IV

PHILONOUS Hello, my friend. Why so gloomy, though you sit by such a beautiful brook?

HYLAS Hello, Philonous. Indeed, I confess that neither the beauty of the landscape nor anything else pleases me after you shattered my most firmly held beliefs. I feel I know nothing anymore. The mystery of consciousness, just thinking about it depresses me: in a thousand years, we have not advanced a single step in understanding it. The sciences approach perfection and terminology cannot be more subtle, yet the same chasm yawns between consciousness and matter, and any attempts at analysis end up in an awful circulus vitiosus, in which the mind is trapped as if on a treadmill with no exit. Abomination!

PHILONOUS Too many words, so much confusion and chaos! What are you saying, Hylas? What chasm? What mystery of consciousness?

HYLAS If I examine a person as a neurologist would, I will find that sound waves reach the ear and transform into nerve impulses that travel to the brain, where they are sent to a part of the cerebral cortex. From there the impulses travel through nerves to the muscles in the hand that the person raises. I can describe the entire process, from the arrival to the ear of the sound waves carrying the command to raise the hand to the command’s execution as a chain of physical causes and effects, in every consecutive phase of which atoms participate—nothing but vibrating, dancing atoms. There is no place in this chain where consciousness might be hiding—unless a certain subset of those dancing atoms is consciousness. But how is it possible that one group of atoms is, and another group is not, consciousness? What are atoms but a vacuum in which minuscule electrical charges circle in quantized orbits, with their waves of probability, spins, magnetic moments, and the devil knows what else? Does consciousness then consist of a vacuum and electrical charge? I don’t know anything anymore. When in another experiment I take the place of the examined subject, it is my ear that receives the sound waves and my hand that receives the command to raise, and I am fully conscious of the entire process. In the first case, we examined a physical aspect of the process that can be observed externally; in the second case, we experienced its mental aspect. The physical aspect is accessible to everyone, and this kind of phenomena is therefore called public; but the mental aspect is directly accessible only to me—no one else can know whether I raised my hand intentionally, with consciousness involved, or automatically, due to a conditional reflex.

PHILONOUS None of this is news, Hylas. Why does it torment you?

HYLAS How can you ask? Some say that physiological phenomena do not affect the mental ones and vice versa, that they both run in parallel, mutually reflecting each other. This is the view of parallelists. Others, epiphenomenalists, claim that mental phenomena merely supplement or passively reflect the physiological ones and are perceived through the subject’s “inner sense.” There is also a theory of “two sides,” according to which the physiological and the mental are two aspects of the same thing: when I look at a process from the outside (e.g., when I observe your brain), I see it as physiological, but when you experience it “from inside,” it appears to you as mental. Then there are spiritualists and materialists of all stripes and, to top it off, physicalists who sincerely inform us that the entire problem of consciousness is bogus, wherefore scientists can say nothing about it. As if we can walk but cannot even mention our legs. I begin to suspect that a principial “impossibility” of knowing the actual state of the matter is at play here. Is there really no transition from what happens in the mind to what everybody can observe? Could this “prohibition” hide within itself a fundamental mystery of nature just like Heisenberg’s “prohibition” of a precise observation of an atom?

PHILONOUS Don’t be so quick to posit a “prohibition” and despair. What do you think about consciousness?

HYLAS If I only knew! First, it is not a thing or an object but a process or a series of events. Second, it manifests itself exclusively in a living organism at a high stage of evolution, such as a human being. Third—

PHILONOUS Only a living organism can be conscious?

HYLAS Surely, Philonous, you do not doubt this point.

PHILONOUS I do not doubt that consciousness can arise in any system that has certain characteristics, but life is not among them.

HYLAS Are you suggesting that consciousness could arise in a structure built of, say, glass and metal?

PHILONOUS Exactly.

HYLAS But you are contradicting the obvious.

