Full Idea
The S5 theorist's miscontrual of English (in the meaning of 'possibly possible') makes nested modality unseen, but it does not make nested modality vanish. Inaccessible worlds are still worlds.
Gist of Idea
In the S5 account, nested modalities may be unseen, but they are still there
Source
Nathan Salmon (The Logic of What Might Have Been [1989], IV)
Book Reference
Salmon,Nathan: 'Metaphysics, Mathematics and Meaning' [OUP 2005], p.143
Related Idea
Idea 9065 S5 collapses iterated modalities (◊□P→□P, and ◊◊P→◊P) [Keefe/Smith]