11:47
Still, we need some help with our intuitions. How can not perceiving reality as it is be useful? Well, fortunately, we have a very helpful metaphor: the desktop interface on your computer. Consider that blue icon for a TED Talk that you're writing. Now, the icon is blue and rectangular and in the lower right corner of the desktop. Does that mean that the text file itself in the computer is blue, rectangular, and in the lower right-hand corner of the computer? Of course not. Anyone who thought that misinterprets the purpose of the interface. It's not there to show you the reality of the computer. In fact, it's there to hide that reality. You don't want to know about the diodes and resistors and all the megabytes of software. If you had to deal with that, you could never write your text file or edit your photo. So the idea is that evolution has given us an interface that hides reality and guides adaptive behavior. Space and time, as you perceive them right now, are your desktop. Physical objects are simply icons in that desktop.
13:03
There's an obvious objection. Hoffman, if you think that train coming down the track at 200 MPH is just an icon of your desktop, why don't you step in front of it? And after you're gone, and your theory with you, we'll know that there's more to that train than just an icon. Well, I wouldn't step in front of that train for the same reason that I wouldn't carelessly drag that icon to the trash can: not because I take the icon literally -- the file is not literally blue or rectangular -- but I do take it seriously. I could lose weeks of work. Similarly, evolution has shaped us with perceptual symbols that are designed to keep us alive. We'd better take them seriously. If you see a snake, don't pick it up. If you see a cliff, don't jump off. They're designed to keep us safe, and we should take them seriously. That does not mean that we should take them literally. That's a logical error.
14:02
Another objection: There's nothing really new here. Physicists have told us for a long time that the metal of that train looks solid but really it's mostly empty space with microscopic particles zipping around. There's nothing new here. Well, not exactly. It's like saying, I know that that blue icon on the desktop is not the reality of the computer, but if I pull out my trusty magnifying glass and look really closely, I see little pixels, and that's the reality of the computer. Well, not really -- you're still on the desktop, and that's the point. Those microscopic particles are still in space and time: they're still in the user interface. So I'm saying something far more radical than those physicists.
14:45
Finally, you might object, look, we all see the train, therefore none of us constructs the train. But remember this example. In this example, we all see a cube, but the screen is flat, so the cube that you see is the cube that you construct. We all see a cube because we all, each one of us, constructs the cube that we see. The same is true of the train. We all see a train because we each see the train that we construct, and the same is true of all physical objects.
15:23
We're inclined to think that perception is like a window on reality as it is. The theory of evolution is telling us that this is an incorrect interpretation of our perceptions. Instead, reality is more like a 3D desktop that's designed to hide the complexity of the real world and guide adaptive behavior. Space as you perceive it is your desktop. Physical objects are just the icons in that desktop.
15:52
We used to think that the Earth is flat because it looks that way. Then we thought that the Earth is the unmoving center of reality because it looks that way. We were wrong. We had misinterpreted our perceptions. Now we believe that spacetime and objects are the nature of reality as it is. The theory of evolution is telling us that once again, we're wrong. We're misinterpreting the content of our perceptual experiences. There's something that exists when you don't look, but it's not spacetime and physical objects. It's as hard for us to let go of spacetime and objects as it is for the jewel beetle to let go of its bottle. Why? Because we're blind to our own blindnesses. But we have an advantage over the jewel beetle: our science and technology. By peering through the lens of a telescope we discovered that the Earth is not the unmoving center of reality, and by peering through the lens of the theory of evolution we discovered that spacetime and objects are not the nature of reality. When I have a perceptual experience that I describe as a red tomato, I am interacting with reality, but that reality is not a red tomato and is nothing like a red tomato. Similarly, when I have an experience that I describe as a lion or a steak, I'm interacting with reality, but that reality is not a lion or a steak. And here's the kicker: When I have a perceptual experience that I describe as a brain, or neurons, I am interacting with reality, but that reality is not a brain or neurons and is nothing like a brain or neurons. And that reality, whatever it is, is the real source of cause and effect in the world -- not brains, not neurons. Brains and neurons have no causal powers. They cause none of our perceptual experiences, and none of our behavior. Brains and neurons are a species-specific set of symbols, a hack.
18:01
What does this mean for the mystery of consciousness? Well, it opens up new possibilities. For instance, perhaps reality is some vast machine that causes our conscious experiences. I doubt this, but it's worth exploring. Perhaps reality is some vast, interacting network of conscious agents, simple and complex, that cause each other's conscious experiences. Actually, this isn't as crazy an idea as it seems, and I'm currently exploring it.