"Physiological" is an odd term to use here. Did you mean something more like "Psychological"? But I take the point. But it seems to have turned out that the logic used to state the problem can't resolve it.Quine's contribution was to put the problem in terms of substitution, and hence in terms of extensionality, and so presenting it as a puzzle of logical form as opposed to a physiological issue. — Banno
I believe that "Lois believes that Superman is Clark Kent and Superman can fly, so Clark Kent can fly" represents things better. Whether, post Davidson, "Superman is Clark Kent and Superman can fly, so Clark Kent can fly. Lois believes that." is better, I wouldn't care to say. What I'm after is that it's not enough that she believe three separate sentences. She has to put them together, and that's what it is hard to represent in language. Perhaps what I'm trying to say is that there something like a Gestalt at work here, which it is hard to represent with atomic sentences/propositions. I'm thinking of something like Quine's web of belief.In this last we can see the whole in a single context. The problem - so far as there is one - only arises when the contexts are muddled together. That's what Quine pointed out. — Banno
There are many things that I ought to know and do not know. I did not know that Quine has an actual diagnosis and a solution.I suspect that you, Ludwig V, are familiar with all this. — Banno
I'm afraid I'm not competent to express an opinion about what you are trying to say. I don't understand it.Read the exchange with I just had with Banno. You do need to understand the issue of Supervenience though in relation to Mental States/Identity. — I like sushi
I'm afraid I don't know or can't recall exactly what the identity elimination schema. Do you mind just outlining what it is? — Ludwig V
A little more formally, the rule of inference =E can be stated as:
Identity Elimination Schema
Major: t1 = t2
Minor: ϕ(t1)
Conclusion: ϕ(t2)
Here t1 and t2 are expressions which refer to entities (for example, proper names of people or cities). ϕ(t1) is a sentence containing at least one occurrence of t1, and ϕ(t2) is a sentence that results from replacing at least one occurrence of t1 in ϕ(t1) with an occurrence of t2, eliminating the “=” of t1 = t2. Recurring ti presumes that ti is univocal throughout, and recurring ϕ presumes that the sentential context ϕ is not altered, syntactically or semantically, by the replacement. If these uniformity conditions are not met, then the inference scheme is being misapplied, and it is no wonder that false conclusions are derivable. For example, in the inference “The man behind Fred = the man in front of Bill; the man behind Fred saw him leave; therefore, the man in front of Bill saw him leave,” the context “saw him leave” is not uniform, since substitution of “the man behind Fred” by “the man in front of Bill” changes the reference of “him” (Fine 1989:222–3; Linsky 1967:104).
In discussing the problem with apparent substitution-failure by using =E, many examples will be drawn from the fictional story of Superman, treated as if it were true. In the story, a child from the planet Krypton, Kal-El, is sent to Earth, where physical conditions cause him to acquire superpowers. Wearing specific clothing (red cape, blue jumpsuit), Kal-El prevents disasters, rescues endangered innocents, and foils would-be perpetrators of crimes, such as Lex Luthor. People call Kal-El “Superman” when talking about Kal-El’s actions of this kind.
But Kal-El also takes a day job as a reporter, using the name “Clark Kent.” A coworker, Lois Lane, treats him with indifference in the office, but has a pronounced crush on, as she would put it, Superman, unaware they are the same individual.
The problematic examples discussed below involve ascriptions of mental states to Lois (or occasionally Lex), arrived at by applying the rule =E to the major premise “Superman is Clark” and a carefully chosen minor premise. Lois has a crush on Superman (minor premise), so, by =E, Lois has a crush on Clark. But this latter seems false, and would certainly be rejected by Lois herself. Also, Lois believes that Superman can fly, but does not seem to believe that Clark can; she hopes to see Superman again soon, but seems not much to care when she next sees Clark; she would like a date with Superman, but apparently has no interest in one with Clark; and so on — IEP
a. Istanbul is Constantinople.
b. “Istanbul” has eight letters.
c. ∴ “Constantinople” has eight letters.
— IEP
In this case, the problem is coming from the use of Tarskian quotation, which means the quoted part is a word, not a city.
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a. Giorgione is Barbarelli.
b. Giorgione is so-called because of his size.
c. ∴ Barbarelli is so-called because of his size.
— IEP
The flaw here is equivocation. The "so-called because of his size" can't skip from one name to the next.
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a. The number of planets = 3 squared
b. It is contingent that the number of planets = 9
c. ∴ It is contingent that 3 squared = 9.
— IEP — frank
The planet case is a misapplication because the number of planets isn't a proper noun. Both t1 and t2 have to be rigid designators. — frank
the de re reading, contrasting with the more common de dicto reading, [...] relational, contrasting with notional; transparent, contrasting with opaque; and wide scope, contrasting with narrow scope.
— IEP
Also reference, contrasting with sense? (I wonder.) — bongo fury
I'm sympathetic to most of what you have been saying. But this contradiction can easily be resolved. "Superman" and "Clark Kent" are both names for the same person - but each name is assigned to a different persona. This is not particularly strange - pen names, professional names, character names (Barry Humphries, for example), regal names, baptismal names, adoptive names, married names, aliases of all sorts. — Ludwig V
Edit: with Superman we could also avoid belief and still get an apparent error with "Clark Kent appears on the Daily Planet payroll." — Count Timothy von Icarus
On your reasoning, we can disprove the thesis simply by noting that Superman wears a cape whereas Kent does not. — Leontiskos
I don't know I would go that far. That "if" tells me that you have reservations. I suspect there will still be issues to discuss, but it might be a change from going through that argument over and over again.Well, if the personas have different properties then you have solved the "puzzle." — Leontiskos
would be parsed asSteam is H2O
Ice is H2O
Therefore, steam is ice — Count Timothy von Icarus
I don't agree.That's a nice and thought-provoking collection of examples. — Ludwig V
Yep.You aren't using the identity elimination schema there. — frank
No. The problem is that you have moved from individuals to natural kinds.The problem here is an equivocation on "water" as chemical identity versus as a particular phase of that substance. — Count Timothy von Icarus
Referential opacity is to do with individuals, not natural kinds.
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