Full Idea
Predications which answer the question 'what is x?' are often called 'sortal predications' in present-day philosophy.
Gist of Idea
Sortal predications are answers to the question 'what is x?'
Source
David Wiggins (Substance [1995], 4.10.1)
Book Reference
'Philosophy: a Guide Through the Subject', ed/tr. Grayling,A.C. [OUP 1995], p.230
A Reaction
The word 'sortal' comes from Locke. Wiggins is the guru of 'sortal essentialism'. I just can't believe that in answer to the question 'what really is David Wiggins?' that he would be happy with a sequence of categorisations.