Concept Acquisition without a Final Criterion

The absence of a final criterion poses an interesting problem about concept acquisition. On the standard stories about concepts, a person acquires a concept, and so constructs the corresponding psychological category, by stipulating, learning, or otherwise putting in place a final criterion for the category. On the Lockean and prototype theories, the final criterion is assembled from various observable properties, by putting the properties together to form either a definition or a prototype. Note that this operation is not in itself an inference or a judgment. By including the property of yellowness in my concept for gold, I am not inferring that gold is yellow; I am as it were making it so. Of course, the basis for including yellowness in the concept GOLD might be inductive; it might be, for example, the observation that certain properties, among them yellowness, tend to co-occur in nature. (Rosch often argues that prototypes are constructed to capture correlations of observed properties.) But the construction of a definition or prototype is not itself a piece of inductive or any other kind of reasoning.