I Introduction
Let's assume there are psychological generalizations that the folk rely upon in explaining and predicting the behavior of their fellows. Let's further assume these generalizations are intentional, in that they do their explanatory and predictive work by attributing to the subjects in their domain intentional mental states such as beliefs, desires, and the like. Then we can define a broad intentional psychology as one that adverts only to broad, viz. purely denotational/ truth-conditional, mental contents in its generalizations; so the sentences expressing its generalizations should be read transparently. A narrow psychology is one that is not so restricted. Accordingly, sentences expressing narrow generalizations will contain opaque contexts, indicated by ‘that’ -clauses ('believes that…,’ ‘desires that … ,’ and the like). Here is an example of the sort of generalization we have in mind:
(G) If S desires that P and believes that S can bring it about that P, then, ceteris paribus, S will try to bring it about that P.