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Re: live meaning and dead languages

From: rick <rick@rickmurphy.org>
Date: Tue, 10 Feb 2009 09:58:23 -0500
Message-ID: <4991960F.4060203@rickmurphy.org>
To: semantic-web@w3.org

Thanks Richard, Good humor is often missing from lists and I enjoyed the 
laugh!

Richard Cyganiak wrote:
>
> Rick,
>
> Let's continue this debate over on the armchair-semantic-web@w3.org list.
>
> Cheers,
> Richard
>
> (P.S. it's a joke, I have nothing more to say on this topic)
>
>
>
> On 10 Feb 2009, at 03:47, rick wrote:
>
>>
>> See below ...
>>
>> Richard Cyganiak wrote:
>>>
>>> On 8 Feb 2009, at 18:11, rick wrote:
>>>> As I have written before, the model theory on which the semantic 
>>>> web is based is defined in Alfred Tarski's Semantic Conception of 
>>>> Truth.
>>>
>>> Rick, that's overstating the role of model theory on the Semantic Web.
>>
>> The statement above makes no reference to the ROLE of the model 
>> theory on the semantic web. But I'm glad you raised the issue. This 
>> statement asserts the model theory on which the RDF semantics are 
>> based. And the astute critic of the above would actually claim that I 
>> have understated the model theory by not citing Kripke and possible 
>> worlds.
>>
>>> The formal semantics of RDF, as defined in [1], are based on model 
>>> theory.
>>
>> Yes, that's my assertion, too. Did you have something more specific 
>> to say about which model theory? Possibly LBase?
>>
>>> But a lot of the deployed usage of RDF considers it simply as a 
>>> distributed graph data model, and ignores (or even violates) the 
>>> model theoretic semantics.
>>
>> So this statement about the ROLE of model theory raises two important 
>> questions:
>>
>> 1. If one is ignorant of model theory, does that invalidate model 
>> theory?
>>
>> 2. If one violates the model theoretic semantics of the semantic web, 
>> is the deployed usage part of the semantic web?
>>
>> In either case I think there answer is no.
>>
>> First, consider music theory as an analogy. If I play two notes B and 
>> F simultaneously on my guitar that form a harmony called a tritone, 
>> but I am ignorant of the music theory of tritones, are these two 
>> notes any less a tritone? I believe my ignorance does nothing to 
>> invalidate music theory.
>>
>> Second, the RDF semantics is a W3C recommendation which I understand 
>> is a normative document. In addition, the LBase Working Group Note 
>> defines LBase as the model theory of all semantic web languages. By 
>> definition, any language whose model theory is not LBase is not a 
>> semantic web language.
>>
>> Would you suggest the recommendation and note be deprecated to suit 
>> the convenience of usage?
>>
>> Again, my claim is that some arm chair philosophizin' would save the 
>> semantic web community some time. I'm not alone in this opinion, but 
>> I suggest that's a decision made by each individual that best suits 
>> their interests and abilities.
>>
>>> Various non-RDF technologies, such as Topic Maps or microformats are 
>>> often lumped under the Semantic Web umbrella as well.
>>>
>>
>> So is your claim that RDF technologies and non-RDF technologies that 
>> violate the RDF semantics are part of the semantic web? What then are 
>> the criteria for a semantic web technology? And how many other 
>> technologies are semantic web technologies?
>>
>>> So, only a particular part of the Semantic Web technology portfolio 
>>> is based on model theory. I agree, however, that it's the part that 
>>> can benefit most from armchair philosophizing.
>>
>> As above, I suspect there's some good debate in drawing the boundary 
>> around what's in this semantic web technology portfolio. Once the 
>> boundary's drawn and there's agreement on questions 1 and 2 above, 
>> let the philosophizin' begin.
>>
>>>
>>>
>>> Have fun,
>>> Richard
>>>
>>> [1] http://www.w3.org/TR/rdf-mt/
>>>
>>>
