Full Idea
Indexicals are like secondary qualities in not figuring in causal explanations of the interactions of objects: physics omits them not because they are relative and egocentric, but because they do not constitute explanatory predicates of a causal theory.
Gist of Idea
Indexicals do not figure in theories of physics, because they are not explanatory causes
Source
Colin McGinn (Subjective View: sec qualities and indexicals [1983], 2)
Book Reference
McGinn,Colin: 'The Subjective View' [OUP 1983], p.22
A Reaction
They are outside explanatory physics, but not outside explanation. The object moved because a force acted on it; or the object moved because I wanted it moved.