self an Ego Machine. An Ego Machine does not have to be a living
thing; it can be anything that possesses a conscious self-model. It is certainly
conceivable that someday we will be able to construct artificial
agents. These will be self-sustaining systems. Their self-models might
even allow them to use tools in an intelligent manner. If a monkey’s arm
can be replaced by a robot arm and a monkey’s brain can learn to directly
control a robot arm with the help of a brain-machine interface, it
should also be possible to replace the entire monkey. Why should a robot
not be able to experience the rubber-hand illusion? Or have a lucid
dream? If the system has a body model, full-body illusions and out-ofbody
experiences are clearly also possible.
In thinking about artificial intelligence and artificial consciousness,
many people assume there are only two kinds of information-processing
systems: artificial ones and natural ones. This is false. In philosophers’
jargon, the conceptual distinction between natural and artificial systems
is neither exhaustive nor exclusive: that is, there could be intelligent
and/or conscious systems that belong in neither category. With regard
to another old-fashioned distinction—software versus hardware—we
already have systems using biological hardware that can be controlled by artificial (that is, man-made) software, and we have artificial hardware
that runs naturally evolved software.
Hybrid biorobots are an example of the first category. Hybrid biorobotics
is a new discipline that uses naturally evolved hardware and does
not bother with trying to re-create something that has already been optimized
by nature over millions of years. As we reach the limitations of
artificial computer chips, we may increasingly use organic, genetically
engineered hardware for the robots and artificial agents we construct.
An example of the second category is the use of software patterned
on neural nets to run in artificial hardware. Some of these attempts are
even using the neural nets themselves; for instance, cyberneticists at the
University of Reading (U.K.) are controlling a robot by means of a network
of some three hundred thousand rat neurons. Other examples are
classic artificial neural networks for language acquisition or those used by consciousness researchers such as Axel Cleeremans at the Cognitive
Science Research Unit at Université Libre de Bruxelles in Belgium to
model the metarepresentational structure of consciousness and what he
calls its “computational correlates.” The latter two are biomorphic and
only semiartificial information-processing systems, because their basic
functional architecture is stolen from nature and uses processing patterns
that developed in the course of biological evolution. They create
“higher-order” states; however, these are entirely subpersonal.
We may soon have a functionalist theory of consciousness, but this
doesn’t mean we will also be able to implement the functions this theory
describes on a nonbiological carrier system. Artificial consciousness is
not so much a theoretical problem in philosophy of mind as a technological
challenge; the devil is in the details. The real problem lies in developing
a non-neural kind of hardware with the right causal powers:
Even a simplistic, minimal form of “synthetic phenomenology” may be
hard to achieve—and for purely technical reasons.
The first self-modeling machines have already appeared. Researchers
in the field of artificial life began simulating the evolutionary process
long ago, but now we have the academic discipline of “evolutionary robotics.”
Josh Bongard, of the Department of Computer Science at the
University of Vermont, and his colleagues Victor Zykov and Hod Lipson
have created an artificial starfish that gradually develops an explicit internal
self-model. Their four-legged machine uses actuation-sensation
relationships to infer indirectly its own structure and then uses this selfmodel
to generate forward locomotion. When part of its leg is removed,
the machine adapts its self-model and generates alternative gaits—it
learns to limp. Unlike the phantom-limb patients discussed in chapter 4,
it can restructure its body representation following the loss of a limb;
thus, in a sense, it can learn. As its creators put it, it can “autonomously
recover its own topology with little prior knowledge,” by constantly optimizing
the parameters of its resulting self-model. The starfish not only
synthesizes an internal self-model but also uses it to generate intelligent
behavior.
Self-models can be unconscious, they can evolve, and they can be
created in machines that mimic the process of biological evolution.
IN HOW TO BUILD AN ARTIFICIAL CONSCIOUS
SUBJECT AND WHY WE SHOULDN’T DO IT
Under what conditions would we be justified in assuming that a given
postbiotic system has conscious experience? Or that it also possesses a
conscious self and a genuine consciously experienced first-person perspective?
What turns an information-processing system into a subject of
experience? We can nicely sum up these questions by asking a simpler
and more provocative one: What would it take to build an artificial Ego
Machine?
Being conscious means that a particular set of facts is available to
you: that is, all those facts related to your living in a single world. Therefore,
any machine exhibiting conscious experience needs an integrated
and dynamical world-model. I discussed this point in chapter 2, where I
pointed out that every conscious system needs a unified inner representation
of the world and that the information integrated by this repre -
sentation must be simultaneously available for a multitude of processing
mechanisms. This phenomenological insight is so simple that it has frequently
been overlooked: Conscious systems are systems operating on
globally available information with the help of a single internal model of
reality. There are, in principle, no obstacles to endowing a machine with
such an integrated inner image of the world and one that can be continuously
updated.
