but the issue is similar, — Count Timothy von Icarus
All this shows is ~(Israel = Palestine). They are not identical, and so substitution fails.Israel is Palestine
Israel is a Jewish state
Therefore, Palestine is a Jewish state. — Count Timothy von Icarus
I would have thought so, too. But what do we make of Kripke?Referential opacity is to do with individuals, not natural kinds. — Banno
I realize encyclopedias get things wrong, but this coincides with my memory.In Naming and Necessity, Kripke argues that proper names and certain natural kind terms—including biological taxa and types of natural substances (most famously, "water" and "H2O") designate rigidly. — Wikipedia - Rigid designator
That's true. But you don't diagnose the problem.Steam is H2O
Ice is H2O
Therefore, steam is ice
This is obviously incorrect. — Count Timothy von Icarus
Banno is right. Undistributed middle.It's the same as "All cats are mammals, all dogs are mammals, therefore all cats are dogs". — Banno
I have doubts about this. It is not wrong. But it doesn't mean that any old chunk of ice will make a good bridge. Ice only makes for a good bridge if it is handled properly. One could argue that the conclusion is true, provided we specify that it needs to be handled properly (i.e. turned into ice). There's a complication here because the same could be said of water.Ice is water.
Ice makes for a good bridge.
Therefore water makes for a good bridge. — Count Timothy von Icarus
Yes. Mostly, this does not bother us, but in this kind of discussion, it matters.The problem here is an equivocation on "water" as chemical identity versus as a particular phase of that substance. — Count Timothy von Icarus
I think that this is where the example is clearly in a different category from our referential examples. "Water" is a mass term - it doesn't do individuals. The only ways you can identify "the same water" is indirectly, via, for example, a cup. When you borrow a cup of sugar from your neighbour, you will, of course, return it. But you don't have to return the same grains of sugar, do you? The same goes for borrowing money. You repay the money you borrowed, but not the same individual money - the very idea is meaningless.it seems clear that my cup of water is the same water when it has frozen, ... — Count Timothy von Icarus
Well, we agreed, I think, that the problems occur between contexts, which may be one kind of ambiguity. But it is true that there are ambiguities that are not about reference. Nonetheless, I'm beginning to think that there are issues about the "description under which" we think about things that I have not seen discussed.Referential opacity is not about ambiguity. — Banno
There is something I don't understand here. Presumably, the implication goes the other way, so that if we can replace a with b in a formula, then we have a=b. So we need an independent way of establishing one or the other.The schema says that if we have a true formula containing an individual variable a, and if we have a=b, then we can replace a in with b, and the formula will remain true. — Banno
Banno is right. Undistributed middle.
You repay the money you borrowed, but not the same individual money - the very idea is meaningless
but the question of why it is more plausible seems to lie in the ability to equivocate on the way in which water, ice, and steam "are" H2O — Count Timothy von Icarus
I don't understand you. All I'm saying is that "water" is ambiguous and this makes it easy to fall into error. To be sure, we usually manage the ambiguity. BTW. "Cat" is ambiguous between the species and the genus. So there is a similar ambiguity there. I'm sure there are others.A science teacher teaching the water cycle or phases of matter would say just this sort of thing. There isn't a correct context for "cats are dogs." — Count Timothy von Icarus
I'm not sure I know what "fungible" means, but I think I get the point. Exchanging money for money would indeed be pointless. Borrowing and lending money is not a straightforward exchange so it is different.Sometimes people hold money for other people, and they expect them not to mess around with it. Money is fungible though, so exchanging it isn't generally meaningful. — Count Timothy von Icarus
Yes. That was my point.Compare this with something with a strong principle of unity like a tree. Break a tree in half and you have a dead tree, you have timber, not a tree at all arguably. Break it up more and you have lumber that is clearly not a tree. — Count Timothy von Icarus
Natural kinds - ice, water, and so on - are not individuals. Referential opacity is a problem for individuals.But what do we make of Kripke? — Ludwig V
Ice is water.
Ice makes for a good bridge.
