[extropy-chat] Re: cryonics (was: Science and Fools)

[Brett Paatsch]

Hal Finney wrote:

[Thanks Hal for a very thought provoking post, comments below]

> I have two problems with the notion of "identity as continuity",
> which suggests that even an apparently successful cryonics revival
> would be a new person who is a mere copy of the old one.
>
> The first problem is that this view tends to see identity in black
> and white terms.  Either some future person is the same identity
> as me, or they are not.  There is no room for the idea of someone
> being partially the same identity as me, say 90% or 30% or some
> other percentage. Instead, in this view there is an actual "fact of the
> matter" about whether someone is the same identity as me.  It's not
> just a matter of definition or perspective.  If my future replacement's
> identity is not the same as mine, then I have died in a real, factual
> sense.
>
> The problem is that this position is vulnerable to a sorites attack.
> This is the greek paradox which says that day turns gradually into
> night, you can never identify an instant at which it ceases to be day
> and becomes night, yet day seems fundamentally different from night.
> The resolution to this paradox is to recognize that day is actually
> not fundamentally different from night, but that both are simply the
> same thing, to different degrees.  Day has more sunlight than night,
> and there is a gradual change in the amount of sunlight between them.
>
> In the case of identity, it is possible to set up a series of thought
> experiments which provide a similar gradual degree of changes
> between situations where identity is preserved and where identity is
> lost. For example, if someone believes their identity would be lost if
> the atoms in their brain ceased motion by being frozen, you can
> imagine a series of cases in which the atoms are merely cooled to
> different degrees. When they are not cooled at all, identity is
> preserved.  When they are cooled all the way, identity is lost.  And
> there are an essentially infinite degree of gradations between the two.
>  It seems inconceivable that identity will be preserved at one
> temperature, but completely lost at an infinitesimally lower temperature.
>
> If someone is OK with freezing but is concerned about disassembly and
> reassembly, we can similarly imagine a series of cases where different
> numbers of atoms are removed and replaced, from none to all of them.

> Most other models for identity can be attacked in the same way.
>
> The point is that any boolean or binary notion of identity is inconsistent
> with the nature of reality, which is essentially continuous and "sloppy".
> The apparently discrete and fixed nature of our identity is something of
> an illusion, and as we pursue these thought experiments it is easy to
> show that the seemingly sharp dividing line between systems that share
> our identity and those that don't is actually blurred and fuzzy.
>
> That's the first problem I have with this view.  The other is somewhat
> related in that it also has to do with the discrete nature of identity
> and the position that certain transformations preserve it completely,
> while others destroy it 100%.
>
> The problem is that there is apparently no objective way to measure,
> detect or report the degree of identity preservation in a transformation.
> There is no identity meter that we can attach to a brain.  Not only
> are there no objective ways to detect it, it is apparently not even
> subjectively perceivable.  You can imagine a cryonics patient who wakes
> up and thinks he is the same person he was before.  All of his memories
> and personality traits are the same as the person was before he was
> frozen. Yet, to a believer in this model of identity, he is not the same
> person. But he can't detect this fact by introspection.  He doesn't feel 
> the
> loss of identity.  Only by philosophical reasoning can he deduce that
> his identity must have changed and that the original person was dead.
>
> The problem is that, if we believe that there is an actual fact of the
> matter about whether identity is preserved through some transformation,
> we might be wrong about what transformations are OK.  And there
> would be no way to tell if we are wrong!  We can't tell objectively and
> we  can't tell subjectively.
>
> Worse, since identity preservation has no objective or subjective
> consequences, there is no reason for evolution to have made identity
> preservation a priority.  If we accept the possibility that we are wrong
> about the facts, and add the absence of any evolutionary pressure to
> make identity preservation match our desires, it is entirely possible
> that our identities are far more fragile than we suppose.  What would
> stop our identity from being lost every night when we go to sleep, with
> us having a new identity in the morning?  How could we be sure that this
> is not happening?  Nothing in our perception or memories upon
> awakening would give us a clue.
>
> Or even worse, what if our identities are not even being preserved from
> second to second?  What if every second, we (in some sense) die and
> are replaced by a new person?  We wouldn't even know!  Yet,
> throughout the world, a terrible tragedy is occuring on a scale so vast
> that we can barely imagine it (balanced by the equally marvelous miracle
> of new birth, I suppose).
>
> The problem, then, is that it is philosophically fragile to to adhere
> to a model of identity which has no objective or subjective effects.
> There are too many possibilities, none of which can be ruled out by any
> conceivable experiment or perception.  This is not a basis for making
> decisions about actions.
>
> These are the problems I have with this simple model of identity.
> The first can be dealt with by going to a more sophisticated, gradual
> model, based on degrees of identity.  However, this may be
> unattractive for those who prefer the simple and clean view of yes-or
> -no identity, which in some ways matches our naive perceptions.  The
> second is harder to deal with because it goes directly to the abstract
> and imperceivable nature of identity.  If not even the possessor of an
> identity can tell when it is lost, does it really exist enough that it 
> should
> be a guideline for actions?

