Full Idea
According to the view I advocate, terms for natural kinds are much closer to proper names than is ordinarily supposed. …'Common name' is appropriate for species …and also for certain mass terms such as 'gold' and 'water'.
Gist of Idea
Terms for natural kinds are very close to proper names
Source
Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 3)
Book Reference
Kripke,Saul: 'Naming and Necessity' [Blackwell 1980], p.127