David Deutsch - AI, America, Fun, & Bayes

**Dwarkesh Patel** (0:05)
Okay, today, I'm speaking with David Deutsch. Now, this is a conversation that I've been eagerly wanting to have for years, so this is very exciting for me. So first, let's talk about AI.
Can you briefly explain why you anticipate that AIs will be no more fundamentally intelligent than humans?

**David Deutsch** (0:24)
I suppose you mean AGI's?

**Dwarkesh Patel** (0:27)
Yes.

**David Deutsch** (0:29)
And by fundamentally intelligent, I suppose you mean capable of all the same types of cognition as humans are in principle?

**Dwarkesh Patel** (0:42)
Yes.

**David Deutsch** (0:42)
Well, so that would include doing science and doing art and in principle also falling in love and being good and being evil and all that.
So, the reason is twofold. And one half is about computation hardware, computation hardware, and the other is about software. So if we take the hardware, we know that our brains are touring complete bits of hardware and therefore can exhibit the functionality of running any computable function program for any computable function. Now when I say any, I don't really mean any, because you and I sitting here, you know, we're having conversation and we could say, you know, we could have any conversation.
Well, we can assume that maybe in 100 years time, we'll both be dead. And therefore, the number of conversations we could have is strictly limited. And also some conversations depend on speed of computation. So you know, if we're going to be solving the traveling salesman problem, then there are many traveling salesman problems that we wouldn't be able to solve in the age of the universe. So when I say any, what I mean is that we're not limited in the programs we can run apart from by speed and memory capacity. So all limitations on us, hardware limitations on us, boil down to speed and memory capacity. And both those can be augmented to the level of any other entity that is in the universe. Because if somebody builds a computer that can think faster than the brain, then we can use that very computer or that very technology to make our thinking go just as fast as that. So that's the hardware. As far as explanations go, can we reach the same kind of explanations as any other entity? Let's say, usually this is said not in terms of AGI's, but in terms of extraterrestrial intelligences. But also it's said about AGI's, you know, what if they are to us as we are to ants and so on? Well, again, part of that is just hardware, which is easily fixable by adding more hardware. So let's forget about that.
So really, the idea is, are there concepts that we are inherently incapable of comprehending? I think Martin Rees believes this.
He thinks that we can comprehend quantum mechanics, apes can't, and maybe the extraterrestrials can comprehend something beyond quantum mechanics, which we can't comprehend. And no amount of brain add-ons with extra hardware can give us that, because they have hardware that is adapted to having these concepts, which we haven't. The same kind of thing is said about maybe certain qualia, that maybe we can experience love, and AGI couldn't experience love because it has to do with our hardware, not just memory and speed, but specialized hardware. And I think that falls victim to the same argument. The thing is, this specialized hardware can't be anything except a computer. And if there's hardware that is needed for love, let's say that somebody is born without that hardware, then that hardware, that bit of the brain that does love or that does mathematical insight or whatever, it's just a bit of the brain and it's connected to the rest of the brain in the same way that the other part of the brain is connected to the rest of the brain, namely by neurons passing electrical signals and by chemicals, whose concentrations are altered and so on. So therefore, an artificial device that computed which signals were to be sent and which chemicals were to be adjusted, could do the same job and it would be indistinguishable and therefore a person augmented with one of those who couldn't feel love, could feel love after that augmentation. And I think those two things are the only relevant ones.
So that's why I think that AGI's and humans have the same range in the sense I've defined.

**Dwarkesh Patel** (6:18)
Okay, interesting.
Okay, so I think the software question is more interesting than the harder one immediately, but I do want to take issue with the idea that the memory and speed of human brains can be arbitrarily and easily expanded, but we can get into that later. We can just start with this question.