

Zombies - infinity
http://plato.stanford.edu/entries/zombies/

======
memetichazard
Having read through the first third of the paper or so, here's some thoughts.

I'm not convinced by the fact that showing 'possibility' of zombies is enough
to eliminate physicalism. The argument they use is too slippery for me to
grasp, but it basically sounds to me something like this:

Skeptics think that the laws of physics are sufficient to describe the
universe. It suffices to show that magic is possible, and then skepticism is
false. This is why opponents of skepticism do not have to point to actual
cases of magic being performed; it is enough if such things are possible.

Second, along the lines of conceivable -> possible, here's an interesting
thought experiment.

I can conceive of an immovable object. An object such that when it is inserted
into our universe, it can never be moved with respect to some frame of
reference. Such an object is much easier to conceive of than a zombie.

I can conceive of an irresistable object. This object is such that it moves
with constant velocity relative to some frame of reference, and its velocity
can never be changed.

I find it hard to accept that the possibility of such concepts can be used to
show anything useful about the universe.

Further on, I found that the best counterexample included was that of Daniel
Dennett, who compares the idea of consciousness against the idea of health -
to quote the quotation:

Supposing that by an act of stipulative imagination you can remove
consciousness while leaving all cognitive systems intact — a quite standard
but entirely bogus feat of imagination — is like supposing that by an act of
stipulative imagination, you can remove health while leaving all bodily
functions and powers intact. … Health isn’t that sort of thing, and neither is
consciousness (1995, 325). <end quotation>

Finally, it's nice that they went out and mentioned all the issues with
semantics around the concepts of 'conceivable' and 'possible', because that
was the part that feels like it wants to give me a migraine.

Last thought: One of the ideas was that whatever it is that distinguishes us
from zombies does not exist in a physical sense. But we have devices that can
read our thoughts - or at least show that our physical state is changing while
we think.

My MRI shows brain activity, therefore I am.

~~~
gjm11
The alleged inference from "zombies are possible" to "physicalism is wrong"
isn't quite what you say. It goes more like this. (1) If physicalism is
correct, then (e.g.) mental states are _identical to_ physical brain states.
(Or something along those lines.) (2) But if A is identical to B, then A = B
in all possible worlds; that is, A is _necessarily_ the same as B. (3)
Therefore, if physicalism is correct, then in no possible world are there
zombies; necessarily, there are no zombies. (4) In other words, if it is
possible that there are zombies, then physicalism is wrong.

I think this argument is rubbish. Claim 2 seems like obvious bullshit, unless
"identical" is given some weird technical meaning that makes claim 1 bullshit
instead. Further, with the sense of "possible" that's relevant here it's very
far from clear that anyone's shown that zombies are possible. (The SEP page
treats this point quite well.)

I have used the following parallels before: I can imagine electric current
flowing without any charged particles being present, "therefore" electric
current is not the same thing as the movement of charged particles; I can
imagine my computer continuing to do what it does without its circuitry and
what happens therein, "therefore" the processing my computer does is not a
mere activity of its circuitry. What twaddle. (See
<http://www.mccaughan.org.uk/g/log/2007/inconceivable.html> for a longer rant
on the subject, complete with a couple of quotations to show that some
philosophers really do think such silly things in the case of consciousness.)

~~~
Asmodeus
(2) Is most certainly true.

If A == B, then B just is A, we're saying A == A. A possible world where B !=
A is a world where A != A. You seem to believe that A != B even in our world.

(1) is the essence of the physicalist claim. You can certainly declare it
bullshit if you want...

The leap in in (3). While brains and mental states as we know them must be
identical, according to physicalists, other worlds may do brain-like and
mental-state-like things _not_ as we know them.

For instance, we may have misunderstood our own world.

Oddly, (4) gets back on track. If zombies can be proven to be possible (which
conceivability does not do) then physicalism is false. (Although, this
generally implies epiphenomenon, which also implies causality is false, which
puts consciousness outside of logic {P -> Q} let alone physics.)

~~~
gjm11
Whether 2 is true depends on how you understand "identical". For sure, if you
mean something like "synonymous", then probably "identical" things are the
same in all possible worlds. But if you take it broadly enough that, e.g.,
"consciousness is identical with something that happens in the brain" isn't
false _by definition_ then I don't see how your argument works.

I only think 1 is bullshit if you use something like the "synonymous"
definition. (Can we agree that it's crazy to say that physicalism requires
believing that "consciousness" just _means_ some particular set of brain
processes?)

I think your comment about 3 basically amounts to agreeing with me that
physicalism doesn't say that mental states and brain states are "identical" in
any sense that makes the rest of the zombie argument work.

I agree, of course, that if 1-3 are correct then "zombies are possible"
implies "physicalism are wrong".

Epiphenomenalism doesn't imply that causality is false. And if consciousness
is "outside of logic" then I say: so much the worse for the notion of
consciousness. (But I don't see any reason why we should think consciousness
is outside of logic, whether zombies are possible or not.)

------
req2
Eliezer Yudkowsky lays out the Bayesian reductionist argument in his Zombies
sequence: <http://wiki.lesswrong.com/wiki/Zombies_(sequence)>

It's a good accessible read, mentions a few of the interesting questions
zombies can shed light on, and has a fair number of reader comments and
responses.

