"Getting up each day, you probably take the idea that there is such a thing as a "self" for granted. Even if you do think about it, the existence of self seems obvious - what else would be asking whether it existed? But push harder, and it all gets very strange. Nearly thirty years after his best-selling book Gödel, Escher, Bach, cognitive scientist and polymath Douglas Hofstadter has returned to his extraordinary theory of self in his latest book. Mike Holderness caught up with him recently
Why do we need to challenge the common-sense idea of a "self"?
Because the harder you think about the common-sense notion, the less sense it makes. Let's start with a rather extreme philosophical thought experiment. Suppose I get into a teleporter cabin, where my body, and therefore my brain, is destroyed in the process of scanning it. The machine sends a blueprint of me to Mars and Venus simultaneously, and atoms on Mars and on Venus are reassembled into exact replicas of me. If it went only to Mars, people might be happy to say: "Oh look, you were reconstructed on Mars. You simply travelled." But if I am transported to two planets, people would worry, and say: "You can't be in two places at once." Although it's counter-intuitive to the highest degree for us humans, we have to accept the fact that there would be two instances of me, and that the question "Where am I?" would not be answerable in that case.
But what about here in the world as we know it?
There are twins among us, and they serve a similar purpose for our thought experiment. I devised a philosophical fantasy world I call "Twinwirld" to help me think about identity and self and the language we use to describe them. In Twinwirld, 99 per cent of births are identical twins, who spend all their time together and hire themselves out for work as a single unit - I call them "a pairson". There's no need to refer to half a pairson, except when you ask which half stubbed its toe. The halves aren't as deeply fused as our two cerebral hemispheres, but they're closer than identical twins, even than husband and wife in our world. And in our world, it's plausible to refer to twins who grow up virtually inseparable as a two-bodied entity, as one "pairson". What I'm trying to do with this is to open people's minds, to get them to feel there can be something more abstract about a self that isn't absolutely rigidly locked into one physical object - even though the brain is not a physical object in the normal sense because it is something that changes all the time.
So what is self if not tied to a physical object?
It's a pattern. Think of a smile. There are no atoms that compose it, it doesn't have mass or dimensions. A particular smile can not only be seen at a distance and recognised, it can also be heard if, say, I'm smiling broadly while I'm on the telephone. You can see "my smile" on my children's faces. So what is this thing called a smile? Of course there are no physics of smiles that say they move at certain speeds. A smile persists for a while, and then vanishes. Where is your smile when it's not on your face? It's a potential. Once more, it's a pattern - like a whirlpool or a tornado.
In what sense does a smile exist then?
Someone's smile changes over time, from babyhood, through childhood to old age. Yet people may say: "I still see the same smile I could see 50 years ago." It can exist in different media, on different substrates if you prefer. I see it in the mirror, in photographs. And, again, a bit of it is on my children's faces if they happen to be smiling. So if someone asks: "Your smile yesterday and your smile today: which one is the 'real' smile?" I'd reply: neither, both are genuine, my smile comes in multiple instances. With this analogy I'm trying to get across that "I" can exist in multiple spots in the world, that it can flicker in and out of existence the way a smile can.
If people ask which is the real "you", don't they want one that is persistent, continuous, singular?
I guess it's very comforting and simple to feel there's some fixed entity that persists and that it is uniquely linked to a fixed physical entity. Consider the identity of a novel. When we publish translations of Alexander Pushkin's Eugene Onegin, nobody screams: "This is a lie!" - even if not one word of the Russian remains. One temptation is to say: "Of course a novel is a pattern, it's a sequence of words." You must resist that temptation, because the pattern exists at many levels other than word order: characters, events, places, cultures, style. And one essential in preserving its identity across media or languages, in deciding whether a translation really is Eugene Onegin, for example, is the "grain size", the resolution. A summary isn't a novel, it's too coarse.
How does your self differ from a novel or a character in a novel?
This pattern, this self, includes an image of itself. This self-image is at the heart of what I mean by the phrase "strange loop" - and strange loops are integral to selves.
Where does your "strange loop" idea come from?
I first mentioned it in my book Gödel, Escher, Bach in 1979, and it seems to have migrated out widely into the culture - though I spelled out the connection to selves at the end of the book and not everyone got that far. This time I go into it all much more explicitly. Strange loops arise when, moving up or down through a hierarchical system, one finds oneself back where one started. They can involve self-reference, paradox, irony, humour. Classic examples in GEB are the liar paradox and Kurt Gödel's mathematical proof of his first incompleteness theorem, which uses logical structures that talk about themselves.
