Abstract

The aim of this paper is to discuss the philosophical viability of the incommensurability doctrine. In particular I am going to analyse the thesis that changes in meaning of the terms shared by competing theories after a scientific revolution imply reference changes as well. The idea that terms change radically their meanings will be discussed, and the alleged incommensurability of mass will be criticized in detail. Relativity theory, which has provided most of the characteristic examples of incommensurability, becomes also the realm in which to put to the test the viability of this doctrine. My own proposal on incommensurability amounts to restricting its validity to the domain of worldviews, and last to the theoretical vocabulary. I finally suggest that the incommensurability problem disappears in the framework of an instrumentalist point of view on theories and theoretical models From this viewpoint such worldviews become merely useful tools in order to deal with Nature.