Full Idea
If possible worlds are sets of propositions, we need some way to distinguish those sets of propositions that do from those that do not correspond to genuine possibilities.
Gist of Idea
If worlds are sets of propositions, how do we know which propositions are genuinely possible?
Source
Barbara Vetter (Potentiality [2015], 1.2)
Book Reference
Vetter,Barbara: 'Potentiality: from Dispositions to Modality' [OUP 2015], p.6
A Reaction
The idea of a 'genuine' possibility does not seem to play a role in the conceptual scheme of those who treat possibility entirely in terms of possible worlds. If possibility is primitive, or is a set of worlds, there can be no criterion for 'genuine'.