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Truth Journal
DUALISM THROUGH REDUCTIONISM
Hans Moravec
Carnegie-Mellon University
1986
You may think the following proposals are thought
experiments that's fine, as such they still make the point in question.
I happen to think of them as real, highly desirable, possibilities for
the foreseeable future. For me they are a solution to the annoying
certainty that we will be overtaken in every area by future
superintelligent machines, and will be excluded from all the really
interesting developments unless we keep up, personally and intimately,
with the technologies of thought. That these ideas raise and clarify
some interesting metaphysical questions is a bonus.
Transmigration
You are in an operating room. A robot brain surgeon is in
attendance. By your side is a potentially human equivalent computer,
dormant for lack of a program to run. Your skull, but not your brain, is
anesthetized. You are fully conscious. The surgeon opens your brain case
and peers inside. Its attention is directed at a small clump of about
100 neurons somewhere near the surface. It determines the three
dimensional structure and chemical makeup of that clump nondestructively
with high resolution 3D NMR holography, phased array radio
encephalography, and ultrasonic radar. It writes a program that models
the behavior of the clump, and starts it running on a small portion of
the computer next to you. Fine connections are run from the edges of the
neuron assembly to the computer, providing the simulation with the same
inputs as the neurons. You and the surgeon check the accuracy of the
simulation. After you are satisfied, tiny relays are inserted between
the edges of the clump and the rest of the brain. Initially these leave
the brain unchanged, but on command they can connect the simulation in
place of the clump. A button which activates the relays when pressed is
placed in your hand. You press it, release it and press it again. There
should be no difference. As soon as you are satisfied, the simulation
connection is established firmly, and the now unconnected clump of
neurons is removed. The process is repeated over and over for adjoining
clumps, until the entire brain has been dealt with. Occasionally several
clump simulations are combined into a single equivalent but more
efficient program. Though you have not lost consciousness, or even your
train of thought, your mind (some would say soul) has been removed from
the brain and transferred to a machine.
In a final step your old body is disconnected. The computer is installed
in a shiny new one, in the style, color and material of your choice. You
are no longer a cyborg halfbreed, your metamorphosis is complete.
For the squeamish there are other ways to work the transfer. The high
resolution brain scan could be done in one fell swoop, without surgery,
and a new you made, "While-U-Wait". Some will object that the instant
process makes only a copy, the real you is still trapped in the old body
(please dispose of properly). This is an understandable misconception
based on the intimate association of a person's identity with a
particular, unique, irreplaceable piece of meat. Once the possibility of
mind transfer is accepted, however, a more mature notion of life and
identity becomes possible. You are not dead until the last copy is
erased; a faithful copy is exactly as good as the original. These issues
are examined in greater detail later.
If even the last technique is too invasive for you, imagine a more
psychological approach. A kind of portable computer (perhaps worn like
eyeglasses so it can cover your entire visual field) is programmed with
the universals of human mentality, with your genetic makeup and with
whatever details of your life are conveniently available. It carries a
program that makes it an excellent mimic. You carry this computer with
you through the prime of your life, and it diligently listens and
watches, and perhaps monitors your brainwaves, and learns to anticipate
your every move and response. Soon it is able to fool your friends on
the phone with its convincing imitation of you. When you die it is
installed in a mechanical body and smoothly and seamlessly takes over
your life and responsibilities.
What? Still not satisfied? If you happen to be a vertebrate there is
another option that combines some of the sales features of the methods
above. The vertebrate brain is split into two hemispheres connected by a
very large bundle of nerve fibers called the corpus callosum. When brain
surgery was new it was discovered that severing this connection between
the brain halves cured some forms of epilepsy. An amazing aspect of the
procedure was the apparent lack of side effects on the patient. The
corpus callosum is a bundle far thicker than the optic nerve or even the
spinal cord. Cut the optic nerve and the victim is utterly blind; sever
the spinal cord and the body goes limp. Slice the huge cable between the
hemispheres and nobody notices a thing. Well, not quite. In subtle
experiments it was noted that patients who had this surgery were unable,
when presented with the written word "brush", for instance, to identify
the object in a collection of others using their left hand. The hand
wanders uncertainly from object to object, seemingly unable to decide
which is "brush". When asked to do the same task with the right hand,
the choice is quick and unhesitating. Sometimes in the left handed
version of the task the right hand, apparently in exasperation, reaches
over to guide the left to the proper location. Other such quirks
involving spatial reasoning and motor coordination were observed.
