July 27, 2015
What do you think this thing we call “self-awareness and consciousness” is?
I don’t know. I think that it’s a way of describing certain kinds of behaviors, and so on. It’s a way of labeling the world, it’s a way of—okay, let me give a different example, which I think is somewhat related, which is free will. It’s not quite the same thing as consciousness and self-awareness, but it’s a thing in that same soup of ideas. And so you say, “Okay, what does it take to have free will?”
Well, if something outside you can readily predict what you will do, you don’t seem to have free will. If you are the moth that’s just repeatedly bashing itself against the glass around the light, it doesn’t seem like it has free will. The impression of free will comes typically when you can’t predict what the system is going to do. Or another way to say it is, when the will appears to be free of any deterministic—well, not any deterministic—rules, but it’s not purely determined by rules that you can readily see. Now, people get very confused because they say, “Oh, gosh! Absent things about quantum mechanics, and so on, the laws of physics seem to be fundamentally deterministic”. How can it be the case, then, that we have free will if everything about the universe—and people like me actually believe this is how the whole of physics works—is ultimately deterministic, is ultimately determined by a fixed set of rules that just get run where there’s a unique possible next step, given the rule, given what happened before? How can that be consistent with free will? Well, I think the point is that it’s a consequence of something I call “computational irreducibility”. It’s a consequence of the fact that even though you may know the rules by which something operates, when the thing actually runs and applies those rules many times, the result can be a sophisticated computation—in fact, a computation sufficiently sophisticated that you can’t predict its outcome much faster than just having the computation run itself and seeing what happens.