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Re: [ontolog-forum] Truth

To: ontolog-forum@xxxxxxxxxxxxxxxx
From: Ron Wheeler <rwheeler@xxxxxxxxxxxxxxxxxxxxx>
Date: Fri, 29 Jun 2012 12:04:32 -0400
Message-id: <4FEDD210.4070608@xxxxxxxxxxxxxxxxxxxxx>
On 29/06/2012 10:30 AM, John F Sowa wrote:
> Avril and Chris,
>
> I am writing a short book entitled _Principles of Logic and Ontology_,
> which I promised the publisher that I would finish by December.  The
> intended audience is the kind of people who subscribe to Ontolog Forum,
> attend Semantic Technology conferences, develop software that uses basic
> ideas of logic and ontology, and professors who teach courses to them.
>
> The tutorial I presented at SemTech in San Francisco a few weeks ago
> has a large overlap with what I'm writing for that book:
>
>      http://www.jfsowa.com/talks/kdptut.pdf
>
> As you may notice, there is a lot of historical material.  I include it
> for background and for showing how the basic ideas appear and reappear
> in different guises.  But the principles I want to emphasize are ones
> that are easy to explain, easy to learn, and mostly foolproof    (01)

> -- i.e.,
> they minimize the amount of confusing and distracting detail, and they
> don't depend on fine distinctions that generate endless debate.    (02)

Now if we could just adjust the conversation here to follow the same 
principle we all might learn something useful.    (03)

I am still trying figure out how    (04)

  "'p' is true" if and only if p.    (05)

changes what I thought I knew before I read that line and the endless 
discussion preceding and following its appearance.    (06)

I am afraid that while we have endless discussions that seem to more 
about different people's view of the definition of "it" which seems to 
depend more on the writer's knowledge of English or subject matter 
experience than anything else, the rest of the world (Google, IBM and 
others) is developing a more realistic way to process information shared 
by people and machines that recognizes that you need more than 
definitions to understand how ideas are expressed.    (07)

BTW    (08)

"'p' is true" if and only if I believe "'p' is true" reflects the actual 
application of "truth" in the real world.
To top it all off, my beliefs are under constant revision.    (09)


Ron    (010)

>
> AS
>> There are many different 1kg particulars which all share the identical
>> property 1kg. Alternatively, one can say that there are several unidentical
>> 1kg properties, where a property is thought to include its constituents
>> in the fashion of tropes. Then again, instead of 'constituents', one can
>> use 'particular'. That is, some form of property-particular or property-
>> constituent dichotomy is needed.
> I would never write anything like that in my book.  I admit abstract
> things like measures in the ontology, and I introduce triadic relations,
> such as hasMeasure(x, y, kg).  I also define the measure kg by saying
> that one can choose some object whose mass is defined to be 1 kg.
>
> Then the relation hasMeasure(x, y, kg) can be determined by comparing
> the object x to the object that defines the standard measure of 1 kg
> by using some appropriate mechanism that computes the ratio y to 1.
>
> This explanation avoids the terms 'universal', 'particular', 'property',
> 'trope', 'property-particular', and 'property-constituent dichotomy'.
> The only place where such terms would occur in my book is in a glossary
> of obsolete terms that one might accidentally bump into.
>
> I'd also like to go back to an earlier point Chris mentioned:
>
> JFS
>>> ... the observation that
>>>
>>>    "p is true" if and only if p.
> CM
>> Misplaced right quote there; should be:
>>
>>     "p" is true if and only if p.
> I would prefer to use the following punctuation:
>
>      "'p' is true" if and only if p.
>
> As you know, I prefer to use a Tarski-style stratified hierarchy
> of metalevels:
>
>      Object level statement:  p.
>
>      Metalevel statement:  'p' is true.
>
>      Meta-metalevel statement:  "'p' is true" if and only if p.
>
> I'll admit that it's possible to have a logic that talks about
> truth values without having a strict hierarchy of metalevels.
>
> But I want to use a formalism that is easy to teach to students and
> easy to apply to a large number of practical problems.  A hierarchy
> with clearly marked metalevels is much easier for me to explain and
> much, much easier for the readers to learn and use without getting
> into trouble.
>
> Note:  As in Tarski's hierarchy, I would allow metalevel N to include
> every statement in level N-1 plus the truth values for level N-1.  But
> it would not include the truth values for level N itself.
>
> For simplicity, I allow the words 'true' and 'false' to be indexicals
> so that the qualifiers about the level can be omitted.  For example,
> If 'p' is at the object level N, a statement "'p' is true" is at
> level N+1 and 'true' specifies truth for level N.  when multiple
> levels occur in the same statement, the words 'true' and 'false'
> can have subscripts to indicate the level.
>
> John
>   
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>    (011)


-- 
Ron Wheeler
President
Artifact Software Inc
email: rwheeler@xxxxxxxxxxxxxxxxxxxxx
skype: ronaldmwheeler
phone: 866-970-2435, ext 102    (012)


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