The explanation offered is that the callosum indeed is the main
communications channel between the brain hemispheres. It has fibers
running to every part of the cortex on each side. The brain halves,
however, are fully able to function separately, and call on this channel
only when a task involving co-ordination becomes necessary. We can
postulate that each hemisphere has its own priorities, and that the
other can request, but not demand, information or action from it, and
must be able to operate effectively if the other chooses not to respond,
even when the callosum is intact. The left hemisphere handles language
and controls the right side of the body. The right hemisphere controls
the left half of the body, and without the callosum the correct
interpretation of the letters "brush" could not be conveyed to the
controller of the left hand.
But what an opportunity. Suppose we sever your callosum but then connect
a cable to both severed ends leading into an external computer. If the
human brain is understood well enough this external computer can be
programmed to pass, but also monitor the traffic between the two. Like
the personal mimic it can teach itself to think like them. After a while
it can insert its own messages into the stream, becoming an integral
part of your thought processes. In time, as your original brain fades
away from natural causes, it can smoothly take over the lost functions,
and ultimately your mind finds itself in the computer. With advances in
high resolution scanning it may even be possible to have this effect
without messy surgery - perhaps you just wear some kind of helmet or
headband.
Vernor Vinge devised a particularly slow and gentle transfer method in
True Names, his novel of the near future. The world of True Names is
interconnected by a computer network containing processes linked to
every vital function of society. Experienced hackers connect to the net
through innovative terminals they have developed; like radio amateurs
early in the century they are at the leading edge of the new technology,
ahead of the establishment. The hackers' terminals are bi-directional
electroencephalogram (brain wave) machines; they enable a computer to
read the human's brain waves and also to induce them. Through years of
practice, experimentation and programming the hackers have discovered a
combination of mental and computer techniques that permit a dreamlike
trance in which information from the computer controls elements of a
lucid dream, and actions in the dream affect the computer. In the dream
data objects are represented by metaphor - a locked computer file, for
instance, might appear as a steel safe with a combination lock. Guessing
and dialing the right combination unlocks the file. The interface is
tremendously fast and effective because the full mind of the human is
coupled to the machine.
The hackers meet in the network, each in an imaginative guise. Sometimes
their computer personas continue to operate under control of special
programs even when their owners temporarily disconnect. A new potential
of the net reveals itself as the story unfolds. One of the characters
has augmented her thinking in the net by directly incorporating computer
subroutines. In real life she is an old woman suffering from advanced
senility. In the network, by contrast, she appears extraordinarily swift
and intelligent because of the computer routines she has written to
substitute for her lost natural abilities. Her illness is progressive,
and she is constantly programming new capabilities as her natural ones
disappear. Her goal is to complete the process before she dies. With
success she will continue to live in her computer persona though her
physical body no longer exists.
Afterlife
Whatever style you choose, when the transfer is complete
advantages become apparent. Your computer has a control labelled speed.
It had been set to slow, to keep the simulations synchronized with the
old brain, but now you change it to fast. You can communicate, react and
think a thousand times faster. But wait, there's more!
The program in your machine can be read out and altered, letting you
conveniently examine, modify, improve and extend yourself. The entire
program may be copied into similar machines, giving two or more
thinking, feeling versions of you. You may choose to move your mind from
one computer to another more technically advanced, or more suited to a
new environment. The program can also be copied to some future
equivalent of magnetic tape. If the machine you inhabit is fatally
clobbered, the tape can be read into a blank computer, resulting in
another you, minus the experiences since the copy. With enough copies,
permanent death would be very unlikely.
As a computer program, your mind can travel over information channels. A
laser can send it from one computer to another across great distances
and other barriers. If you found life on a neutron star, and wished to
make a field trip, you might devise a way to build a neutron computer
and robot body on the surface, then transmit your mind to it. Nuclear
reactions are a million times quicker than chemistry, so the neutron you
can probably think that much faster. It can act, acquire new experiences
and memories, then beam its mind back home. The original body could be
kept dormant during the trip to be reactivated with the new memories
when the return message arrived. Alternatively, the original might
remain active. There would then be two separate versions of you, with
different memories for the trip interval.
Two sets of memories can be merged, if mind programs are adequately
understood. To prevent confusion, memories of events would indicate in
which body they happened. Merging should be possible not only between
two versions of the same individual but also between different persons.
Selective mergings, involving some of the other person's memories, and
not others would be a very superior form of communication, in which
recollections, skills, attitudes and personalities can be rapidly and
effectively shared.
Your new body will be able to carry more memories than your original
biological one, but the accelerated information explosion will insure
the impossibility of lugging around all of civilization's knowledge. You
will have to pick and choose what your mind contains at any one time.
