Full Idea
English modals are context-dependent through and through; there is no stable 'outer modality'.
Gist of Idea
Modal terms in English are entirely contextual, with no modality outside the language
Source
Theodore Sider (Writing the Book of the World [2011], 12.7)
Book Reference
Sider,Theodore: 'Writing the Book of the World' [OUP 2011], p.281
A Reaction
Sider has been doing so well up to here. To me this is swallowing the bait of linguistic approaches to philosophy which he has fought so hard to avoid.