PHILONOUS Please, Hylas, refrain from using the word “obvious” in our discussions. Many rifts in philosophy occur precisely because what is obvious to one is not obvious to another. It was not obvious once that people didn’t walk upside down on the opposite hemisphere or that simultaneity cannot exist between events occurring on two stars far away from each other. For me, a scientist, nothing is entirely “obvious” or “self-evident”; every statement deserves a rigorous analysis and an experimental confirmation of its consequences. So do you maintain, Hylas, that consciousness cannot arise in a structure made of metal?

HYLAS I do. Can you prove otherwise?

PHILONOUS I will show you a place where metal is the source of consciousness.

HYLAS Indeed. And where is that?

PHILONOUS Here, in your head.

HYLAS You are joking.

PHILONOUS Not at all. You must know that your body and therefore also your brain contain iron—in the molecules of respiratory enzymes. Without those enzymes, hence without the iron in them, you would not think or even live for a second.

HYLAS True, but—

PHILONOUS Because iron is an inseparable element of tissues including those that form your brain, it plays a role in the processes that are the basis of consciousness. Quod erat demonstrandum. What do you say to that?

HYLAS I say that when iron is in an organic molecule, a protein, it loses its regular properties—

PHILONOUS I must interrupt, because you are talking nonsense. What properties does iron lose when it becomes a part of the enzyme oxidase? Perhaps those that show in a nail or a horseshoe? So you think the iron in a horseshoe is ordinary and that in an enzyme not?

HYLAS I only mean that this iron—as a part of a greater whole—has been drawn into a system of life processes.

PHILONOUS Whereas in the horseshoe it appears in its perfectly pure form, isolated and autonomous? Is there any “immanent” iron? If we agreed to such a terminology, surely the criterion of purity of the element would not be met by a horseshoe, whose microcrystalline structure is full of various additives. Is it not better to say that the iron atoms found in a crystalline structure with additives of carbon and sulfur exhibit properties that we observe in a horseshoe, whereas the iron atoms complexed with a protein molecule exhibit properties that are different? In each case, we observe a manifestation of particular characteristics in a particular system, that’s all.

HYLAS Are you saying that the presence of the iron atoms in my head implies that if my head were made exclusively of iron, I could think, feel, and have consciousness?

PHILONOUS Provoked, I must respond: yes, this is exactly what I am saying, but with one important reservation—that the iron is in a structure functionally equivalent to your brain.

HYLAS You are being careful, Philonous, but is it not just playing with words? You say “an iron brain would think if it had the same functional properties as the living brain” or “an iron brain would be alive if it had the same functional properties as the living brain.” But an iron brain cannot be alive; therefore it cannot develop consciousness. An iron brain is a contradictio in adiecto.

PHILONOUS I think that this way, we get nowhere. You maintain that the processes of life and consciousness are inseparable and specifically, that not every life process is conscious, but every conscious process is also a life process. Yes?

HYLAS That is my opinion.

PHILONOUS Then we must first consider what exactly consciousness is. We, incessantly talking about it, find this entity as essential for survival as, e.g., sight. But in reality, consciousness is an abstraction. When I say that I am conscious of something, it means that I understand it, perceive it, or think of that something. Nothing more. Because when I see or think, it does not mean that I also, somehow “in addition” or “above and beyond” that perceiving or thinking, have awareness of it. When you are conscious of me approaching, it simply means that you see me coming closer, nothing more. Do you agree?

HYLAS In principle, yes. Normally, I do not see an object in such a way that I am conscious of being conscious of seeing it, but when I deliberately concentrate on that act of seeing, it does happen that, in addition to the seeing itself, I become aware of the act of seeing.

