Hi. I have no idea what Milton just said, so - (Laughter) If it was bad, you will tell me, won't you? (Laughter) We human beings can be quite clever when we try, and over the centuries we've managed to solve many of the great mysteries of the world, of life. We know now that the sky is not really held up with four tent poles and that stars are not really tiny little things. They're just a very long way away. We even know that teenagers are not really possessed by demons. (Laughter) They're just clinically insane. (Laughter) But there are still some mysteries left. There's the origin of the universe. That's quite a big one. And there's a lot of mysteries about how a tiny little egg cell can grow and develop into something as complex and wonderful and tremendously attractive as you. And there's the mystery of consciousness, the great secret of consciousness. How come there's a me inside my head looking out? I'd love to talk to you about all three of those things, but I only have thirteen minutes, so I'm just going to solve the secret of consciousness. I don't want to leave you in suspense, because frankly, when you hear the answer, you're just going to be bitterly disappointed anyway. So I'll tell you the secret straightaway, and then I'll try to make you feel better about it. So, okay, here we go. Are you ready? The great secret of consciousness is ... No, actually, I'll tell you a story first. (Laughter) When my son Christopher was a little boy, about that big, one of his teachers asked him what he wanted to be, what he wanted to do when he grew up. And Christopher very confidently answered, "I want to study how one thing affects another." And as career plans go, I think his teacher felt that was a little bit vague, but I was really proud of him. For a start, you can never be unemployed with a skill like that, can you? (Laughter) You want to solve the problems of cancer, you want to find out why wars get started, you want to design better spacecraft, who better to ask than somebody who knows how one thing leads to another? But he was right. You can study how one thing affects another. It's called cybernetics, in fact. Because there's not that many ways in which one thing can affect another. And if you're quite good at patterns, you start to see that the same kinds of dynamics occur in many, many levels of scale. Chris was kind of simplifying - because it was a teacher, you know - and what he really meant was not how one thing affects another, but how one thing affects another that affects the first thing again. So something called circular causality or feedback, and cybernetics is the study of feedback. This is really important because basically everything you see around you exists because of feedback. The atoms in the seat in front of you, the mind and the body of the person sitting in that seat, the words I'm using, Portugal, even TED. All of these things exist because of feedback, because they are self-reinforcing or self-regulating in some way. Because if they weren't, they'd just disappear. So everything is feedback and feedback is everything. Anyway, where was I? Consciousness. Alright. This time. (Laughter) The great secret of consciousness is ... By the way, (Laughter) have you ever spent much time thinking about the fact that you are actually a colony of single-celled creatures? It's kind of freaky, but it's also quite wonderful. You are. You are a society of 100 trillion little creatures, and 90% of them are bacteria, which is kind of embarrassing, but you can't live without them, so collectively they're you. And even the ones that have human genes, they're really just little single-celled animals, and they reproduce asexually; they divide into two, then four, then eight and sixteen. And almost the only thing that's special about them is the fact that they're covered in glue, so they kind of end up stuck together in a lump instead of swimming off and living happy independent lives. So basically you are a lump of sticky little creatures. The reason I tell you this partly is that it kind of explains what I do for a living. I work in a field called artificial life, which basically means using technology to explore biology. And so I spend my days making artificial creatures. Sometimes robots. In fact I have a full-sized female, mini-skirted robot sitting in my bedroom, (Laughter) which causes a big shock to anyone who comes in to do something in my apartment. But mostly, I make virtual creatures that live inside a computer. The only thing worth knowing about this is that they are also communities. So I don't try to program computers to behave like animals; I try to program computers to behave like brain cells and kidney cells and liver cells, and then I try to find ways to plug them together into systems, into communities, that collectively have thoughts and feelings and hopes and dreams. And many, many years ago, about 20,000 years ago, I took some of my little creatures and put them into a computer game and let people play with them, and the results were wonderful. At least a million people started looking after my little creatures, and they did great things. They would set up adoption agencies, write lots of