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The problem of identity

Posted by davidvc on August 31, 2005 at 9:09 PM PDT

One of the key aspects of database design is coming up with a
unique identity for each
record in the database. This may seem like a simple database design problem, but it actually has significant impacts on life in our society.

Numerous problems occur when unique identity
is not possible. Take for example the problems the airlines have been having with mistaken identity on the no-fly
list. In some cases families have been preventing from boarding
a plane because their toddler matched
a name on the no-fly list
. Here is a great
from the SF Chronicle's Bad Reporter (Don Asmussen) about
this. Another common example is if a credit bureau mixes you up with
someone else with the same name, and all of a sudden you can't get
any credit.

There is also the opposite issue of the
same thing being mixed up as two different things. I experienced
this myself when I couldn't get my driver's license renewed because I
had registered my last name as “Van Couvering” whereas my
Social Security information has my last name as “Vancouvering”
(incorrect),. The computers decided I was not the same person and
would not renew my license. I had to work with the Social Security
office to change it before I could drive again.

So, this raises the question, when you can't rely on some
guaranteed generate unique identifier, how do
you identify something? What does it mean to be identical? This
refers to 'Liebniz's Law' which states
that two objects are defined to be identical if and only if each and every property
of the two objects are the same. But with databases you only have a
certain number of properties to go by; what if all of these are the
same – is it the same thing or isn't it? The answer is: you
just don't know.

As more and more of our lives are
controlled and driven by databases about us, and we are identified
not by who we are but by properties about us, this becomes less and
less a philosophical question and more and more of a real issue. A
prime example of this is identity theft: if someone can obtain enough
of your “properties” they can convince others that they
are you.
I know there are a lot of important social issues
around things like biometrics and embedded RFID chips, but in this
growing informational society, part of me would love to have a way to
have undeniable proof that I
am me and not someone else, and that someone else is not me.

On a completely different note, here's
another issue around identity. If something
changes over time, is it or is it not still the same thing? This is
called the paradox of the Ship
of Theseus

All the cells of a human being are
replaced every six years. We grow older. Some people get sex change
operations. Some people dye their hair. We can get cosmetic
surgery. We can have organ transplants. There are no observable
qualities of a person that can be guaranteed to be unique and
unchanging over time. But you and I know that we are still the same
person. We know this because we have the feeling: I exist, I am. It
is our inner experience of identity. You and I will both say with
full certainty that I am and always have been “me.”

But now I posit something to you:
if the experience of “I am” is our only truly reliable measure of
identity, what if my experience of “I am” is exactly the
same as your experience of “I am?” Are we then
identical? This odd conclusion is actually what many spiritual
traditions of the East claim: that the experience of “I am”
is the nature of God, and that it is identical in each person: at our
core we are all the same. That doesn't help when you are trying to
prove you're not on the no-fly list, but it is something to think