RE: Some TAG review of "Cool URIs for the Semantic Web"

Pat Hayes

| >| Then let us be honest about this. When I am thinking of unicorns,
| >| there is in fact nothing I am thinking *about*. There are 
| concepts of
| >| unicorns, thoughts of unicorns, and so on; and even (if one is
| >| willing to stretch ones ontology this far, which in fact I 
| am, though
| >| many are not) *possible* unicorns; but there are no unicorns. It is
| >| impossible to talk *about* unicorns. The use of unicorn-talk (as
| >| Quine might have put it) is either non-referential, or must be
| >| understood as referring to something else.
| >
| >If this is true, it would force us to say: "If we use the phrase 
| >{the North Korean A-bomb | the Higgs boson particle |
| >extra-terrestial life } we do not know whether we are talking about 
| >something or not; we may find out in the future
| >whether we were or not."
| 
| Quite. And surely this is correct. In the past people spoke at length 
| about phlogiston. We now know they weren't talking about it, however, 
| because it wasn't there.

Pat, you take "about" in a much too referential way. As Frege pointed out, words
can have sense and reference, and you take "about" to mean "has a referent".
"Bilbo Baggins" has a sense but no reference, but it's a perfectly legitimate
question to ask what you know *about* Bilbo, such as his being Frodo's uncle
etc. And one thing you know *about* Bilbo is that he has no referent. Answering
"I know nothing about Bilbo" is simply false (assuming you know something about
Tolkien's works).

Exactly like we can find out that two words with different senses ("morning
star" and "evening star") have the same referent (Venus, the thing) it's just as
fine to find out about phlogiston that is has no referent. As long as
"phlogistion" has a sense, then when you say "phlogiston has no referent", you
are talking about phlogiston, and as Quine showed, you are not committed to
phlogiston's existence through making this utterance. 

Marc de Graauw

http://www.marcdegraauw.com

Received on Tuesday, 25 September 2007 20:45:14 UTC