Full Idea
In Wiggins's theory, necessity carries over from the kind to constitution. If Toby is necessarily a dog and 'dog' is a natural kind term, then Toby necessarily has the constitution of a dog, the features of which make up the real essence of being a dog.
Gist of Idea
A thing is necessarily its highest sortal kind, which entails an essential constitution
Source
report of David Wiggins (Sameness and Substance Renewed [2001]) by Peter F. Strawson - Review of 'Sameness and Substance' p.605
Book Reference
-: 'Mind' [-], p.605
A Reaction
The essence will then presumably consist of all and only the characteristics which are shared by all dogs whatsoever. So how do you decide the borderline between wolf and dog? Why isn't a wolf a dog?
Related Ideas
Idea 14362 Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P]
Idea 14363 Identity a=b is only possible with some concept to give persistence and existence conditions [Wiggins, by Strawson,P]