
String theorist Edward Witten says consciousness “will remain a mystery” - RubyMyDear
http://blogs.scientificamerican.com/cross-check/world-s-smartest-physicist-thinks-science-can-t-crack-consciousness/
======
xg15
Personal opinion: I can imagine that the reason of how we _experience_
consciousness might be unsolvable, much as the question how the color blue
feels is hard to answer objectively.

However, I think there are a lot less fuzzy questions that are strongly
connected with consciousness that I'm hoping can be find answers for - and
that could shed some more light on what consciousness is and what it isn't.
Such as:

\- what are memories? Could we build some machine to extract or even
manipulate them? Is it possible to compare memories of different people?

\- what are dreams?

\- different parts of our body are affected differently by our consciousness:
Some things we can control directly, like hands, feet, speech, etc; some
processes we cannot control but we do experience them, such as hunger or
sleep; and some we neither control nor experience such as digestion,
homeostasis etc, even though they are also regulated by the brain. Even more
couriously, many of those autonomous processes _are_ greatly affected by
conscious thoughts even though we don't experience them as directly
controllable - such as fear and arousal. Inversely, conscious actions often
have autonomous "sub routines", such as walking. So what what mechanism in the
brain governs which processes are conscious and which are not?

\- Suppose we could actually do brain transplants. Assume we put an adult
human brain in a jar and connect it with some kind of VR. Could the brain
learn to control a non-human body such as a spider? How about a human body
with different proportions?

~~~
adrusi
These are all part of the easy problem of consciousness, so yes, I don't think
anyone doubts that they can be answered in principle. But there's the hard
problem of consciousness, which this article talks about.

[https://en.m.wikipedia.org/wiki/Hard_problem_of_consciousnes...](https://en.m.wikipedia.org/wiki/Hard_problem_of_consciousness)

~~~
xiler
In particular see the "Mary the super-scientist" thought experiment for a nice
explanation of the difference between the two.

[https://en.wikipedia.org/wiki/Knowledge_argument](https://en.wikipedia.org/wiki/Knowledge_argument)

[http://philosophyfaculty.ucsd.edu/faculty/rarneson/Courses/F...](http://philosophyfaculty.ucsd.edu/faculty/rarneson/Courses/FrankJacksonphil1.pdf)

~~~
omginternets
I would also read Daniel Dennett's _Consciousness Explained_ for a counter-
point about why "Mary the super-scientist" is based on a faulty premise, and
why the Hard/Easy distinction is fallacious.

[https://en.wikipedia.org/wiki/Consciousness_Explained](https://en.wikipedia.org/wiki/Consciousness_Explained)

------
HONEST_ANNIE
Witten:

> But I think there probably will remain a level of mystery regarding why the
> brain is functioning in the ways that we can see it, why it creates
> consciousness or whatever you want to call it. How it functions in the way a
> conscious human being functions will become clear. But what it is we are
> experiencing when we are experiencing consciousness, I see as remaining a
> mystery...

Understanding the difference between __workings__ and experience of
consciousness, the hard problem of consciousness [1], is crucial for
understanding what Witten says. Witten says that while science will figure out
how mind works in great detail the hard problem of consciousness remains
outside science.

It's easy to be sympathetic to Witten. The problem with consciousness seems to
be with intuitive meaning of a word and concept.

Imagine that someone builds small programs -- or really small brains in a vat
-- that are conscious of color blue, or feel universal love and nothing else.
Program's attention and awareness never goes elsewhere and it performs no
other cognitive tasks than being conscious in the moment without long term
memory. Can you imagine scientists going trough the __workings__ -- code,
neuron diagrams or state representations -- of it's mind and going, oh this
thing clearly conscious, we can see it now and agree.

There seems to be assumption that the hard problem of consciousness is tied to
multiple high level cognitive capabilities. I don't see the connection. The
crux of being conscious is having the cognitive ability of aware-consiouns-
attentative-reflective at least tiny amount of time. If we could
scientifically determine what consciousness is, we should be able to make nice
hyper-aware-of-blue-and-knowing-it program and it would be relatively simple
one.

[1]:
[http://www.scholarpedia.org/article/Hard_problem_of_consciou...](http://www.scholarpedia.org/article/Hard_problem_of_consciousness)

------
paulofalcao
The article is based on a video from 2014.
[https://www.youtube.com/watch?v=RfwsvSjXkJU](https://www.youtube.com/watch?v=RfwsvSjXkJU)

~~~
S4M
I you want to check the video I'd recommend to skip to approximately minute
13, as the beginning is pretty boring - 1 minute of musical introduction, then
the hand of Edward Witten looking in his notes, and then some introduction in
what I believe is Dutch.

