Full Idea
On Russell's pre-war conception it is obvious that a complex cannot be negative. If a complex were true, what would make it false would be its non-existence, not the existence of some other complex.
Gist of Idea
There can't be a negative of a complex, which is negated by its non-existence
Source
comment on Bertrand Russell (The Theory of Knowledge [1913]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 41 'Neg'
Book Reference
Potter,Michael: 'The Rise of Anaytic Philosophy 1879-1930' [Routledge 2020], p.276
A Reaction
It might be false because it doesn't exist, but also 'made' false by a rival complex (such as Desdemona loving Othello).