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Zombies Redacted

33 Post author: Eliezer_Yudkowsky 02 July 2016 08:16PM

I looked at my old post Zombies! Zombies? and it seemed to have some extraneous content.  This is a redacted and slightly rewritten version.


Your "zombie", in the philosophical usage of the term, is putatively a being that is exactly like you in every respect—identical behavior, identical speech, identical brain; every atom and quark in exactly the same position, moving according to the same causal laws of motion—except that your zombie is not conscious.

It is furthermore claimed that if zombies are "conceivable" (a term over which battles are still being fought), then, purely from our knowledge of this "conceivability", we can deduce a priori that consciousness is extra-physical, in a sense to be described below.

See, for example, the SEP entry on Zombies.  The "conceivability" of zombies is accepted by a substantial fraction, possibly a majority, of academic philosophers of consciousness.


I once read somewhere, "You are not the one who speaks your thoughts—you are the one who hears your thoughts".

If you conceive of "consciousness" as a quiet, passive listening, then the notion of a zombie initially seems easy to imagine.  It's someone who lacks the the inner hearer.

Sketching out that intuition in a little more detail:

When you open a refrigerator and find that the orange juice is gone, you think "Darn, I'm out of orange juice."  The sound of these words is probably represented in your auditory cortex, as though you'd heard someone else say it.

Why do I think the sound of your inner thoughts is represented in the auditory cortex, as if it were a sound you'd heard?  Because, for example, native Chinese speakers can remember longer digit sequences than English-speakers.  Chinese digits are all single syllables, and so Chinese speakers can remember around ten digits, versus the famous "seven plus or minus two" for English speakers.  There appears to be a loop of repeating sounds back to yourself, a size limit on working memory in the auditory cortex, which is genuinely phoneme-based.

It's not only conceivable in principle, but possibly possible in the next couple of decades, that surgeons will lay a network of neural taps over someone's auditory cortex and read out their internal narrative.  Researchers have already tapped the lateral geniculate nucleus of a cat and reconstructed recognizable visual inputs.

So your zombie, being physically identical to you down to the last atom, will open the refrigerator and form auditory cortical patterns for the phonemes "Darn, I'm out of orange juice".  On this point, p-zombie advocates agree.

But in the Zombie World, allegedly, there is no one inside to hear; the inner listener is missing.  The internal narrative is spoken, but unheard.  You are not the one who speaks your thoughts, you are the one who hears them.

The Zombie Argument is that if the Zombie World is possible—not necessarily physically possible in our universe, just "possible in theory", or "conceivable"—then consciousness must be extra-physical, something over and above mere atoms.  Why?  Because even if you knew the positions of all the atoms in the universe, you would still have be told, as a separate and additional fact, that people were conscious—that they had inner listeners—that we were not in the Zombie World.

The technical term for the belief that consciousness is there, but has no effect on the physical world, is epiphenomenalism.

Though there are other elements to the zombie argument (I'll deal with them below), I think that the intuition of the inner listener is what first persuades people to zombie-ism.  The core notion is simple and easy to access:  The lights are on but nobody's home.

Philosophers are appealing to the intuition of the quiet, passive inner listener when they say "Of course the zombie world is imaginable; you know exactly what it would be like."

But just because you don't see a contradiction in the Zombie World at first glance, it doesn't mean that no contradiction is there.  Just because you don't see an internal contradiction yet within some set of generalizations, is no guarantee that you won't see a contradiction in another 30 seconds.  "All odd numbers are prime.  Proof:  3 is prime, 5 is prime, 7 is prime..."

So let us ponder the Zombie Argument a little longer:  Can we think of a counterexample to the assertion "Consciousness has no third-party-detectable causal impact on the world"?

If you close your eyes and concentrate on your inward awareness, you will begin to form thoughts, in your internal narrative, along the lines of "I am aware" and "My awareness is separate from my thoughts" and "I am not the one who speaks my thoughts, but the one who hears them" and "My stream of consciousness is not my consciousness" and "It seems like there is a part of me which I can imagine being eliminated without changing my outward behavior."

You can even say these sentences out loud.  In principle, someone with a super-fMRI could probably read the phonemes right out of your auditory cortex; but saying it out loud removes all doubt about whether you have entered the realms of physically visible consequences.

This certainly seems like the inner listener is being caught in the act of listening by whatever part of you writes the internal narrative, a causally potent neural pattern in your auditory cortex, which can eventually move your lips and flap your tongue.

Imagine that a mysterious race of aliens visit you, and leave you a mysterious black box as a gift.  You try poking and prodding the black box, but (as far as you can tell) you never elicit a reaction.  You can't make the black box produce gold coins or answer questions.  So you conclude that the black box is causally inactive:  "For all X, the black box doesn't do X."  The black box is an effect, but not a cause; epiphenomenal, without causal potency.  In your mind, you test this general hypothesis to see if the generalization is true in some trial cases, and it seems to be true in every one—"Does the black box repair computers?  No.  Does the black box boil water?  No."

