On Necessary and Sufficient Conditions

It is often said that prototypically structured concepts are a counterexample with regard to the classical view of categorization, viz. that categories always have a single definition in terms of necessary and sufficient conditions. However, such statements about the nature of prototypicality do not take into account the distinction between vagueness and ambiguity. In particular, they are never accompanied by a specification of the criteria according to which the allegedly prototypical concepts are indeed a single semantic category. An exploration of the distinction between analytic and introspective criteria for ambiguity shows that prototypicality is part of a larger class of phenomena exhibiting discrepancies between both approaches. Specifically, prototypicality and autohyponymy together make clear that analyticdistinctness of meaningisneithera necessary nor a sufficient condition for introspectively recognized ambiguity, such as it determines the truth conditions of utterances.