Silicon Reflections

Clark Glymour

I am in a quandary, and I am increasingly certain there is no escape. 
Philosophy and my health have conspired to leave me only dreadful
alternatives. It is futile, I am sure, even to state my difficulties,
as though some reader might see the true and correct path through
my plight. Still, the illusion consoles me, and so I will tell my story.

It all began in the 1980's, nearly three decades ago now, with certain
advances in artificial limbs. Not, of course, that I have an artificial
limb, but that is where it began. In earlier years those unfortunates
who had lost a hand or leg or arm had the part replaced by a mechanical
device which could support the body or which could be mechanically manipulated
to grasp and hold. But by the middle of the 1980's neurosurgeons and
artificial limb makers had found ways to connect artificial limbs to
the sensory and motor nerves of the stump. The limbs were able to
respond to pressure and communicate the stimulus, by electrical means,
to the nerve cell membrane of sensory nerves. Similarly, the limbs
were able to detect and respond appropriately to increases in the
concentrations of neurotransmitter chemicals in the motor nerves.
Through these ingenious mechanisms, those with artificial limbs
were enabled to feel pressure and to move their limbs much as
they had before dismemberment.

Now it happened that at the same time there was formed a Society of
Dretskeans, both in the United States and in England, whose members
vehemently, and even violently, opposed the use of "neuro-prosthetics",
as these ingenious artificial limbs were called. The members of
the Society took as their guide a then newly appeared book by an
eminent philosopher. Unfortunately, they took the author's sensible views to
logical extremes, with consequent miseries that I am about to describe.
According to their reading of
 this philosophical work, mechanical devices, no matter how
ingeniously contrived to imitate human behavior, cannot have mental
states. Mechanical devices such as computers cannot feel, think, see
or hear or wish or understand. They cannot be conscious, even if they
act as if they are. Only brains and nervous systems such as those in
humans, or something with equivalent causal powers (which mechanical
devices are not) can have mental states. Machines have syntax; only
brains, or objects with equivalent causal powers, have semantics.
This doctrine alone might not have caused so much trouble, were it not
for another of the philosopher's doctrines which the members of the society also
took to a logical extreme. This second doctrine is that mental properties
are not properties of individual cells of the brain, or even of a few
cells together, but rather properties of the brain as a whole. Now
the original members of the Dretskean Society reasoned this way: The
nervous system is but an extension of the brain, and mental properties
are really therefore properties of the nervous system as a whole. But
if the whole is changed by replacing a part of it with a mechanical
device, then the nervous system as a whole is not the same as it was
before the replacement. If even a part of the nervous system is replaced
by a mechanical device, they concluded, the whole of the nervous
system must be affected, and lose its power to produce mental states.

The Dretskeans formed the conviction that those who had neuro-prosthetics
attached to their nervous systems thereby lost all powers of consciousness,
of thought, reflection and feeling. It did no good to plead with the Dretskeans
that their reasoning was specious, or to say that since the greater part
of the nervous system and all of the higher cortex was left intact, 
those with neuro-prosthetics still have thoughts and feelings. The Dretskeans
insisted that anything with such an appendage was part machine and part
human tissue, and they pointed to passages in the philosopher's book
that argued that even a complete human within a machine need not make
altogether a system that understands and feels, even if it acts as if
it does.

Nor did it avail to point out to them the passages from the
esteemed philosopher's writings with which I have begun this lament.
The Dretskeans took such stuff to be mere temporizing done for the sake
of disputing critics, and they would have none of it. 
To those who turned the texts against them, and claimed that the humanity
of neuro-prosthetes is a testable, empirical issue, the Dretskeans rejoined
with a question that proved rhetorical: what test would decide? Turing's
famous test, they insisted, was refuted by the philosopher's parable
of the Chinese speaking box. The helplessness of sensible men and women
in the face of this curious challenge only strengthened the Dretskeans
in their prejudices. Many vainly tried to impress upon the Dretskeans
their philosopher's insistence upon the first-person point of view. With
typical casuistry, the members of the Society claimed that each of us
could only engage himself, and not any other, from that distinguished 
point of view. Only analogy and philosophy could decide whether other
things have minds, they claimed, and their philosophical conclusion was
that humans with neuro-electronic legs no more have mental states than
would thermostats fitted with biological arms.

I suppose that the course of action the Dretskeans undertook was understandable
given the firmness of their convictions, but it was undeniably regrettable.
The members of the Society took to bombing factories that manufactued
neuro-prosthetics, and performing armed raids on hospitals to prevent the
implantation of the devices. The Dretskeans would stop at nothing to prevent
the attachment of neuro-prosthetics, and their slogan was everywhere:
"Neuro-prosthesis is murder!"  What was still worse, once a neuro-prosthetic
had been attached to some poor soul, the Dretskeans ceased to treat him
as a fellow human, or as a sentient creature at all. Dretskeans created
great carnage by refusing to stop their automobiles when meeting pedestrians
in crosswalks who sported artificial limbs. They kidnapped former cripples
as soon as they received an implant, and held them in slavery.