PHILONOUS Of course we can make ourselves aware of an act of perceiving, but so what? Seeing me, you may think, “I see Philonous” or “I am conscious of seeing Philonous,” where your awareness of seeing coincides with your seeing. Just as I can merely sing, or sing about my singing (that is, I sing that I am singing), I can say to myself that I perceive that I am perceiving. I am attempting, when I do this, to generalize the experience while it is happening, that is, to assign it to the class of phenomena that are called conscious. You likewise are attempting to create a generalizing distance from the simple act of seeing, which sets you on the path to the creating of the abstraction “consciousness in general.” If I think about something, I simply think about it, but I can also think about the thinking process itself. If “thinking about thinking” is qualitatively different from “thinking about eating” and you accept the idea of “consciousness of consciousness,” you also must accept the possibility of a next level, to wit, Hylas is thinking about thinking about his thinking, which gives you “consciousness to the third power,” and this regressus may be repeated ad infinitum. The inevitable conclusion is that there are infinitely many levels of consciousness. Which is absurd. Obviously we can abstract on any topic, including the topic of abstracting, but each such act of the mind must be limited to a single, defined topic. The idea of consciousness, as you can see, comprises diverse mental phenomena—feeling, thinking, seeing, and so on. If you ask a child of six or seven if she has consciousness, she will have no idea what you are talking about, yet you would not deny her consciousness, would you?

HYLAS So in your opinion consciousness does not exist at all. You have cleverly “explained it away,” and nothing remains to be said on the subject. Are you suggesting that the problem is just apparent? Have you become a physicalist? As for the example of the child, don’t forget that one can speak in prose without having any idea what prose is. One can be conscious without being conscious of it.

PHILONOUS A good argument against those who believe that “Hylas’s consciousness” is qualitatively different from “Hylas’s existence,” that consciousness, instead of being a generalization of a series of phenomena, is a primal property, fundamental, obvious, and absolutely a priori. Only philosophers, thanks to their habituation to this notion and being “professionally conscious,” as it were, came to this conclusion. “Speaking in prose,” and even “prose” itself, is a generalization, just like consciousness, and we can live just fine without making those generalizations. When I say, “This is prose,” I am actually saying, “If we take into account certain stylistic, rhythmic, and other features, this articulation can be characterized as prose and therefore belongs in the category of all possible sentences expressed in prose.” Similarly, consciousness is definitely not an “apparent problem” but rather a generalization of a series of mental phenomena that we group into a category under the name “the phenomena of consciousness” or, in short, consciousness. With this in mind, let us now build “your iron head that thinks.” We will put together an electronic brain made of iron (or another metal). Is this possible?

HYLAS It is. But that brain is dead matter.

PHILONOUS It is dead matter, and yet it is capable of thought.

HYLAS Thought that is only formal, that only applies certain operational rules to certain signs (symbols). Such a brain cannot think meritoriously. Even some cyberneticists refer to the processes taking place in an electronic brain as “pseudo-thinking.”

PHILONOUS True. If you like, we can use the term “pseudo-thinking,” even though we will use its results exactly as we use the results provided by living calculators. We can also reserve the name penicillin only for the antibiotic produced by a living mold and call synthetic penicillin “pseudo-penicillin.” Why not? I just don’t understand what we want to accomplish by making that distinction. Is the intention to put up a wall between the electronic network of the electronic brain and the neural network of the protein-based brain? What is the worth of such a wall if it is only made of words? Why limit ourselves voluntarily by saying up front that this or that is impossible? Would it not be better to examine the question of impossibility sine ira, with the methods of logic and empiricism?

HYLAS Very well, I withdraw the word “pseudo-thinking.” But I still retain the conviction that no electronic brain can think substantively, that is, with comprehension and subjective understanding.

PHILONOUS First, you will have to prove that consciousness cannot arise where there is no substantive thinking. But let us proceed step by step. We construct our electronic brain and give it powerful “word memory stores” and a scanning device so it can read. Is this possible?

HYLAS It is.

PHILONOUS Can we have a conversation with such a brain?

HYLAS How?

PHILONOUS Of course, we would need to attach to it a device for analyzing sound waves. Such a device already exists as a prosthesis for the deaf. We would also have to scale up the brain considerably, making it much larger than any in existence today.

HYLAS Yes, this is possible.

