The mind does not understand its own reason for being.
—René Magritte
A picture without a frame is not a picture.
—John Archibald Wheeler
Perhaps you’ve seen the painting: A pipe, depicted with photographic realism, floats above a line of careful, schoolboy script that reads Ceci nest pas une pipe—.” This is not a pipe.” Rene Magritte painted it in the 1920s, and people have been talking ever since about what it means.
Did Magritte intend to remind us that a representation is not the object it depicts—that his painting is “only” a painting and not a pipe? Such an interpretation is widely taught to undergraduates, but if it is true, Magritte went to an awful lot of trouble—carefully selecting a dress-finish pipe of particularly elegant design, making dozens of sketches of it, taking it apart to familiarize himself with its anatomy, then painting its portrait with great care and skill—just to tell us something we already knew. After all, nobody really confuses paintings with reality, and the danger that people will try to smoke paintings of pipes or eat paintings of pears does not rank high among the hazards confronting the working artist.
Perhaps it was with an eye toward discouraging simplistic explanations of his famous pipe that Magritte returned to the same motif toward the end of his career. In The Air and the Song, painted in 1964, just three years before Magritte’s death, the pipe is found inside a representation of an elaborate, carved frame, as if to emphasize that it is only a painting—yet smoke from its bowl billows up out of the painted “frame”! In another canvas, The Two Mysteries, Magritte is even more insistent: The original pipe painting, complete with caption, is depicted as sitting on an easel that rests on a plank floor; but above it to the left hovers a second pipe, larger (or closer) than the painted canvas and its frame. What we have here is a painting of a paradox. Obviously the smaller pipe is a painting and not a pipe. But what is the second pipe, the one that looms outside the represented canvas? And if that, too, is but a painting, then where does the painting end?
We’ve been set on the road to infinite regress. Suppose, for instance, that Magritte had glued a real pipe to the actual frame of The Two Mysteries: Would the genuine pipe qualify as a pipe, or did it become something else once Magritte affixed it to the frame? (The same riddle is posed by Andy Warhol’s Brillo Pad boxes, which are indistinguishable from the Brillo boxes on sale in any supermarket. Had Warhol captioned one with the words, “This is not a Brillo Box,” would the caption be true or false?)
It seems to me that the roots of the paradox reside in the concept of the frame. When we look at a realistic painting—Raphael’s portrait of Pope Leo X and his nephews, say, or Breughel’s Peasant Wedding—we accept by convention that it represents real people and actual objects. When that convention is denied, as in Magritte’s pipe paintings or in the many impossible scenes depicted by his fellow surrealists—locomotives emerging from fireplaces, clocks limp as jellyfish—the point is not to remind us that paintings are not real. That much is true, but trivial. The point is to challenge the belief that everything outside the frame is real.
The enemy of surrealists like Magritte, and of artists generally, is naive realism—the dogged assumption that the human sensory apparatus accurately records the one and only real world, of which the human brain can make but one accurate model. To the naive realist, every view that does not fit the official model is dismissed as imaginary (for those who “know” that they err when they entertain contradictory ideas) or insane (for those who don’t). Naive realism is flattering—to set one’s self up as the sole judge of what is actual is to taste the delights of godlike power—but it is also stultifying. Once the realist settles on a single representation of reality, the gate slams shut behind him, and he is doomed to live thereafter in the universe to which he has pledged allegiance. This universe may be elegant and adamantine as the Taj Mahal, but it is a prison nonetheless, and the prisoner’s spirit, if it is still awake, will beat its wings against the bars until it weakens and dies.
The truth, of course, is that nobody can grasp reality whole, that each person’s universe is to some extent unique, and that this circumstance makes it impossible for us to prove that there is but one true reality. Even if we could free ourselves from fantasy and delusion (not that to do so would necessarily be a good idea), we could at most agree upon small swatches of reality. Everything thus is framed, cut from its cosmic context by the limitations and peculiarities of our sensory apparatus, the prejudices of our presuppositions, the multiplicity of each individual mind, and the restrictions of our language. We may feel more comfortable with our own frame of reference than with that of others, and assume it to be more valid, but the frames are there nonetheless. There’s no escaping them; the known universe is and always will be in some sense a creation of our (hopefully creative) minds. Magritte made this point overtly in a 1933 painting. It depicts a canvas on an easel that records every detail of the view outside the window it partially obscures, right down to the drifting cumulus clouds. He titled this work The Human Condition,
If modern artists have labored to call attention to the fact that our understanding of reality is limited and variegated, so too have modern scientists. Many people are surprised to hear this. They think of science as a collection of hard facts mined from bedrock reality, through a process as uncreative as coin collecting. The scientists, however, have come to know better. Astronomers understand that each act of observation—photographing of a galaxy, taking an ultraviolet spectrum of an exploding star—extracts but a small piece of the whole, and that a montage of many such images is still only a representation, a painting if you will. The quantum physicists go further: They appreciate that the answers they obtain through experiment depend to a significant degree on the questions they ask, so that an electron, asked if it is a particle or a wave, will answer “Yes” to both questions. (I will say more about this in the final chapter of this book.) Neuroscientists studying the other side of the mind-nature dialogue have learned that the brain is no monolith, either. Each of us harbors many intelligences, and insofar as my various minds take varying views of reality—in terms, say, of spatial relationships versus language, or of sentimental versus rational education—I can no more legitimately impose a single model on myself than I can expect to impose it on others.
