Full Idea
The naturalness of a class depends as essentially on the nature of the observers who classify as it does on the nature of the objects that they classify. ...It depends on our perceptual apparatus, and on our relatively mutable needs and interests.
Gist of Idea
The naturalness of a class depends as much on the observers as on the objects
Source
Anthony Quinton (The Nature of Things [1973], 9 'Nat')
Book Reference
Quinton,Anthony: 'The Nature of Things' [RKP 1973], p.263
A Reaction
This seems to translate 'natural' as 'natural for us', which is not much use to scientists, who spend quite a lot of effort combating folk wisdom. Do desirable sports cars constitute a natural class?