Full Idea
Characteristic of value-words is that they name 'supervenient' properties. If we are discussing whether a picture is a good picture, ..and there is another picture that is a replica of it, we cannot say 'they are alike, but one is good and the other not'.
Gist of Idea
The goodness of a picture supervenes on the picture; duplicates must be equally good
Source
Richard M. Hare (The Language of Morals [1952], 5.2)
Book Reference
Hare,R.M.: 'The Language of Morals' [OUP 1972], p.80
A Reaction
[compressed] Horgan says this is the passage which introduced 'supervenience' into contemporary discussions. I think the best simple word for it is that the goodness of the picture 'tracks' its physical characteristics. It also depend on them.