 Initially, Feyerabend had a more concrete characterization of the nature and origins of incommensurability than Kuhn. On Feyerabend’s view, because the nature of objects depends on the most advanced theories about them, and because the meaning of observation statements depends on the nature of those objects, the interpretation of an observation language is determined by the theories we use to explain what we observe. Kuhn, by contrast, was initially much less sure about the exact meaning of his notion of incommensurability, especially regarding world change, which he saw as the most fundamental aspect of incommensurability. Kuhn frankly confessed to have been at a loss: “In a sense that I am unable to explicate further, the proponents of competing paradigms practice their trades in different worlds” (1962, 150). He suggested that “we must learn to make sense of statements that at least resemble these” (1962, 121), and then spent a great deal of effort attempting to do so.