 The theory-observation distinction has been attacked heavily and is presumably discredited by a large number of philosophers of science. Still, this distinction continues to permeate a number of important strands in the philosophy of science, such as scientific realism and its alternatives and the logical analysis of scientific theories. A case in point is the recent interest in the Ramsey account of scientific theories which emerged in the wake of Worral’s structural realism (cf. Ladyman 2009). We have seen, moreover, that the formal accounts of theoretical terms work well with a theory-observation distinction that is relativized to a particular theory. Critics of that distinction, by contrast, have commonly attacked a global and static division into theoretical and observational terms (Maxwell 1962; Achinstein 1965). Note finally that Carnap assigned no ontological significance to the theory-observation distinction in the sense that entities of the one type would be existent in a more genuine way than ones of the other.