There will often be knowledge and skills available from others superior
to your own, and the incentive to substitute those talents for yours
will be overwhelming. In the long run you will remember mostly other
people's experiences, while memories you originated will be floating
around the population at large. The very concept of you will become
fuzzy, replaced by larger, communal egos.
Mind transferral need not be limited to human beings. Earth has other
species with brains as large, from dolphins, our cephalic equals, to
elephants, whales, and giant squid, with brains up to twenty times as
big. Translation between their mental representation and ours is a
technical problem comparable to converting our minds into a computer
program. Our culture could be fused with theirs, we could incorporate
each other's memories, and the species boundaries would fade.
Non-intelligent creatures could also be popped into the data banks. The
simplest organisms might contribute little more than the information in
their DNA. In this way our future selves will benefit from all the
lessons learned by terrestrial biological and cultural evolution. This
is a far more secure form of storage than the present one, where genes
and ideas are lost when the conditions that gave rise to them change.
Our speculation ends in a super-civilization, the synthesis of all solar
system life, constantly improving and extending itself, spreading
outward from the sun, converting non-life into mind. There may be other
such bubbles expanding from elsewhere. What happens when we meet? Fusion
of us with them is a possibility, requiring only a translation scheme
between the memory representations. This process, possibly occurring now
elsewhere, might convert the entire universe into an extended thinking
entity, a probable prelude to greater things.
What Am l?
The idea that a human mind can be transferred to a new body
sometimes meets the following strong objection from some who dispute
neither the possibility, nor its objective manifestations as described.
"Regardless of how the copying is done the end result will be a new
person. If it is I who am being copied, the copy, though it may think of
itself as me, is simply a self-deluded imposter. If the copying process
destroys the original then I have been killed. That the copy may then
have a great time exploring the universe using my name and my skills is
no comfort to my mortal remains."
Naturally, this point of view, which I will call the Body
Identity position, makes life extension by duplication
considerably less personally interesting.
I believe the objection can and should be overcome by intellectual
acceptance of an alternate position I will name Pattern
Identity. Body identity assumes that a person is defined by the
stuff of which a human body is made. Only by maintaining continuity of
body stuff can we preserve an individual person. Pattern identity, on
the other hand, defines the essence of a person, say myself, as the
pattern and the process going on in my head and body, not the machinery
supporting that process. If the process is preserved, I am preserved.
The rest is mere jelly.
Matter Transmitters
Matter transmitters have appeared often in the science fiction
literature, at least since the invention of facsimile machines in the
late 1 the. I raise the idea here only as a thought experiment, to
simplify some of the issues in the mind transfer proposal.
A facsimile transmitter scans a photograph line by line with a light
sensitive photocell, and produces an electric current that varies with
the brightness of the scanned point in the picture. The varying electric
current is transmitted over wires to a remote location where it controls
the brightness of a light bulb in a facsimile receiver. The receiver
scans the bulb over photosensitive paper in the same pattern as the
transmitter. When this paper is developed, a duplicate of the original
photograph is obtained. This device was a boon to newspapers, who were
able to get illustrations from remote parts of the country almost
instantly, rather than after a period of days by train.
If pictures, why not solid objects? A matter transmitter might scan an
object and identify, then knock out, its atoms or molecules one at a
time. The identity of the atoms would be transmitted to a receiver where
a duplicate of the original object would be assembled in the same order
from a local supply of atoms. The technical problems were mind boggling,
and well beyond anything foreseeable, but the principle was simple to
grasp.
If solid objects, why not a person? Just stick him in the transmitter,
turn on the scan, and greet him when he walks from the receiver. But is
it really the same person? If the system works well, the duplicate will
be indistinguishable from the original in any substantial way. Yet,
suppose you fail to turn on the receiver during the transmission
process. The transmitter will scan and disassemble the victim, and send
an unheard message to the inoperative receiver. The original person will
be dead. Doesn't, in fact, the process kill the original person whether
or not there is an active receiver? Isn't the duplicate just that,
merely a clever imposter? Or suppose two receivers respond to the
message from one transmitter. Which, if either, of the two duplicates is
the real original?
Pattern Identity
The body identity position is clear. A matter transmitter is an
execution device. You might as well save your money and use a gas
chamber, and not be taken in by the phony double gimmick.
Pattern identity gives a different perspective. Suppose I step into the
transmission chamber. The transmitter scans and disassembles my
jelly-like body, but my pattern (me!) moves continuously from the
dissolving jelly, through the transmitting beam, and ends up in other
jelly at the destination. At no instant was it (I) ever destroyed.