------
visarga
Rather than physics, I think computational neurology and machine learning /
deep learning / AI have a much better chance at elucidating what consciousness
is.

~~~
balazsdavid987
I can't tell whether you are being sarcastic or not. Machine learning has
absolutely nothing to do with consciousness. From where people get that
connection?

~~~
eutectic
Does human learning have anything to do with consciousness?

~~~
visarga
I don't think there is something magical in flesh. Consciousness is a process
of constructing compact and effective representations of the external world
which are necessary in order to learn behavior that maximizes rewards
(survival). More sophisticated organisms also develop a model of the world and
operate on it by imagination or memory recall, so there is also consciousness
of internal mental processes. Such mental processes look like a neural turing
machine (read from memory, write to memory, focus on specific parts of sensory
field / attention). The mental programs to operate over memory and attention
are learned by reinforcement learning. Physical control and operating in the
external environment are learned by RL too. The notion of self and language
emerge naturally from the need to cooperatively solve problems together with
other agents. The teaching signal (reward) is based on the environment and
inborn instincts (such as hunger, sleep, defense, sex, cooperation) which are
evolutionarily evolved. Part of the perception process is based on
unsupervised learning, where raw sense data is encoded in the latent semantic
space and then, by a top-down process, is tested by regenerating the original
input data. It learns by propagating the error (differences) from the data it
generates compared to the original sense data. All these processes have been
already implemented, albeit crudely, by machine learning.

Deep Mind has stated that their purpose this year is to build a rat level AI
([https://www.youtube.com/watch?v=MAMuNUixKJ8](https://www.youtube.com/watch?v=MAMuNUixKJ8)).
That would entail rat-level consciousness too.

------
danieltillett
Of course it will remain a mystery until we can get to an agreed definition of
what consciousness is. Until then it is just an argument in semantics.

On a personal note I have never been very impressed with arguments over the
importance of consciousness. I have had too many experiences in life where
consciousness is grey to feel it is anything other than a just-so story of
what happened.

------
JulianMorrison
See, if a neuroscientist went and had an opinion on sub-atomic physics, people
would say "that's nice" and pat them on the head in a patronizing way. But the
problem is general. A scientist outside their field _is a layman_.

~~~
AReallyGoodName
Is a neuroscientist more qualified than a physicist on this particular topic?

Personally I'd leave it to the philosophy guys since we're that far from any
understanding of it.

~~~
JulianMorrison
If I was to give my unqualified, layperson opinion, I'd say "horse feathers".
Consciousness probably isn't "hard" at all. It's a massively parallel brain
architecture (which by its widely-spread and slow nature can't accurately self
monitor) using theory-of-mind circuitry (developed to handle interpersonal
social relations) to model and monitor its own operation.

But it feels more sparkly and special to treat it as a mystery.

~~~
igf
Okay, fine, but why am _I_ in here experiencing it?

~~~
JulianMorrison
You mostly don't self-experience. Mostly you experience what's going on around
you, and what you're doing and physically feeling. Mostly, you don't act
consciously. But when you direct attention at your own experiencing, or at
your own actions in a deliberate way, a subsystem dedicated to that task wakes
up and provides you with a homunculus self-model. That would be the 'I'.

~~~
TheOtherHobbes
And how do you get from a homunculus self-model to the subjective experience
of the colour blue? (Or any other colour?)

...Which would be a subjective experience that seems to have curiously
objective elements to it, because colours have been shown to correlate with
specific sensations and associations across populations.

And _then_ there's the much deeper question of the extent to which quantum
phenomena need an objective observer.

