Full Idea
The proposition that 'a material thing cannot be in two places at once' is not empirical at all, but linguistic; ..we could so alter our definitions that the proposition came to express a self-contradiction instead of a necessary truth.
Gist of Idea
By changing definitions we could make 'a thing can't be in two places at once' a contradiction
Source
A.J. Ayer (Language,Truth and Logic [1936], Ch.2)
Book Reference
Ayer,A.J.: 'Language, Truth and Logic' [Penguin 1974], p.77
A Reaction
This seems a striking anticipation of Quine's famous challenge to the analytic/synthetic distinction.