Full Idea
The trouble with propositions, as cognitive meanings of eternal sentences, is individuation. Given two eternal sentences, themselves visibly different linguistically, it is not sufficiently clear under when to say that they mean the same proposition.
Gist of Idea
The problem with propositions is their individuation. When do two sentences express one proposition?
Source
Willard Quine (Propositional Objects [1965], p.140)
Book Reference
Quine,Willard: 'Ontological Relativity and Other Essays' [Columbia 1969], p.140
A Reaction
If a group of people agree that two sentences mean the same thing, which happens all the time, I don't see what gives Quine the right to have a philosophical moan about some dubious activity called 'individuation'.