Kuhn’s incommensurability thesis presented a challenge not only to positivist conceptions of scientific change but also to realist ones. For a realist conception of scientific progress also wishes to assert that, by and large, later science improves on earlier science, in particular by approaching closer to the truth.  A standard realist response from the late 1960s was to reject the anti-realism and anti-referentialism shared by both Kuhn’s picture and the preceding double-language model. If we do take theories to be potential descriptions of the world, involving reference to worldly entities, kind, and properties, then the problems raised by incommensurability largely evaporate. As we have seen, Kuhn thinks that we cannot properly say that Einstein’s theory is an improvement on Newton’s in the sense that the latter as deals reasonably accurately (only) with a special case of the former. Whether or not the key terms (such as ‘mass’) in the two theories differ in meaning, a realist and referentialist approach to theories permits one to say that Einstein’s theory is closer to the truth than Newton’s. For truth and nearness to the truth depend only on reference and not on sense. Two terms can differ in sense yet share the same reference, and correspondingly two sentences may relate to one another as regards truth without their sharing terms with the same sense. And so even if we retain a holism about the sense of theoretical terms and allow that revolutions lead to shifts in sense, there is no direct inference from this to a shift in reference. Consequently, there is no inference to the inadmissibility of the comparison of theories with respect to their truth-nearness.