Full Idea
Propositional attitudes are really three-place relations, between a creature, a proposition, and a mode of presentation (which are sentences of Mentalese).
Gist of Idea
Propositional attitudes are propositions presented in a certain way
Source
Jerry A. Fodor (The Elm and the Expert [1993], §2.II)
Book Reference
Fodor,Jerry A.: 'The Elm and the Expert' [MIT 1995], p.47
A Reaction
I'm not sure about 'really'! Why do we need a creature? Isn't 'hoping it will rain' a propositional attitude which some creature may or may not have? Fodor wants it to be physical, but it's abstract?