This is not to say that every opinion about the universe deserves equal attention—as if schoolteachers, in much the same way as they are being urged by fundamentalists to teach biblical creation myths alongside Darwinism, should also be enjoined to give equal weight to the flat-earth theory, ESP, or the notion that little Sally in the back row was empress dowager of China in a former life. That no one theory of the universe can deservedly gain permanent hegemony does not mean that all theories are equally valid. On the contrary: To understand the limitations of science (and art, and philosophy) can be a source of strength, emboldening us to renew our search for the objectively real even though we understand that the search will never end. I often reflect on a remark made to me one evening over dinner in a Padua restaurant by the English astrophysicist Dennis Sciama, teacher of Roger Penrose and Stephen Hawking. “The world is a fantasy,” Sciama remarked, “so let’s find out about it.” To me, that heroic statement encapsulates the spirit of science: to seek to learn something while accepting that one will never know everything.
Science is young—it has been a going concern for only about three hundred years, and the word scientist itself was unknown before about 1825—yet it has already transformed our world view. Thanks to science, educated men and women can contemplate an astonishing array of invigorating facts—that we are kin to the animals, that the tenure of our species has amounted to but a moment compared to the age of the earth, that the sun is one star among many, and that seemingly solid objects are themselves as empty as cosmic space, strewn with atoms lonely as stars.
Owing to its great prestige, however, science often is given credit for understanding more than it really does about what things really are. Actually, science seldom has much to say about what something “is.” Science studies and predicts phenomena, not essences, and to attempt to use it to assert, for instance, that living organisms “are” machines is to choose the wrong tool to do the job. A scientific theory provides a model that enables us to reason about unfamiliar phenomena by translating them into terms with which we are familiar. It is a kind of language, and as such itself exemplifies the dialogue between mind and nature.
To clarify what I mean, consider that science rests on a tripod whose legs are hypothesis, observation, and faith.
A scientific hypothesis (which aspires to become a theory, which if extraordinarily successful and far-reaching might attain the status of a law) begins as an idea about how something works. A scientist may come up with a hypothesis more or less inductively, by working with raw data for many days or years before it occurs to her. That’s the hard way, much esteemed by the work-ethic Victorians: it’s more or less how Darwin arrived at his theory of evolution, which is one reason that the Victorians found it impossible to dismiss Darwin even though many were repelled by his idea that we share an ancestor with the apes and chimps. Alternately, a hypothesis may arise suddenly and intuitively. That’s more romantic, and we tend to lionize “pure” theorists like Richard Feynman, who got a Nobel Prize for a line of thought that began when he was idly watching a waiter toss a plate in the air in a cafeteria, or Stephen Hawking, a victim of paralysis who thought up his theory of black hole evaporation while his nurse was putting him to bed. But chance, as Pasteur said, favors the prepared mind; the theorist may work with only a pencil and paper, but she is immersed in her field of research, and that field in turn depends on the work of the experimentalists.
Scientific ideas live or die by the verdict of observation. An observation may be overtly intrusive, as when a physicist slams clouds of protons together in a particle accelerator, or relatively passive, as when an astronomer takes the spectrum of a star to learn its chemical composition. In either case the goal is to obtain objectively reliable data. By “objectively reliable” I mean that the result should be replicable: Another experimenter, using another particle accelerator or telescope, should achieve essentially the same result.
Precisely because observation is so important, we need to appreciate its limits.
The most conspicuous of these is observational error. It’s easy to make a mistake when measuring, say, the velocity of a faint galaxy near the edge of the observable universe, or differences in the thickness of cortical tissue in laboratory rats that have been raised in enriched and deprived environments. In practice, the observer relies to some extent on the guidance of a promising theory that predicts what he ought to find, even though this may mean disregarding at least some data that contradict a persuasive theory. Albert Einstein ignored the results of an early experiment that seemed to invalidate the special theory of relativity. Einstein happened to be right in this instance (the experimental data were wrong) but there are obvious dangers in leaning too heavily on theory—in discarding, as “noise,” those data that deny a theory while retaining, as “signal,” those that confirm it. In practice one keeps muddling along, experimenting and observing, hoping that the truth will emerge.
