[ExI] Is the brain a digital computer?

Stathis Papaioannou stathisp at gmail.com
Mon Feb 22 14:22:20 UTC 2010

On 23 February 2010 00:37, Gordon Swobe <gts_2000 at yahoo.com> wrote:
> --- On Mon, 2/22/10, Stathis Papaioannou <stathisp at gmail.com> wrote:
>>> In general, nature "follows" no supposed laws or
>>> algorithms. She just does what she does, and humans talk
>>> about it with computations and so-called laws of physics.
>> Yes, this is something I more or less said before. There is
>> no fundamental low level difference between a computer
>> implementing a program and a brain generating thought.
> You start your first sentence with "yes" as if you agree with my words, but your second sentence shows that either you disagree or misunderstand.
> I consider computations of natural processes as acausal descriptions of material processes. By "acausal", I mean that although we may ascribe computational descriptions to natural processes, those computations will reflect no real underlying causal mechanisms. Such programs *describe* and *predict* natural processes but they do not *cause* natural processes.

The computations undergo the same causal mechanisms as anything else.
This bit hits that bit, which rolls onto the other bit, which closes
the circuit and makes a light flash, and so on. At the basic physical
level there is no "program", that's just something the human mind
superimposes on a certain type of physical activity. But you make the
outrageous claim that any machine which could be seen as implementing
a program loses any hope of being conscious. We might run into an
alien intelligence which everyone assumes to be conscious until we
figure out that there's a NAND gate made of protein in the ion
channels of its neurons - and then suddenly we realise that it must be
a zombie.

> This means we cannot actually duplicate natural processes with software. We can only *simulate* those processes, and simulations of natural processes have no real-world qualities; they exist only as digital descriptions of real things, as digital models of real things, as digital depictions of real things.
> Consider the example of a computation of a weather system, let us say a hurricane. Given enough information and the correct inputs, our computation will in principle perfectly describe and predict the hurricane's behavior. I think you will agree however such a perfect simulation would not prove that programs actually *cause* hurricane behavior.
> I do not believe the brain qualifies for any special exception to this rule. What applies to hurricanes and other natural processes applies also to the human brain. Despite the fact that we sometimes think of the brain as an "information processor", on close inspection our use of that term does not justify abandoning the view that the brain exists as just another natural object in nature, especially as it concerns consciousness. So then just as real hurricanes do not exist as computations, neither do real brains exist as computations.

We can certainly duplicate natural processes with computers. We do it
all the time. With the weather, we could have a computer controlling
the blowing air and dropping water here and there. With language, we
could have a computer interpreting an audio feed and responding via a
loudspeaker. But you say the computer can do anything else in the
universe (since you agree that physics is computable) *except* be
conscious. Consciousness has a magical status distinguishing it from
the rest of physics.

Stathis Papaioannou

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