OK, now I promised you to tell you some of the outrageous things said about consciousness, and just because of shortage of time, I am only going to mention four of the worst.
One: “Consciousness does not exist. It is an illusion, like sunsets.” Science has shown sunsets and rainbows are illusions, so consciousness is an illusion.
Two: “Maybe it exists, but it is really something else, it’s a computer program running in the brain.”
Three: “No, the only thing that exists is really behavior!” It’s embarrassing how influential behaviorism was, but I will get back to that.
And four: “Maybe consciousness exists, but it can’t make any difference to the world. How could spirituality move anything?” And whenever somebody tells me that, I think: “You want to see if spirituality moves something? Watch!” I decide consciously to raise my arm and the damn thing goes up.
Furthermore, notice this — we do not say: “Well, it’s a bit like the weather in Geneva, some days it goes up and some days it doesn’t go up.” No! It goes up when I right damn well want it to. OK, I am going to tell you how that is possible.
Now, I haven’t yet given you a definition, you can’t do this if you don’t give a definition. People always say: “Consciousness is very hard to define.” I think it is rather easy to define if you are not trying to give a scientific definition. We are not ready for a scientific definition, but here is the common sense definition: consciousness consists of all those states of feelings, or sensations, or awareness; it begins in the morning when you wake up from a dreamless sleep, and it goes on all day, until you fall asleep, or die, or otherwise become unconscious. Dreams are a form of consciousness on this definition. Now that’s the common sense definition, that’s our target; if you are not talking about that, you are not talking about consciousness.
But they think:”Well, that’s it. That’s an awful problem. How can such a thing exist as part of the real world?” And this, if you have ever had a philosophy course, this is known as the famous “mind-body problem.” I think that has a simple solution to it and I am going to give it to you. And here it is: all of our conscious states, without exception, are caused by lower-level neurobiological processes in the brain. And they are realized in the brain as higher-level or system features. It is about as mysterious as the liquidity of water, right? The liquidity is not an extra juice squirted out by the H2O molecules, it’s a condition that the system is in. And just as the jar full of water can go from liquid to solid, depending on the behavior of the molecules, so your brain can go from a state of being conscious to a state of being unconscious, depending on the behavior of the molecules. The famous “mind-body problem” is that simple.
All right. But now, we get into some harder questions. Let’s specify the exact features of consciousness so that we can then answer those four objections that I made to it.
Well, the first feature is it is real and irreducible. You can’t get rid of it. You see, the distinction between reality and illusion is the distinction between how things consciously seem to us and how they really are. If consciousness seems like… I like the French “arch”, it seems like there’s an arch in the sky, or it seems like the sun is setting over the mountains, it consciously seems to us but that’s not really happening. But for that distinction, between how things consciously seem and how they really are, you can’t make that distinction for the very existence of consciousness. Because where the very existence of consciousness is concerned, if it consciously seems to you, that you are conscious, you are conscious. I mean if a bunch of experts come to me and say: “We are heavy-duty neurobiologists and we’ve done a study on you Searle,” and we are convinced you are not conscious. You’re a very cleverly constructed robot.”
I don’t think: “Well, maybe these guys are right.” I don’t think that for a moment. Because, I mean, Descartes may have made a lot of mistakes but he was right about this: you cannot doubt the existence of your own consciousness. That’s the first feature of consciousness. It is real and irreducible. You cannot get rid of it by showing that it’s an illusion, in a way that you can with other standard illusions.
The second feature is this one that has been such a source of trouble to us. And that is all of our conscious states have this qualitative character to them; there is something that it feels like to drink beer, which is not what feels like to do your income tax, or listen to music.
And this qualitative field automatically generates a third feature, namely, conscious states are by definition subjective, in the sense that they only exist as experienced by some human or animal subjects, some self that experiences them. Maybe we will be able to build a conscious machine. Since we don’t know how our brains do it, we are not in the position so far to build a conscious machine.
Okay, another feature of consciousness is that it comes in unified conscious fields. So I don’t just have the sight of people in front of me, and the sound of my voice, and the weight of my shoes against the floor, but they occur to me as part of one single great conscious field that stretches forward and backward. That is the key to understanding the enormous power of consciousness. And we have not been able to do that in a robot. The disappointment of robotics derives from the fact that we don’t know how to make a conscious robot, so we don’t have a machine that can do this kind of thing.