Full Idea
If we have a science of the healthy, and the healthy happens to be white, the science of the healthy does not deal with the white.
Gist of Idea
If health happened to be white, the science of health would not study whiteness
Source
Aristotle (Metaphysics [c.324 BCE], 1077b30)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.399
A Reaction
Given this point, we certainly cannot think of Aristotle as believing in simple abstractionism. The problem of the coextension of renates and cordates looms here (Idea 7317). 'Relevant' similarities require extensive cross-referencing.
Related Idea
Idea 7317 'Renate' and 'cordate' have identical extensions, but are not synonymous [Quine, by Miller,A]