Full Idea
There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past.
Gist of Idea
It is possible the world came into existence five minutes ago, complete with false memories
Source
Bertrand Russell (The Analysis of Mind [1921], p.159)
Book Reference
Russell,Bertrand: 'The Analysis of Mind' [Routledge 1995], p.159
A Reaction
One of the great sceptical arguments! At a stroke it undermines forever any dreams that memories are totally certain. This is an extra scepticism, which arises if you decide that current experience IS totally certain.