Full Idea
One motivation for dialetheism is the view that there are impossible worlds.
Clarification
'dialetheism' says a proposition might be both true and false
Gist of Idea
Belief in impossible worlds may require dialetheism
Source
Jonathan Schaffer (On What Grounds What [2009], 2.3)
Book Reference
'Metametaphysics', ed/tr. Chalmers/Manley/Wasserman [OUP 2009], p.368