Therefore water makes for a good bridge. — Count Timothy von Icarus
Yeah, it is.It is not wrong. — Ludwig V
Not quite. Not just a formula, but all formula. If in all formula we can substitute a for b, without altering any truth value, then a=b. That's Leibniz's law.Presumably, the implication goes the other way, so that if we can replace a with b in a formula, then we have a=b. — Ludwig V
"Water" can mean the liquid only, or it can mean any of liquid, solid, and gas. If we assert that water = H₂O, we are asserting the latter, since we are also by symmetry asserting that H₂O = water. I don't see an issue, provided we are clear here. Tim's post seems tangential.
Stop equivocating
"Water" can mean the liquid only, or it can mean any of liquid, solid, and gas. If we assert that water = H₂O, we are asserting the latter, since we are also by symmetry asserting that H₂O = water.
Dude, H₂O≠ liquid water.
That's right. The problem with the ice/bridge argument, IMO, is although one could argue that the first premiss tells us that the wider sense applies, the conclusion is misleading, because the substitution of "water" for "ice" suggests that the narrow sense applies. Does that work?"Water" can mean the liquid only, or it can mean any of liquid, solid, and gas. If we assert that water = H₂O, we are asserting the latter, since we are also by symmetry asserting that H₂O = water. I don't see an issue, provided we are clear here. Tim's post seems tangential. — Banno
Yes. I'm a bit slow sometimes. I finally realize that referential opacity is the result of cross-contextual confusion, but old-fashioned equivocation, which is what @Count Timothy von Icarus is talking about takes place within a single context. Is that right?Referential opacity is a different issue to referential equivocation. — Banno
Yep.substitution of "water" for "ice" suggests that the narrow sense applies. — Ludwig V
There's an ambiguity between the two uses of "water", the first refering to any state, solid, liquid, gas, the second to the liquid only. But we might have:Water is H₂O, and water is always a liquid.
Same ambiguity, two states.Water is H₂O, and Alice believes that water is always a liquid.
The ice bridge argument is just invalid. It's another undistributed middle.
Is not an undistributed middle. — Count Timothy von Icarus
This?I just brought that one up because it is an example that seems like obvious equivocation that is not actually equivocation — Count Timothy von Icarus
(i = w) ∧ Bridge(I) ⊢ Bridge(w) — Count Timothy von Icarus
If that's how you mean it, then it's wrong, since ice is water in it's solid form; ice is never liquid water....it's also the case that if "ice is water (any phase)" is meant as identity — Count Timothy von Icarus
The writer's intention is irrelevant. The book says "Superman can fly" not "Clark Kent can fly", and any one who says otherwise would be misquoting. Substitution of co-referents is not licensed inside quotation or belief reports.Consider a book, rather than a believer. A book says something like: "Superman can fly" or "Mark Twain is a best seller." Does the book also say that Clark Kent can fly and that Samuel Clemens is a best seller? Does identity substitution work here? Now, on one view, we could ask what the writer intended. If the writer intended to express their beliefs and has no idea that Mark Twain = Samuel Clemens, and the text is taken as an expression of belief, then it seems that we cannot substitute? Whereas, on a "death of the author view" it would seem to be the reader who determines in substitution holds in ambiguous situations. — Count Timothy von Icarus
Formal logic depends on treating language as a structure - unless someone has begin devising a logic that includes speakers - who would be an abstraction anyway.Can opacity vis-á-vis belief wholly semantic and logical? — Count Timothy von Icarus
I think we would treat such texts as if there were a speaker. The text itself posits an author. The author of the text is not necessarily the same as any specific person. It's a trope in literary studies.But, if we want to keep to a view where opacity is purely a function of language/contexts itself, what of ambiguous statements in the context of something like an anonymous text, a p-zombie, random text generator, or AI? — Count Timothy von Icarus
I have a feeling that what you meant to say was that the writer's intention is irrelevant for the purposes of logic. That's true. But if you know that Dostoevsky was a devout Christian, you will be licensed to interpret his texts in the light of that knowledge. Surely?The writer's intention is irrelevant. The book says "Superman can fly" not "Clark Kent can fly", and any one who says otherwise would be misquoting. Substitution of co-referents is not licensed inside quotation or belief reports. — Banno
That's why we can't take "believes that.." as something like a quotation.So the book example illustrates why opaque contexts may not be exhausted by local quotation rules — a single quote can’t capture the interpretive force of a whole body of text. That’s where holism starts to look more natural. — Banno
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