But you can see the black box; it absorbs light, and weighs heavy in your hand.  This, too, is part of the dance of causality.  If the black box were wholly outside the causal universe, you wouldn't be able to see it; you would have no way to know it existed; you could not say, "Thanks for the black box."  You didn't think of this counterexample, when you formulated the general rule:  "All X: Black box doesn't do X".  But it was there all along.

(Actually, the aliens left you another black box, this one purely epiphenomenal, and you haven't the slightest clue that it's there in your living room.  That was their joke.)

If something has no causal effect, you can't know about it.  The territory must be causally entangled with the map for the map to correlate with the territory.  To 'see' something is to be affected by it.  If an allegedly physical thing or property has absolutely no causal impact on the rest of our universe, there's a serious question about whether we can even talk about it, never mind justifiably knowing that it's there.

It is a standard point—which zombie-ist philosophers accept!—that the Zombie World's philosophers, being atom-by-atom identical to our own philosophers, write identical papers about the philosophy of consciousness.

At this point, the Zombie World stops being an intuitive consequence of the idea of an inner listener.

Philosophers writing papers about consciousness would seem to be at least one effect of consciousness upon the world.  You can argue clever reasons why this is not so, but you have to be clever.  You are no longer playing straight to the intuition.

Let's say you'd never heard of the Zombie World and never formed any explicit generalizations about how zombies are supposed to exist.  The thought might spontaneously occur to you that, as you stand and watch a beautiful sunset, your awareness of your awareness could be subtracted from you without changing your outward smile.  But then ask whether you still think "I am aware of my inner awareness", as a neural pattern in your auditory cortex, and then say it out loud, after the inner awareness has been subtracted.  I would not expect the generalization "my inner awareness has no effect on physical things" to still seem intuitive past that point, if you'd never been explicitly indoctrinated with p-zombieism.

Intuitively, we'd suppose that if your inward awareness vanished, your internal narrative would no longer say things like "There is a mysterious listener within me," because the mysterious listener would be gone and you would not be thinking about it.  It is usually immediately after you focus your awareness on your awareness, that your internal narrative says "I am aware of my awareness"; which suggests that if the first event never happened again, neither would the second.

Once you see the collision between the general rule that consciousness has no effect, to the specific implication that consciousness has no effect on how you think about consciousness (in any way that affects your internal narrative that you could choose to say out loud), zombie-ism stops being intuitive.  It starts requiring you to postulate strange things.

One strange thing you might postulate is that there's a Zombie Master, a god within the Zombie World who surreptitiously takes control of zombie philosophers and makes them talk and write about consciousness.

Human beings often don't sound all that coherent when talking about consciousness.  It might not be that hard to fake.  Maybe you could take, as a corpus, one thousand human amateurs trying to discuss consciousness; feed them into a sufficiently powerful but non-reflective machine learning algorithm; and get back discourse about "consciousness" that sounded as sensible as most humans, which is to say, not very.

But this speech about "consciousness" would not be produced within the AI.  It would be an imitation of someone else talking.  You might as well observe that you can make a video recording of David Chalmers (the most formidable advocate of zombieism) and play back the recording.  The cause that shaped the pattern of the words in the video recording was Chalmers's consciousness moving his lips; that shaping cause is merely being transmitted through a medium, like sounds passing through air.

A separate, extra Zombie Master is not what the philosophical Zombie World postulates.  It's asserting that the atoms in the brain are quark-by-quark identical, moving under exactly the same physical laws we know; there's no separate, additional Zombie Master AI Chatbot making the lips move in ways that were copied off the real David Chalmers.  The zombie you's lips are talking about consciousness for the same causal reason your lips talk about consciousness.

As David Chalmers writes:

Think of my zombie twin in the universe next door. He talks about conscious experience all the time—in fact, he seems obsessed by it. He spends ridiculous amounts of time hunched over a computer, writing chapter after chapter on the mysteries of consciousness. He often comments on the pleasure he gets from certain sensory qualia, professing a particular love for deep greens and purples. He frequently gets into arguments with zombie materialists, arguing that their position cannot do justice to the realities of conscious experience.

And yet he has no conscious experience at all! In his universe, the materialists are right and he is wrong. Most of his claims about conscious experience are utterly false. But there is certainly a physical or functional explanation of why he makes the claims he makes. After all, his universe is fully law-governed, and no events therein are miraculous, so there must be some explanation of his claims.

...Any explanation of my twin’s behavior will equally count as an explanation of my behavior, as the processes inside his body are precisely mirrored by those inside mine. The explanation of his claims obviously does not depend on the existence of consciousness, as there is no consciousness in his world. It follows that the explanation of my claims is also independent of the existence of consciousness.

