1A) Hesperus is Phosphorus. — MetaphysicsNow
Kind of my issue with Frege - the assumption is that syntax and semantics is the whole story for natural language, whereas it is not (although it might be for formal languages).Statements such as "John is John" in your example, insofar I understand them, presuppose information without that it is not possible to make sense of it
Btw, I don't think of names, unlike descriptions, as ever being translated, though they do get localized. It's an odd area.
Hesperus = Venus
Venus = Phosphorus
Therefore Hesperus = Phosphorus — MetaphysicsNow
Still not clear what mistake you think Frege is making though. — MetaphysicsNow
Is a valid and sound argument based on the transitivity of identity. — MetaphysicsNow
Hesperus = Venus
Venus = Phosphorus
Therefore Hesperus = Phosphorus — MetaphysicsNow
Kind of my issue with Frege - the assumption is that syntax and semantics is the whole story for natural language, whereas it is not (although it might be for formal languages). — MetaphysicsNow
But something about that isn't quite right. The reason we feel there are different uses for "Hesperus is Hesperus" and "Hesperus is Phosphorus" is precisely because we feel they don't contain the same information. So it is with "4 = 4" and "2 + 2 = 4". It's that sense that these two equations carry different information -- they "say different things" -- that drives their different uses. So the semantics drives the pragmatics here. — Srap Tasmaner
Whether the use of a particular name (or nickname or description) is appropriate may not change the truth conditions of sentences it's used in, appropriately or not. I think if my son pointed at Venus of an evening and said, "Look, the Morning Star has risen," that would be true if a bit arch. — Srap Tasmaner
BlueBanana = banana
The banana Belter ate = banana
Therefore I am the banana Belter ate, and therefore I am dead.
With this, however, I agree.My problem with Frege is his that he account natural languages equalities by reducting them to formal ones, so the problem of saying/showing emerges when we think about concrete examples.
I'm still not clear what you're saying. — Srap Tasmaner
But we do not use natural language identities to say non-informative tautologies but to make identifications between words (synonymy relation) and a word and an object (reference relation). — Belter
If we're unable to use (1a) or (1b), we must take "Hesperus is Phosphorus" as (2). — Srap Tasmaner
Frege's view is that "Hesperus" and "Phosphorus" have different senses but refer to the same object. — Srap Tasmaner
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