 The defender of the view that expressions have meanings which determine extensions seems forced to say that “line” and “door” are homophonous expressions, like “bank”. But that seems implausible; when one uses the expressions “fishing line” and “line of thought” one seems to be using “line” in recognizably the same sense. (This is a point of contrast with standard examples of homophony, as when uses “bank” once to refer to a financial institution and then later to refer to the side of a river.) The internalist, by contrast, is not forced into treating these as cases of homophony; he can say that the meaning of “line” is an instruction to fetch one of a family of concepts.