more from Mark Sainsbury

Single Idea 8983

[catalogued under 7. Existence / D. Theories of Reality / 9. Vagueness / a. Vagueness of reality]

Full Idea

Sets have sharp boundaries, or are sharp objects; an object either definitely belongs to a set, or it does not. But 'red' is vague; there objects which are neither definitely red nor definitely not red. Hence there is no set of red things.

Gist of Idea

If 'red' is vague, then membership of the set of red things is vague, so there is no set of red things

Source

Mark Sainsbury (Concepts without Boundaries [1990], 2)

Book Reference

'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.352


A Reaction

Presumably that will entail that there IS a set of things which can be described as 'definitely red'. If we describe something as 'definitely having a hint of red about it', will that put it in a set? In fact will the applicability of 'definitely' do?