PHILONOUS Our brain now possesses an organ through which stimuli from the surroundings enter it, as well as an organ through which it sends impulses to its surroundings. Input and output. Now we can communicate with our brain. Agreed?

HYLAS We can communicate with it only in the sense that if we assign it a certain task, it will solve it (provided it can). But the reasoning with which it performs each task will be purely formal and not substantive.

PHILONOUS Your caution is exemplary. Therefore, let us open up the parentheses here and consider what substantive, as opposed to formal, reasoning is. My guess is that you understand it in this way: when I say that a straight railroad track, when observed along its direction, gives the impression that the two rails meet at the horizon, you will understand me at once, right?

HYLAS I will.

PHILONOUS So you grasp my meaning without resorting to formal methods, without using the laws of geometry and the canons of physiological optics. How can you do this? Because you know or “intuitively feel” that the rails in fact appear to meet at the horizon. Can our artificial brain do the same?

HYLAS Yes, but it would test the truth-value of your statement only by formal reasoning. We would need to provide it with definitions of terms like “rails,” “the horizon,” and “meet,” as well as with instructions on the operations to be performed on them using the laws of geometry and optics that you mentioned. Then and only then could it arrive at the correct conclusion.

PHILONOUS Excellent. Now imagine a person who is paralyzed from birth, blind, deaf, and mute, and has no sense of touch except on the palm of one hand. With great effort we have taught this person about his surroundings, by drawing letters on that palm. Now I tell this poor creature, letter by letter, that when one looks at a railroad track, the rails seem to meet at the horizon. Would he understand me at once? Would he immediately grasp the substantive meaning of that phenomenon?

HYLAS  . . .

PHILONOUS You are silent, realizing that the man, although alive and possessing consciousness (his brain functions properly), cannot comprehend the issue because he lacks personal experience with such terms as “to look,” “a distant object,” “a near object,” “optical perspective,” and so on. Yet he can understand what I am telling him. How? By using, yes, formal reasoning. We can teach him geometry and optics (since the laws of both can be expressed in the formalized language of mathematics), and by applying those laws to the problem, that is, through formal reasoning, he can integrate the statement “the rails seem to meet at the horizon” into a logical whole and declare it to be true. As you can see, what for some may be a matter of formal reasoning only, for others may be grasped directly, without resorting to roundabout ways. Please realize that the only instrument of sensation in an electronic brain is the analyzer that reads the perforations on an input card or tape, and for this brain the whole external world is reduced to those perforations. This link with the world is thus even more tenuous than the disabled person had. For an electronic brain to be able to think substantively, we would need, first, to augment enormously its circuitry to provide it with vast possibilities for forming links (associations) between impulses, and, second, to equip it with organs for many kinds of contact with the external world—optical, tactile, chemical, and so on.

HYLAS Why are the engineers not working on this now?

PHILONOUS The engineers are interested not in aping human behavior but in building instruments that efficiently perform narrowly specific tasks. Our current electronic brains are “idiot calculators,” combining the highest speed and precision of formal-mathematical reasoning with great stupidity in all other areas of mental work.

HYLAS Then you believe that, if given the sensors and circuitry needed, an electronic brain would be able to think substantively?

PHILONOUS I do. But I am not belittling the obstacles that lie in the path to the construction of such a brain. We can talk later about the prospect of that construction. My point here is different. Suppose that we have built such a brain. You come to see me, its constructor, and you see the machine reading a book. You ask the machine what it is doing. I am reading, it replies. What are you reading? I am reading a book, it says. And who is reading the book? I am, answers the electronic brain. So it has an “I,” it can read, it can see, and, if equipped with the right circuits if you offended it, it would say that it is offended. Therefore, it also has feelings. Since we have agreed that to feel, read, and perceive is the same as to have consciousness, our augmented brain will be conscious, quod erat demonstrandum. What do you say to that?

HYLAS That consciousness cannot arise where there is no life.

