Is subclassing "strict order" or is it reflexive? RE: [sc34wg3] New SAM PSIs

[Anthony B. Coates]

** Reply to message from Murray Altheim <m.altheim@open.ac.uk> on Mon, 17 Feb
2003 11:30:22 +0000

> By way of your argument, one could say that if one had an
> empty set called "hominids" that no hominids exist. Obviously,
> this is not true. And as for "finding a case", this is hardly
> a way to approach logic. If you can't find aliens on other
> planets they don't exist?

It is not just a matter of *calling* a set "hominids".  If the set of all
hominids is empty, then there are no hominids.  Although sets can be defined by
listing their members, they can also be defined by listing what qualifies their
members.  The only difference I see with classes is that one doesn't think of
classes as ever being specified by listing their members.  However, classes are
sets, like it or not.

Quantum mechanics will tell you that if you can't find aliens on other planets,
then they don't exist.  If you do find them, then you still don't know whether
they existed beforehand, or if they came into existence as a result of your
looking for them.  :-)

	Cheers,
		Tony.
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Anthony B. Coates, Information & Software Architect
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