If you think that question is trivial, try to design an experiment which
provides objective evidence of change without ultimately relying on the
subjective experience of a human experimenter.

~~~
JulianMorrison
They're separate, of course. People tend to over-attribute things to their
consciousness. Blue is an analysis and categorization being done by the visual
processing part of your brain. That part of your brain is grown by basically
the same genes as everyone else's. It would be more surprising if it wasn't
similar in operation.

Your subjectivity is your brain is you. But only tiny scraps of it are
consciously accessible. Nearly all of it just _does_ , it doesn't reflect on
the doing. You only notice your visual processing when you force it to glitch
or strain with optical illusions and the like.

------
paulofalcao
If the simulation theory is true, our memory, and all brain activity is done
in the simulation (aka real world), but consciousness no. With no
consciousness we could have a identical behavior, we would be intelligent
zombies. Its cool to think that the world is rendered only when conscious
beings see the world ("is the moon there when nobody looks?"). Or... are YOU
the only one with consciousness? :)

~~~
chriswarbo
> all brain activity is done in the simulation (aka real world), but
> consciousness no.

The simulation hypothesis does not make such dualistic arguments.

------
hacker_9
We understand consciousness perfectly, being conscious beings an all. It's the
physical world that doesn't make any sense.

------
tpm
A very good book about what we currently (minus 3 years, perhaps) know:
[https://www.amazon.com/Consciousness-Brain-Deciphering-
Codes...](https://www.amazon.com/Consciousness-Brain-Deciphering-Codes-
Thoughts/dp/0143126261/)

~~~
acqq
The approach I like is:

[https://www.amazon.com/Consciousness-Social-Brain-Michael-
Gr...](https://www.amazon.com/Consciousness-Social-Brain-Michael-
Graziano/dp/0199928649)

An article by the same author:

[http://www.theatlantic.com/science/archive/2016/03/phlegm-
th...](http://www.theatlantic.com/science/archive/2016/03/phlegm-theories-of-
consciousness/472812/)

~~~
tpm
I like his approach very much, but I think he is a bit too generous with the
artistic license and short on actual research, which is the opposite with
Dehaene. I might be wrong of course. But Graziano is perhaps the best writer
among current neuroscientists.

------
golergka
I have no evidence or proof, but personally, I believe that the whole
consciousness thing is an illusion. There's certain level of abstraction
required for a bran as advanced as human's, but in the end, it's just matter
following the laws of physics, same as everything else.

~~~
warrenpj
The problem with this language is that the very word "illusion" implies an
observer.

To whom is it an illusion? And, what are the properties of this illusion? Can
we make artificial minds that are also suffering from the same illusion?

The very fact that there is (let's suppose) such an illusion requires an
explanation. Suppose the brain has somewhere encoded the idea of
consciousness, but no "actual" consciousness. Why do we require the extra step
of "actual" consciousness rather than mere "illusory" consciousness?

Of course the real explanation of consciousness will be both profound
(beautiful, unexpected) and mundane (non supernatural).

~~~
espadrine
> _Of course the real explanation of consciousness will be both profound and
> mundane_

The expectation of something does not guarantee its existence. Words are
created to define the expectation of something unexplained, only to be
discarded when the expectation is unmet.

Take the word "miasma". At some point in history, a belief was born that all
diseases came from gaseous poisons emitted by rot. Then the miasma theory got
definitely discarded when we got the ability to view germs, which are simply
distant cousins.
[https://en.wikipedia.org/wiki/Miasma_theory](https://en.wikipedia.org/wiki/Miasma_theory)

Take the word "aether". Since waves on the sea were carried by water and sound
waves by air, it was assumed that interplanetary space was filled with a
substance that light (assumed to be just a wave back then) was carried
through. It was called aether. It turns out the real explanation of aether is
not profound nor mundane: there is nothing, and that nothing expands.
[https://en.wikipedia.org/wiki/Aether_theories](https://en.wikipedia.org/wiki/Aether_theories)

I don't really understand why it is hard to accept that there is no after-
life, that all our activities are the sole result of chemical transmission of
signals in our brains... that there is no point of view, just local chemical
storage of information.