stories, do scientific experiments on them, study their genetics. Actually quite a lot of them went on, when they grew up, they went on to become scientists and stuff, because of the experiments they had been doing on my little artificial life forms. But the most important thing was that they asked a lot of questions, deep questions about what is life, what is the mind, what is consciousness. And I just loved that; it made my whole life worth living. Because these questions really matter. How do we know, how can we make good judgements about ethical questions like abortion or animal cruelty if we don't know what consciousness is? You can't be cruel to something unless it knows you're being cruel to it. But how do we know whether it knows? I live in America, and over there, abortion is a huge political subject. It sometimes seems to me like half the population believe this, and the other half of the population believe that. They can't both be right. They could of course both be wrong. Are they sitting down around a really long table, having discussions and trying to work out what the right answer is about abortion? Well no, of course not. It's America. They just shoot each other. (Laughter) So it's a mess. We don't know what we're talking about, and part of the reason is, I think, that we're stuck. We're stuck, we can't move forward with these problems, because we don't know what the secret of consciousness is. I guess that's me there. Third time lucky, I'll tell you. This time, I'll tell you, and you're not going to like it. Alright, so the great secret of consciousness is ... that there is no secret of consciousness. (Laughter) I'll tell you the bad news first, and then I'll try to convince you that it's actually good news. The thing is - Over the last few years, I've been building some new creatures, and I really think that now, I am starting to get a glimmer of consciousness out of these creatures. And for me that's great. I really wanted to bring them along. I'm so sorry, but they misbehaved and I just couldn't do it. (Laughter) So for me it's great because this is my life's work. I've spent 35 years doing this stuff, and it's nice to feel that I'm starting to get close to something. But a lot of people don't feel that way about these things, because these creatures are artificial. They live in a computer. So they can't have a supernatural soul, and they can't even have freaky, weird things like quantum mechanics to explain the consciousness and all the other things that we concoct to try to make ourselves feel better about how special we are. They're machines, and therefore, if I'm right, so are we, and nobody wants to be called a machine. You just don't want to tell people that. They don't want to be it. It's not exactly special, and machines wear out. So what do I do? What do you do if it bothers you? Well, all that stuff I was telling you about Christopher and feedback and collections of little cells, that's where the answer lies. I can't explain it to you now, but if you want to know how to deal with the fact that we are machines - and that's not a bad thing - that's where to look. But let me try and finish with a cosmogony, a little story of a better origins, the creation story. You know the biblical creation story. Basically, God created the universe perfect and fully formed, and then some people came along and screwed it all up, and it's all been downhill ever since. So that creation story is all about decline and decay. But in my field, complexity studies, complexity theory, we can offer a different kind of creation story. And in that story the universe wasn't created fully formed and perfect; it was very, very simple and very, very, very, very, very, very boring. But it's a creative universe, a self-organizing universe, a universe that discovers and invents things that didn't exist before - all the time. Essentially thanks to the power of feedback, an empty universe once discovered how to make matter out of empty space. And once it had figured out how to make matter and the matter cooled down enough, it discovered it could do chemistry with it. And the chemistry practiced and practiced and practiced for billions of years and eventually figured out it could make life. And then as soon as life showed up, it was never going to go away again, so it experimented with different ways of plugging cells together into communities to do different things that enabled it to survive, made it self-sustaining, and during that process, eventually, it needed to build models of the world so that it could make plans and predict things, and I think that's where consciousness came from. So it's just what happens when a certain kind of machine is working. There's nothing freaky about it. But this is a pretty cool universe because we emerged out of all this. So what I'm saying is that, yes, we are machines, but we're not just machines; we're amazing machines. We're the product of 14 billion years of experiment by an incredibly creative universe. And so hopefully that makes you feel a little bit better about being a machine. So my advice is to try and embrace you're in a machine, and it's not a bad thing to be. So thank you. (Applause)