The outrages of the Dretskeans finally provoked the wrath of every 
sensible citizen. The Society was outlawed, and most of its members
captured and imprisoned, despite their insistence that they had done
no injury to person or property in killing and kidnapping the handicapped.
The Society effectively vanished, although it is rumored that to this
day a few adherents to the original Dretskean doctrine still live in 
isolation in the State of Utah.

But Dretskeanism is a vital doctrine, and not easily eliminated. No sooner
had the Society of Dretskeans been destroyed than a new and more
influential body sprang up, the Reformed Society of Dretskeans. The
members of the Reformed Society held that the orginal Dretskeans had
misinterpreted and distorted the doctrine by confusing the essential
parts of the brain responsible for consciousness, thought and feeling
with the nervous system as a whole. The original Dretskean doctrine was
correct, they held, but not for the nervous system as a whole, only
for the cerebral cortex. The optic nerve and other nerve tracts from
the brain to the periphery could be replaced by whatever mechanical
devices might serve, without affecting the power of the cortex to 
produce thought and feeling.

And here, at last, is where my personal woes began. I suffer a curious
and progressive disease, characterized by the softening and eventual
death of parts of my cerebral cortex. Because of my disorder, which
is uncommon but not unique, and because neurophysiology during my
lifetime has made dramatic advances, I have served as a kind of
neurological guinea pig. If you will forgive a macabre pun, it is
because of my condition that I have lived on the cutting edge of 
neuro-science. The philosophical author whose writings and radio talks
inspired the Dretskean movement assured us that with the advance of
neuro-science, the mysteries of intentionality and of consciousness
would be revealed. Alas, it has not turned out that way, and neuro-
science has left me, in particular, with the most awesome and dreadful
puzzle.

The first notice I had of my disorder was an inability to feel a pin
or other sharp object when it was stuck into my left thumb. Rejecting
the diagnosis of my psychoanalyst (it was, he claimed, an hysterical
anesthesia), I consulted a neurologist, who after many elaborate
tests informed me that a small part of my cerebral cortex, merely a few
connected cells, had perished. The function of these cells, he explained,
was to receive signals indicating prickle sensations from my left thumb.
Along with the news, he offered me a remarkable prospect. There had 
recently been developed a device which he termed a "cortical patch",
about which I had never before heard. Through micro-surgical techniques,
the neurologist explained, the now defunct cells of my cortex could be
removed and replaced with an electronic and chemical device which would
act in their stead. The fine termini of the device would be connected
to all of the living cells to which my dead cortical cells were attached
at synaptic junctions. Certain ends of the cortical patch would be attached
to long nerve fibres ending in the cortex and connected to my left thumb.
These ends of the cortical patch would detect an increase in the concentration
of certain chemicals, principally acetylcholine, associated with the
transmission of nervous impulses. The cortical patch would then change
the electrical polarity of the end attached to the nerve fiber. Other
ends of the cortical patch would be attached to synaptic junctions with
healthy cortical cells, the same cells to which my dead cortical cells
were attached. When one end of the cortical patch detected an increase
in chemical transmitters at the end of the nerve fibre, the other
termini of the patch, attached to the cortical cells, would stimulate
the membranes of these cells, exactly as the deceased cells had done
when they were living and healthy. The result would be that I would
once again feel prickles in my left thumb. Because the procedure
was experimental, my neurologist assured me, the replacement would
be performed free of charge.

I am not sure whether it was fascination, curiosity, or vanity that
drove me, but I accepted the offer. I wish now that I had not, but the
past cannot be changed. News of the surgery somehow got out, and much
to my discomfort I became the subject of a great deal of popular discussion,
much of it fueled by the speculations of the Reformed Dretskeans.
Almost unanimously, the Reformed
Dretskeans held that the surgery would not work at all.
When the cortical patch was in place, I still would not feel any prickle
in my thumb, and I would say as much, or so they claimed. The neuro-scientists
confidently predicted that I would feel a prickle, and would say so.
As it turned out, the neuro-scientists were right. After I awoke from
the surgery, a nurse stuck a needle in my left thumb and I yelped.
That yelp shook apart the Reformed Society of Dretskeans.

Some of the Dretskeans maintained that although I said I felt a
pain, saying as much was only an aspect of acting as if I had a pain.
But if the neuro-surgeons had their wiring correctly done, the argument 
continued, I should certainly act as if I had a pain, even though
I didn't have one. The Dretskeans paid me a visit after my release from the
hospital, and presented me with this argument. To which I responded
that I knew what a prickle pain felt like because my other cortical
cells had been working fine, and I knew what my left thumb felt like,
because I had continually been sensitve to heat and aches in my left
thumb. So if I heard myself saying "I feel a prickle pain in my left
thumb" when in fact I didn't feel  anything like a prickle pain
in my left thumb, I would certainly know that something was amiss,
and I did not know any such thing. 

