Full Idea
If we say that the whiteness of this sheet is the whiteness of another sheet, every man perceives this to be absurd; but when he says both sheets are white, this is true and perfectly understood.
Gist of Idea
No one thinks two sheets possess a single whiteness, but all agree they are both white
Source
Thomas Reid (Essays on Intellectual Powers 5: Abstraction [1785], 3)
Book Reference
Reid,Thomas: 'Inquiry and Essays', ed/tr. Beanblossom /K.Lehrer [Hackett 1983], p.242
A Reaction
Well said. Only a philosopher could think the whiteness of one sheet is exactly the same entity as the whiteness of a different sheet. We seem to have brilliantly and correctly labelled them both as white, and then thought that one word implies one thing.