Full Idea
We use sentences with indexicals or relativized propositions to individuate belief states, for the purposes of classifying believers in ways useful for explanation and prediction.
Gist of Idea
Indexicals individuate certain belief states, helping in explanation and prediction
Source
John Perry (The Problem of the Essential Indexical [1979], 'Obvious')
Book Reference
'Self-Knowledge', ed/tr. Cassam,Quassim [OUP 1994], p.181
A Reaction
He goes on to apparently connect this with some sort of moral integrity involved in 'owning up' to the fact that the person in question is you (who has spilled the sugar etc.).