Book Review: Dennett’s Intuition Pumps

When I first picked up the book ‘Intuition Pumps: Tools for Thinking’ authored by the philosopher Daniel Dennett, I thought I knew exactly what it was I was buying. I suspected that I was about to be swept off on a journey similar to the one I had travelled whilst reading books like ‘Thinking, Fast and Slow’ by Kahneman or ‘Irrationality’ by Stuart Sutherland.

I had expected that contained within the pages of Dennett’s book would be the same hints and warnings about heuristics I had encountered in these other brilliant publications. But I was wrong!

However, I was wrong in a profoundly positive way. Dennett’s book not only provides tips for thinking, along with thinking pitfalls he calls ‘boom crutches’ but how these thinking tools can be applied to seemingly insurmountable philosophical questions.

Layout

Dennett’s ‘Intuition Pumps’ is laid out so that after the introduction describing intuition pumps, a section providing some generalised thinking tools is provided. This section comprises 12 chapters which are easily digestible since the chapters are incredibly short, usually no more than a page or two.

Of course, in this section Occam’s Razor appears, though with some warning about taking the ‘law’ too far, which provides a nice counterbalance. Then the reader is introduced to Occam’s Broom an invention of the molecular biologist Sidney Brenner. Occam’s Broom simply put, is what Dennett calls a boom crutch — something that hinders thinking rather than fosters it. Occam’s Broom is the tendency for inconvenient facts to be swept away where they are hidden from view and only appreciable or detectable by specialists.

The book really gets started after this worthy primer, with sections on meaning, evolution, consciousness, and free will. Each topic gets its own intuition pumps that the reader can play around with to help think about the topic.

Intuition Pumps

In essence, Dennett’s intuition pumps are fable-like stories capable of stoking one’s intuition. Therefore it allows the reader to start contemplating seemingly insurmountable philosophical questions such as what is consciousness? Or if the universe is deterministic, how is possible to have free will? These are heavy questions, that most try not to think about since it’s hard to find a decent foundation. Dennett provides the foundation by providing these intuition pumps that rely on narrative fictions to help provoke insight.

One such pump I’ll provide:

Dennett is talking about belief and he invites the reader to think about an intuition pump called ‘An Older Brother Living in Cleveland’. The intuition pump goes a little like this:

Imagine a neurosurgeon in the far future who is able to insert a belief into an individual’s brain (Dennett names the individual Tom, I’ll do likewise). The inserted belief is that Tom has an older brother living in Cleveland. Once Tom awakes and is sitting in a bar somewhere, we can imagine a conversation taking place wherein someone asks Tom about his family.

Bartender: Do you have any brothers?

Tom: Yes, I have an older brother living in Cleveland.

Bartender: What’s his name?

Here we run straight into a brick wall, Tom’s fictional brother doesn’t have a name. So Tom might respond by saying that he doesn’t in fact have an older brother, or that he is both an only child and has an older brother living in Cleveland.

What Dennett is keen to point out is that the neurosurgeon hasn’t really ‘installed’ or ‘programmed’ a belief since Tom is merely parroting something that is completely paradoxical. Dennett describes Tom’s insistence as a tic rather than a belief since one cannot be both an only child and also have a brother. If Tom denies the older brother due to his being an only child, then his rationality wipes out the ‘programmed’ belief outright. And if he irrationally holds to holding two contradictory statements then Dennett disqualifies this as a belief since Tom won’t be able to understand this sentence of being an only child and having a brother and thus is parroting rather than having a genuine belief. In either case, the neurosurgeon’s attempts have failed.

What Dennett attempts to demonstrate through this bizarre fable is that beliefs don’t stand in isolation. Having an older brother in Cleveland is tied to a name, an occupation etc.

With every intuition pump Dennett employs, he encourages the reader to ‘turn the knobs’ of intuition. He encourages playing around with the scenario to see whether anything novel can be appreciated from the thought experiment.

What I love about all the examples is that Dennett is not primarily interested in getting you to come to the same conclusions as he does from the intuition pumps. Rather he wants to move the reader to at least start asking the questions that really matter. And the intuition pumps are a way for the reader to embrace the more complex issues already mentioned.

Along the way, the reader will have a chance to play around with some interesting exercises such as composing on paper a register machine to perform various functions. This was an exceptionally fun part of the book that allowed me to not only better understand the growing complexity of computer systems from a few simpler functions, but how this might translate into the complexity of the human brain arising from denser more ‘stupid’ parts that only have to deal with less complex operations. The term homuncular functionalism comes into play and was a compelling argument for the materialistic explanations of consciousness rather than requiring what he calls ‘wonder tissue’ explanations.

Conclusion

There is so much to this book, that I cannot possibly cover all or even a fraction of the subtlety of the arguments in this small review. I can only say that after closing this book, I knew I would have to read it again knowing that I would gleam even more the second time around reading it. A book like this requires a certain mood, so I would advise not picking it up until you can be sure of some quiet and are feeling reflective about some of the deeper questions of existence.

With that said, Dennett writes with wit and with an openness that places upon the reader the impression that he not only loves philosophy but that he wants you to love philosophy too. And with that in mind, Dennett creates easily digestible chapters that present each intuition pump in as few words as possible whilst losing any of the astounding implications.

I give this book 10/10