The biggest confusion comes from the question of duplicates. It is
rooted in all our past experience that one person corresponds to one
body. In the light of the possibility of matter and mind storage and
transmission this simple, natural, and obvious identification becomes
confusing and misleading. Suppose the matter transmitter is connected to
two receivers instead of one. After the transfer there will be a copy of
you in each one. Surely at least one of them is only a mere copy - they
can't both be you, right? Wrong!
A Metaphor
Consider the message "I am not jelly". As I type it , it goes
from my brain, into the keyboard of my computer, through myriads of
electronic circuits and over great amounts of wire, and after countless
adventures shows up in bunches of books like the one you're holding. How
many messages were there? I claim it is most useful to think there is
only one, despite its massive replication. If I repeat it here: "I am
not jelly", there is still only one message. Only if I change it in a
significant manner: "I am not peanut butter" do we have a second
message. And the message is not destroyed until the last written version
is lost, and until it fades sufficiently in everybody's memory to be
unreconstructable. The message is the information conveyed, not the
particular encoding. The "pattern and process" that I claim is the real
me has the same properties as the message above. Making a momentary copy
of my state, whether on tape or in another functional body, doesn't make
two persons.
There is a complication because of the "process" aspect; as soon as an
instance of a "person message" evolves for a while it becomes a
different person. If two of them are active, they will diverge, and
become two different people by my definition. Just how far this
differentiation must proceed before you grant them unique identities is
about as problematical as the question "when does a fetus become a
person?" But if you wait zero time, then you don't have a new person.
If, in the dual receiver version of the matter transmitter, you allow
the two copies to be made and kill one (either one) instantly on
reception, the transmitted person still exists in the other copy. All
the things that person might have done, and all the thoughts she might
have thought, are still possible. If, on the other hand, you allow both
copies to live their separate lives for a year, and then kill one, you
are the murderer of a unique human being.
But, if you wait only a short while, they won't differ by much, and
destruction of one won't cause too much total loss. This rationale
might, for instance, be a comfort in danger if you knew that a tape
backup copy of you had been made recently. Because of the divergence the
tape contains not you as you are now, but you as you were: a slightly
different person. But still, most of you would be saved should you have
a fatal accident, and the loss would be nowhere near as great as without
the backup.
Intellectual acceptance that a secure and recent backup of you exists
does not necessarily protect you from an instinctive selfpreservation
overreaction if faced with imminent death. This is an evolutionary
hangover from your one-copy past. It is no more a reflection of reality
than fear of flying is an appropriate response to present airline
accident rates. Inappropriate intuitions are to be expected when the
rules of life are suddenly reversed from historical absolutes.
Soul in Abstraction
Although we've reasoned from strictly reductionistic
assumptions about the nature of thought and self, the pattern identity
position has clear dualistic implications. Though mind is entirely the
consequence of interacting matter, the ability to copy it from one
machine or storage medium to another gives it an independence and an
identity apart from its machinery.
The dualism is especially apparent if we consider some of the variations
of encoding possible.
The Float
Some supercomputer designs call for myriads of individual
computers interconnected by a network that allows free flow of
information among them. An operating system for this arrangement might
allow individual processes to migrate from one processor to another in
mid computation, in a kind of juggling act that permits more processes
than there are processors.
If a human mind is installed in a future machine of this variety,
functions originally performed by particular cell assemblies might be
encoded in individual processes. The juggling action would ensure that
operations occurring in fixed areas in the original brain would move
rapidly from place to place within the machine. If the computer is
running other programs besides the mind simulation, then the simulation
might find itself shuffled into entirely different sets of processors
from moment to moment. The thinking process would be uninterrupted, even
as its location and physical machinery changed continuously, because the
immaterial pattern would keep its continuity.
Acceleration and Diffusion
A process that is described as a long sequence of steps can
sometimes be transformed mathematically into one that arrives at the
same conclusion in far fewer operations.
As a young boy the famous mathematician Friedrich Gauss was a school
smart-aleck. As a diversion a teacher once set him the problem of adding
up all the numbers between I and 100. He returned with the correct
answer in less than a minute. He had noticed that the hundred numbers
could be grouped onto fifty pairs, 1+100, 2+99, 3+98, 4+97 and so on,
each pair adding up to 101. Fifty times 101 is 5,050, the answer, found
without a lot of tedious addition.
Similar speedups are possible in complex processes. So called optimizing
compilers have repertoires of accelerating transformations, some very
radical, to streamline programs they translate. The key may be a total
reorganization in the order of the computation and the representation of
the data. A very powerful class of transformations takes an array of
values and combines them in different ways to produce another array.
