Full Idea
Sincerity can never be verified, so fiction infuses all speech, which means that reality is also fictional.
Gist of Idea
Sincerity can't be verified, so fiction infuses speech, and hence reality also
Source
Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction
Book Reference
Stocker,Barry: 'Derrida on Deconstruction' [Routledge 2006], p.65