Full Idea
A fierce debate has raged between proponents of 'pictorial' conceptions of imagery (Kosslyn) and those who take imagery to be propositional (Pylyshyn).
Gist of Idea
Is mental imagery pictorial, or is it propositional?
Source
John Heil (Philosophy of Mind [1998], Ch.6)
Book Reference
Heil,John: 'Philosophy of Mind' [Routledge 1998], p.212
A Reaction
This may not be a simple dilemma. Pure pictorial imagery seem possible (abstract patterns) and pure propositions are okay (maths), but in most thought they are inextricable. The image is the proposition (a nuclear cloud).