But it was hard for our ancestors to fathom that humans were part of a
phylogenetic tree encompassing all Earth life forms, that we as a species were
not special. It was hard for them to fathom that space is relative, that there
is no center. I suppose it is always hard to accept that there is no reference
point in the universe.

~~~
warrenpj
> that there is no point of view, just local chemical storage of information.

You have just restated the problem of consciousness, except as an assertion
that it doesn't exist.

The problem of reductionism is that it doesn't stop; just as there aren't
really points of view, there aren't really any chemicals, and there isn't
really such a thing as (classical, let's say) information. All of these things
are "just" emergent phenomena.

The explanations which made "aether" and "miasma" obsolete are beautiful,
unexpected at the time (in a trivial sense), and of course, not supernatural.

I agree with you about the afterlife. However consider this: if the universe
is infinite, isn't it likely that there will be copies of you which arise
spontaneously, in all conceivable circumstances? The older you get, the less
likely you are to be in a place or time that is causally connected to your
birth, because most causal chains involve your death. (This is just a specific
case of a Boltzmann Brain[1])

Of course, this sort of nonsense thought experiment runs afoul of the Measure
Problem [2]. But this is precisely the kind of problem that I hope the
explanation of consciousness would help to resolve.

[1]
[https://en.wikipedia.org/wiki/Boltzmann_brain](https://en.wikipedia.org/wiki/Boltzmann_brain)

[2]
[https://en.wikipedia.org/wiki/Measure_problem_(cosmology)](https://en.wikipedia.org/wiki/Measure_problem_\(cosmology\))

~~~
espadrine
> _You have just restated the problem of consciousness, except as an assertion
> that it doesn 't exist._

Things that don't exist are rarely problematic. But in fairness, I cannot
guarantee that there is no consciousness, just as I cannot guarantee that
gravity exists — it could be part of a simulation in which I was put since
birth, and the real world could have very different laws of physics. Nothing
new here, it is Occam's razor.

> _it doesn 't stop; just as there aren't really points of view, there aren't
> really any chemicals, and there isn't really such a thing as (classical,
> let's say) information._

There is such a thing as a point of view. I object to the notion of
consciousness solely because of how it is used. Plants have points of view
too; jellyfish do too, without the need for a brain. They react intelligently
to their environment. Are those conscious? It is clearer to talk about
"brains" and "points of view" than it is to talk about "consciousness".

> _The explanations which made "aether" and "miasma" obsolete are beautiful,
> unexpected at the time (in a trivial sense), and of course, not
> supernatural._

I suppose that's up to each of us to judge. I don't find the idea that
throughout my body, millions of tiny unicellular parasites are having a snack,
particularly beautiful. Similarly, the idea that there is an invisible energy
pulling everything apart always felt supernatural to me.

> _if the universe is infinite, isn 't it likely that there will be copies of
> you_

The probability is above zero, but given that space is overwhelmingly empty,
and given how much information defines my identity (including my average DNA,
which is inherited from millions of years of evolution in extremely specific
circumstances), it seems unlikely. If there is a copy of me in the universe,
the most probable location would be on Earth, extremely close to where I sit.

------
acqq
In my experience all those "consciousness is otherworldly magic" people are at
least heavily influenced (1) by the religious interpretation of the "magical
uniqueness" of the humans compared to the all other living beings. Wishful
thinking. Then comes the "free will" and other also "magical" thinking.
Especially easy to sell in the US (2)

And we aren't made of anything other than what all the animals are made of,
and the underlying processes in our brains aren't physically unique. And
there's no "spirit" or "soul" needed to explain anything.

The word spirit comes from Latin spiritus "breath." Ditto for the term for
soul "psyche" which comes from the ancient Greek psykhe with the original
meaning "breath." That's all that "leaves us" when we die (as we "have our
last breath") and from where all the magical thinking came.

The consciousness is just a product of evolution, and "a kind of self
awareness" exists by animals too. Not much different from what we observe by
ourselves, and actually of direct evolutionary advantage.