Or hope that part of the truth will emerge, given that the universe is vast and the conclusions of scientific theories and observations almost absurdly narrow. This nasty little fact often gets overlooked in popular accounts that stress the grandeur of the scientific world view. Science does not customarily pose big questions. It poses small questions. As the thermodynamicist Ludwig Boltzmann put it:
The scientist asks not what are the currently most important questions, but “which are at present solvable?” or sometimes merely “in which can we make some small but genuine advance?” As long as the alchemists merely sought the philosopher’s stone and aimed at finding the art of making gold, all their endeavors were fruitless; it was only when people restricted themselves to seemingly less valuable questions that they created chemistry. Thus’ natural science appears completely to lose from sight the large and general questions.
Yet it is by such peephole-squinting that science, more than any other discipline, has cast fresh light on the big questions. Research into the family relationships of subatomic particles has produced insights into the early evolution of the entire universe, while studies of the chemistry of radioactive isotopes have made it possible to age-date moon rocks and pre-Columbian Indian campsites. Boltzmann again: “But all the more splendid is the success when, groping in the thicket of special questions, we suddenly find a small opening that allows a hitherto undreamt of outlook on the whole.” Never more resoundingly than in modern science have we seen demonstrated the truth of Lao Tzu’s and Jesus’ dictum that the great and transcendent is to be found in the small and ordinary.
What one gets from science, generally speaking, are relations. Ask a particle physicist what happens when a quark is knocked out of a proton, and she will tell you without hesitation that the result will most likely be the creation of a meson. Ask her what a quark is, however, and the only genuinely honest answer will be no answer at all. (Or, perhaps, a relational answer—”Quarks are the building blocks of hadrons”—which defines these particles in terms of other particles.) Ask an astronomer what a star “is,” and the result will be similarly unsatisfying if viewed from the old metaphysical perspective: The astronomer is likely to explain “star” in terms of its relationship to other astronomical bodies, or merely to offer a definition, which by definition will say more about the word than the star. (“A star is a celestial object massive and dense enough for thermonuclear process to have taken place at its core.”) Science is silent about the essences of quark-ness or star-ness.
Lost, too, is the comfort of absolute certitude. The philosophers of old could claim with assurance to have discovered exactly how nature works; they did not have to worry about contradictory experimental results, and in any event their formulations typically were too vague to be wrong. Scientists today enjoy no such luxury. They must live with the knowledge that even their most esteemed theories may in the long run turn out to be flawed. The philosopher of science Karl Popper made this point when he argued that no observation can prove a theory true, but can at best permit it to survive until it is tested again.
What science does, then, is to construct mental models of natural processes. These models must make sense; it is the faith of science that nature is rationally intelligible. The models should be efficient; the scientist believes that nature, given the choice, will elect a simple, economical process over a complex and inefficient one. The models should also have predictive power, which is another way of saying that they should remain vulnerable to disproof by observation.
What has all this to do with Magritte’s pipe? Just this: that each act of observation, and each scientific model based on observation, puts a frame around a piece of nature. We may then extrapolate, projecting the model onto a larger screen. We are encouraged if it holds up (every star and planet ever observed obeys Newton’s and Kepler’s laws) but our belief in the model remains forever tentative (Newton’s and Kepler’s laws fail inside black holes). The model is not reality; it is but a painting, and it has a frame.
The tendency to put imaginary frames around things is not unique to science. We all do it all the time, usually without thinking about it. Here is a little puzzle that illustrates what I mean. Try to connect all nine dots, using only four straight lines, without retracing or lifting up your pencil.
Most people have trouble with this riddle until they are given a hint—that the straight line may extend beyond the box described by the dots. The problem is that we automatically and often arbitrarily frame the problem. Often that helps, but in this case it makes the puzzle harder to solve.
The way we interpret a physical process can similarly be altered by the size of the frame we put around it. Suppose we view a videotape showing an area one inch square. On the tape we see a wooden hammer striking a wire and producing sound waves in the surrounding air. We would be inclined to describe this process as strictly deterministic: There is a cause, the hammer blow, and an effect, the sound waves. Now pull the camera back, enlarging the reference frame, and we see that the hammer is one of eighty-eight in a piano. Now the process begins to look voluntary; we assume the piano is being played by a pianist, who can choose to play whatever she wants. Pull back farther, though, and we see that it’s a player piano: The keys are being struck not by a pianist but by a machine. The system looks deterministic again. Pull back farther still, in time as well as space, and we see a composer writing a piece for the player piano; now the situation looks volitional once more.
