamental, evaluative, and linguistic—we will address two general approaches regarding the possibility or impossibility of linguistic incommensurability. On the one hand, we will refer to the view of those like Davidson, who, in contrast to those like MacIntyre, defend the commensurability and reject the incommensurability between different traditions and cultures. On the other hand, we will critique and evaluate these two general approaches. In the issue of linguistic incommensurability, the emphasis is on whether it is still possible to compare cultures, traditions, and schools of thought arising from them, given the different terms, language, and contexts in which they are formed in different cultures.

The book: Incommensurability of Scientific Paradigms written by Gholam Hossein Moghadam Heidari published by Nashre Ney in 2006. The author’ s aim is to illustrate the theory of incommensurability of Thomas Kuhn by explaining it. The structure of the book is formed based on explaining the theoretical foundations of Kuhn’ s theory according to historiography, Gestaltism, the definition of the concept of incommensurability, and at last, by studying the function of this theory. The strong points of the book cause the incommensurability approach of Kuhn in his work: The Structure of Scientific Revolutions, to be explained simply and clearly by using historical evidence. So, this paper tries to find an answer to this question: Whether the author of this book could be able to present Kuhn’ s theory of incommensurability from all its aspects and according to his intellectual evolution or not?

Incommensurability is a concept that entered into the literature of contemporary philosophy of science through Thomas Kuhn and Paul Feyerabend. Any discussion of this concept is related to semantics and methodology, and brings up a debate on the possibility of translation between languages. A review of Kuhn’s works shows that, over several decades, he has presented different interpretations of the incommensurability of scientific theories, while he is mainly well-known for his early excessive position, emphasizing incommensurability between scientific mega-theories and paradigms. Indent Such a position has caused challenges in contemporary philosophy of science. Some scholars argue that Kuhn has gradually moved away from his early position, so that he has recognized, in his later positions, a kind of comparability of scientific theories and paradigms.This paper, making use of Howard Sankey’s approach, presents a comprehensive classification of different features and variants of Kuhn’s conception of incommensurability, examines the change of this concept in his philosophy of science, and shows that he, in his later positions, has restricted incommensurability to untranslatability between some terms of natural kinds. This, showing the rationality of empirical science and the process of selection between scientific theories, would make possible to do comparison between rival scientific theories.