“Cognitive significance” puzzles are especially problematic for anti-Fregean theories of reference, which, in particular, make it difficult to explain the informativeness of such identity sentences as “Hesperus is Phosphorous”. Frege can explain this in terms of the different senses associated with the names, Russell by appealing to different associated definite descriptions. It is argued that the “classical” direct reference solution to the puzzle advanced by Kaplan and Perry, which combines singular propositions with modifications of Frege’s modes of presentation, fails. The views of Putnam and Kripke are discussed in support of the idea that modes of presentation are not central to cognitive significance.
Keywords: Frege’s puzzle, informativeness, Kaplan, Kripke, modes of presentation, Perry, Putnam, singular propositions,