Full Idea
In perception, the idea of the subject appears to be a logical fiction, like mathematical points and instants; it is introduced, not because observation reveals it, but because it is linguistically convenient and apparently demanded by grammar.
Gist of Idea
In perception, the self is just a logical fiction demanded by grammar
Source
Bertrand Russell (The Analysis of Mind [1921], Lec. VIII)
Book Reference
Russell,Bertrand: 'The Analysis of Mind' [Routledge 1995], p.141
A Reaction
In 1912, Russell had felt that both the Cogito, and the experience of meta-thought, had confirmed the existence of a non-permanent ego, but here he offers a Humean rejection. His notion of a 'logical fiction' is behaviouristic. I believe in the Self.