Abstract

This paper criticizes Kripke’s and Putnam’s theory of the semantics of natural kind terms (KPT) and develops an alternative theory. It first examines description theories of natural kind terms, to see what their flaws are and what can be preserved of them. It then presents the KPT and makes three main criticisms. These rely on the meaning of elementary particles’ names, on reactions to the absence of a common essential nature, and on applications of old terms to new cases. Lastly, it develops a theory that takes noun phrases to be plural referring expressions, and shows how that theory meets the objections to the KPT.