Another lesson from the beginning of this book was that, in its very
essence, consciousness is the presence of a world. In order for a world to
appear to it, an artificial Ego Machine needs two further functional
properties. The first consists of organizing its internal information flow
in a way that generates a psychological moment, an experiential Now.
This mechanism will pick out individual events in the continuous flow
of the physical world and depict them as contemporaneous (even if they
are not), ordered, and flowing in one direction successively, like a mental
string of pearls. Some of these pearls must form larger gestalts, which
can be portrayed as the experiential content of a single moment, a lived
Now. The second property must ensure that these internal structures
cannot be recognized by the artificial conscious system as internally
constructed images. They must be transparent. At this stage, a world
would appear to the artificial system. The activation of a unified, coherent
model of reality within an internally generated window of presence,
when neither can be recognized as a model, is the appearance of a
world. In sum, the appearance of a world is consciousness.
But the decisive step to an Ego Machine is the next one. If a system
can integrate an equally transparent internal image of itself into this
phenomenal reality, then it will appear to itself. It will become an Ego
and a naive realist about whatever its self-model says it is. The phenomenal
property of selfhood will be exemplified in the artificial system, and it will appear to itself not only as being someone but also as being there. It
will believe in itself.
Note that this transition turns the artificial system into an object of
moral concern: It is now potentially able to suffer. Pain, negative emotions,
and other internal states portraying parts of reality as undesirable
can act as causes of suffering only if they are consciously owned. A system
that does not appear to itself cannot suffer, because it has no sense
of ownership. A system in which the lights are on but nobody is home
would not be an object of ethical considerations; if it has a minimally
conscious world model but no self-model, then we can pull the plug at
any time. But an Ego Machine can suffer, because it integrates pain signals,
states of emotional distress, or negative thoughts into its transparent
self-model and they thus appear as someone’s pain or negative
feelings. This raises an important question of animal ethics: How many
of the conscious biological systems on our planet are only phenomenalreality
machines, and how many are actual Ego Machines? How many,
that is, are capable of the conscious experience of suffering? Is
RoboRoach among them? Or are only mammals, such as the macaques
and kittens, sacrificed in consciousness research? Obviously, if this
question cannot be decided for epistemological reasons, we must make
sure always to err on the side of caution. It is precisely at this stage of development
that any theory of the conscious mind becomes relevant for
ethics and moral philosophy.
An Ego Machine is also something that possesses a perspective. A
strong version should know that it has such a perspective by becoming
aware of the fact that it is directed. It should be able to develop an inner
picture of its dynamical relations to other beings or objects in its environment,
even as it perceives and interacts with them. If we do manage
to build or evolve this type of system successfully, it will experience itself
as interacting with the world—as attending to an apple in its hand, say, or
as forming thoughts about the human agents with whom it is communicating.
It will experience itself as directed at goal states, which it will represent
in its self-model. It will portray the world as containing not just a
self but a perceiving, interacting, goal-directed agent. It could even have a
high-level concept of itself as a subject of knowledge and experience. just sketched describe new forms of what philosophers call representational
content, and there is no reason this type of content should be restricted
to living systems. Alan M. Turing, in his famous 1950 paper
“Computing Machinery and Intelligence,” made an argument that later
was condensed thus by distinguished philosopher Karl Popper in his
book The Self and Its Brain, which he coauthored with the Nobel Prize–
winning neuroscientist Sir John Eccles. Popper wrote: “Specify the way
in which you believe a man is superior to a computer and I shall build a
computer which refutes your belief. Turing’s challenge should not be
taken up; for any sufficiently precise specification could be used in principle
to programme a computer.”Of course, it is not the self that uses the brain (as Karl Popper would
have it)—the brain uses the self-model. But what Popper clearly saw is
the dialectic of the artificial Ego Machine: Either you cannot identify
what exactly about human consciousness and subjectivity cannot be implemented
in an artificial system or, if you can, then it is just a matter of
writing an algorithm that can be implemented in software. If you have a
precise definition of conciousness and subjectivity in causal terms, you
have what philosophers call a functional analysis. At this point, the mystery
evaporates, and artificial Ego Machines become, in principle, technologically
feasible. But should we do whatever we’re able to do?
