Thanks. I understand the logical sense of 'tautology'. And my point stands. The metalinguistic sentence is just a sentence, and its truth-predicate does nothing to disguise the fact that it's the same sentence either side of the biconditional, cited on the left and simply asserted on the right.Consul wrote: ↑June 28th, 2022, 1:41 pmYou're not using "tautology" in the logical sense (as defined above), in which it doesn't mean "the repetition (esp. in the immediate context) of the same word or phrase, or of the same idea or statement in other words" (OED). In "Snow is white" is true iff snow is white we have a metalinguistic sentence about the sentence "Snow is white" on the left side and an object-linguistic sentence about the worldly state of affairs of snow's being white, which is the truth-condition of the sentence "Snow is white".Peter Holmes wrote: ↑June 28th, 2022, 5:12 amGood grief. This is to rehash Saussure's mistake - sign = signifier + (magically) signified - and its absurd but inevitable consequences, in Derrida and others.Consul wrote: ↑June 27th, 2022, 4:52 pm"A logical combination of sentences that is always true, regardless of the truth or falsity of the constituent sentences, is known as a 'tautology'."
(Rucker, Rudy. Mind Tools: The Five Levels of Mathematical Reality. London: Penguin, 1988. p. 211)
Thus defined, T<p> <—> p is a logical tautology, because every sentential substitution for p results in a true biconditional, no matter whether p is true or false. For example, it is false that Joe Biden is the president of Canada; but it is still true that the sentence "Joe Biden is the president of Canada" is true if and only if Joe Biden is the president of Canada.
Despite being tautological, the right side of T<p> <—> p is world-involving, which means that truth depends or supervenes on how the world is or isn't.
There's nothing canine about the word dog, or the word canine. Who could think there is? Ah - a correspondence theorist.
Let's see. The assertion 'snow is white' is true iff snow is white. 'Despite being tautological' (saying the same thing twice), this 'is world-involving'. Let's just keep on mistaking what we say about things for the way things are. Swot we've always done.
The idea that we can use language to get outside language is a delusion. And logic deals with language, not the reality outside language. This is why I think we have to make a sharp distinction between features of reality and what we say about them. Muddling them up has led and leads to no end of philosophical confusion - witness correspondence and truth-maker/bearer theories.