(Although it is true that Kuhn uses the expression ‘physical referent’ in the passage quoted above, this should not be taken to mean an independently existing worldly entity. If that were the case, Kuhn would be committed to the worldly existence of both Newtonian mass and Einsteinian mass (which are nonetheless not the same). It is implausible that Kuhn intended to endorse such a view. A better interpretation is to understand Kuhn as taking reference, in this context, to be a relation between a term and a hypothetical rather than worldly entity. Reference of anything like the Fregean, worldly kind plays no part in Kuhn’s thinking. Again this may be seen as a reflection of the influence of one or other or both of the (later) Wittgensteinian downplaying of reference and of the positivist view that theories are not descriptions of the world but are in one way or another tools for the organization or prediction of observations.)