Here is a thought experiment, aimed not at epistemology but at
ethics. Imagine you are a member of an ethics committee considering
scientific grant applications. One says:
We want to use gene technology to breed mentally retarded human
infants. For urgent scientific reasons, we need to generate
human babies possessing certain cognitive, emotional, and perceptual
deficits. This is an important and innovative research
strategy, and it requires the controlled and reproducible investigation
of the retarded babies’ psychological development after
birth. This is not only important for understanding how our own
minds work but also has great potential for healing psychiatric
diseases. Therefore, we urgently need comprehensive funding. No doubt you will decide immediately that this idea is not only absurd
and tasteless but also dangerous. One imagines that a proposal of
this kind would not pass any ethics committee in the democratic world.
The point of this thought experiment, however, is to make you aware
that the unborn artificial Ego Machines of the future would have no
champions on today’s ethics committees. The first machines satisfying a
minimally sufficient set of conditions for conscious experience and selfhood
would find themselves in a situation similar to that of the genetically
engineered retarded human infants. Like them, these machines
would have all kinds of functional and representational deficits—various
disabilities resulting from errors in human engineering. It is safe to assume
that their perceptual systems—their artificial eyes, ears, and so
on—would not work well in the early stages. They would likely be halfdeaf,
half-blind, and have all kinds of difficulties in perceiving the world
and themselves in it—and if they were true artificial Ego Machines, they
would, ex hypothesi, also be able to suffer.
If they had a stable bodily self-model, they would be able to feel sensory
pain as their own pain. If their postbiotic self-model was directly anchored
in the low-level, self-regulatory mechanisms of their hardware—
just as our own emotional self-model is anchored in the upper brainstem
and the hypothalamus—they would be consciously feeling selves.
They would experience a loss of homeostatic control as painful, because
they had an inbuilt concern about their own existence. They would have
interests of their own, and they would subjectively experience this fact.
They might suffer emotionally in qualitative ways completely alien to us
or in degrees of intensity that we, their creators, could not even imagine.
In fact, the first generations of such machines would very likely have
many negative emotions, reflecting their failures in successful self-regulation
because of various hardware deficits and higher-level disturbances.
These negative emotions would be conscious and intensely felt,
but in many cases we might not be able to understand or even recognize
them.
Take the thought experiment a step further. Imagine these postbiotic
Ego Machines as possessing a cognitive self-model—as being intelligent
thinkers of thoughts. They could then not only conceptually grasp the bizarreness of their existence as mere objects of scientific interest but
also could intellectually suffer from knowing that, as such, they lacked
the innate “dignity” that seemed so important to their creators. They
might well be able to consciously represent the fact of being only secondclass
sentient citizens, alienated postbiotic selves being used as interchangeable
experimental tools. How would it feel to “come to” as an
advanced artificial subject, only to discover that even though you possessed
a robust sense of selfhood and experienced yourself as a genuine
subject, you were only a commodity?
The story of the first artificial Ego Machines, those postbiotic phenomenal
selves with no civil rights and no lobby in any ethics committee,
nicely illustrates how the capacity for suffering emerges along with
the phenomenal Ego; suffering starts in the Ego Tunnel. It also presents
a principled argument against the creation of artificial consciousness
as a goal of academic research. Albert Camus spoke of the
solidarity of all finite beings against death. In the same sense, all sentient
beings capable of suffering should constitute a solidarity against suffering.
Out of this solidarity, we should refrain from doing anything that
could increase the overall amount of suffering and confusion in the universe.
While all sorts of theoretical complications arise, we can agree
not to gratuitously increase the overall amount of suffering in the universe—
and creating Ego Machines would very likely do this right from
the beginning. We could create suffering postbiotic Ego Machines before
having understood which properties of our biological history, bodies,
and brains are the roots of our own suffering. Preventing and
minimizing suffering wherever possible also includes the ethics of risktaking:
I believe we should not even risk the realization of artificial phenomenal
self-models.
Our attention would be better directed at understanding and neutralizing
our own suffering in philosophy as well as in the cognitive
neurosciences and the field of artificial intelligence. Until we become
happier beings than our ancestors were, we should refrain from any attempt
to impose our mental structure on artificial carrier systems. I
would argue that we should orient ourselves toward the classic philosophical
goal of self-knowledge and adopt at least the minimal ethical principle of reducing and preventing suffering, instead of recklessly embarking
on a second-order evolution that could slip out of control. If
there is such a thing as forbidden fruit in modern consciousness research,
it is the careless multiplication of suffering through the creation
of artificial Ego Tunnels without a clear grasp of the consequences.
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