Shadows of Forgotten Ancestors (26 page)
Read Shadows of Forgotten Ancestors Online
Authors: Carl Sagan,Ann Druyan
When we characterize such beings as only robots, we are also in danger of losing sight of the possibilities in robotics and artificial intelligence over the next few decades. Already, there are robots that read sheet music and play it on a keyboard, robots that translate pretty well between two very different languages, robots that learn from their own experiences—codifying rules of thumb never taught to them by their programmers. (In chess, for example, they might learn that it is generally better to position bishops near the center than near the periphery of the board, and then teach themselves circumstances in which an exception to this rule is warranted.) Some open-loop chess-playing robots can defeat all but a handful of human chess masters. Their moves surprise their programmers. Their completed games are routinely analyzed by experts who speculate about what the robot’s “strategy,” “goals,” and “intentions” must have been. If you have a large enough pre-programmed behavioral repertoire and if you are able to learn enough from experience, don’t you begin to appear to an outside observer
as if
you’re a conscious being making voluntary choices—whatever may or may not be going on inside your head (or wherever you keep your neurons)?
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And when you have a massive collection of mutually integrated programs, capability for learned behavior, data-processing prowess, and means of ranking competing programs, might it not start feeling, on the inside, a little bit like thinking? Might our penchant for imagining someone inside pulling the strings of the animal marionette be
a peculiarly human way of viewing the world?
*
Could our sense of executive control over ourselves, of pulling our own strings, be likewise illusory—at least most of the time, for most of what we do? How much are we really in charge of ourselves? And how much of our actual everyday behavior is on automatic pilot?
Among the many human feelings that, although culturally mediated, may be fundamentally preprogrammed, we might list sexual attraction, falling in love, jealousy, hunger and thirst, horror at the sight of blood, fear of snakes and heights and “monsters,” shyness and suspicion of strangers, obedience to those in authority, hero worship, dominance of the meek, pain and weeping, laughter, the incest taboo, the infant’s smiling delight at seeing members of its family, separation anxiety, and maternal love. There is a complex of emotions attached to each, and thinking has very little to do with any of them. Surely, we can imagine a being whose internal life is nearly wholly composed of such feelings, and nearly devoid of thought.
——
The spider builds her web near our porch light. The fine, tough thread reels out from her spinneret. We first notice the web glistening with tiny droplets after a rainstorm, the proprietor repairing a damaged circumferential strut. The elegant, concentric, polygonal pattern is carefully stabilized with a single guy thread extending to the cowl of the lamp itself, and another to a nearby railing. She repairs the web even in darkness and foul weather. At night, when the light is on, she sits at the very center of her construction, awaiting the hapless insect who is attracted by the light and whose eyesight is so poor that the web is quite invisible. The moment one becomes entangled, news of this event travels to her in waves along the threads. She rushes down a radial strut, stings it, quickly wraps it in a white cocoon, packaging it for future use, and rushes back to her command center—composed, a marvel of efficiency, not even, as far as we can see, a little out of breath.
How does she know to design, construct, stabilize, repair, and utilize this elegant web? How does she know to build it near the lamp, to which the insects are attracted? Did she scamper all over the house tallying the abundance of insects in various potential campsites? How could her behavior be pre-programmed, since artificial lights have been invented much too recently to be taken account of in the evolution of spiders?
When spiders are given LSD or other consciousness-altering drugs, their webs become less symmetrical, more erratic, or, we might say, less obsessive, more freeform—but also less effective in catching insects. What has a tripping spider forgotten?
Maybe its behavior is entirely pre-programmed in its ACGT code. But then, couldn’t much more complex information be locked away in a much longer, much more elaborate code? Or maybe some of this information is learned from past adventures in spinning and repairing webs, immobilizing and eating prey. But then look how small that spider’s brain is. How much more sophisticated behavior might emerge out of the experience of a much larger brain?
