Full Idea
Only if the thing that is cold to me is precisely identical with the thing that is not cold to you can Protagoras launch his argument, but then it is seen to be the thing in itself that exists absolutely speaking.
Gist of Idea
You can only state the problem of the relative warmth of an object by agreeing on the underlying object
Source
comment on Protagoras (fragments/reports [c.441 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.8
Book Reference
Benardete,José A.: 'Metaphysics: The Logical Approach' [OUP 1989], p.54