And how do they relate to the self?
To some extent, as I say in my book, there are lots of times when we are cognitively or emotionally split: part of us wants to do A and another part wants to do B, and in that sense we are sort of two sub-selves. Most of the time we have this sense of being "integrated", of being one self that wants a thing. The best way of saying it is that there is one loop, the self-representation. And our loops include things we know about other people as well - I see it as importing parts of their strange loops into ours. When I was quite young, I played with another sort of loop that is relevant here. I wondered about pointing a television camera at the TV displaying its output. The assistant in the TV store told me the feedback would destroy the TV, but it doesn't. You get a vortex of images of the frame and surround, spiralling in to what might as well be infinity. These are very rich patterns in the loop - and that's where they are, not in the hardware. I have the sense that each person has a kind of hidden "infinity" inside them. It's a self-representation spiralling way back to their childhood.
But isn't a self more than self-representation?
We create an image of who we are inside our self. The image then becomes very deeply entrenched, and it becomes the thing that we attribute responsibility to - we say "I", "I" did this because "I" wanted to, because "I" am a good person or because "I" am a bad person. The loop is the fact that we represent our selves, our desires, hopes, dreads and dreams: it is the way in which we conceive of ourselves, rather than the way we conceive of Mount Everest or of a tree. And I say it exists entirely in the loop: the self is an hallucination hallucinated by an hallucination.
What about other people, other selves?
We have partial copies of other people in our brains, so we have copies of other strange loops in our brains. There are lots of low-resolution copies of us floating around in other people's minds, but there's only one that has high resolution, one you would agree is "the real you". But if we could make higher-resolution copies with finer grain size, then there'd be some rivalry over which is the genuine one. And if we ever got a copy that was just as high-resolution, then there would be no answer any more to "where is the self?".
Does your view of self affect how you live?
My wife died 14 years ago, when we were in Italy. Small copies of the pattern that was her, persisting in my mind, made me make all sorts of decisions. Our children and I continued the year we'd begun in Italy to its conclusion: Carol and I had made a decision together to spend a year in Italy, and we'd do that. We wanted our children to be bilingual, in English and Italian, and when I returned to America I continued to speak Italian. So I kept alive a joint dream and brought our children up in a fashion that was completely different from most children in the US. If she were to walk in the house today, she'd say: "It's very similar to how it always used to be - the same old pots and pans, the same old silverware, the same paintings on the walls, the same cars." The reason I keep things like this is that I feel that Carol persists in my brain, and this physical environment I live in and the image of Carol in my brain resonate with each other, they reinforce each other. Other people do the opposite: when a loved one dies, they get rid of all of their belongings, move, and do all they can to get rid of the pain, to get rid of the constant confrontation.
How long can these partial copies persist in other minds?
If you were brought up as a traditional Christian perhaps you would believe that you would live for ever. My fundamental orientation is scientific, and says that a pattern cannot persist forever. It persists in my brain for a while, then my brain disintegrates and little copies exist in a few places, then they disintegrate too and it's pretty much all over.
In the book, you often talk of selves as "souls", and of their size. What makes a soul larger?
It's not just about how much someone reflects other people in their brain, it's about how. It's a question of reflecting them with empathy, with the ability to put yourself in their place, to suffer along with them. I am a very deep believer in trying to see things from the viewpoint of other people, especially people who are suffering, and projecting myself into other people's mindsets as much as I can.
And do we treat people differently on the basis of the "size of their soul"?
We do. We don't acknowledge it, but if you like somebody because you think they're nice, you treat them better. And you probably like them because they are empathetic. So empathy is favoured in the world. The political scientist Bob Axelrod explored the evolution of cooperation using game theory. He set up tournaments between computer programs playing the Prisoner's Dilemma game where a player that betrays another gets a certain pay-off, and so on. The simplest strategy, which he called "Tit for Tat" but you might call "Do unto others as they have just done unto you: a smile for a smile, a slap for a slap", won. I don't think that's an accident. Fundamentally, in the end, cooperation wins out over selfishness.
Does that suggest society is built on a strange loop involving all of us?
Absolutely. Go back to Axelrod's book The Evolution of Cooperation. It may be that there's some slightly better strategy if you make more elaborate tournaments or simulations, but I think basically there's a sort of law of the universe that says cooperation is a very good strategy. It's sort of a law about the way the world works."
Douglas Hofstadter is professor of cognitive science and computer science at Indiana University, Bloomington. His latest book, I am a Strange Loop, is published in the US this month by Basic Books.
From New Scientist magazine, 10 March 2007, page 46-48