Full Idea
Wiggins says an identity a=b stands no chance of being true unless there is some concept f under which a falls and under which b falls, which 'determines identity, persistence and existence conditions for members of its extension'.
Gist of Idea
Identity a=b is only possible with some concept to give persistence and existence conditions
Source
report of David Wiggins (Sameness and Substance Renewed [2001]) by Peter F. Strawson - Review of 'Sameness and Substance' p.604
Book Reference
-: 'Mind' [-], p.604
A Reaction
This is the first clear statement I have met of Wiggins's central idea, upon which his sortal essentialism is built. Strawson's exposition adds that each thing necessarily falls under the 'highest' appropriate sortal ('dog', rather than 'terrier').
Related Idea
Idea 14362 Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P]