Quora answer: How do you define quality?

See Persig Zen and the Art of Motorcycle Maintenance on Quality

I believe that the real source of ideas about Quality in this popular book is not Plato but really . . .

PEPPER (Stephen).   Concept and Quality.   La Salle, Ill., Open Court, 1966.

See Stephen C. Pepper and Chinese Philosophy of Art http://www.thomehfang.com/suncrates6/Stephen%20C.%20Pepper%20and%20Chinese%20Philosophy%20of%20Art2.htm

http://archives.lib.siu.edu/index.php?p=collections/findingaid&id=2238&q=&rootcontentid=36591