[ExI] Next moment, everything around you will probably change

[Lee Corbin]

Jef writes

> On 6/17/07, Lee Corbin <lcorbin at rawbw.com> wrote:
> 
>> "Personal continuity" is a mistaken notion.  Aren't you
>> the same person you were before last month?  And so what
>> would change if miraculously last month really had never
>> happened, your molecules just happened to assume their
>> current configuration?  It would not diminish your identity
>> an iota.  Continuity is a red-herring.
> 
> While Lee makes some good points and is rightfully proud of discarding
> belief in an essential self, he does not yet comprehend that
> similarity is also a red-herring.
> 
> With regard to personal identity, as the physical Lee changes over
> days, weeks, months, and years, his identity doesn't degrade or
> require constant renewal; he is actually considered **exactly** the
> same person for all practical purposes by others, by himself, by our
> social and legal systems.

What others think isn't important if one believes there to be a
truth to the matter of whether "one is still the same person that
one was".  As in Damien's (quite good) novel Post Mortal Syndrome
http://www.cosmosmagazine.com/fiction/online/serials/post_mortal_syndrome/cover>
we usually regard a single biological human being as capable of
hosting distinct personalities.  Just because a few people, or the
law, doesn't happen to recognize this truth  doesn't change it. Although
personality tests do confirm our hunch about the reality, it would be
strange indeed if you deny the possibility of multiple personalities.

Therefore, it seems logical that while you really do believe that your
wife is the same person from day to day, a sufficiently powerful
personality change could alter her into someone that you would
consider to be a different person.  I myself had certain friends in
the 8th grade who, within just a few years, had turned into
"different people".  So as a practical matter, the similarity 
criterion works for me.  It's hard to believe that it doesn't work
for you despite your claim about agency.

In your scenario you consider some very selfish person who
forks and then is at odds with his other self. You suggest that
it would be inappropriate to suggest that they're still the same
person.  Well, if personality tests and people who knew them
affirmed that they were still the same person, I would simply
conclude that the two instances of that person were not
capable of seeing this truth (or chose to deny it), and were
not capable of acting on this truth.

Lee

> Personal identity is about agency.  Similarity is only a special case.
> 
> Those who believe in an essential self will not be able to follow this
> argument.  Those like Lee who have let go of the essentialist position
> and are loitering around the similarity-based position may wish to
> take this further step to a more coherent and extensible understanding
> of personal identity.