# RE: A calculus of personal identity

From: Lee Corbin <lcorbin.domain.name.hidden>
Date: Sun, 2 Jul 2006 09:31:21 -0700

Stathis also wrote in the same email, Sent: Friday, June 30, 2006 12:24 AM
To: everything-list.domain.name.hidden
Subject: Re: A calculus of personal identity

> Brent wrote
> > That's why I suggest that OMs are not an adequate ontological basis for a world model. On the other
> > hand, if we include brain processes, or more abstractly, subconscious thoughts, then we would have
> > enough information to string them together.
>
> I know some people on this list have attempted world-building
> with OMs, but my starting point is the less ambitious idea that
> consciousness can in principle extend across time and space
> without being specially linked. If a person's stream of consciousness
> were chopped up into seconds, minutes, days or whatever, using
> whatever vehicle it takes to run a human mind, and these moments
> of consciousness randomly dispersed throughout the multiverse,
> they would all connect up by virtue of their information content.
> Do you disagree that it would in principle be possible?

So if I understand you right, this is where the difference between
a book and a person arises. When a book's letters are scattered over
the cosmos, the information is lost, but when the observer moments
are so scattered, the subjective experience still remains.

Now we suppose from quantum mechanics that the Bekenstein bound
on the number of states a human can be in is less than 10^10^45.
(Tipler, 1993, "The Physics of Immortality".) So each state of
your life is a very special small subset of all those states.
Let's do something special with just *one* life that you've
led (will lead) in the universe, one life, that is, in a particular
spacetime.

I propose to take something quite a bit like observer-moments and
of your brain is made corresponding to each 10^-42 seconds of your
life. This gives us about 10^42 * 10^7 * 70years, or about 10^50
states (a far cry from all those possible for humans, 10^10^45).

We place those 10^50 states in a long row, and then, for an audience,
we round up all the billions of observers in the visible universe
to watch the show. First the spotlight is on your brain the second
after you were born. Then one 10^-42 seconds later the spotlight
moves to the next frozen brain, and so forth.

The audience is placed in the same frame of reference as the moving
light, and so they see an apparently continuous evolution of your
brain.

How is this any different from what happened to you actually? From
an external scientific point of view, it seems remarkably identical.
(I am ultimately to claim that something essential---but not
"consciousness" or anything like that is missing, but rather
*causality* is missing.)

I suppose that you would assert that a first person experience was
attached to this performance, a performance moving against a background
of stars as the stage. Is that correct?

Next we begin a process of deconstruction. First, on one century's
performance, there is trouble with the spotlight, and it's very dim
although the audience can still see the show. But a few performances
(centuries) later, the spotlight goes out altogether. Still, the
audience knows from the notes passed out exactly what is happening.
On another night, the audience fails to show up. Do these things
really affect whether or not a first person experience attends the
brain?

In other performances, the spotlight dances all around, from a
trillionth of a trillionth of a trillionth of a hundred trillionth
of a second (about 10^-50 seconds) from your brain in midlife to
then to the geezer Stathis brain, and so on, completely wrecking
the order. Now from what you wrote above about

> it takes to run a human mind, and these moments
> of consciousness randomly dispersed throughout the multiverse,
> they would all connect up by virtue of their information content.

one might surmise that you believe that the order that these frozen
brains appear is irrelevant. (I happen to agree---my own view is
that as soon as there was no longer causality connecting each
frozen brain with another brain---that is, that no real computation
was taking place---the first person experience no longer occurred.)

But if I have surmised correctly, then you wouldn't care that the
frozen brains were not only shown sometimes out of sequence, but
that there did not have to be an audience, nor was the spatial
relative locations of the brains relevant. They could be jumbled
all over the cosmos.

But next, what about the neurons making up the brains? What would
be lost if they too were dispersed through time and space? Finally,
just when, if any time, would anything be lost: what if the neurons
are themselves separated into atoms and dispersed?

Well, to me this is the ultimate reductio, because it means that
among the dust in the vast, vast, vast volumes of the cosmos, each
of your brain states already exists. (To me this is as absurd as
some of Hilary Putnam's claims, or Greg Egan's in Permutation City.
(For the record, Greg Egan made it clear in an interview that he
does *not* necessarily believe in the notions presented in all his
books.))

The only place in all this chain of reasoning where it seems that
first person experience could be lost is when one state no longer
followed *causally* from a preceding state, or, in other words
(in my opinion) when a true computation involving information
flow no longer occurred.