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The Notebook

Katherine Power explores the advantage of having an extended mind.

A common view amongst philosophers of mind is that mental states are ‘physically realised’. This means that if I believe that Magritte was a painter, there is something physical in the world which makes up that belief. Let’s say the belief is realised by a neural pattern of activation in my brain. If we took that pattern away, and did not replace it with another physical state serving the same role, I would no longer believe that Magritte was a painter.

If you agree so far, you might ask what kind of physical states realise mental ones. Do they have to be brain states? Not according to Andy Clark and David Chalmers. In their 1998 paper ‘The Extended Mind’, they argue that mental phenomena can be realised outside the skull. To convince us, they compare an ordinary case of belief with a case where an external object, a notebook, plays a crucial role. Clark and Chalmers argue that the differences between the two cases are superficial, and therefore that they are both cases of belief.

I agree with the general idea that the mind can be externally realised, but in the story below I show how there are important functional differences between ordinary belief and the kind of extended belief Clark and Chalmers describe. The point isn’t to find fault with their example. My argument is that one of the exciting features of externally-realised mental states is that external objects allow us to do more than we could otherwise. They introduce new kinds of cognition.

This fits in well with Clark’s idea, explored in Natural Born Cyborgs (2003), that our ability to ‘bond with technology’ is what made some of our greatest cognitive achievements possible. We can do simple sums in our heads, but try learning how to do them without external aids like pen and paper. Or try proving Fermat’s last theorem, or calculating a moon-shot.

“Consider a normal case of belief embedded in memory. Inga hears from a friend that there is an exhibition at the Museum of Modern Art, and decides to go see it. She thinks for a moment and recalls that the museum is on 53rd Street, so she walks to 53rd Street and goes into the museum. It seems clear that Inga believes that the museum is on 53rd Street, and that she believed this even before she consulted her memory. It was not previously an occurrent [presently-conscious] belief, but then neither are most of our beliefs. The belief was sitting somewhere in memory, waiting to be accessed.

“Now consider Otto. Otto suffers from Alzheimer’s disease, and like many Alzheimer’s patients, he relies on information in the environment to help structure his life. Otto carries a notebook around with him everywhere he goes. When he learns new information, he writes it down. When he needs some old information, he looks it up. For Otto, his notebook plays the role usually played by a biological memory. Today, Otto hears about the exhibition at the Museum of Modern Art, and decides to go see it. He consults the notebook, which says that the museum is on 53rd Street, so he walks to 53rd Street and goes into the museum.

“Clearly, Otto walked to 53rd Street because he wanted to go to the museum and he believed the museum was on 53rd Street. And just as Inga had her belief even before she consulted her memory, it seems reasonable to say that Otto believed the museum was on 53rd Street even before consulting his notebook. For in relevant respects the cases are entirely analogous: the notebook plays for Otto the same role that memory plays for Inga. The information in the notebook functions just like the information constituting an ordinary non-occurrent belief; it just happens that this information lies beyond the skin.” (Clark & Chalmers, ‘The Extended Mind’, Analysis 58: 7-19, 1998.)

Otto sits on a bench and takes his laptop out. He calls it his notebook, because that’s how it all started, with an actual old fashioned notebook. He soon ran out of space. His nephew, Mark, bought him a laptop as a replacement.

“Plenty of space here,” Mark said. “And you’ll see how quickly you’ll be able to look things up with the program I’ve installed.”

“I’m an old man with Alzheimer. It’ll be wasted on me. My PC is already more than I need.”

“Your PC isn’t exactly portable. Your notebook is full, and, trust me, not that easy to search. Give this a go for a month. Please.”

So Otto got down to work, inserting into the database all the information contained in the original notebook, and adding new facts – such as the location of the Museum of Modern Art – as he learnt them. He started to keep a detailed journal as well, updating it as the day progressed.

‘16:47. Sitting in front of Magritte’s ‘The Lovers’. Have enjoyed exhibition so far. Luckily the Museum isn’t too full. I think I’ll go for a cup of tea now,’ he writes – and then he notices a familiar face, a little wrinklier than he remembers, but the features still defined, the eyes still lively and slightly mischievous... Inga!

Many years ago, when Otto and Inga were in their twenties, they had been out on a few dates. She’d been a delight, pretty and playful; but it was summer and Inga always visited family in Germany in the summer. By the time she got back they were both dating other people. A few months afterwards, Otto and Martha got engaged. Inga and Jonas soon followed. Otto and Inga remained friends through the years, meeting occasionally, by arrangement or by accident, at museums, art galleries, theatres and music parlours.

Otto doesn’t need to look any of this up. He searches for ‘Inga’, however, quickly checking recent diary entries.

Ah! They met two months ago. In the very same place.

“Inga!” he says, walking towards her. “I’m pleased to see you are fond of Magritte as well as Pollock.”

“Otto! You remember?”

“I do,” says Otto, patting his laptop.

“Of course. I hope it doesn’t say anything bad in there.”

“Wouldn’t you like to know! Password protected, I’m afraid,” says Otto with a smile. “I was just about to go for a cup of tea. Care to join me?”

They order. Otto sits the laptop on the table.

“Is Martha well?”

Otto types in ‘Martha’.

“She’s fine, thanks. Busy planting yet more flowers in that tiny terrace of ours.”

He types ‘Jonas’ before asking after him.

“Oh,” says Otto, his face darkening. “Almost two years ago.”

“A stroke,” says Inga. “At least it was quick. No long illness or deterioration. I miss him though. I’m lucky to have my children, my sisters, and still many friends, but I do get lonely sometimes.”

They sit in silence for a moment. The waitress arrives with a pot of tea, two cups, and two slices of pecan pie.

“Do you ever show anyone the contents of your laptop?”

“The notebook,” laughs Otto. “Let’s put it this way: you let me read the bits of your brain that make up your memory, and I’ll consider letting you read mine.”

“I suppose you must also worry that someone might tamper with it.”

“Very much so. I need to trust the notebook, or it will be no use to me.”

“But can you really trust it? Can you trust yourself?”

“What do you mean?”

“What if you made things up or failed to record important information?”

“I wouldn’t.”


“Perhaps under extraordinary circumstances.”

“It could be useful, you know, having the power to edit your memories like that. Could spare you a lot of guilt.”

“This conversation is getting a little spooky! How’s the pecan pie?”

“Lovely,” says Inga. “You know, Otto, I think you are too keen on the idea that the notebook should function exactly like someone’s ordinary memory. I can see that it serves a similar role, but there are differences –”

“Such as?”

“Memory is a funny thing. Your entries don’t decay with time. They don’t change every time you bring them up again.”

“Sometimes I edit them, and I could always ask Mark to install one of his clever programs. I’m sure he could make it so that entries I never search were compressed and maybe even wiped out in time.”

“What would be the point?”

“To save space.”

“I don’t know much about computers, but I get the impression space isn’t likely to be an issue.”

“So that I can say: ‘This works just like anyone’s memory’.”

“And maybe you could keep tinkering with your so-called notebook until you could really say such a thing... but my point is, why bother? You’ve got something similar to memory there. In some ways it may be worse, in some ways it may be better. By all means, address the problems, but take advantage of the perks.”

“Such as?”

“The power. You decide what goes in and what doesn’t. Use that.”


“The same way you did the last time we met, Otto. After we had pretty much this very same conversation. My place is only a short cab ride away,” says Inga, her eyes twinkling.

© Katherine Power 2006

Katherine E. Power lives in Brighton, where she is training as a journalist. She grew up in Italy, but moved to the UK as a teenager. Her MPhil thesis was on the extended mind theory.

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