“Hesperus is Phosphorus” is a pure analytic proposition, hence necessarily true. — Mww
If x and y are identical, that means x and y are two different names for the same object. Like say John's nickname is Tweezer. x is John and y is Tweezer. now plug that into the argument. — frank
That this table is not made of ice is known a posteriori - by examining the table. Yet that this table is not made of ice is a necessary fact about this table - if it were made of ice, it would not be this table.
We cannot know a priori if the table is made of ice or of wood. But given that it is not made of ice, it is necessarily not made of ice. — Banno
You're asking what earth shattering consequences follow from Leibniz's law. Kripke is just setting the stage to show off a contradiction. That's all. Keep going. — frank
What does "if two objects have all the same properties, they are in fact necessarily one and the same" add to "if two objects have all the same properties, they are in fact one and the same" — RussellA
our language of logic is what makes it so more than what is the case. We can say what we like, and define what we like, and while that will change how we talk about things that won't change whatever "stuff" is. — Moliere
But we are substituting this into an opaque context - whether they are empirical facts. — Banno
So it seems we are left with empirically discovered necessities. — Banno
WHere's the argument? — Banno
Knowledge is experience, experience is always changing with time, so knowledge is always changing with time, therefore knowledge is contingent on time.
— Mww
Well, we know 4=2+2, but that doesn't change over time... an we know water boils at 100℃, at any given time; that doesn't change. So that doesn't work. — Banno
might be of further interest to Mww.
That this table is not made of ice is known a posteriori - by examining the table. Yet that this table is not made of ice is a necessary fact about this table - if it were made of ice, it would not be this table. — Banno
Rorty is just an ontological anti-realist. There's a whole spectrum of that including various hard and soft options. It's all analytical philosophy, though. If you want to read an article about it, it will be an analytical philosopher you're reading. Nothing particularly reformed about it, I don't think — frank
I'd say necessity is implicit in Leibniz's law. He's just making it explicit because he's about to challenge the notion that apriori=necessary, and aposteriori=contingent. He's going to show that there can be a statement that is known aposteriori, but is necessarily true. — frank
If we are given two analytic propositions "Hesperus is Phosphorus" and "Hesperus is not Phosphorus"….. — RussellA
….how do we know which is true…. — RussellA
….if the truth of an analytic proposition is independent of any empirical knowledge ? — RussellA
If we are given two analytic propositions "Hesperus is Phosphorus" and "Hesperus is not Phosphorus", — RussellA
(4) For every x and y, if x equals y, then, it is necessary that x equals y — RussellA
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