by Sam Kean
Dennett waited until the group talked itself into a muddle, then broke in. He speaks slowly, melodiously, in the confident tones of a man with answers. When he uses philosophical lingo, his voice goes deeper, as if he were distancing himself from it. “The big mistake we’re making,” he said, “is taking our congenial, shared understanding of what it’s like to be us, which we learn from novels and plays and talking to each other, and then applying it back down the animal kingdom. Wittgenstein”—he deepened his voice—“famously wrote, ‘If a lion could talk, we couldn’t understand him.’ But no! If a lion could talk, we’d understand him just fine. He just wouldn’t help us understand anything about lions.”
“Because he wouldn’t be a lion,” another researcher said.
“Right,” Dennett replied. “He would be so different from regular lions that he wouldn’t tell us what it’s like to be a lion. I think we should just get used to the fact that the human concepts we apply so comfortably in our everyday lives apply only sort of to animals.” He concluded, “The notorious zombie problem is just a philosopher’s fantasy. It’s not anything that we have to take seriously.”
“Dan, I honestly get stuck on this,” a primate psychologist said. “If you say, well, rocks don’t have consciousness, I want to agree with you”—but he found it difficult to get an imaginative grip on the idea of a monkey with a “sort of” mind.
If philosophy were a sport, its ball would be human intuition. Philosophers compete to shift our intuitions from one end of the field to the other. Some intuitions, however, resist being shifted. Among these is our conviction that there are only two states of being: awake or asleep, conscious or unconscious, alive or dead, soulful or material. Dennett believes that there is a spectrum, and that we can train ourselves to find the idea of that spectrum intuitive.
“If you think there’s a fixed meaning of the word consciousness, and we’re searching for that, then you’re already making a mistake,” Dennett said.
“I hear you as skeptical about whether consciousness is useful as a scientific concept,” another researcher ventured.
“Yes, yes,” Dennett said.
“That’s the ur-question,” the researcher replied. “Because, if the answer’s no, then we should really go home!”
“No, no!” Dennett exclaimed, as the room erupted into laughter. He’d done it again: in attempting to explain consciousness, he’d explained it away.
In the nineteenth century, scientists and philosophers couldn’t figure out how nonliving things became living. They thought that living things possessed a mysterious life force. Only over time did they discover that life was the product of diverse physical systems that, together, created something that appeared magical. Dennett believes that the same story will be told about consciousness. He wants to tell it, but he sometimes wonders if others want to hear it.
“The person who tells people how an effect is achieved is often resented, considered a spoilsport, a party-pooper,” he wrote, around a decade ago, in a paper called “Explaining the ‘Magic’ of Consciousness.” “If you actually manage to explain consciousness, they say, you will diminish us all, turn us into mere protein robots, mere things.” Dennett does not believe that we are “mere things.” He thinks that we have souls, but he is certain that those souls can be explained by science. If evolution built them, they can be reverse-engineered. “There ain’t no magic there,” he told me. “Just stage magic.”
It’s possible to give an account of Dennett’s life in which philosophy hardly figures. He is from an old Maine family. By the turn of the eighteenth century, ancestors of his had settled near the border between Maine and New Hampshire, at a spot now marked by Dennett Road. Dennett and his wife, Susan, live in North Andover, Massachusetts, a few minutes’ drive from Tufts, where Dennett co-directs the Center for Cognitive Studies. But, in 1970, they bought a 200-acre farm in Blue Hill, about five hours north of Boston. The Dennetts are unusually easygoing and sociable, and they quickly became friends with the couple next door, Basil and Bertha Turner. From Basil, Dennett learned to frame a house, shingle a roof, glaze a window, build a fence, plow a field, fell a tree, butcher a hen, dig for clams, raise pigs, fish for trout, and call a square dance. “One thing about Dan—you don’t have to tell him twice,” Turner once remarked to a local mechanic. Dennett still cherishes the compliment.
