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Re: [ontolog-forum] Watchout Watson: Here comes Amazon Machine Learning

To: Rich Cooper <metasemantics@xxxxxxxxxxxxxxxxxxxxxx>, "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Thomas Johnston <tmj44p@xxxxxxx>
Date: Sat, 2 May 2015 19:44:50 +0000 (UTC)
Message-id: <939221402.503186.1430595890968.JavaMail.yahoo@xxxxxxxxxxxxxx>

An indexical is a sub-sentential _expression_ which varies from one context to another, and which, until resolved in each specific use of a sentence (each token of that sentence), prevents the sentence/token from having a truth value. (Declarative sentences with all indexicals resolved pretty well line up with Quine's notion of "occasion sentences".)

  • "He is 30 years old". The truth-value depends on who "he" is.
  • "It was raining outside yesterday". The truth value depends on what day it is today; also (though not explicitly) on where it is the speaker is alluding to.
  • "The president has veto power". The truth value depends on which organization the person alluded to is the president of.
So, as to my previous point, none of the declarative expressions in quotation marks above are statements because none of them, until dis-ambiguated by assigning a value to its indexicals, has a truth value. None of them says any one definite thing.

Lack of (implicit and explicit) Indexicality resolution is a major cause of ambiguity in statements. Note that this is a different matter than ambiguity in concepts, i.e. in sub-sentential expressions.

The Standard Encyclopedia of Philosophy has an article on indexicality which, because it's the SEP, I assume is a good one.

On Saturday, May 2, 2015 1:06 PM, Rich Cooper <metasemantics@xxxxxxxxxxxxxxxxxxxxxx> wrote:

Thomas and John,
Please define the word "indexicality" as you are using it.  I think you mean the binding between FOL variables and their substituted constants but the term itself is not used much in engineering AFAIK.
Rich Cooper,
Rich Cooper,
Chief Technology Officer,
MetaSemantics Corporation
MetaSemantics AT EnglishLogicKernel DOT com
( 9 4 9 ) 5 2 5-5 7 1 2
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Thomas Johnston
Sent: Saturday, May 02, 2015 9:17 AM
To: [ontolog-forum]
Subject: Re: [ontolog-forum] Watchout Watson: Here comes Amazon Machine Learning - ZDNet-2015.04.10
The classical definition of a statement, as I understand it, is that it is a declarative sentence with all indexicals resolved. So, as a statement, a fluent is a statement schema such that resolving its temporal indexical produces a statement. (If we move on to propositions, we get into some deep issues, such as whether or not any propositions can change their truth values over time.) In other words, a fluent is a family of statements all identical except for the point or period of time associated with them.
Sounds like an interesting concept. More generally, we can conceive of a statement-family as a statement schema in which one or more indexicals are not resolved -- place, time, person, perhaps even propositional attitude.
Are such statement families worth reifying? Or is it enough simply to understand that many apparent statements are not statements because of indexicality?
On Saturday, May 2, 2015 10:11 AM, John F Sowa <sowa@xxxxxxxxxxx> wrote:
Rich and Tom,

> I think you are describing what is best represented as fluents in the
> table.  A "fluent" row comprises the predicate's specified value of
> true or false, and its parametric bindings to objects and properties.

> Which suggests that I must currently fail to understand what you mean
> by "fluents". Can you enlighten me?

The term 'fluent' was introduced by John McCarthy and Pat Hayes in the
classic paper "Some philosophical problems from the standpoint of AI":

JMC & PJH (1969) http://www-formal.stanford.edu/jmc/mcchay69.pdf
> A fluent is a function whose domain is the space Sit of situations.

For example, the sentence "It is raining" is a _propositional fluent_.
For any situation in which it is raining, that fluent has value true.

Another fluent is the phrase 'the president', which depends on the
organization and the time.  For the situation of the USA at this moment,
the value of that fluent is a human named Barack Obama.

The term 'fluent' is a useful generic for many terms that have the
modifier 'context dependent'.  For related documents, search for the
word 'context' in http://www.jfsowa.com/ikl/ .

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