Lessons from Frege's Puzzle.

摘要

Although the problem in the philosophy of language known as "Frege's Puzzle" is well known, it is not well known that 3 different, but related, puzzles have all been identified as "Frege's Puzzle". Each puzzle poses its own unique challenge to Millianism, the view that the meaning or propositional contribution or semantic content of a name is just its referent. It is argued here that every Millian solution to "Frege's Puzzle" that has been proffered hitherto fails to solve it. The reason for failure is that no single solution can be a solution to all 3 puzzles. No single size fits all.;The dissertation sharply demarcates each puzzle from the other two, articulates the unique challenge posed by each and draws the appropriate lessons.;The first lesson is that there are two conceptions of what Frege calls the, "erkenntniswert" translated "cognitive value" or "cognitive worth", of a meaningful expression. According to one conception, the sentences, "ketchup is a breakfast condiment" and "catsup is a breakfast condiment" do not differ in cognitive value in that they are perfectly synonymous, i.e., encode the same proposition. "Ketchup" and "catsup" are perfectly synonymous. According to another conception however, the two sentences however also differ in cognitive value in that a person who fully understands both can rationally believe that they differ in truth-value.;The second lesson is that we have to move away from a standard semantics, where sentences like, "Elton John is Elton John" and "Elton John is Reginald Dwight" differ in the propositions they encode if "Elton John" and "Reginald Dwight" differ in their semantic contents. It seems pretty clear that these sentences differ in informational value---while the former is trivial and a priori, the latter is non-trivial and a posteriori. But, on a standard semantics, the only way to get a difference informational value between the two sentences is by rejecting Millianism. What this shows is that we have to move to a non-standard semantics, which I call, "Collapse Semantics", where we can get a difference in the propositions encoded by the two sentences without rejecting Millianism.;The third is that we have to modify our conceptions of the attitude verbs like, "belief", "know", "doubt", etc. Our ordinary conceptions of these verbs lead to incoherence. On our modified conceptions, they are only partially defined.