Full Idea
There can be no essentialist explanations constructed in any field where the subject matter is not naturally divided into kinds.
Gist of Idea
To give essentialist explanations there have to be natural kinds
Source
Brian Ellis (Scientific Essentialism [2001], Intro)
Book Reference
Ellis,Brian: 'Scientific Essentialism' [CUP 2007], p.10
A Reaction
A crux. I like individual essences, such as the character of a particular person. However, Ellis may be right, since while we may identify an individual essence as the source of a behaviour, we may not then be able to give any 'explanation'.