More about all that:

[http://www.vice.com/read/sorry-religions-human-
consciousness...](http://www.vice.com/read/sorry-religions-human-
consciousness-is-just-a-consequence-of-evolution)

[http://www.livescience.com/26338-crabs-feel-
pain.html](http://www.livescience.com/26338-crabs-feel-pain.html)

[http://backreaction.blogspot.com/2016/01/free-will-is-
dead-l...](http://backreaction.blogspot.com/2016/01/free-will-is-dead-lets-
bury-it.html)

[https://en.wikipedia.org/wiki/The_Demon-
Haunted_World](https://en.wikipedia.org/wiki/The_Demon-Haunted_World)

\---

1) if themselves not explicitly declared believers or at least philosophers,
the latter having all the incentives to mystify the topic and stay away from
the hard sciences

2) 4 of 10 in the US believe "that God created humans in their present form
10,000 years ago: [http://www.gallup.com/poll/170822/believe-creationist-
view-h...](http://www.gallup.com/poll/170822/believe-creationist-view-human-
origins.aspx)

~~~
chriswarbo
> The consciousness is just a product of evolution

Exactly. Nothing makes sense in biology except in the light of evolution (
[https://en.wikipedia.org/wiki/Nothing_in_Biology_Makes_Sense...](https://en.wikipedia.org/wiki/Nothing_in_Biology_Makes_Sense_Except_in_the_Light_of_Evolution)
).

Why do some digger wasps only count their own contribution to a nest (
[https://www.researchgate.net/publication/245965580_Do_Digger...](https://www.researchgate.net/publication/245965580_Do_Digger_Wasps_Commit_the_Concorde_Fallacy)
), and why do some perform redundant nest-checking (
[https://en.wikipedia.org/wiki/Sphex#Uses_in_philosophy](https://en.wikipedia.org/wiki/Sphex#Uses_in_philosophy)
)?

For the same reason we don't calculate exact solutions to large travelling
salesman problems; it's much more economical and evolutionarily advantageous
to use heuristics, even if they have quirky side-effects and edge-cases.

------
moonshinefe
It may be a mystery for some time, but I suspect we'll figure it out
eventually. Given the rapid pace medical science understanding has gone
through in the last several hundred years, it seems likely.

------
Angostura
This reminds me rather of Roger Penrose's foray into consciousness in The
Emperor's New Mind.

If you wade your way through it, you'll find the tl;dr is 'consciousness must
be a quantum thing because quantum things are mysterious and so is
consciousness- oh and look at those microtubules in those neurons - you might
get quantum effects in there.'

Rather disappointing for such a brilliant man.

~~~
fdej
Yep. Penrose's argument goes something like this (oversimplified): 1) Turing
machines can't solve the halting problem. 2) Humans can solve the halting
problem. 3) Therefore, humans can't be Turing machines.

There are two problems with this line of reasoning. The first problem is that
2) is unsubstantiated. A human can see immediately that 15 = 3 x 5, but this
doesn't mean that we have a magical ability to factor integers instantly. By
the frivolous theorem of arithmetic, almost all natural numbers are very,
very, very large. We have some ability to analyze formal systems, but the
systems we have managed to understand are very simple in the grand scheme of
things. Almost all formal systems are very, very, very complex, and there is
no evidence that we can understand them all and/or that our understanding
process actually is correct (consistent) when extended indefinitely. Penrose's
actual argument is of course more technical, and others have made more precise
rebuttals.

The second problem is that the argument does not solve the problem of
consciousness. Scott Aaronson put it nicely: "Even if we supposed the brain
was solving a hard computational problem, it's not clear why that would bring
us any closer to understanding consciousness. If it doesn't feel like anything
to be a Turing machine, then why does it feel like something to be a Turing
machine with an oracle for the halting problem?"

------
thedonkeycometh
And he would know... <insert punchline here>

------
Vanit
Insert opinion on consciousness here, because having it means I understand it
at a low level.

~~~
Natsu
It's a subjective experience, so I'm not sure we can reason very well about
what anything fundamentally unlike ourselves subjectively experiences. I mean,
I can program my computer to print out "I calculate, therefore I am" but who
knows what, if anything, the processor experiences as it calculates that.

------
mozumder
Consciousness is based on a fifth fundamental force in the universe, and
certain structures, like DNA, are tuned into that force, like an antenna.

~~~
Scea91
Statements like this, without any arguments to support them, are quite
uninteresting.

~~~
mozumder
Nothing is intrinsically interesting. Everything is just habit, based on what
you are used to.