The web is anchored opportunistically to a local geometry of lamp cowling, metal railing, and wood siding. That could not per se have been pre-programmed. There must have been some element of choice, of decision making, of connecting a hereditary predisposition to an environmental circumstance never before encountered.
Is she “only” an automaton, unquestioningly performing actions that seem to her the most natural thing in the world—and being rewarded, her behavior reinforced by an ample supply of food? Or might there be a component of learning, decision making, and self-consciousness?
Adopting high standards of engineering precision, she spins her web now. She reaps the reward later, maybe much later. She patiently waits. Does she know what she’s waiting for? Does she dream of succulent moths and foolish mayflies? Or does she wait with her mind a blank, idling, thinking of nothing at all—until the telltale tug sends her scurrying down one of the radial struts to sting the struggling insect before it frees itself and escapes? Are we really sure she doesn’t have even a faint and intermittent spark of consciousness?
We would guess that some rudimentary awareness flickers in the most humble creatures, and that with increasing neuronal architecture
and brain complexity, consciousness grows. “When a dog runs,” said the naturalist Jakob von Uexküll, “the dog moves his legs; when a sea urchin runs, the legs move the sea urchin.”
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But even in humans, thinking is often a subsidiary state of consciousness.
If it were possible to peer into the psyche of a spider or a goose, we might detect a kaleidoscopic progression of inclinations—and maybe some premonitions of conscious choice, actions selected from a menu of possible alternatives. What individual nonhuman organisms may perceive as their motivations, what they feel is happening inside their bodies, is for us one of the nearly inaudible counterpoints to the music of life.
When an animal goes out to seek food, it often does so according to a definite pattern. A random search is inefficient, because the path would turn back on itself many times; the same places would then be examined again and again. Instead, while the animal may dart off to left and right, the general search pattern is almost always progressive forward motion. The animal finds itself on new ground. The search for food becomes an exercise in exploration. A passion for discovery is hardwired. It’s something we like to do for its own sake, but it brings rewards, aids survival, and increases the number of offspring.
Perhaps animals are almost pure automatons—with urges, instincts, hormonal rushes, driving them toward behavior which in turn is carefully honed and selected to aid the propagation of a particular genetic sequence. Perhaps states of consciousness, no matter how vivid, are as Huxley suggested, “immediately caused by molecular changes in the brain substance.” But from the point of view of the animal, it must seem—as it does with us—natural, passionate, and occasionally even thought out. Perhaps a flurry of impulses and intersecting subroutines at times feels something like the exercise of free will. Certainly the animal cannot much have an impression of being impelled
against
its will. It voluntarily chooses to behave in the manner dictated by its contending programs. Mainly, it’s just following orders.
So when the days become long enough, it feels an unfocused restlessness, something like spring fever. It hasn’t thought through conception, gestation, the optimum season for the birth of the young and the continuance of its genetic sequences; all that is far beyond its
abilities. But from the inside it may well feel as though the weather is intoxicating, life is tempestuous, and moonlight becomes you.
——
We do not mean to be patronizing. The depth of understanding exhibited by our fellow creatures is of course limited. So is ours. We also are at the mercy of our feelings. We too are profoundly ignorant about what motivates us. Some of those beings have, as familiar aspects of their everyday lives, sensibilities wholly absent in humans. Other beings have different tastes and appreciations of the outside world—“To a worm in horseradish, the horseradish seems sweet,” as an old Yiddish folk adage has it. Beyond that, the horseradish worm lives in a world of smells, tastes, textures, and other sensations unknown to us.
Bumblebees detect the polarization of sunlight, invisible to uninstrumented humans; pit vipers sense infrared radiation and detect temperature differences of 0.01°C at a distance of half a meter; many insects can see ultraviolet light; some African freshwater fish generate a static electric field around themselves and sense intruders by slight perturbations induced in the field; dogs, sharks, and cicadas detect sounds wholly inaudible to humans; ordinary scorpions have micro-seismometers on their legs so they can detect in pitch darkness the footsteps of a small insect a meter away; water scorpions sense their depth by measuring the hydrostatic pressure; a nubile female silkworm moth releases ten billionths of a gram of sex attractant per second, and draws to her every male for miles around; dolphins, whales, and bats use a kind of sonar for precision echo-location.