Chalmers is not arguing against zombies; those are his actual beliefs!

This paradoxical situation is at once delightful and disturbing.  It is not obviously fatal to the nonreductive position, but it is at least something that we need to come to grips with...

I would seriously nominate this as the largest bullet ever bitten in the history of time.  And that is a backhanded compliment to David Chalmers:  A lesser mortal would simply fail to see the implications, or refuse to face them, or rationalize a reason it wasn't so.

Why would anyone bite a bullet that large?  Why would anyone postulate unconscious zombies who write papers about consciousness for exactly the same reason that our own genuinely conscious philosophers do?

Not because of the first intuition I wrote about, the intuition of the quiet inner listener.  That intuition may say that zombies can drive cars or do math or even fall in love, but it doesn't say that zombies write philosophy papers about their quiet inner listeners.

No, the drive to bite this bullet comes from an entirely different intuition—the intuition that no matter how many atoms you add up, no matter how many masses and electrical charges interact with each other, they will never necessarily produce a subjective sensation of the mysterious redness of red.  It may be a fact about our physical universe (Chalmers says) that putting such-and-such atoms into such-and-such a position, evokes a sensation of redness; but if so, it is not a necessary fact, it is something to be explained above and beyond the motion of the atoms.

But if you consider the second intuition on its own, without the intuition of the quiet listener, it is hard to see why irreducibility implies zombie-ism.  Maybe there's just a different kind of stuff, apart from and additional to atoms, that is not causally passive—a soul that actually does stuff.  A soul that plays a real causal role in why we write about "the mysterious redness of red".  Take out the soul, and... well, assuming you just don't fall over in a coma, you certainly won't write any more papers about consciousness!

This is the position taken by Descartes and most other ancient thinkers:  The soul is of a different kind, but it interacts with the body.  Descartes's position is technically known as substance dualism—there is a thought-stuff, a mind-stuff, and it is not like atoms; but it is causally potent, interactive, and leaves a visible mark on our universe.

Zombie-ists are property dualists—they don't believe in a separate soul; they believe that matter in our universe has additional properties beyond the physical.

"Beyond the physical"?  What does that mean?  It means the extra properties are there, but they don't influence the motion of the atoms, like the properties of electrical charge or mass.  The extra properties are not experimentally detectable by third parties; you know you are conscious, from the inside of your extra properties, but no scientist can ever directly detect this from outside.

So the additional properties are there, but not causally active.  The extra properties do not move atoms around, which is why they can't be detected by third parties.

And that's why we can (allegedly) imagine a universe just like this one, with all the atoms in the same places, but the extra properties missing, such that every atom moves the same as before, but no one is conscious.

The Zombie World might not be physically possible, say the zombie-ists—because it is a fact that all the matter in our universe has the extra properties, or obeys the bridging laws that evoke consciousness—but the Zombie World is logically possible: the bridging laws could have been different.

But why, oh why, say that the extra properties are epiphenomenal and undetectable?

We can put this dilemma very sharply:  Chalmers believes that there is something called consciousness, and this consciousness embodies the true and indescribable substance of the mysterious redness of red.  It may be a property beyond mass and charge, but it's there, and it is consciousness.  Now, having said the above, Chalmers furthermore specifies that this true stuff of consciousness is epiphenomenal, without causal potency—but why say that?

Why say that you could subtract this true stuff of consciousness, and leave all the atoms in the same place doing the same things?  If that's true, we need some separate physical explanation for why Chalmers talks about "the mysterious redness of red".  That is, there exists both a mysterious redness of red, which is extra-physical, and an entirely separate reason, within physics, why Chalmers talks about the "mysterious redness of red".

Chalmers does confess that these two things seem like they ought to be related, but why do you need to assert two separate phenomena?  Why not just assert one or the other?

Once you've postulated that there is a mysterious redness of red, why not just say that it interacts with your internal narrative and makes you talk about the "mysterious redness of red"?

Isn't Descartes taking the simpler approach, here?  The strictly simpler approach?

Why postulate an extramaterial soul, and then postulate that the soul has no effect on the physical world, and then postulate a mysterious unknown material process that causes your internal narrative to talk about conscious experience?

Why not postulate the true stuff of consciousness which no amount of mere mechanical atoms can add up to, and then, having gone that far already, let this true stuff of consciousness have causal effects like making philosophers talk about consciousness?

I am not endorsing Descartes's view.  But at least I can understand where Descartes is coming from.  Consciousness seems mysterious, so you postulate a mysterious stuff of consciousness.  Fine.

But now the zombie-ists postulate that this mysterious stuff doesn't do anything, so you need a whole new explanation for why you say you're conscious.

