Full Idea
If vagueness is semantic indeterminacy, then wherever we have vague statements, we have several alternative precisifications of the vague language involved, all with equal claims of being 'intended'.
Gist of Idea
Semantic vagueness involves alternative and equal precisifications of the language
Source
David Lewis (Vague Identity: Evans misunderstood [1988], p.318)
Book Reference
'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.318