The direction, range, amplitude, and frequency of sounds reflected back to echo-locating bats are systematically mapped onto adjacent areas of the bat brain. How does the bat perceive its echo-world? Carp and catfish have taste buds distributed over most of their bodies, as well as in their mouths; the nerves from all these sensors converge on massive sensory processing lobes in their brains, lobes unknown in other animals. How does a catfish view the world? What does it feel like to be inside its brain? There are reported cases in which a dog wags its tail and greets with joy a man it has never met before; he turns out to be the long-lost identical twin of the dog’s “master,” recognizable by his odor. What is the smell-world of a dog like? Magnetotactic
bacteria contain within them tiny crystals of magnetite—an iron mineral known to early sailing ship navigators as lodestone. The bacteria literally have internal compasses that align them along the Earth’s magnetic field. The great churning dynamo of molten iron in the Earth’s core—as far as we know, entirely unknown to uninstrumented humans—is a guiding reality for these microscopic beings. How does the Earth’s magnetism feel to them? All these creatures may be automatons, or nearly so, but what astounding special powers they have, never granted to humans, or even to comic book superheroes. How different their view of the world must be, perceiving so much that we miss.
Each species has a different model of reality mapped into its brain. No model is complete. Every model misses some aspects of the world. Because of this incompleteness, sooner or later there will be surprises—perceived, perhaps, as something like magic or miracles. There are different sensory modalities, different detection sensitivities, different ways the various sensations are integrated into a dynamic mental map of … a snake, say, in full hunting slither.
But Descartes was unimpressed. He wrote to the Marquis of Newcastle:
I know, indeed, that brutes do many things better than we do, but I am not surprised at it; for that, also, goes to prove that they act by force of nature and by springs, like a clock, which tells better what the hour is than our judgment can inform us.
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——
As life evolved, the repertoire of feelings expanded. Aristotle thought that “in a number of animals we observe gentleness or fierceness, mildness or cross-temper, courage or timidity, fear or confidence, high spirit or low cunning, and, with regard to intelligence, something equivalent to sagacity.”
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Emotions that Darwin argued are manifested by at least some mammals other than humans—chiefly dogs, horses, and monkeys—include pleasure, pain, happiness, misery, terror, suspicion, deceit, courage, timidity, sulkiness, good temper, revenge, selfless love, jealousy, hunger for affection and praise, pride, shame, modesty, magnanimity, and a sense of humor.
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And at some point, probably long before the first humans, a new set
of emotions—curiosity, insight, the pleasures of learning and teaching—also slowly emerged. Neuron by neuron, the partitions began to go up.
ARE ANIMALS MACHINES? FOUR VIEWS
A Seventeenth-Century View: Descartes:
[A]s you may have seen in the grottoes and the fountains in royal gardens, the force with which the water issues from its reservoir is sufficient to move various machines, and even to make them play instruments, or pronounce words according to the different disposition of the pipes which lead the water …
The external objects which, by their mere presence, act upon the organs of the senses; and which, by this means, determine the corporal machine to move in many different ways, according as the parts of the brain are arranged, are like the strangers who, entering into some of the grottoes of these waterworks, unconsciously cause the movements which take place in their presence. For they cannot enter without treading upon certain planks so arranged that, for example, if they approach a bathing Diana, they cause her to hide among the reeds; and if they attempt to follow her, they see approaching a Neptune, who threatens them with his trident; or if they try some other way, they cause some other monster, who vomits water into their faces, to dart out; or like contrivances, according to the fancy of the engineers who have made them. And lastly, when the
rational soul
is lodged in this-machine, it will have its principal seat in the brain, and will take the place of the engineer, who ought to be in that part of the works with which all the pipes are connected, when he wishes to increase, or to slacken, or in some way to alter their movements …
All the functions which I have attributed to this machine (the body), as the digestion of food, the pulsation of the heart and of the arteries; the nutrition and the growth of the limbs; respiration, wakefulness, and sleep; the reception of light, sounds,
odours, flavours, heat, and such like qualities, in the organs of the external senses; the impression of the ideas of these in the organ of common sense and in the imagination; the retention, or the impression, of these ideas on the memory; the internal movements of the appetites and the passions; and lastly, the external movements of all the limbs, which follow so aptly, as well as the action of the objects which are presented to the senses, as the impressions which meet in the memory, that they imitate as nearly as possible those of a real man: I desire, I say, that you should consider that these functions in the machine naturally proceed from the mere arrangement of its organs, neither more nor less than do the movements of a clock, or other automaton, from that of its weights and its wheels; so that, so far as these are concerned, it is not necessary to conceive any other vegetative or sensitive soul, nor any other principle of motion, or of life.