~~~
gjm11
In particular, anyone with a passing familiarity with the issue is likely to
find the movie script at <http://lesswrong.com/lw/pn/zombies_the_movie/>
extremely funny.

------
gort
The problem with philosophical zombies ("p-zombies") is that, since they're
indistinguishable from normal humans, some of them must go around talking
about qualia and consciousness and so on; it's mysterious what's causing them
to do this, since they don't actually have any qualia or consciousness.

This is the strongest argument that mind is matter: mental things like qualia
clearly do cause physical events (e.g. discussions about qualia), which seems
to suggest that qualia etc are themselves physical, since we expect physical
events to have physical causes.

(And yet I can't stop wondering how being a collection of atoms feels like
anything.)

~~~
WilliamLP
I've never understood why that's an argument, or why talking about qualia and
consciousness depends on having them, any more than a program that prints
"ouch" when you stop it feels real pain.

To me, there just seems to be an undecidable knot there that can never go
away, even if you say it doesn't exist like Dennett and others.

Another thing that never gets said is that questions of consciouness are
really questions about solipsism in disguise. The real question isn't whether
what it's like to be my neighbour is different than what it's like to be
someone who died 100 years ago. The only real "obvservable" difference is that
it's like something else to be _me_.

~~~
gort
"I've never understood [...] why talking about qualia and consciousness
depends on having them"

It doesn't, but _someone_ has to have them in order for the concepts to get
introduced in the first place.

Imagine a world that has always been populated entirely by p-zombies. By
definition, that world should be indistinguishable from this world, so how on
earth did they get started talking about consciousness and qualia?

In your example of the "ouch" printing program, someone had to have pain and
say "ouch" before such a program was made.

~~~
gloob
_Imagine a world that has always been populated entirely by p-zombies. By
definition, that world should be indistinguishable from this world, so how on
earth did they get started talking about consciousness and qualia?_

The answer to the question "how did they get started talking about qualia" is:
by definition, the hypothetical Z-world is indistinguishable from ours. In our
world, people talk about qualia. Therefore, in the Z-world, zombies talk about
qualia. What's more, the beginning of "zombies talking about qualia" would be
the same as the beginning of "people talking about qualia".

I have a feeling I'm misunderstanding you.

 _In your example of the "ouch" printing program, someone had to have pain and
say "ouch" before such a program was made._

Why? What if the program is the output of a random number generator? Does that
mean the random number generator experiences pain?

~~~
orangecat
_The answer to the question "how did they get started talking about qualia"
is: by definition, the hypothetical Z-world is indistinguishable from ours. In
our world, people talk about qualia. Therefore, in the Z-world, zombies talk
about qualia._

Right. Which implies that the reason that we talk about qualia is not that we
have them (otherwise zombies wouldn't), but for some completely different
reason that just happens to exactly line up with the qualia that we in fact do
have. That would be an astounding coincidence and is a major strike against
the theory per Occam's Razor.

------
maudineormsby
I've lost count of the number of times Zombies came up in our Philosophy of
Mind classes. The classic question was always "if consciousness can be
entirely reduced to physical phenomena, then isn't the only difference between
a zombie and a person that they have different brain states (or a lack of
certain ones)?"

That made people very uncomfortable about a lot of things, and really
demonstrated the group feeling that consciousness has to be some other
substance. A lot of great conversations about verifiability, positivism,
philosophy of mind, and naturalism/materialism were started with Zombies.

~~~
electromagnetic
I always like these kinds of debates, but they always strike me of being
fundamentally futile.

The arguments always assume that we have qualia as a prerequisite and that a
zombie doesn't. However, the very people who believe in qualia will themselves
say that animals don't possess qualia as they're not conscious. Yet we as
conscious thinking humans do. So how did we acquire this from a logical
standpoint? Because surely a biologically identical zombie, built atom for
atom the same way as a human would itself possess qualia. If the zombie
doesn't posses qualia, how did we acquire it? I'm genetically related to a rat
and at one point in history we were the same species, so how did I acquire
qualia and it not?

It eventually just strikes me that it's an asinine argument, and only
unthinking zombies would waste their time with it, thus we have proof of
p-zombies in the form of the qualophiles and qualophobes, because no one else
gave a big enough shit for long enough to think past an initial idea and the
two camps have been left arguing as futilely as if they were arguing over the
existence of god.

------
joeyo
For some reason these arguments all seem to start with the assumption that
_we_ are not all zombies. I have yet to see any good evidence that we aren't
and it seems like the simplest explanation.

