Full Idea
Imaginability can give us access to conceptual possibility, when we come to believe situations to be conceptually possible by reflecting on their descriptions and seeing no contradiction or incoherence.
Gist of Idea
Imagination reveals conceptual possibility, where descriptions avoid contradiction or incoherence
Source
Sydney Shoemaker (Causal and Metaphysical Necessity [1998], VI)
Book Reference
Shoemaker,Sydney: 'Identity, Cause and Mind' [OUP 2003], p.424
A Reaction
If take the absence of contradiction to indicate 'logical' possibility, but the absence of incoherence is more interesting, even if it is a bit vague. He is talking of 'situations', which I take to be features of reality. A priori synthetic?