In the course of a few summers, he fixed up the Blue Hill farmhouse himself, installing plumbing and electricity. Then, for many years, he suspended his academic work during the summer in order to devote himself to farming. He tended the orchard, made cider, and used a Prohibition-era still to turn the cider into Calvados. He built a blueberry press, made blueberry wine, and turned it into aquavit. “He loves to hand down word-of-mouth knowledge,” Steve Barney, a former student who has become one of the Dennetts’ many “honorary children,” says. “He taught me how to use a chain saw, how to prune an apple tree, how to fish for mackerel, how to operate a tractor, how to whittle a wooden walking stick from a single piece of wood.” Dennett is an avid sailor; in 2003, he bought a boat, trained his students to sail, and raced with them in a regatta. Dennett’s son, Peter, has worked for a tree surgeon and a fish biologist, and has been a white-water-rafting guide; his daughter, Andrea, runs an industrial-plumbing company with her husband.
A few years ago, the Dennetts sold the farm to buy a nearby waterfront home, on Little Deer Isle. On a sunny morning this past December, fresh snow surrounded the house; where the lawn met the water, a Hobie sailboat lay awaiting spring. Dennett entered the sunlit kitchen and, using a special, broad-tined fork, carefully split an English muffin. After eating it with jam, he entered his study, a circular room on the ground floor decorated with sailboat keels of different shapes. A close friend and Little Deer Isle visitor, the philosopher and psychologist Nicholas Humphrey, had emailed a draft of an article for Dennett to review. The two men are similar—Humphrey helped discover blindsight, studied apes with Dian Fossey, and was, for a year, the editor of Granta—but they differ on certain points in the philosophy of consciousness. “Until I met Dan,” Humphrey told me, “I never had a philosophical hero. Then I discovered that not only was he a better philosopher than me; he was a better singer, a better dancer, a better tennis player, a better pianist. There is nothing he does not do.”
Dennett annotated the paper on his computer and then called Humphrey on his cell phone to explain that the paper was so useful because it was so wrong. “I see how I can write a reaction that is not so much a rebuttal as a rebuilding on your foundations,” he said, mischievously. “Your exploration has helped me see some crucial joints in the skeleton. I hope that doesn’t upset you!” He laughed and invited Humphrey and his family to come over later that day.
He then turned to a problem with the house. Something was wrong with the landline; it had no dial tone. The key question was whether the problem lay with the wiring inside the house or with the telephone lines outside. Picking up his walking stick and a small plastic telephone, he went out to explore. Dennett has suffered a heart attack and an aortic dissection; he is robust but walks slowly and is sometimes short of breath. Carefully, he made his way to a little gray service box, pried it open using a multitool, and plugged in the handset. There was no dial tone; the problem was in the outside phone lines. Harrumphing, he glanced upward to locate them: another new joint in the skeleton.
During the course of his career, Dennett has developed a way of looking at the process by which raw matter becomes functional. Some objects are mere assemblages of atoms to us and have only a physical dimension; when we think of them, he says, we adopt a “physicalist stance”—the stance we inhabit when, using equations, we predict the direction of a tropical storm. When it comes to more sophisticated objects, which have purposes and functions, we typically adopt a “design stance.” We say that a leaf’s “purpose” is to capture energy from sunlight, and that a nut and bolt are designed to fit together. Finally, there are objects that seem to ha
ve beliefs and desires, toward which we take the “intentional stance.” If you’re playing chess with a chess computer, you don’t scrutinize the conductive properties of its circuits or contemplate the inner workings of its operating system (the physicalist and design stances, respectively); you ask how the program is thinking, what it’s planning, what it “wants” to do. These different stances capture different levels of reality, and our language reveals which one we’ve adopted. We say that proteins fold (the physicalist stance), but that eyes see (the design stance). We say that the chess computer “anticipated” our move, that the driverless car “decided” to swerve when the deer leaped into the road.