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An Eighteenth-Century View: Voltaire:
What a pitiful, what a sorry thing to have said that animals are machines bereft of understanding and feeling, which perform their operations always in the same way, which learn nothing, perfect nothing, etc.!
What! that bird which makes its nest in a semi-circle when it is attaching it to a wall, which builds it in a quarter circle when it is in an angle, and in a circle upon a tree; that bird acts always in the same way? That hunting-dog which you have disciplined for three months, does it not know more at the end of this time than it knew before your lessons? Does the canary to which you teach a tune repeat it at once? Do you not have to spend a considerable time in teaching it? Have you not seen that it has made a mistake and that it corrects itself?
Is it because I speak to you, that you judge that I have feeling, memory, ideas? Well, I do not speak to you; you see me going home looking disconsolate, seeking a paper anxiously, opening the desk where I remember having shut it, finding it, reading it joyfully. You judge that I have experienced the feeling of distress and that of pleasure, that I have memory and understanding.
Bring the same judgment to bear on this dog which has lost its master, which has sought him on every road with sorrowful cries,
which enters the house agitated, uneasy, which goes down the stairs, up the stairs, from room to room, which at last finds in his study the master it loves, and which shows him its joy by its cries of delight, by its leaps, by its caresses.
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A Nineteenth-Century View: Huxley:
Consider what happens when a blow is aimed at the eye. Instantly, and without our knowledge or will, and even against the will, the eyelids close. What is it that happens? A picture of the rapidly-advancing fist is made upon the retina at the back of the eye. The retina changes this picture into an affection of a number of the fibres of the optic nerve; the fibres of the optic nerve affect certain parts of the brain; the brain, in consequence, affects those particular fibres of the seventh nerve which go to the orbicular muscle of the eyelids; the change in these nerve-fibres causes the muscular fibres to alter their dimensions, so as to become shorter and broader; and the result is the closing of the slit between the two lids, round which these fibres are disposed. Here is a pure mechanism, giving rise to a purposive action, and strictly comparable to that by which Descartes supposes his waterwork Diana to be moved. But we may go further, and inquire whether our volition, in what we term voluntary action, ever plays any other part than that of Descartes’ engineer, sitting in his office, and turning this tap or the other, as he wishes to set one or another machine in motion, but exercising no direct influence upon the movements of the whole …
Descartes pretends that he does not apply his views to the human body, but only to an imaginary machine which, if it could be constructed, would do all that the human body does; throwing a sop to Cerberus unworthily; and uselessly, because Cerberus was by no means stupid enough to swallow it …
… [W]hat living man, if he had unlimited control over all the nerves supplying the mouth and larynx of another person, could make him pronounce a sentence? Yet, if one has anything to say, what is easier than to say it? We desire the utterance of certain words: we touch the spring of the word-machine, and they are spoken. Just as Descartes’ engineer, when he wanted a particular hydraulic machine to play, had only to turn a tap, and what he wished was done. It is because the body is a machine that education
is possible. Education is the formation of habits, a superinducing of an artificial organisation upon the natural organisation of the body; so that acts, which at first required a conscious effort, eventually became unconscious and mechanical. If the act which primarily requires a distinct consciousness and volition of its details, always needed the same effort, education would be an impossibility.
