Here is a soundbite about Sellar’s view of Mental predicates as objects. Sellars was Paul Churchland’s advisor. The quote is from an article profiling the churchlands in New Yorker. [pdf]. I would go further, and say that not only mental predicates, but all nouns refer to theories. Individuation, or the identification of macroscopic entities in the Pworld, amounts to the construction of theories, providing objects among which relations can obtain.