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by Zaphods 2618 days ago
> It's because it is effectively a computer. Not in the vague sense of "it has stuffs connected to stuffs and there's electricity involved", but in the more specific sense that it takes inputs, produces complex outputs, has clearly identifiable hardware and indirectly identifiable software. It even has internal structure we're only beginning to understand, but that we know enough about to reasonably infer what computations happen where. There's little reason to assume there's some metaphysical mystery here, as exactly zero other things in the universe that we studied since the dawn of humanity turned out to be magic.

You're conflating the ability to compute with ontology. Computers compute. That's all they do. They're programmed to do only that. Humans have other abilities, such as imagination, that are not computational. Computers cannot imagine, not because of limited hardware or software; they can't imagine because they only compute. Imagination isn't computational. All throughout your response you are using the terminology of computers and software as if they are completely intuitive, but we have other terminology to define those things: medical terms define parts as the brain as parts of the brain not as hardware because that's a metaphor; the cerebelum is like this part of the computer. What they are is not the same as what they can do. That's not some magical mystery, or even obscure metaphysics. A car's horsepower is not in its carburetor, or its gas, or its manifold, because the horsepower of a car is what it can do, its an ability, a power. In the same sense the brain can compute, but that doesn't mean it is a computer.

What else could it be? A brain. Animals have them. They are not computers. But they can compute. The field of computer science and software development only slightly aligns with studying the brain.

> If I know the limit of applicability of my computer knowledge, I sure can comment on brain and consciousness.

Yes and when it is no longer applicable it is no longer right or wrong: it's just assumption. That you can fuzzily attach assumptions to arguments about the brain does not mean the brain is a computer. It means you can fuzzily model the brain on a computer, but that model will have glaring gaps. You can build from your assumptions but you have to accept the limitations of that assumption. Assuming the brain is a computer comes with glaring limitations.

2 comments

> A car's horsepower is not in its carburetor, or its gas, or its manifold, because the horsepower of a car is what it can do, its an ability, a power. In the same sense the brain can compute, but that doesn't mean it is a computer.

A car's horsepower is in the engine. That's what an engine does. Burns fuel, provides work over time. Work over time is denominated in horsepower - or, in saner company, in watts. Categories like "engine" or "computer" are not excluding. That thing in the car can be "an engine", "a hunk of metal" and "an expensive paperweight" at the same time. Similarly, if brain can compute, it is a computer. It's also an organ.

> Humans have other abilities, such as imagination, that are not computational.

Evidence needed. Why would it not be computational? We can, and do, easily build imagination-like computations. A fuzzy search on a graph. A series of simulations with relaxed constraints and somewhat randomized initial states. They all resemble aspects of imagination; it's not a big leap to conclude that imagination is nothing but a more complex variant of such computations.

> It means you can fuzzily model the brain on a computer, but that model will have glaring gaps.

Models exist on a map, not in the territory. So do brains and computers. The territory is made of whatever sub-quark substrate the reality is made of. When you say "brain", what you're really referring to is a model, and a pretty black-boxy one. Viewing the brain as a computer is an attempt to apply a model that's little more transparent (and therefore more useful); as long as it matches observable evidence (and it does), it's the right thing to do.

Sorry, I didn't see that you'd replied to my comment until today.

> A car's horsepower is in the engine.

Where is it in the engine? The engine can go 180hp. But the engine does not contain 180 hp. That's what the concept of an ability or a power is. A broken engine cannot go 180 hp. But, if as you say, it is in the engine, then that distinction would be irrelevant. We would still say a broken engine can go 180 hp. But we don't.

> Similarly, if brain can compute, it is a computer. It's also an organ.

Right, you'll see I have never said the brain can't compute. But that doesn't mean it is simply a computer. If the assumption that the brain is a computer is to stand then the abilities of a computer should be compared to the abilities of a brain, or a person. There are those that match. We agree on that. But there are those that do not. And that means the assumption that the brain simply is a computer is flawed. It is an organ that can compute. But to extend from that that it is a computer is eliding the crucial difference between the two. That is your assumption.

> Evidence needed. Why would it [imagination] not be computational?

Let's ignore that the premise you are making: that imagination is computational, requires you to support it as well;

> imagination-like computations

> A fuzzy search on a graph

> A series of simulations with relaxed constraints and somewhat randomized initial states

All require you to posit things that are -like, or somewhat like imagination. But computers are programmed. They can't think new thoughts. They are closed deterministic systems. That their output seems imaginative or novel does not mean the computer has the ability to imagine, it means the computational output was unexpected to you or the people who wrote the code. The idea that imagination is computational is a category error.

> not a big leap to conclude that imagination is nothing but a more complex variant of such computations

This is actually an enormous leap. Can computers imagine? You will find zero agreement in that regard. That doesn't prove your point. You'll need to provide evidence that computers can actually violate their programming, cannot just compute and instead imagine. But that's not what computers do. Computers compute. That they can do things that seem like imagination to you does not mean they can imagine.

>> It means you can fuzzily model the brain on a computer, but that model will have glaring gaps.

> Models exist on a map, not in the territory. So do brains and computers. The territory is made of whatever sub-quark substrate the reality is made of. When you say "brain", what you're really referring to is a model, and a pretty black-boxy one. Viewing the brain as a computer is an attempt to apply a model that's little more transparent (and therefore more useful); as long as it matches observable evidence (and it does), it's the right thing to do.

Excuse my original words, I meant "fuzzily model the brain as a computer

Again, I don't think applying the computer as a model is completely invalid. But it has limitations. You can't just brush off those limitations when you talk about the brain as a computer. They fundamentally mean the comparison is less useful. Supposing it is 1 to 1, which you are doing leads you to build on assumptions that are unsupported. You have to accept that the assumption that the brain is a computer has serious criticisms brought against it. And you have to defend that assumption. You can't simply ignore them and argue that you are right.

For instance viewing the brain as computer frequently does not match the observable evidence. We can imagine. Computers cannot. That is observable. So how do you support the assumption that the brain is a computer in spite of that?

Computers "imagine" things all the time. The fact that we do not use the word "imagine" to describe it is immaterial. Words to not dictate the behavior.