According to Descartes, then, all the functions which are common to man and animals are performed by the body as a mere mechanism, and he looks upon consciousness as the peculiar distinction of the
“chose pensante,”
of the “rational soul,” which in man (and in man only, in Descartes’ opinion) is superadded to the body. This rational soul he conceived to be lodged in the pineal gland, as in a sort of central office; and here, by the intermediation of the animal spirits, it became aware of what was going on in the body, or influenced the operations of the body. Modern physiologists do not ascribe so exalted a function to the little pineal gland, but, in a vague sort of way, they adopt Descartes’ principle, and suppose that the soul is lodged in the cortical part of the brain—at least this is commonly regarded as the seat and instrument of consciousness.
.. [T]hough we may see reason to disagree with Descartes’ hypothesis that brutes are unconscious machines, it does not follow that he was wrong in regarding them as automata. They may be more or less conscious, sensitive, automata; and the view that they are such conscious machines is that which is implicitly, or explicitly, adopted by most persons. When we speak of the actions of the lower animals being guided by instinct and not by reason, what we really mean is that, though they feel as we do, yet their actions are the results of their physical organisation. We believe, in short, that they are machines, one part of which (the nervous system) not only sets the rest in motion, and co-ordinates its movements in relation with changes in surrounding bodies, but is provided with special apparatus, the function of which is the calling into existence of those states of consciousness which are termed sensations, emotions, and ideas. I believe that this generally accepted view is the best expression of the facts at present known.
… It is quite true that, to the best of my judgment, the argumentation
which applies to brutes holds equally good of men; and, therefore, that all states of consciousness in us, as in them, are immediately caused by molecular changes of the brain-substance. It seems to me that in men, as in brutes, there is no proof that any state of consciousness is the cause of change in the motion of the matter of the organism. If these positions are well based, it follows that our mental conditions are simply the symbols in consciousness of the changes which take place automatically in the organism; and that, to take an extreme illustration, the feeling we call volition is not the cause of a voluntary act, but the symbol of that state of the brain which is the immediate cause of that act. We are conscious automata …
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A Twentieth-Century View: James L. and Carol G. Gould:
In considering the issue of mental experiences in animals, we have begun to wonder if the implicit assumption that humans are almost wholly conscious and aware (and hence fully competent to evaluate our cognitively less sophisticated animal brethren) is correct. Could it be that the degree to which conscious thinking is involved in the everyday lives of most people is greatly overestimated? We know already that much of our learned behavior becomes hardwired: despite the painfully difficult process of learning the task originally, who has to concentrate consciously as an adult on how to walk or swim, tie a shoe, write words, or even drive a car along a familiar route? Certain linguistic behavior, too, falls into such patterns. Michael Gazzaniga, for instance, tells the story of a former physician who suffered from a left (linguistic) hemisphere lesion so serious that he could not form even simple three-word sentences. And yet, when a certain highly touted but ineffective patent medicine was mentioned, he would launch into a well-worn and perfectly grammatical five-minute tirade on its evils. This set piece had been stored on the undamaged right side (along with the usual collection of songs, poetry, and epigrams) as a motor tape requiring no conscious linguistic manipulation to deliver.
… Indeed, what evidence is there that those sublime intellectual events known as “inspiration” involve any conscious thought? Most often our best ideas are served up to us out of our
unconscious while we are thinking or doing something perfectly irrelevant. Inspiration probably depends on some sort of repetitive and time-consuming pattern-matching program which runs imperceptibly below the level of consciousness searching for plausible matches.
It strikes us that a skeptical and dispassionate extraterrestrial ethologist studying our unendearing species might reasonably conclude that
Homo sapiens
are, for the most part, automatons with overactive and highly verbal public relations departments to apologize for and cover up our foibles.
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