Full Idea
The null class is a fiction.
Gist of Idea
The null class is a fiction
Source
Bertrand Russell (The Principles of Mathematics [1903], §079)
Book Reference
Russell,Bertrand: 'Principles of Mathematics' [Routledge 1992], p.81
A Reaction
This does not commit him to regarding all classes as fictions - though he seems to have eventually come to believe that. The null class seems to have a role something like 'Once upon a time...' in story-telling. You can then tell truth or fiction.