Never is the danger of distortion greater than when we extrapolate from a limited reference frame to the infinite universe. Yet all cosmological models do just that, and all, therefore, should be taken with a grain of salt. (Or with a trainload of salt, which is about enough salt grains to equal the number of stars in the Milky Way galaxy.) A cosmologist can describe the shape of the universe in terms of a few numbers—the Friedmann-Robertson-Walker metric, for instance—and if in a rash mood may declare: “There! That is the universe.” But it is not. It is at best only one cut through the universe, and a paper-thin cut at that. The real universe glides on about its business, without stopping to read the scientific journals.
Outside our frame of reference forever hovers something else—the larger reality, embracing every bird’s egg and mud puddle, every star and planet, every poem and crime in the gigantic and eternally incomprehensible universe. This—this equation, this theory, the finest model concocted by the wisest mind in the universe, or the sum total of all the scientific models, and all the artistic and philosophical ones, too—this is not the universe.
The other night I had a dream about frames. In the dream, a man and his wife, on a stroll near the outskirts of a small town, stop to look into the window of a dusty antiques shop. The man becomes fascinated by an odd object he sees in the window: It is a model of a cottage, fashioned painstakingly if inexpertly with tiny individual slate tiles on the roof, checked curtains at the windows, a painted front door with brass knocker and keyhole. A figurine of a man is kneeling at the stoop, peeking through the keyhole at a couple who are sitting inside by a fire, she knitting, he reading a newspaper.
The man tries to interest his wife in buying this little model. She’s not interested. Over her objections, the husband takes her into the shop and asks the price. He is told the cottage is not for sale. The husband presses the shop owner to name a price, but the old man won’t budge. The couple leaves. Over lunch they quarrel about his insistence on buying the toy cottage. She goes back to their hotel. He returns to the antique shop and finds it closed.
The early afternoon sun bakes the empty street. Water trickles from a fire hydrant valve that has been left slightly ajar, a wrench still affixed to the bolt on top. The man knocks on the shop door but there is no reply. After pondering the situation for a few moments, he removes the wrench from the fire hydrant and throws it through the shop window. A burglar alarm goes off. The man steps up through the shattered window and reaches for the model of the cottage.
A police patrolman in a blue serge uniform arrives to investigate the alarm. He finds the window intact and unbroken. The wrench is on the fire hydrant; the policeman tightens it to stop the trickle of water, then pockets the wrench. He rattles the doorknob on the front door of the shop and the alarm stops ringing. He looks in the window, and his eyes come to rest on the little cottage. He bends down to look more closely. Inside the cottage, instead of the couple, now sits the figure of a solitary man. Kneeling outside the front door, peering through the keyhole, is a figurine of a policeman in a blue serge uniform.
A psychiatrist might place other interpretations on it, and I wouldn’t argue with them, but to my way of thinking this is a dream about how the mind frames its relationship with the wider universe. We look through a peephole at nature, as Boltzmann said, and interpret the whole in terms of what little we have been able to see. But we, too, are part of the whole—and we, like the universe, are more than the sum of the observations made of us. All swim in an ocean of enigma. “Science cannot solve the ultimate mystery of Nature,” wrote Max Planck, the founder of quantum physics. “And it is because in the last analysis we ourselves are part of the mystery we are trying to solve.”
The artists have long understood this. “When I look at my work I think I’m in the heart of mystery and there’s nothing in the world which can explain it,” Magritte said. He added, on another occasion, that “the feeling we experience while we look at a picture is not to be distinguished from the picture or from ourselves. The feeling, the picture, and ourselves are united in our mystery.” Magritte’s words are echoed by the American physicist and philosopher of science John Archibald Wheeler, who writes, “The vision of the universe that is so vivid in our minds is framed by a few iron posts of true observation—themselves resting on theory for their meaning—but most of the walls and towers in the vision are of papier-mâché, plastered in between those posts by an immense labor of imagination and theory.”
We are confronted, then, not with the universe, which remains an eternal riddle, but with whatever model of the universe we can build within the mind. Every thinking creature in the universe shares this predicament; for all, the ultimate subject of inquiry is not the outer universe but the nature of its dance with the mind. In searching for signs of extraterrestrial intelligence, our aim is to better understand the dance by learning how others dance. We hope to widen our perspective, to broaden the base of our perceptions and analysis, to improve the little universes of mind and make them answer more smartly to the vast whole. And what is the emblem of a sound mind, if not conformance between the inner model and the outer reality? What we seek among the stars is sanity.