Full Idea
Time- and person-relative epistemic possibility can be asserted even when logical possibility cannot, such as undecided mathematical propositions. 'It may be that p' just comes to 'For all I know, not-p'.
Gist of Idea
We assert epistemic possibility without commitment to logical possibility
Source
Ian McFetridge (Logical Necessity: Some Issues [1986], §1)
Book Reference
-: 'Aristotelian Society' [], p.137
A Reaction
If it is possible 'for all I know', then it could be actual for all I know, and if we accept that it might be actual, we could hardly deny that it is logically possible. Logical and epistemic possibilities of mathematical p stand or fall together.