[ExI] The Reality of Categories (was Next Moment Around You...)

[Lee Corbin]

Stathis writes

> Lee wrote:
>> [Gordon wrote]
>> > I'm quite certain I'm not the same person I seemed to be at age five and  
>> > in my view it follows logically that neither am I the same person I seemed  
>> > to be five minutes ago.
>>
>> Now that's logic for you.  Since it's not the same season it was a few
>> months ago, then it must follow logically that today it's not the same
>> season it was yesterday.  On the contrary, logic grabs you by the throat
>> and forces you to admit that things change gradually.
>>
>> Okay, so Gordon a.k.a. [gts] is a convenient fiction.  What do you care
>> whether this convenient fiction lives or dies?
> 
> There is no absolute sense in which it is the same season today as it
> was yesterday. The Earth moves in its orbit every day and it is only
> by convention, not by logic, that we decide there are four seasons in
> a year.

Somewhat bad example on my part. My example is rescued only by
the informal usage in which season's have no exact beginning and ending
days.  I should have said "ancient times" vs. "modern times", and pointed
out that just because Julius Caesar lived in ancient times, so yesterday
must have been ancient times too (by my alleged imputation of what
Gordon was saying).

You are right, though:  it isn't by *logic* (at least in the strict sense),
it's by the natural naming convention that says that anything that 
changes imperceptively over time is deemed to be "the same",
and that this captures an incredibly important truth about reality.

> With personal identity it is stronger than convention, since
> we have a very profound psychological tendency to believe that we are
> the same person from day to day. This is a useful belief from an
> evolutionary point of view, perhaps the single most useful belief.

Do you believe that a particular large stone in your garden is the
same stone it was yesterday?  Now, we know all the facts:  we
know that the wind dislodged a very, very relatively few molecules
and that a relatively very few particles also accumulated on its
surface that did not use to belong to the rock.

But it is not *merely* a useful belief to say that it is the same rock.
Because if you cannot say that this rock is "the same rock" as it
was yesterday, then you are slipping away into nominalism (and
if that doesn't scare you I don't know what will   :-)

Categories exist and are real.  And firmly maintaining that the old
oak tree (before it burned down) was *not* the rock in your garden
is as ontologically correct as it is to say that the rock in your garden
that changed only infinitesimally *is* the same rock as it was yesterday.

> Nevertheless, it is possible to deny this belief without being guilty
> of either an error of logic

Touche.

> or an error of fact, because in the end "same person" is just as much
> a matter of convention as "same season".

We still disagree here.

Lee