Each final value reflects all the original values, and each original
value affects all the results. An operation on a single transformed
quantity can substitute for a whole host of operations on the original
array, and enormous efficiencies are possible. Analogous transformations
in time also work: a sequence of operations is changed into an
equivalent one where each new step does a tiny fraction of the work of
every one of the original steps. The localized is diffused, and the
diffuse is localized.
A program can quickly be altered beyond recognition by a few
mathematical rewrites of this power. Run on a multiprocessor, single
events in the original formulation may appear only as correlations
between events in remote machines at remote times in the transform.
Certain operations that don't matter in the long run may be skipped
altogether. Yet the program is fundamentally unchanged. You know what's
coming. If we thus transform a program that simulates a person, the
person remains intact. Soul is in the mathematical equivalence, not in
any particular detail of the process. It has a very etherial
character.
The Message is the Medium
If a mind can survive repeated radical restructurings, infusion
into and out of different types of hardware and storage media, and is
ultimately a mathematical abstraction, does it require hardware at
all?
Suppose the message describing a person is written in some static
medium, like a book. A superintelligent being, or just a big computer,
reading and understanding the message might be able to reason out the
future evolution of the encoded person, not only under a particular set
of experiences but also under various alternative circumstances.
Existence in the thoughts of a beholder is no more abstract than as a
transformed person-program described in the previous section, but it
does introduce an interesting new twist.
The superintelligent being has no obligation to accurately model every
single detail of the beheld, and may well choose to skip the boring
parts, to jump to conclusions that are obvious to it, and to lump
together different alternatives it does not choose to distinguish. This
looseness in the simulation can also allow some time reversed action -
our superintelligent being may choose a conclusion then reason
backwards, deciding what must have preceded it. Authors of fiction often
take such liberties with their characters. The same parsimony of thought
applies to the parts of the environment of the contemplated person that
are themselves being contemplated. Applied a certain way, this parsimony
will affect the evolution of the simulated person and his environment,
and may thus be noticeable to him. Note that the subjective feelings of
the simulated person are a part of the simulation, and with them the
contemplated person feels as real in this implementation as in any
other.
It happens that quantum mechanics describes a world where unobserved
events happen in all possible ways (another way of saying no decision is
made as to which possibility happens), and the superposition of all
these possibilities itself has observable effects. The connection of
this observation with those of the previous paragraph leads us into
murky philosophical waters.
To get even muddier, ask the question implicit in the title of this
section. If the subjective feelings of a person are part of the
person-message, and if the evolution of the message is implicit in the
message itself, then aren't the future experiences of the person
implicit in the message? And wouldn't this mere mathematical existence
feel the same to the person encoded as being simulated in a more
substantial way? I don't think this is mere sophistry, but I'm not
prepared to take it any further for now.
Immortality and Impermanence
Wading back into the shallows, let's examine a certain dilemma
of existence, presently overshadowed by the issue of personal death,
that will be paramount when practical immortality is achieved. It's
this: in the long run survival requires change in directions not of your
own choosing. Standards escalate with the growth of the inevitable
competitors and predators for each niche. In a kind of cosmic Olympic
games the universe molds its occupants towards its own distant and
mysterious specifications.
An immortal cannot hope to survive unchanged, only to maintain a limited
continuity over the short run. Personal death differs from this
inevitability only in its relative abruptness. Viewed on a larger scale
we are already immortal, as we have been since the dawn of life. Our
genes and our culture pass continuously from one generation to the next,
subject only to incremental alterations to meet the continuous demand
for new world records in the cosmic games.
In the very long run the ancestral individual is always doomed as its
heritage is nibbled away to meet short term demands. It slowly mutates
into other forms that could have been reached from a range of starting
points; the ultimate in convergent evolution. It's by this reasoning
that I concluded earlier that it makes no ultimate difference whether
our machines carry forward our heritage on their own, or in partnership
with direct transcriptions of ourselves. Assuming long term survival
either way, the end results should be indistinguishable, shaped by the
universe and not by ourselves.
Since change is inevitable, I think we should embrace rather than retard
it. By so doing we improve our day to day survival odds, discover
interesting surprises sooner, and are more prepared to face any
competition. The cost is faster erosion of our present constitution. All
development can be interpreted as incremental death and new birth, but
some of the fast lane options make this especially obvious, for instance
the possibility of dropping parts of one's memory and personality in
favor of another's. Fully exploited, this process results in transient
individuals constituted from a communal pool of personality traits.
Sexual populations are effective in part because they create new genetic
individuals in very much this way. As with sexual reproduction, the
memory pool requires dissolution as well as creation to be effective. So
personal death is not banished, but it does lose its poignancy because
death by submergence into the memory pool is reversible in the short
run.
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