Full Idea
The fact that the 'myth' of possible worlds happens to produce the correct modal logic is itself a phenomenon in need of explanation.
Gist of Idea
Why does the 'myth' of possible worlds produce correct modal logic?
Source
Stewart Shapiro (Philosophy of Mathematics [1997], 7.4)
Book Reference
Shapiro,Stewart: 'Philosophy of Mathematics:structure and ontology' [OUP 1997], p.233
A Reaction
The claim that it produces 'the' correct modal logic seems to beg a lot of questions, given the profusion of modal systems. This is a problem with any sort of metaphysics which invokes fictionalism - what were those particular fictions responding to?