De dicto belief ascription: (1) Jones believes that the tallest spy is a spy.
De re belief ascription: (2) Jones believes, of the tallest spy, that he is a spy.
I find the latter puzzling. Does it commit us to haecceities, or deep facts about the identities of things? Hopefully we may account for the phenomenon without such metaphysical cost. Here's the vital question: what must the world be like in order to satisfy the ascription made in #2?
I don't think it requires any mysterious identity facts. One platitude about de re belief is that its object must actually exist. (I can have de dicto beliefs about unicorns, but there is no unicorn such that I have beliefs about it.) Further, de re belief requires some kind of causal acquaintance (however indirect) with its object. So perhaps #2 is just a convenient way to describe the conjunctive fact that Jones believes (de dicto) that the person he bears such-and-such relation to is a spy, and Jones does indeed bear such-and-such relation to someone (who is now counted as the object of the belief when we ascribe it in de re terms).
(3) Jones believes that Smith is the tallest spy.
Unlike in the previous case, this seems to imply the corresponding de re ascription:
(4) Smith is believed by Jones to be the tallest spy.
Jackson accounts for this via his descriptivist analysis of proper names. The representational content of 'Smith' (for Jones) is just some unique associated descriptive property that builds in the aforementioned acquaintance relation, and thus licenses "exportation" to de re ascription.
Does that do the trick, or is there more to de re belief than captured above? (Do some philosophers deny that de re belief is reducible in this way to the de dicto?)