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Perplexed comments on Unsolved Problems in Philosophy Part 1: The Liar's Paradox - Less Wrong
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Tarski left out some of the fine print. That "if and only if" works only under the prior assumption that "snow" designates snow, "white" designates white, and "is" designates the appropriate infix binary relation.
In other words, "Snow is white" is true only if we know that "Snow is white" is a sentence in the English language.
Not really. If "snow" designates grass, and "white" designates green, then "'snow is white' is true if and only if snow is white" is still correct. Same if "snow" designates the sky and "white" designates green.
I'm afraid I don't understand your point.
It should have read: "Same if "snow" designates the sky and "white" designates blue."
It was apparently a nitpick of your first paragraph, ignoring your second paragraph.
That can't be right. If he both misinterpreted 'prior assumption' and made a serious typo, his comment would not have been twice upvoted, would it?
If you can't take as a given that statements actually are in the language they appear to be in no statement can have any knowable truth value. If "snow" in the utterance is a word in the same language as the identically spelled word in the statement, and the same for "white" (and "is"), and the rest of the statement means exactly the same as it does in English then the statement is still correct. But if "white" might designate orange "true" might just as well designate bubblegum or "only" designate "to treat like a second cousin".
And further the grammar of English is being assumed... as well as the very concept of languages.
Let me see if I understand you. "Snow is white" is true if and only if "snow" means snow, "is" means is, "white" means white, and snow is white? Because that still only makes sense if there's a fact of the matter about whether or not snow is white. And as ata pointed out, it's also false.
Edit: Maybe Tarski's undefinability theorem applies here. It says that no powerful formal language can define truth in that language. So if, as you say, truth is an attribute of linguistic objects, you have to invoke a metalanguage in which truth is defined. Then you need a meta-meta-language, etc. Of course English is not a formal language, and there is no formal meta-language for English - we talk about the truth of English sentences in English - but that is my point, that it relies for certain things on non-linguistic definitions. When we start discussing sentences like "This sentence is false", there's a tendency to forget that English does not and cannot define the truth of all English sentences.
No, that is not what I said. I said that IF "snow" means snow, "is" means is, and "white" means white, THEN "Snow is white" is true iff snow is white.
I never denied that. But the fact has nothing to do with truth unless you bring language into the discussion. Only linguistic objects (such as sentences) can be true.
Somehow, I feel that we are talking past each other.
ETA:
And now I know we are talking past each other.
That makes a lot more sense, thanks.
I think we're getting somewhere. I thought that you were saying that whether or not a statement is true is a property of language. Tarski's saying that whether or not a sentence is true is determined by whether it corresponds to reality. You're saying that whether or not it corresponds to reality is determined by the meaning the language assigns to it.
I'm still not convinced that truth is to do with language, though. Consider a squirrel trying to get nuts out of a bird-feeder, say. The squirrel believes that the feeder contains nuts, that there's a small hole in the feeder, and that it can eat the nuts by suspending itself upside down from a branch to access the hole. The squirrel does actually possess those beliefs, in the sense that it has a state of mind which enables it to anticipate the given outcome from the given conditions. The beliefs are true, but I'm certain that the squirrel is not using a language to formulate those beliefs in.
That sounds right. I think if we describe a sentence as being "true" then we're really saying that it induces a possibly-nonverbal mental model of reality that is true (or very accurate), but we can say the same about mental models that were nonverbal to begin with.