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book review

‘Intuition Pumps and Other Tools for Thinking’ by Daniel Dennett

Daniel Dennett.

Bettina Strauss

Daniel Dennett.

In his long career, philosopher and cognitive scientist Daniel Dennett has made substantial contributions to — and stirred considerable controversy in — our thinking about human behavior and the very nature of the human mind.

In books like “Brainstorms” and “Consciousness Explained’’ he tries to demystify consciousness and argues that the brain is, essentially, a kind of computer. In “Elbow Room’’ and “Freedom Evolves’’ he attempts to demystify free will, arguing that a purely mechanical organism without a soul or immaterial mind can nevertheless be genuinely free. And in “Darwin’s Dangerous Idea” and “Breaking the Spell’’ Dennett, a committed atheist, suggests that the most important aspects of human life, including culture, morality, and religion, are best understood through the lens of Darwinian evolution via natural selection.

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“Intuition Pumps and Other Tools for Thinking’’ lies at the intersection of these three areas, and in some way serves as a summary statement of the Tufts professor’s thinking on key philosophical topics. “This book is a collection of my favorite thinking tools,” he writes. “I will not just describe them; 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.”


Daniel C. Dennett
Number of pages:
496 pp.
Book price:

Dennett begins by offering readers examples of these “tools,’’ which are aids for thinking and learning about complicated ideas — for instance, inventing examples or analogies and metaphors that can help us to understand and remember complex concepts or to see through and avoid tempting mistakes. And his “intuition pumps’’ are “thought experiments,” which can help test ideas. Take, for instance, the “Whimsical Jailer’’: If a jailer opens cell doors every night after inmates fall asleep are the inmates free during that time? If not, what does this tell us about the concept of freedom?

Some of these thinking tools will be well known to any philosophy student. Others, including many of Dennett’s own invention, will be familiar to those who have read his previous work. Indeed, “Intuition Pumps’’ mostly reproduces ideas, and sometimes entire passages, from Dennett’s prior books. It makes an excellent introduction to Dennett’s body of thought, but the already initiated will find it largely redundant.

It’s also a bit of a shaggy dog. It isn’t always clear whether a particular thought experiment is supposed to make a contribution to the larger argument or is simply of interest in its own right, and there are sections that seem quite disconnected from the rest.

After introducing a number of general tools, the book moves on to the question of how language and mental states can have meanings, the nature of evolution (which according to Dennett involves real, not apparent, design, albeit design without a designer), and the nature of human consciousness. Dennett heaps scorn on those who believe that the explanation of consciousness presents a “Hard Problem” that resists scientific explanation.

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The way to understand consciousness, he argues, is to understand how computers work, for the mind itself is a computer. Dennett’s critics have responded by accusing him of rendering the Hard Problem easy by denying that the most mysterious aspects of consciousness, those that computers could not have — conscious experiences themselves, like sensations or feelings — even exist. (Indeed, after Dennett’s “Consciousness Explained’’ was published in 1992 many philosophers amused themselves by coming up with alternate titles, including “Consciousness Denied,’’ “Consciousness Ignored,’’ and “Consciousness Explained Away.’’)

Whether Dennett actually denies the existence of conscious experiences — or what, precisely, it is that he denies — is a matter of considerable obscurity. He allows that consciousness, in some sense, exists, but at times he does seem simply to be using that word in a nonstandard way. There are moments, for instance, when he seems to be saying that there is no such thing as the taste of coffee.

“Seems’’ is important here, though: It isn’t always quite clear just what Dennett is saying or denying. This lack of clarity manifests itself elsewhere, too, and is one of the frustrations of “Intuition Pumps.’’ Dennett is so deeply immersed in his own work, ideas, arguments, and positions that it is sometimes difficult for him to explain them to others.

In the end, “Intuition Pumps and Other Tools for Thinking,’’ while often witty and quite readable, is not for everyone. It is certainly worthwhile for those interested in thinking deeply about evolution, consciousness, or free will — or even those interested in a lesson in the ways thought tools and intuition pumps can help sort out complicated ideas. The book is frequently helpful, sometimes challenging, and interesting more often than not.

This book will not placate those critics who claim that by viewing whatever science cannot get at as irrelevant, Dennett merely pretends to deal with hard problems, pretending that they are easier than they are. (The philosopher John Searle once said that philosophers like Dennett made him think of the joke about the drunk man looking for his keys under a streetlamp: “No, I dropped them in the bushes — but the light is better here!”)

But even if he is sometimes reluctant to focus his inherent skepticism on his own more radical suggestions, Dennett can still be read profitably both as a synthesizer of research and as a provocateur. His intellectual curiosity is deep and wide-ranging. And at his best, when he slows down and takes care with his writing, he can be both entertaining and enlightening in articulating difficult concepts.

Troy Jollimore is author of “Love’s Vision” and “At Lake Scugog: Poems.” He can be reached at

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