Michael Pelczar, "Wittgensteinian Semantics"

The family resemblance of philosophical expressions like 'knows' or 'causes' can be explained in terms of a conjunction of 'topical indexicality', which is a characteristic of terms with a single meaning but variable contents depending on the situations in which they are used, and 'semantic openness', which is a characteristic of expressions that leave room for discretion in their application. If philosophical expressions are topically indexical, then the method of finding counterexamples for analyses of 'knows', for example, is a completely wrongheaded approach to doing philosophy (as is the activity of refining analyses).