PHILONOUS How do you know this? So far it has not happened because there have been no electronic brains. But now there are. Granted, an electronic brain with which one could communicate as we have described does not exist yet. It would need to be a million times more complex than the machines today, but that is a technical question, which for us, theorists of knowledge, is beside the point.

HYLAS There must be an error somewhere in your reasoning. Why are people—all organisms, for that matter—not made of iron, nickel, or glass? Why are there no inanimate minds? Why was there only one evolution—the biological one, I mean—and why only it has managed to produce beings that are immeasurably complex? Does this not prove that the increase in organization and life are inseparable, that neither can appear in nature independently, just as there cannot be matter without mass?

PHILONOUS Finally, you are on the right track. Let us take a closer look at this issue. You ask why we are not made of metal and glass but of colloidal proteinaceous compounds instead. I will try to answer. First, although the organs of our body are indeed made of living tissue, living tissue is not necessary for them to function properly.

HYLAS What do you mean?

PHILONOUS Take, for instance, a heart, a blood vessel, or a kidney. An artificial, mechanical replacement of any of them functions well for an extended period.

HYLAS That is true.

PHILONOUS Let us then define certain sets. All possible systems that perform the same function will belong to one set. Only the function decides; the building material, size, and technical or structural details are irrelevant. Thus the set of all possible pumps will contain piston and pistonless pumps, centrifugal and vacuum pumps, absorption and mercury pumps, and so on. In this set there will also be the hearts of living creatures. In the set of all possible filters there will also be the kidneys of living creatures. And in the set of feedback networks there will also be the brains of living creatures.

HYLAS How is this an answer to my question?

PHILONOUS It is just the preamble. We have established that the function of some organs in our body can be continued, even improved, by devices made of nonbiological material. The field of prosthetics is developing slowly but has great potential. Cybernetics has contributed to this field significantly. Advances are being made today for prosthetics for the deaf and blind. But let us return to your question of why we are built out of colloidal proteins rather than metallic conductors, tiny wheels, screws, and so on. When, as a constructor, I set out to design a heart or kidney prosthetic, or an artificial eye, the conditions I must take into account in my preparation are totally different from those that Nature faced billions of years ago when she set out to make organisms. “Nature,” of course, is only symbolic shorthand here, because there was no constructor then to gather appropriate molecules and keep fitting and joining them until the first bacteria popped up. Nothing like that ever happened; there was only a primordial, warm ocean with dissolved organic and inorganic salts in it, and nothing else. As we know today, biological evolution in its proper sense was preceded by a long evolution of organic molecules or, more precisely, an evolution of chemical reactions through their mutual competition and “natural selection.” In the course of many simultaneous reactions, large molecules composed of tangled threads of atoms, called polymers, came into being, and at a certain stage of this process, they separated from the ocean in the form of tiny colloidal droplets. This phenomenon resulted from the operation of the fundamental laws of physical chemistry, and we can readily reproduce it in the laboratory. The droplets were not yet cells, but cells arose from them in the course of the subsequent “chemical evolution,” perhaps a billion or several hundred million years later. Please note that the colloidal character of the protoplasmic droplets, the future building blocks of multicellular organisms, was determined at a very early stage of evolution, since the “natural selection” of chemical reactions could not take place anywhere else except in these droplets which constituted a concentrated, reactive phase of specific groups of compounds. This was the beginning. Afterward, the plasma adapted to changing conditions, but various features of the structure and functions of our body indicate that life originated in the ocean whose waters were as salty as our blood. Nature built organisms where it was possible—in this case, in the water—because at temperatures prevailing on Earth, corpora non agunt nisi solute, compounds do not react unless they are in solution.1