The Dretskeans withdrew and divided into three camps. The Radical 
Dretskeans maintained that since my surgery I no longer
had @i(any) mental properties. I and other Dretskeans regarded this
opinion as a revival of the doctrines of the original Society of
Dretskeans, and promptly obtained the intervention of the police.
The Radical Dretskeans fled to Utah, where they hide, few in number
and ineffective. The Fictive Dretskeans sought to remain true to
their philosophical author's doctrine by means of a curious 
casuistry. They held that I had mental states, consciousness, thoughts
and beliefs. But, they continued, I did not have any feeling of 
of prickle pains in my left thumb. I merely thought I had such feelings.
My conviction was sincere, they claimed, and could move me to act
just as if I really had a prickle pain, but I didn't and couldn't.
Finally, the Holistic Dretskeans maintained that I really did have
a prickle pain, and I was pleased to learn of their conclusion.
Almost exactly reversing the reasoning
of the original Society of Dretskeans, they argued that I had the pain
because consciousness and pain
and other mental states are properties of the whole cerebral cortex,
and as long as some part of my cerebral cortex was intact it sufficed
to cause the appropriate mental states when I was in the appropriate
functional states. So long as a good bit of my cortex was attached
to the cortical patches, and so long as the cortical patches bore the
same input and output relations to one another as did the cells
they replaced, I would have thoughts and pains and pleasures just
as before.

I myself found the doctrines of the Fictive Dretskeans perverse and
repugnant, insofar as I could understand them at all. Still, their
doctrine, and the Society of Fictive Dretskeans, endured and is with
us today. I found far more plausible the views of the Holistic
Dretskeans, so much that I began to attend their meetings, and they
began to think of me as a convert. I was never that. But sane men
live by possibilities, and their doctrine is surely possible.

The cortical patch entirely relieved the difficulties with my left thumb,
and after me many others had small cortical patches inserted. But
the patch did not stop my illness. Only a few years after my surgery
another behavioral difficulty arose, the details of which I shall
not embarass myself with in print. Again, the neurologists diagnosed
a softening of a part of the cortex, in this case cells some of 
which were connected with the cortical patch, although
my physicians assured me that the cortical patch was not responsible.
Another cortical patch was recommended, to be connected partly to the
old cortical patch and partly to other cortical cells connected to
the cells of my cortex which had ceased to function properly. The
second patch was duly installed, as sucessfully as the first. To
all appearances, so long as I wore my hat upon my head, I was 
perfectly normal. What's more, I felt perfectly normal.

Unfortunately, the deterioration of my cortical cells accelerated.
With increasing frequency, new cortical patches had to be inserted,
replacing more and more of my natural substance. I am now convinced
that the introduction of the first cortical patch accelerated
the softening of my brain tissues, and that in all probability
had I learned to live with a left thumb that could not feel prickles,
I would have suffered no further loss of function. In any case,
the succession of cortical patches all worked as they should, and
I am able to think and feel and sleep much as I did before.

I have now only a middling piece of cerebral cortex left, and my
neurosurgeons tell me it must go. It is a quite central piece, and
when it softens I will find myself with only the capacities of an
idiot, a prospect I cannot endure. They have readied a final cortical
patch to replace it, and if I let the surgery go on, they assure
me that while my higher cortex will have been entirely replaced with
bits of silicon and germanium and whatnot, all of the functional
relations of the original cortex will be preserved. I will think
and feel and remember like any ordinary person; like myself, in fact.

But now the doctrines of the Fictive and Holistic Dretskeans have
converged, and except among neurosurgeons are almost universal, 
for when and if I have the final patch implanted both
Societies will concur in their judgement of me: I will be
without thought or reflection, without any higher mental states.
Nothing I say or do will redeem me, any more than saying and doing
would make them believe a digital computer thinks.

Of course I am frightened of their power and influence, just as 
some thirty years ago the recipients of neuro-prosthetics were 
frightened of the original Society of Dretskeans. But my agony is
deeper than mere fright at my treatment after surgery; it is an agony
about whether there will be an I to be treated, and about the
unspeakable solitude I will endure if there is. The Dretskean Societies
are very influential, and they clamor to outlaw the procedure to
which I am to be subjected. I will surely be the first person to have
a cortex of silicon, and whatever the outcome of my surgery, I will
very likely also be the last. If the Dretskeans
are wrong, (and surely, in my case, the Fictive Dretskeans must be
wrong, for how could I only think I think?) then should I survive
my surgery I will remain. But no one will know of my sentience except myself,
and no one could know of it save another like me, and there will be none.
And if the Dretskeans are correct, and I cease to exist and am replaced by
a mindless automaton that acts as I do, then no one at all will know it, 
although many will believe themselves to know it.