Subject: Re: [lojban] Set of answers encore

From: [email-masked]
Date: Tue, 25 Sep 2001 12:22:09 EDT

In a message dated 9/25/2001 10:34:50 AM Central Daylight Time, 
[email-masked] writes:

> #But then next morning, looking at it again, I see that it is very 
> different, 
> #for I doubt that John (even this one) even thinks about "the extension of 
> " 
> #some property. In fact, I doubt that most people, who use indirect 
> question 
> #all the time, would even understand the locution. So, if the property is 
> #within the scope of the believing, where, because of intensioonality, it 
> has 
> #to be that property and not something incidentally equivalent to it, then 
> I 
> #would say that it was very rarely the case that anyone had an opinion 
> about 
> #who the first American President was. But, of course, the other version, 
> #which moves the property outside still works ok.
> 
> Jorge raised this objection at the time that I originally made the proposal.
> My answer is that if the extension-claim analysis correctly characterizes
> the logic of indirect questions, then if John knows that 'Bill' is the 
> answer
> to 'Who went', then John knows that {Bill} is the extension of the
> category of goers.
> 

Well, it is quite possible that John knows that Bill went, without knowing 
that "Bill" is the answer to the question "Who went?" for the very reason you 
note later, that he never thought of the question. It is also not at all 
clear that the equation of the two things John knows works intensionally.
The first problem does offer some evidence for the set-of-answers theory, 
since even if John never thinks of the question "Who went?" he does know the 
answer to that question, since "Bill went" is just that answer. I suspect 
that this fact can be mechanically transformed into an extension-claim 
version, though doing so makes the analysis more wordy apparently. (The 
second problem does not arise for set-of-answers.)

<However, there is a valid case not quite covered by my extension-claim
analysis. An example is where John knows that Chelsea is Bill's
daughter but doesn't know that Bill has no other daughters [by Hillary,
that is, I hasten to add, having watched the splendid Primary Colours
twice in the last week). So, as it were, John knows who Bill's daughters 
are, but doesn't know he knows. The extension-claim analysis can 
handle John's actual beliefs thus:

   la djan djuno tu'odu'u da cmima tu'o -extension be tu'odu'u la bil patfu 
ce'u>

This seem complex compares to {la djan djuno lo du'u la bil patfu makau}, 
which says he knows some, but not necessarily all, the answers. That it may 
turn out to be all is an open case. I suppose the simplicity is in the lack 
of unpacking, but set-of-answers doen't need much unpacking, since it stays 
at about the same level, without metalanguage: da poi cmima lo'i du'u la bil 
patfu makau zo'u la djan djuno da
Notice that there appears to be no de-intensionalization problem here.

<And the version where we deintensionalize our description of John's
knowledge can, I very very very tentatively think, be done thus:

  da poi ke'a du'u de -extension tu'odu'u la bil patfu ce'u zo'u la djan 
djuno da

I am very much not convinced that this solution is valid, but if it isn't, 
it's just a
further instance of the more general problem of how to refer to se djuno
and se jinvi extensionally rather than intensionally, and any solution of
the more general problem will also resolve the residual problems with the
extension-claim analysis.>

Your version seems to say merely that John knows "Bill is the father of ..." 
has an extension, which seems a) not likely to be somehting John thought of, 
and, b) if he did -- or if you want it not to matter that he did, is too 
trivial to help explain what "John knows who Bill is the father of" means. I 
think that something ahs to be done with that floating {de} to make any sense 
at all and I don't feel comfortable enough with the extesnion-claim format to 
suggest what that something might be.