Kuhn’s view as expressed in the passage quoted above depends upon meaning holism—the claim that the meanings of terms are interrelated in such a way that changing the meaning of one term results in changes in the meanings of related terms: “To make the transition to Einstein’s universe, the whole conceptual web whose strands are space, time, matter, force, and so on, had to be shifted and laid down again on nature whole.” (1962/1970a, 149). The assumption of meaning holism is a long standing one in Kuhn’s work. One source for this is the later philosophy of Wittgenstein. Another not unrelated source is the assumption of holism in the philosophy of science that is consequent upon the positivist conception of theoretical meaning. According to the latter, it is not the function of the theoretical part of scientific language to refer to and describe unobserved entities. Only observational sentences directly describe the world, and this accounts for them having the meaning that they do. Theories permit the deduction of observational sentences. This is what gives theoretical expressions their meaning. Theoretical statements cannot, however, be reduced to observational ones. This is because, first, theoretical propositions are collectively involved in the deduction of observational statements, rather than singly.  Secondly, theories generate dispositional statements (e.g. about the solubility of a substance, about how they would appear if observed under certain circumstances, etc.), and dispositional statements, being modal, are not equivalent to any truth-function of (non-modal) observation statements. Consequently, the meaning of a theoretical sentence is not equivalent to the meaning of any observational sentence or combination of observational sentences. The meaning of a theoretical term is a product of two factors: the relationship of the theory or theories of which it is a part to its observational consequences and the role that particular term plays within those theories. This is the double-language model of the language of science and was the standard picture of the relationship of a scientific theory to the world when Kuhn wrote The Structure of Scientific Revolutions. Kuhn’s challenge to it lay not in rejecting the anti-realism implicit in the view that theories do not refer to the world but rather in undermining the assumption that the relationship of observation sentence to the world is unproblematic. By insisting on the theory-dependence of observation, Kuhn in effect argued that the holism of theoretical meaning is shared by apparently observational terms also, and for this reason the problem of incommensurability cannot be solved by recourse to theory-neutral observation sentences.