[foaf-dev] Fwd: relationship vocab

Dan Brickley danbri at danbri.org
Mon Dec 13 13:16:12 CET 2010


On Mon, Dec 13, 2010 at 11:55 AM, Toby Inkster <tai at g5n.co.uk> wrote:
>> -------- Forwarded Message --------
>> From: Toby Inkster <mail at tobyinkster.co.uk>
>> To: Ian Davis <lists at iandavis.com>, foaf-dev at lists.foaf-project.org
>> Subject: relationship vocab
>> Date: Mon, 13 Dec 2010 07:59:38 +0000
>> Mailer: Claws Mail 3.7.2 (GTK+ 2.18.9; i586-mandriva-linux-gnu)
>>
>> Ian,
>>
>> Any chance of relaxing some of the domains and ranges?
>>
>> My cats are brothers, but it would be pushing the definition of
>> foaf:Person to assert that they're people.

"""The Person class represents people. Something is a Person if it is
a person. We don't nitpic about whether they're alive, dead, real, or
imaginary. """ http://xmlns.com/foaf/spec/#term_Person

If you describe your cat as a foaf:Person, you're just saying the cat
is a person. Many might disagree with you, but philosophers have been
arguing the toss over this for centuries and debatewise I expect it's
only going to get worse with the progress of science, rather than
better.

( I'd start with apes rather than cats, perhaps
http://en.wikipedia.org/wiki/Great_Ape_Project ...)

It's not FOAF's place as a technology to either decide whether (say)
human embryos at n weeks, or various living great apes, are 'persons'.
As a piece of the technology landscape, all we can do is help you
express yourself in a way that is more machine-friendly than plain
text. The exact boundary of personhood is horribly contested (see
debates around abortion law, for a major example). What we do in FOAF
is just ground the class foaf:Person in the natural language term
'person'. We could've said human, but we didn't; and it wouldn't help
much anyway. Similarly, we don't here try to say whether
http://en.wikipedia.org/wiki/File:Homo_sapiens_neanderthalensis.jpg
depicts the remains of a 'person'; or
http://en.wikipedia.org/wiki/File:Homo_ergaster.jpg or
http://en.wikipedia.org/wiki/File:Homo_heidelbergensis-Cranium_-5.jpg
...

If you want to say your cat is a person, you can do that. It's not
wrong to do so, just a little unconventional or metaphorical. If you
want to say something about your cat without asserting personhood,
don't use foaf:Person.

RDF's built-in modeling style doesn't fit well with the idea that
category membership is a matter of degree rather than a simple
objective boolean. This goes against most cognitive science research
on how human categorisation actually works, but has the benefit of
being easy to compute with. W3C made the right choice, but we have to
balance that be always remembering it was a choice, and that
categorisation isn't such a crisp business really. So RDF lives in a
simple-minded cartoon world of absolutes, even if we don't. Feel free
to call your cat a Person if that captures how you feel! :)

cheers,

Dan

ps. yup, +1 on broadening the domains


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