The Metaphorical Fallacy

The mind is not literally a computer, but the mind is literally information–or at least the important bits are. And while it’s impossible to upload, say, a chessboard into a computer, it’s quite easy to upload the relevant information of the chessboard.

It may be the case that Robin means the human mind is _literally_ a computer. Many people with a formal computer science background use the term “computer” differently from laypeople.

Sure, sometimes they mean the same type of physical object as laypeople. But often they mean something roughly equivalent to “information processor”.

In this case, “The mind is a computer” is not a metaphor. Robin is asserting that the human mind obeys a set of information processing rules. All systems that obey such rules can provably be “uploaded” to a generic enough information processor. Therefore, human minds can be “uploaded”.

Now, you can argue that the mind doesn’t follow such rules or that there’s some fundamental limitation against us building a generic enough information processor, but simply asserting that he’s using a metaphor when in fact he isn’t won’t carry the argument.

2. A computer will overheat if its fan breaks.

This is only true for computers that use a fan for thermal regulation. Some computers use other means, such as a blood supply, sweating etc.

In more detail: the argument for uploading doesn’t depend on any special feature of the brain as compared to anything else in life or any other physical phenomenon. The assertion is that any physical phenomenon – a plant growing, a landslide, earthquakes on neutron stars, stalactite formation, whatever – is in principle amenable to simulation on a computer if we can gather enough information and throw enough computing power at it, and the brain is no different. This is broadly the Church-Turing thesis.

A friend simulates acoustics at the drilling point of oil wells. They scan the cavern the drill bit is in, reconstruct it in a computer, and simulate to predict how the acoustics will affect future drilling. This process is exactly analogous to how brain emulation might work, but no-one is asserting that the cavern is a computer.

The metaphorical fallacy is just another name for a false analogy, isn’t it?

Step 1 should be stated something like “a mind is computationally equivalent to a computer and is thus able to be simulated by a computer.” It’s not a metaphor.

I think Bryan’s point is spot on. Even if you assume the human mind only performs computable operations (which is dangerously close to assuming the conclusion IMO), that doesn’t mean it automatically can be uploaded and run on a digital computer.

Any digital computer can be simulated on a Turing machine. But the converse is not true, because Turing machines have an infinite amount of data storage. What if a brain is more like a Turing machine than a digital computer?

Perhaps more practically, the amount of processing power needed to fully simulate a brain might well be prohibitive. The mind has 10^11 neurons with 10^14 analog connections between then, all running in parallel. Proponents tend to use Moore’s Law to handwave that complexity away, but Moore’s Law is not a law of nature, it’s just a handy guide to what has happened in the past.

An analogy of my own: From 1900 to 1960, we went from horses to cars to planes to rockets. Everyone who thought about it figured it was obvious we’d have a base on the moon, space hotels, and flying cars by 2000. Yeah, not so much, eh?

I’m starting to suspect computing devices may be the same way. It’s easy to look at the last forty years and assume there will be just as much progress in the next forty years. But we’re already starting to hit the limits of current approaches.

Personally, in 1990, I just assumed we’d have strong AI by 2010. Today it seems much less likely to me that we’ll have strong AI in 2032. And strong AI is more or less equivalent to brain uploading….

“Ludicrous, but oh so tempting – especially if you’re part of a subculture that loves the metaphor in question.”

It’s not that the subculture LOVES the metaphor, it’s that the subculture LITERALIZES the metaphor, as Brian’s knows from his appreciation of the work of Tom Szasz, and as is evident from the comments above…

I’ve never seen Robin make the argument that is attributed to him here. He could well be wrong,and in general, I appreciate Bryan’s attempts to apply simple, common-sense arguments to simplify broad areas of study. In this case, though, the attack is against a complete straw man. It serves nothing.

In the interest of trying to raise the bar, let’s take a look at something Robin actually says to defend brain uploads:

http://hanson.gmu.edu/uploads.html

“Imagine that before we figure out how to write human-level software, but after we have human-level hardware, our understanding of the brain progresses to the point where we have a reasonable model of local brain processes. That is, while still ignorant about larger brain organization, we learn to identify small brain units (such as synapses, brain cells, or clusters of cells) with limited interaction modes and internal states, and have a ‘good enough’ model of how the state of each unit changes as a function of its interactions. The finiteness and locality of ordinary physics and biochemistry, and the stability of brain states against small perturbations, should ensure that such a model exists, though it may be hard to find. [4]

“Imagine further that we learn how to take apart a real brain and to build a total model of that brain — by identifying each unit, its internal state, and the connections between units. [5] A ‘good enough’ model for each unit should induce in the total brain model the same general high-level external behavior as in the real brain, even if it doesn’t reproduce every detail. That is, if we implement this model in some computer, that computer will ‘act’ just like the original brain, responding to given brain inputs with the same sort of outputs.”

This doesn’t look remotely like Bryan’s argument from metaphor.

what is consciousness ?
-> neurons firing, taking input from external systems and feeding it to complex neural networks.
Networks so complex that it can produce infinite o/p to single i/p.
it is recursion, we take in information and give it to our-self’s.
It is continuous recursion.
We call it consciousness.

Consciousness is no different from a stone rolling down a hill.
Consciousness, it is trivial.

it was bound to happen.

assuming physics law exists, and universe is there(existed) for (trillionx10^999…) of years:-
*just as a stone on a mountain slop has a good probability of rolling down, it is of no surprise that complex exotic reaction(that formed elements from energy…see fusion) lead to formation of things like complex proteins, which overlapped and folded on each other to give a DNA.

This would require a really long time.

A stone rolls over a slope because of the laws of physics, it has motion, it does something, it degenerates on the way down, it breaks some peaces, it disturbs the earth, it breaks other stones, it causes vibration in air. Technically it is as much as conscious as us.

Compared to what is there in the universe:consciousness, It is trivial.

Are similes better than metaphors?

A Thermodynamic Limit on Brain Size

If our brains have to be cooled like computer chips, is there a limit on how big they can be?
[Jan Karbowski at the Sloan-Swartz Center for Theoretical Neurobiology at the California Institute of Technology] points out that brain cooling is not a classic problem of surface-area to volume. Instead, brain cooling is more closely comparable to that in a combustion heat engine where a liquid coolant removes heat… This implies that the thermodynamics of heat balance does not restrict the brain size. And this in turn suggests that brains could be heavier than 5 kg, says Karbowski.