Further, Nature built from what was at hand: in the ocean, some compounds were abundant, some present only in traces, and some totally absent, and the composition of our body reflects that. But today’s engineer who wants to build a brain prosthetic has at his disposal much more than aqueous suspensions of sticky colloids at relatively low temperatures: he can use various kinds of machinery, rare substances, high temperatures and pressures, and so on. My point is that the structures of our body and brain reflect not only the biological purposes that they have been serving up to now but also the monumental, long, and complicated path of the entire biological evolution. That is why we carry traces of both the early prebiotic phase and the later formation of living organisms in biological evolution through natural selection, changes in the environment, and inter- and intraspecies competition. Furthermore, evolution was in fact not a ceaseless upward movement; there were stumbles and defeats. It improved and perfected structures and processes but also regressed, degenerated, and eliminated forms and species. The road from unicellular organisms to human beings was full of zigzags, wrong turns, and blind alleys, and our body carries traces and consequences of those “tactical maneuvers” of the evolutionary process even today. Of course, the engineer of the brain prosthetic or electronic brain does not need to concern himself with those zigzags, those traces of the long-gone evolutionary stages or the vestiges of adaptation to conditions in which the prehistoric ancestors of humans lived. Because I like digressions, I add that a limited lifespan is not a consequence of some “construction error” on the part of evolution; it is the consequence of an engineering necessity, for evolution is driven by the variability of forms and their succession. Where there is no death of some forms, room is not made for others to follow, and there can be no evolution. Individual death is the price we pay for the possibility of the continued development of our species. But to return to the topic: biological evolution was the only possible way to reach and cross the threshold of the minimum complexity mentioned earlier. The path from aqueous solutions to colloidal droplets to cells to multicellular organisms to humans was the only path allowed by the conditions on our planet. Once the threshold of the minimum complexity was reached and organisms became protected against deleterious effects of degenerative tendencies, the proper organismal evolution could begin. But of course, none of this interests the engineer of prosthetics, artificial hearts, kidneys, eyes, or brains. Nature faced many difficult conditions, but the constructor today encounters just a few. And this is the reason why the engineer of the future will be able to construct a conscious machine from glass or metal and not bother with sticky proteins in solution.

HYLAS You really think that life and consciousness are not inseparable and that there may exist a structure made from nonliving elements that can house consciousness?

PHILONOUS Definitely. I also think that the fundamental rules of the brain’s functioning must be the same in all corners of the material universe, though other beings who have brains may differ from us as a star differs from a starfish. Their mentation will still share the same principles of induction, deduction, and Ockham’s razor (a sparingness of hypotheses).

HYLAS I have a few more questions about consciousness.

PHILONOUS Go ahead, my friend.

HYLAS I accept your thesis that consciousness is a group term that applies to an entire class of phenomena. But where, in your opinion, is my consciousness located? In my head?

PHILONOUS Where else could it be?

HYLAS Can you then point it out to me with a finger?

PHILONOUS My digestion takes place in my abdomen. Can you point it out to me with a finger?

HYLAS I could show you, and the world, your digestion processes by surgically opening your abdomen under local anesthesia. But if you open my skull under local narcosis and show me (in a mirror) my brain, neither you nor I will see my consciousness. We will not even see any of the processes that together constitute this group term. Because it is impossible to see my perceiving or thinking of clouds or my toothache. So I submit to you that consciousness is not located in physical, objective space at all. If we accepted that consciousness had a location we would arrive at some very funny notions. For example, when I bow before a meal, my hunger also goes down, or when, suffering from unrequited love, I bang my head against the wall my love also periodically hits the wall?

PHILONOUS Please, Hylas, tell me where in physical space “the repulsion of bodies with equal charges” is located?

HYLAS I see. “The repulsion as such” I cannot show you, because it is an abstraction. But I can show you the direct act of mutual repulsion of two equally charged bodies.

PHILONOUS You think so? You will show me only how the distance between the two bodies increases. One can see the movement but not the repulsion. Repulsion is a generalization, an abstract term, like love. If we elevate the laboratory bench on which you perform your experiment with the equally charged bodies, will you say that the repulsion was elevated too? Or, for another example, can you see an electron?

HYLAS Of course, in a Wilson cloud chamber or on a photographic film.