Later, at a rickety antique table in the living room, Dennett taught me a word game he’d perfected called Frigatebird. Real frigate birds swoop down to steal fish from other birds; in Frigatebird, you steal words made of Scrabble tiles from your opponents. To do so, you use new letters to transform their stems: you can’t steal “march” by making “marched,” but you can do it by making “charmed.” As we played, I tried to attend to the workings of my own mind. How did I know that I could use the letters “u,” “t,” and “o” to transform Dennett’s “drain” into “duration”? I couldn’t quite catch myself in the act of figuring it out. To Dennett, this blindness reflects the fact that we take the intentional stance toward ourselves. We experience ourselves at the level of thoughts, decisions, and intentions; the machinery that generates those higher-order properties is obscured. Consciousness is defined as much by what it hides as by what it reveals. Over two evenings, while drinking gin on the rocks with a twist—a “sort of” cocktail—we played perhaps a dozen games of Frigatebird, and I lost every time. Dennett was patient and encouraging (“You’re getting the hang of it!”), even as he transformed my “quest” into “equations.”
A running joke among people who study consciousness is that Dennett himself might be a zombie. (“Only a zombie like Dennett could write a book called ‘Consciousness Explained’ that doesn’t address consciousness at all,” the computer scientist Jaron Lanier has written.) The implicit criticism is that Dennett’s account of consciousness treats the self like a computer and reflects a disengagement from things like feeling and beauty. Dennett seems wounded by this idea. “There are those wags who insist that I was born with an impoverished mental life,” he told me. “That ain’t me! I seem to be drinking in life’s joys pretty well.”
Dennett’s full name is Daniel Clement Dennett III. He was born in Boston in 1942. His father, Daniel C. Dennett, Jr., was a professor of Islamic history who, during the Second World War, was recruited by the Office of Strategic Services and became a secret agent. Dennett spent his early childhood in Beirut, where his father posed as a cultural attaché at the American Embassy. In Beirut, he had a pet gazelle named Babar and learned to speak some Arabic. When he was five, his father was killed in an unexplained plane crash while on a mission in Ethiopia. In Dennett’s clearest memory of him, they’re driving through the desert in a Jeep, looking for a group of Bedouins; when they find the camp, some Bedouin women take the young Dennett aside and pierce his ears. (The scars are still visible.)
After his father’s death, Dennett returned to the Boston suburbs with his mother and his two sisters. His mother became a book editor; with some guidance from his father’s friends, Dennett became the man of the house. He had his own workshop and, aged six, used scraps of lumber to build a small table and chair for his Winnie-the-Pooh. As he fell asleep, he would listen to his mother play Rachmaninoff’s Piano Prelude No. 6 in E-Flat Major. Today, the piece moves him to tears—“I’ve tried to master it,” he says, “but I could never play it as well as she could.” For a while, Dennett made money playing jazz piano in bars. He also plays the guitar, the acoustic bass, the recorder, and the accordion, and can still sing the a-cappella tunes he learned, in his twenties, as a member of the Boston Saengerfest Men’s Chorus.
As a Harvard undergraduate, Dennett wanted to be an artist. He pursued painting, then switched to sculpture; when he met Susan, he told her that she had nice shoulders and asked if she would model for him. (She declined, but they were married two years later.) A photograph taken in 1963, when Dennett was a graduate student, shows him trim and shirtless in a courtyard in Athens, smoking a pipe as he works a block of marble. Although he succeeded in exhibiting some sculptures in galleries, he decided that he wasn’t brilliant enough to make a career in art. Still, he continued to sculpt, throw pots, build furniture, and whittle. His whittlings are finely detailed; most are meant to be handled. A life-sized wooden apple comes apart, in cross-sections, to reveal a detailed stem and core; a fist-sized nut and bolt turn smoothly on minute, perfectly made threads. (Billed as “haptic sculptures,” the whittles are currently on display at Underdonk, a gallery in Brooklyn.)
