The incommensurability thesis

In both cases the concept came from mathematics and in its original sense is defined as the absence of a common unit of measurement that would allow a direct and exact measurement of two variablessuch as the prediction of the diagonal of a square from the relationship of its sides. The term commensurability was coined because of a series of problems that both authors found when trying to interpret successive scientific theories. Without doubt its implementation is better understood thanks to the critiques that both Kuhn and Feyerabend have made in response to certain theses proposed by followers of the received view of theories. These include the famous thesis on the accumulation of scientific knowledge, which states that the body of scientific knowledge has been increasing with the passage of time.

The incommensurability thesis

A Response to Mizrahi and Patton. The PDF of the article gives specific page numbers.

The incommensurability thesis

Although Mizrahi distinguishes between taxonomic and methodological incommensurability theses, he limits his remarks to the TI thesis. He defines TI accordingly Periods of scientific change in particular, revolutionary change that exhibit TI are scientific developments in which existing concepts are replaced with new concepts that are incompatible with the older concepts.

The new concepts are incompatible with the old concepts in the following sense: According to this definition, TI pertains principally to the conceptual incompatibility between two competing theories, which is related to their lexical taxonomies.

Moreover, conceptual incompatibility involves concepts that are contradictory or opposed to one another, while incommensurability also pertains to concepts that share no common measure or do not intersect with one another conceptually.

In other words, incompatibility refers to right or wrong concepts while incommensurability to non-overlapping concepts in which truth and falsity are relevant but not determinant of conceptual conflict or tension. Incompatibility then is not equivalent to incommensurability, as Mizrahi suggests in the above definition of TI.

In other words, incommensurability includes more than just conceptual incompatibility.

Life and Career

Additionally, Kuhn later divides incommensurability into global and local versions, with the former representing wholesale changes in the lexical taxonomy and the latter more constrained changes.

Thus, what constitutes a general notion of incommensurability is not as simple as identifying it with incompatibility. Deductive support, according to Mizrahi, would take the following logical form.

If competing theories were taxonomically commensurable, then terms would still refer to the same things in new theories… TI2: Terms do not refer to the same things in new theories… Therefore: Competing theories are taxonomically incommensurable As constructed, this is a modus tollens argument or inference and it is valid.

But, he takes issue with the truth of the premise TI1 and thereby the soundness of the argument. The truth of TI1, according to Mizrahi, depends on satisfying the following two conditionals.

Biological and folk taxonomies are taxonomically incommensurable However, this example is not as apposite, as Mizrahi presumes, since biological taxonomy and folk taxonomy are not competing scientific theories to explain the taxonomic relationship of living organisms.

A better example would be two competing biological taxonomic theories Atran Finally, Mizrahi summarizes the argument concerning the lack of deductive support for TI as follows, 1 Reference change [or discontinuity] is conclusive evidence for TI only if reference change [or discontinuity] entails incompatibility of conceptual content.

This argument is certainly valid, i. But it is different in logical form and content, especially in terms of premises, from the earlier modus tollens argument.

For example, the above argument introduces the notion of conceptual incompatibility whereas the earlier one does not.and adjustments of Kuhn’s incommensurability thesis over the years and the arguments delivered by Kuhn’s main opponents, Davidson, Kripke and Putnam, as well as comments by some authors of .

Feyerabend characterized this wider notion of incommensurability as a historical, anthropological thesis (, ), but also applied it to different stages of the development of thought and perception in the individual (, ).

incommensurability thesis because, from the fact that the reference of the same kind terms changes or discontinues from one theoretical framework to another, it does not necessarily follow that these two theoretical frameworks are taxonomically incommensurable. More specifically, TP is the normative counterpart of Feyerabend's descriptive Incommensurability Thesis (IT).

Both IT and TP bear some debt to Popper's views, which Feyerabend imbibed throughout the s. The Structure of Scientific Revolutions (; second edition ; third edition ; fourth edition ) is a book about the history of science by the philosopher Thomas S. publication was a landmark event in the history, philosophy, and sociology of scientific challenged the then prevailing view of progress in "normal .

One might object that Kuhn’s incommensurability thesis seems to block the overlapping matrix move, but Rowbottom proclaims that the falsity of Kuhn’s incommensurability thesis follows “as a consequence of the way that piecemeal change can occur” ().

Thomas Kuhn (Stanford Encyclopedia of Philosophy)