PHILONOUS Not at all. In the cloud chamber you only see a streak of vapor condensed on the ions that something has formed, and on the basis of atomic theory you conclude that that something was an electron. And on the photographic film you see only a few blackened grains of an emulsion. You do not see an electron directly; you always only deduce its presence on the basis of certain traces and physical theories. Similarly, when neurophysiology progresses sufficiently, I will soon be able to show you certain electrochemical processes in your brain and on the basis of which I deduce that you are seeing, hearing, or thinking (e.g., thinking of a special person “with tenderness and devotion,” which is an expression of love). A distinct group of processes take place in your brain when and only when you are sad, and so sadness exists in the same way that consciousness does. Both are abstractions encompassing a series of phenomena that are interconnected and therefore can be assigned to the same set.

HYLAS I am not convinced. A person can feel sadness or a toothache directly but cannot experience or feel electrostatic repulsion or an electron.

PHILONOUS Consider what is happening when you feel hungry. Why are you hungry? Because your empty stomach sends signals to your brain, no?

HYLAS And so? Those nerve impulses can be observed by any observer with a galvanometer, but it will not make the observer feeling my hunger. That is my private perception, as opposed to the publicly observable nerve impulses from the stomach to the brain. Don’t try to erase that difference, please.

PHILONOUS I am erasing nothing. Look into your belly, and you will see, thanks to the information traveling through the nerves from your eye to your brain, that your stomach is performing certain movements called “hunger pangs.” And you feel hunger because of the information traveling, through other nerves, from your stomach to your brain. The only difference is that the information about hunger is addressed only to your brain, because your stomach is connected to no other. In contrast, anyone can see your stomach in your opened belly. Other people, of course, could only see, not feel, the pangs. But if we connected the nerves from your stomach to my brain, it would be me who feels the hunger even though the empty stomach is yours.

HYLAS You posit an unnatural procedure.

PHILONOUS Nonsense, Hylas! Connecting your nerve with mine is an “unnatural procedure”? Then using an electron microscope to study atomic structures is an unnatural procedure too. In both cases we are conducting an experiment to confirm our assumptions and gain new knowledge about the world (which includes both objects around us and inside us). If you forbid scientists to act “unnaturally,” we will have to limit ourselves to satisfying our hunger, thirst, and sex drive. Nothing beyond that, because only that is “natural.” You cannot be serious with this objection.

HYLAS What an outburst! Very well, I withdraw my objection regarding the “unnatural.” Continue.

PHILONOUS We have thus established that the distinction between “private” and “public” facts boils down to the relation between a given person and given information. Information about what is happening inside the person’s body is directly accessible (through the nerve connections) only to that person. Information from outside the person is directly accessible to everyone present. That is all the mystery.

HYLAS Let me repeat. You are saying that the difference between a subjective perception (“I am hungry”) and an objective perception (“I see a photograph”) reduces to the relation between the information and its addressee. Information about internal processes is fed through the nerves exclusively to the brain of that organism, while information from the surroundings is accessible to everyone.

PHILONOUS Yes. From this it also follows that any particular information may reach your brain in two ways if it originates in your body. You can either observe your stomach with your eyes (after we have opened your belly) or “feel” it, that is, “feel its emptiness” through the direct nerve connection. Needless to say, this distinction results from evolutionary adaptation, for it would be useless, or even harmful, if we felt someone else’s hunger or toothache.

HYLAS But what is the source of the information that I am sad, that I am experiencing sadness?

PHILONOUS That information is a message to your brain about its own state through the system’s “internal feedback.” I think that now we have dispelled all doubts that anyone can have on this subject and are ready to tackle the main problem: the functional analysis of a system belonging to the set of “feedback networks” mentioned earlier.

HYLAS Cybernetics studies such systems?

PHILONOUS It does. But the topic is vast and challenging, and tackling it requires considerable intellectual effort. So let us postpone it to our next meeting. In the meantime, please, think about the issues that we covered today, above all—evolution viewed from the constructor’s standpoint.