Abstract

Th e present paper examines three kinds of theories concerning the rigidity of general terms—extensionalist, essentialist and intensionalist theories. It is argued that both essentialist and intensionalist theories cannot deal successfully with a number of problems and that the notions of rigidity they propose for general terms lack suffi cient explanatory power. A version of the extensionalist theory, supplemented with a hierarchy of intensions, is defended. Th e theory has surprising consequences, e.g., that ‘tiger’ and some other natural kind terms are, contrary to the widespread opinion, non-rigid