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Re: [ontolog-forum] {Disarmed} Re: OWL and lack of identifiers

To: Pat Hayes <phayes@xxxxxxx>
Cc: Ontolog Forum <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Waclaw Kusnierczyk <Waclaw.Marcin.Kusnierczyk@xxxxxxxxxxx>
Date: Mon, 30 Apr 2007 11:30:52 +0200
Message-id: <4635B74C.30004@xxxxxxxxxxx>

Pat Hayes wrote:
>> Pat Hayes wrote:
>>>> Pat Hayes wrote:
>>>>>>  Reality doesn't exist in the absence of perspective.  Reality is
>>>>>>  subjective, not objective.
>>>>>  Absolute nonsense. Reality existed for billions
>>>>>  of years before there was anything that could
>>>>>  form a subjective view of it. If, as seems quite
>>>>>  possible, this planet contains the only life
>>>>>  capable of having a subjective view, and our sun
>>>>>  goes nova and wipes us all out, the universe will
>>>>>  carry on being objectively real without noticing
>>>>>  our passing.
>>>>>>   When people speak, they speak the truth if
>>>>>>  they say what is real for them.
>>>>>  No. They speak the truth when what they say is in
>>>>>  fact the case, in the actual world.
>>>>>>  The *real* worlds are the worlds that
>>>>>>  are real *for persons*.
>>>>>  No, the real world is the one that persons
>>>>>  inhabit and are part of. There is only one of it.
>>>> haven't you just said that logical semantics is a theory of truth?  
>>>> what
>>>> about the semantics of modal logics?  isn't it a theory of truth which
>>>> consists of multiple, concurrent so-called 'possible worlds'?
>>> Not necessarily concurrent. And as you say, 'so-called'. What these 
>>> are depends on the modality in question. Temporal logic for example 
>>> has 'possible worlds' being snapshots of a single temporal plenum, 
>>> which IMO is the single real world. Alethic modalities (necessary and 
>>> possible) are often described as being about entire possible worlds, 
>>> but (as Kripke, the inventor of these semantics, says) one can think 
>>> of these most usefully as being ways the actual world might be, 
>>> rather than fully-fledged alternative worlds. IN fact, Lewis' 
>>> interpretation, which gives all possible worlds the same status, is 
>>> widely (and IMO correctly) seen as an extreme and perhaps untenable 
>>> position. The Kripke view, expounded in his "naming and necessity", 
>>> is that alethic talk is really about lack of information. We don't 
>>> know exactly how the world actually is, and so there are many ways it 
>>> might be consistent with the information we have. These ways it might 
>>> be are the 'possible worlds' that the Kripke semantics envisions.
>> agree.  but, as you yourself say, there are those who disagree, and 
>> the best thing you can say is that IYO (note the 'O') they are incorrect.
> Well, I wouldnt even say that, actually. But if you recall, the original 
> debate was whether or not model theory (Tarskian or Kripkean) amounted 
> to an objective theory of truth.    (01)

yes, of course.    (02)

>>> But in any case, I was referring to Tarskian semantics for non-modal 
>>> languages earlier in the thread. Most ontology languages aren't modal.
>> yes.  one problem that i can see with tarskian and the like semantics 
>> as a theory of truth is that it requires you to take a snapshot of the 
>> world, necessarily excluding its dynamics.
> I dont think so. You just have to construe the Tarskian universe as 
> 4-dimensional, which is a powerful ontological framework in any case 
> (though admittedly controversial).    (03)

well, this answer was expected.  what you do is just make time another 
dimension, and describe the universe as a 4d one (presuming it was 
described as 3d before) -- still taking snaphots.  the point is, while 
you speak of the world (now 4d), it does not change.  if you speak of an 
object (or whatever) located within a particular region of the 4d space, 
neither the object nor its location change.  in a sense, you immobilize 
time.  all statements made in the logic are effective at the same time 
(i admit that now we got the tricky issue of which time is meant;  to 
say that they are in effect simultaneously only makes the issue less 
apparent).    (04)

but whether this has any influence on the pragmatics, is another story 
(intuitively, i'd say so, but i can't state it precisely now).  so think 
of it as an artificial problem, until i come with some good arguments to 
the contrary (if i come to that).    (05)

vQ    (06)

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