1) Purely imaginary tragedies aren't tragic. If we don't experience them
we can't feel them.

2) You use of the world "philosophy" as in "philosophical reasoning"
and "philosophically fragile" is redundant. Plain "reasoning" and
"fragile" would seem to amount to the same thing.  Don't you agree?

3) Can you provide a link to "a more sophisticated, gradual model,
based on degrees of identity"?

I'd be curious to see if there is one that maps the territory of the real
world better than alternatives. I'm generally sceptical of models that
only add the sort of complexity that enables wish fulfillment.  I suspect
the 'information theoretic criteria of death' to be such a model.

4) You ask "If not even the possessor of an identity can tell when it is
lost, does it really exist enough that it should be a guideline for actions?

Good question.

If the 'I', the 'self', or present 'consciousness' are not real then I can
have no poor choices (or good choices for that matter) to make.

If they are real (as they usually seem to be) then I may have some
choices perhaps including the choice to act towards self-preservation
or termination or to focus on other things altogether. Given these two
classes of possibility, I may as well assume I have choices and "play
the hand I am dealt" as it appears to me.

It appears to me that my "self", my "identity" is a phenomena that
arises only in association with a matter substrate of biological cells.
Perhaps if I was born into a different or future world things would
be different.

Brain cells not atoms seem to be the relevant 'indivisible elements'
making up my memories and personality as well as the memories
and personalities of others.

Now of course brain cells are comprised of atoms at the physical
science level, just as atoms are comprised of sub-atomic particles,
but considering identity at the level of cells (which can divide to
replicate and which can die) seems to be a much more sensible
level of abstraction on which to work.

Discussion about atoms rather than cells suggests that there are
currently ways to translate cells into atoms and sometimes
vice versa known to computer scientists. But to the best of my
knowledge there are no such known ways yet. This does not
mean that there cannot be. But it does mean that we should be
careful about assuming either that the machine equivalent of
living cells will be easy to produce or that some other unknown
means of handling that level of complexity will readily be found
before we have found it.

5) I think most of your "sorites attack" thought experiments that
focus on atoms rather than cells as the indivisible fundamentals
underlying "identity as continuity" may in the end constitute a sort
of straw man attack. I don't think you do that deliberately or in
bad faith at all. I do mean that by using atoms rather than cells
you make the targetted model of identity less 'connected' to
reality than it is, and both the attack and any attempt to repell
the attack is then harder to relate to existing biological science.
Its biological science that describes all forms of person that exist
today. I think that if you tried to recast your sorites attacks using
a) temperature and b) disassembly and reassembly on cells rather
than atoms that you'd find that the black and white model of
identity as continuity might not seem as inconceivable. It would
be interesting to see.

We have a lot of cells in our bodies and in our brains. Enough
that we can lose some of them without being conscious of the
loss yet not so many that sometimes the loss of one more of a
particular type like a myocardial cell cannot be the straw that
breaks the camels back causing an infarction that hits the blood
flow that affects homeostasis and causes the death of brain cells
as they don't get oxygenated etc.

We can lose cells and still have enough to sustain a sense of self
but we can't lose too many of any particular sort of cell.

We don't have heaps of experiential data about the increments
of temperature drops just below homeostasis thresholds because
the organisms generally die and there's no identity left to test.

Gradual temperature changes moving just beyond the lower
bounds of what homeostatic defences can hold off could cause
a massive amount of cell death which would cascade upward
into organism death.

So although I think you above post and your method of approaching
the identity as continuity problem is quite an impressive bit of analysis
perhaps the best I've seen it wasn't in the end persuasive for me.

I'd be interested in seeing if you could recast your sorites attacks
on "identity as continuity" when memories and personality traits
are assumed to be embodies at the cellular level rather than just
somewhere above the atomic level.

I really enjoyed your post and found it challenging to think about.

Regards,
Brett Paatsch