[ExI] The Reality of Categories

[Lee Corbin]

Stathis writes

>> But these *lumps* the the quantum fields are real lumps, and
>> very distinct.  When you write "by convention, we agree"  you surely
>> admit that any intelligent evolutionarily derived organism will detect
>> these same real categories that we do.  Are you a nominalist?
> 
> I'm a nominalist, in that I don't believe that categories have a
> separate ontological status. However, this is incidental to the
> question of whether evolved intelligent beings would recognise the
> same categories as we do.

By "incidental" you mean not relevant?  If so, I do differ (naturally)
as you would expect.

> It's easy enough to imagine a very
> intelligent, very precise and pedantic being which does not regard
> anything as being the same thing unless it is *exactly* the same
> thing, which no physical object can be from moment to moment.

It's not easy for *me* to imagine how such a creature could
have evolved. What we think of as things in the world---rivers,
rocks, trees, edible food, etc.---any being must also be able
to distinguish. Even bacteria lump all the nearly infinitely 
different chemical possibilities into just a few categories
(perhaps tens of thousands for all I know), although for many,
yes, they do exhibit a continuous range of reaction (so it's
possible that they could have just two top categories: move
toward and move away from, i.e., "good" and "bad").

Some insects respond in a very fine-tuned way to light stimuli
while others respond only to blunt categories.

The point is that to get by in the world you have to incorporate
some of the actual structure of the world. And the world really
does come in lumps.

> What would you actually say to an alien who thought you were crazy to
> assert that the rock was the same rock as yesterday?

I would first make sure that there was not a communication 
problem.  Then I would ask him why the two rocks were
not the same.  He might say that one was a "today-rock" 
and one was a "yesterday-rock", but that would probably
indicate nothing more than a communication or language
difficulty. He might say that extremely fine changes had
occurred to the rock that were important to his people
or whatever. Still, I would refuse to believe him if he said
that the lake today has more in common with the rock
yesterday than the rock today has in common with the
rock of yesterday. (of course, it's possible that he's been
artificially created by scientists to mouth absurdities, just
like many programs we too have written).

Maybe he's just high.  :-)   Earth people say many strange
things when their brains are functioning incorrectly.

> It is difficult to give a formal reason why a certain amount
> of vagueness should be allowed and another not, although
> there are practical reasons.

Wow, a formal reason?  In some circumstances it will be
appropriate for some creatures to tolerate some vagueness
about some things.   :-)   That's about as far as I'm brave
enough to go!  (But maybe I'm just being lazy.)

Lee