Dennett studied philosophy as an undergraduate with W. V. O. Quine, the Harvard logician. His scientific awakening came later, when he was a graduate student at Oxford. With a few classmates, he found himself debating what happens when your arm falls asleep. The others were discussing the problem in abstract, philosophical terms—“sensation,” “perception,” and the like—which struck Dennett as odd. Two decades earlier, the philosopher Gilbert Ryle, Dennett’s dissertation adviser, had coined the phrase “the ghost in the machine” to mock the theory, associated with René Descartes, that our physical bodies are controlled by immaterial souls. The other students were talking about the ghost; Dennett wanted to study the machine. He began teaching himself neuroscience the next day. Later, with the help of various academic friends and neighbors, Dennett learned about psychology, computer programming, linguistics, and artificial intelligence—the disciplines that came to form cognitive science.
One of Dennett’s early collaborators was Douglas Hofstadter, the polymath genius whose book about the mind, Gödel, Escher, Bach: An Eternal Golden Braid, became an unlikely bestseller in 1979. “When he was young, he played the philosophy game very strictly,” Hofstadter said of Dennett. “He studied the analytic philosophers and the Continental philosophers and wrote pieces that responded to them in the traditional way. But then he started deviating from the standard pathway. He became much more informed by science than many of his colleagues, and he grew very frustrated with the constant, prevalent belief among them in such things as zombies. These things started to annoy him, and he started writing piece after piece to try to destroy the myths that he considered these to be—the religious residues of dualism.”
Arguments, Dennett found, rarely shift intuitions; it’s through stories that we revise our sense of what’s natural. (He calls such stories “intuition pumps.”) In 1978, he published a short story called “Where Am I?” in which a philosopher, also named Daniel Dennett, is asked to volunteer for a dangerous mission to disarm an experimental nuclear warhead. The warhead, which is buried beneath Tulsa, Oklahoma, emits a kind of radiation that’s safe for the body but lethal to the brain. Government scientists decide on a radical plan: they separate Dennett’s brain from his body, using radio transmitters implanted in his skull to allow the brain, which is stored in a vat in Houston, to control the body as it approaches the warhead. “Think of it as a mere stretching of the nerves,” the scientists say. “If your brain were just moved over an inch in your skull, that would not alter or impair your mind. We’re simply going to make the nerves indefinitely elastic by splicing radio links into them.”
After the surgery, Dennett is led into the brain-support lab:
I peered through the glass. There, floating in what looked like ginger ale, was undeniably a human brain, though it was almost covered with printed circuit chips, plastic tubules, electrodes, and other paraphernalia . . . I thought to myself: “Well, here I am sitting on a folding chair, staring through a piece of plate glass at my own brain . . . But wait,” I said to myself, “shouldn’t I have thought, ‘Here I am, suspended in a bubbling fluid, being stared at by my own eyes’?” . . . I tried and tried to think myself into the vat, b
ut to no avail.
Toward the end of the story, the radio equipment malfunctions, and Dennett’s point of view is instantly relocated. It is “an impressive demonstration of the immateriality of the soul, based on physicalist principles and premises,” he writes, “for as the last radio signal between Tulsa and Houston died away, had I not changed location from Tulsa to Houston at the speed of light?” The story contains only neurons and machines, and is entirely materialist; even so, it shows that you aren’t situated “in” your brain the same way you’re situated “in” a room. It also suggests that the intuitions upon which philosophers so confidently rely are actually illusions created by an elaborate system of machinery.
Only rarely do cracks in the illusion of consciousness appear through which one might see the machinery at work. Proust inspected the state between sleep and wakefulness. Coleridge experimented with mind-altering drugs. Neuroscientists examine minds compromised by brain injury. Dennett’s approach has been to look back into evolutionary history. In the minds of other animals, even insects, Dennett believes, we can see the functional components upon which our selfhood depends. We can also see the qualities we value most in human selfhood in “sort of” form. Even free will, he thinks, evolves over evolutionary time. Your amygdala, the part of the brain that registers fear, may not be free in any meaningful sense—it’s effectively a robot—but it endows the mind to which it belongs with the ability to avoid danger. In this way, the winding path leads from determinism to freedom too: “A whole can be freer than its parts.”