For Daniel Dennett, philosophers are like blacksmiths: they make their own tools as they go along. Unlike carpenters, who have to buy their drills and saws at Sears, blacksmiths can use their own hammers, tongs, and anvils to pound out more hammers, tongs, and anvils. Dennett, whose famous white beard gives him the look of both a blacksmith and a philosopher, has been particularly industrious at the anvil. He has been working as a philosopher for 50 years, and in his new book, Intuition Pumps and Other Tools for Thinking, he shares a few tricks to make the hard work easier. He is a master at inventing tools for thought—metaphysical jokes, fables, parables, puzzles, and zany Monty-Python-like sketches that can help thinkers feel their way forward. Dennett calls them hand tools and power tools for the mind, and he’s built dozens and dozens of them over the years.
“Thinking is hard,” he writes. “Thinking about some problems is so hard that it can make your head ache just thinking about thinking about them.” Thinking tools help philosophers work on the really deep, hard questions about life, the universe, and everything. They facilitate what another philosopher has called Jootsing, which stands for Jumping Out Of the System—the goal is to pop out of the goldfish bowl of commonplace ideas without drowning in thin air. Think of Plato’s Cave, for instance. That little story has helped philosophers puzzle about the nature of reality for more than 23 centuries and counting.
Dennett’s own inventions include “Swampman Meets a Cow-Shark,” “Zombies and Zimboes,” and many other thought experiments that illuminate great questions in philosophy. He focuses on problems of free will, evolution, and consciousness. His ideas about consciousness are rather shocking; he can make you feel that the human brain itself is just a collection of tongs, hammers, and intuition pumps. (More about that in a moment.) Dennett has written more than a dozen books about those deep topics. His best known are Darwin’s Dangerous Idea, and Consciousness Explained. He writes very well, in a colorful, lively, clear style, and he is a popular professor at Tufts University, to which he dedicates his new book. And every book and lecture is packed with intuition pumps for juicy, jootsy epiphanies.
In a way, we all use thinking tools, all the time, without thinking twice about them. Everyday speech is full of what Dennett calls “small hand tools,” familiar words and phrases like “wild goose chase” or “feedback” or “slam dunk.” The English language is a tool chest with a million metaphors that serve as a kind of verbal mathematics. They’re informal formulas for describing the way things go. Newton’s equations describe the behavior of a cannonball; “loose cannon” describes the behavior of a certain kind of cannoneer we’ve all had the misfortune to know.
Then there are simple, familiar intuition pumps like Aesop’s “The Boy Who Cried Wolf,” “The Ant and the Grasshopper,” and “The Fox and the Grapes.” We’ve all used those thinking tools too. “Look how much you can say about what somebody has just said by asking, simply, ‘Sour grapes?’” writes Dennett. You can get someone to rethink her position, to consider her situation from a completely different perspective. You can also insult her. (As Dennett observes, “Tools can be used as weapons too.”)
The intuition pumps that he’s created are really philosophical arguments in disguise. Dennett has designed them to push us to see the world his way, and that’s what he’s trying to do by recapitulating them here. “I will not just describe them,” he writes; “I intend to use them to move your mind gently through uncomfortable territory all the way to a quite radical vision of meaning, mind, and free will.”
And his ideas are uncomfortable. His essential claim is that there is no great gulf between nonliving, unconscious gizmos like computers and light switches, on the one hand, and the human brain, on the other. Our strong feeling that there’s something special and inexplicable about consciousness is largely an illusion. It will fade as science advances, like the illusion that the Earth is the center of the universe and everything revolves around us. Biologists used to believe that living things are made of some special material, some elan vital that sets us apart from the stuff of rocks and minerals. Now that we know about DNA, we no longer need an elan vital. Someday we won’t need consciousness either. There’s no metaphysical difference between your body and your mind, or between your laptop and your necktop, so to speak.
That’s a controversial position, obviously. It still feels counterintuitive to most of us, and to most philosophers too, in spite of all of Dennett’s intuition pumps. Does Consciousness Explained explain consciousness, or just explain it away? Check out Dennett’s story “The Sad Case of Mr. Clapgras” and see what you intuit. Mr. Clapgras wakes up one morning and finds that everything he sees is suddenly disgusting. His vision is still normal, but his associations with every color have somehow gone awry overnight. He now hates his old favorite color, red, and prefers his former least favorite, blue. Everything looks the same but nothing feels right. His food looks revolting—he has to eat in the dark. Dennett exploits the tale of poor Mr. Clapgras to raise difficult questions about the nature of perception, and thought, and to disrupt our faith in consciousness itself.
Even if you don’t love logic puzzles, brainteasers, and code-writing, all of which delight Dennett, you may still find this book an entertaining introduction to Dennett’s tenets. As you stretch your mind on his mind-twisters, you begin to feel your way to glimpses of his view of life. At the same time, it’s also something like torture to twist your thoughts into the pretzel-shaped path that Dennett wants you to follow—to walk the Mobius-shaped ribbon of highway on which, no matter how you hurry and scurry ahead, you can never arrive at a place where there is something special about the human mind.
Read this book carefully and you’ll find yourself Jumping Out of the System in all directions. Dennett will lift off the top of your head, and tie your forehead into knots. Is this really where the philosophy of mind is headed? There’s no question that as neuroscience hurtles ahead, our current system of thought is beginning to feel creaky and rusty in the extreme. Some bright new ideas probably are going to have to take its place. It may be that Dennett and his friends are the philosophers who are building them—Dennett most cheerfully of all, in his Santa’s workshop of intuition pumps.