>>>> Briefly, Tarski defines truth in terms of material adequacy and 
>>>> formal correctness. Note that Tarski does not define meaning, only 
>>>> truth. I think everyone would agree that material adequacy applies 
>>>> only to resources can be dereferenced and that it is formal 
>>>> correctness that provides the foundation for inference.
>>>>
>>>> So what can we say about meaning on the semantic web? We can say 
>>>> that URIs are definitions, but we need to be clear that meaning is 
>>>> not definition. Quine writes about this in Two Dogmas of 
>>>> Empiricism. Live meaning as referenced above implies interpretation.
>>>>
>>>> The question then is whether inference is interpretation. I believe 
>>>> inference as used on the semantic web is necessary, but not 
>>>> sufficient for interpretation. Interpretation as it applies to 
>>>> meaning implies abduction as well as induction and deduction. 
>>>> Inference on the semantic web implies formal correctness and truth.
>>>>
>>>> It's not clear whether the semantic web lacks this design principle 
>>>> intentionally, but without this design principle, the semantic web 
>>>> will lag the web in its utility.
>>>>
>>>> As a compelling example, consider how the web serves as a meme pool 
>>>> for cultural transmission. How would we expect the semantic web to 
>>>> serve as a meme pool with dead languages ?
>>>>
>>>>> I think this worry becomes more so as axioms and systems of axioms 
>>>>> become more complicated. (I just about see similarities between 
>>>>> OWL2 and the Shorter Latin Primer I had at high school).
>>>>>
>>>>> A term which is too tightly nailed down in its relationship to 
>>>>> other terms has been dug into an early grave. Having fixed its 
>>>>> meaning, as our world moves on, the term will become useless.
>>>>>
>>>> A semiotic domain is a good next step to start developing this 
>>>> flexibility.
>>>>> The trick, in natural language, is that the meaning of terms is 
>>>>> somewhat loose, and moves with the times, while still having some 
>>>>> limits.
>>>>> This looseness of definition gives rise to some misunderstandings 
>>>>> (aka interoperability failures), but not too many, we hope.
>>>>>
>>>>>
>>>> Pragmatics is a step after semiotics.
>>>>> So I wonder, as some people try to describe some part of their 
>>>>> world with great precision, using the latest and greatest formal 
>>>>> techniques, just how long that way of describing the world will 
>>>>> last. Maybe there is a role in such precision in allowing us to be 
>>>>> clear about differences of opinion --- but it doesn't seem to me 
>>>>> to be a good foundation for building knowledge.
>>>>>
>>>>>
>>>> While I agree that we need to recognize the limitations of where we 
>>>> are today, I think Tarski's Semantic Conception of Truth is a 
>>>> pretty good place to start. We also need to recognize the 
>>>> challenges of moving along the path to live meaning.
>>>>
>>>> If you're looking for some fun reading, Robert Kent has already 
>>>> defined the Information Flow Framework which parameterizes 
>>>> languages, logics, models and theories into a much more flexible 
>>>> approach than the semantic web. But hold onto your towel ...
>>>>
>>>> http://www.ontologos.org/IFF/IFF.html
>>>>> Perhaps fortunately, I am an engineer not a philosopher!
>>>>>
>>>>> Jeremy
>>>>>
>>>>>
>>>>> [1] Don Cupitt, 2001, Emptiness and Brightness, p95
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>> -- 
>>>> Rick
>>>>
>>>> cell: 703-201-9129
>>>> web: http://www.rickmurphy.org
>>>> blog: http://phaneron.rickmurphy.org
>>>>
>>>>
>>>
>>>
>>>
>>>
>>
>> -- 
>> Rick
>>
>> cell: 703-201-9129
>> web: http://www.rickmurphy.org
>> blog: http://phaneron.rickmurphy.org
>>
>>
>
>
>
>

-- 
Rick

cell: 703-201-9129
web:  http://www.rickmurphy.org
blog: http://phaneron.rickmurphy.org
Received on Tuesday, 10 February 2009 14:59:33 UTC

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