Full Idea
By the notion of 'logical necessity' I mean that there is a sense of 'necessary' for which 'It is necessary that A' implies and is implied by 'It is logically contradictory that not A'. ...From this, logical necessity is implicated in logical consequence.
Gist of Idea
Logical necessity is when 'necessarily A' implies 'not-A is contradictory'
Source
Ian Rumfitt (Logical Necessity [2010], Intro)
Book Reference
'Modality', ed/tr. Hale,B/Hoffman,A [OUP 2010], p.35
A Reaction
Rumfitt expresses a commitment to classical logic at this point. We will need to be quite sure what we mean by 'contradiction', which will need a clear notion of 'truth'....