Full Idea
The various kinds of universals are all natural kinds of one sort or another.
Gist of Idea
Universals are all types of natural kind
Source
Brian Ellis (Scientific Essentialism [2001], 1.01)
Book Reference
Ellis,Brian: 'Scientific Essentialism' [CUP 2007], p.19
A Reaction
This doesn't sound right. What about the universals of mathematics, or universals which are a matter of social or linguistic convention? I think Ellis is trying to hijack the word 'universal' in response to Armstrong's more idealistic account.