That isn't vitalism.  That's something so bizarre that vitalists would spit out their coffee.  "When fires burn, they release phlogistonBut phlogiston doesn't have any experimentally detectable impact on our universe, so you'll have to go looking for a separate explanation of why a fire can melt snow."  What?

Are property dualists under the impression that if they postulate a new active force, something that has a causal impact on physics, they will be sticking their necks out too far?

Me, I'd say that if you postulate a mysterious, separate, additional, inherently mental property of consciousness, above and beyond positions and velocities, then, at that point, you have already stuck your neck out.  To postulate this stuff of consciousness, and then further postulate that it doesn't do anything—for the love of cute kittens, why?

There isn't even an obvious career motive.  "Hi, I'm a philosopher of consciousness.  My subject matter is the most important thing in the universe and I should get lots of funding?  Well, it's nice of you to say so, but actually the phenomenon I study doesn't do anything whatsoever."

Chalmers is one of the most frustrating philosophers I know.  He does this really sharp analysis... and then turns left at the last minute.  He lays out everything that's wrong with the Zombie World scenario, and then, having reduced the whole argument to smithereens, calmly accepts it.

Chalmers does the same thing when he lays out, in calm detail, the problem with saying that our own beliefs in consciousness are justified, when our zombie twins say exactly the same thing for exactly the same reasons and are wrong.

On Chalmers's theory, Chalmers saying that he believes in consciousness cannot be causally justified; the belief is not caused by the fact itself, like looking at an actual real sock being the cause of why you say there's a sock.  In the absence of consciousness, Chalmers would write the same papers for the same reasons.

On epiphenomenalism, Chalmers saying that he believes in consciousness cannot be justified as the product of a process that systematically outputs true beliefs, because the zombie twin writes the same papers using the same systematic process and is wrong.

Chalmers admits this.  Chalmers, in fact, explains the argument in great detail in his book.  Okay, so Chalmers has solidly proven that he is not justified in believing in epiphenomenal consciousness, right?  No.  Chalmers writes:

Conscious experience lies at the center of our epistemic universe; we have access to it directly.  This raises the question: what is it that justifies our beliefs about our experiences, if it is not a causal link to those experiences, and if it is not the mechanisms by which the beliefs are formed?  I think the answer to this is clear: it is having the experiences that justifies the beliefs. For example, the very fact that I have a red experience now provides justification for my belief that I am having a red experience...

Because my zombie twin lacks experiences, he is in a very different epistemic situation from me, and his judgments lack the corresponding justification.  It may be tempting to object that if my belief lies in the physical realm, its justification must lie in the physical realm; but this is a non sequitur. From the fact that there is no justification in the physical realm, one might conclude that the physical portion of me (my brain, say) is not justified in its belief. But the question is whether I am justified in the belief, not whether my brain is justified in the belief, and if property dualism is correct than there is more to me than my brain.

So—if I've got this thesis right—there's a core you, above and beyond your brain, that believes it is not a zombie, and directly experiences not being a zombie; and so its beliefs are justified.

But Chalmers just wrote all that stuff down, in his very physical book, and so did the zombie-Chalmers.

The zombie Chalmers can't have written the book because of the zombie's core self above the brain; there must be some entirely different reason, within the laws of physics.

It follows that even if there is a part of Chalmers hidden away that is conscious and believes in consciousness, directly and without mediation, there is also a separable subspace of Chalmers—a causally closed cognitive subsystem that acts entirely within physics—and this "outer self" is what speaks Chalmers's internal narrative, and writes papers on consciousness.

I do not see any way to evade the charge that, on Chalmers's own theory, this separable outer Chalmers is deranged.  This is the part of Chalmers that is the same in this world, or the Zombie World; and in either world it writes philosophy papers on consciousness for no valid reason.  Chalmers's philosophy papers are not output by that inner core of awareness and belief-in-awareness, they are output by the mere physics of the internal narrative that makes Chalmers's fingers strike the keys of his computer.

And yet this deranged outer Chalmers is writing philosophy papers that just happen to be perfectly right, by a separate and additional miracle.  Not a logically necessary miracle (then the Zombie World would not be logically possible).  A physically contingent miracle, that happens to be true in what we think is our universe, even though science can never distinguish our universe from the Zombie World.

I think I speak for all reductionists when I say Huh? 

That's not epicycles.  That's, "Planetary motions follow these epicycles—but epicycles don't actually do anything—there's something else that makes the planets move the same way the epicycles say they should, which I haven't been able to explain—and by the way, I would say this even if there weren't any epicycles."

According to Chalmers, the causally closed system of Chalmers's internal narrative is (mysteriously) malfunctioning in a way that, not by necessity, but just in our universe, miraculously happens to be correct.  Furthermore, the internal narrative asserts "the internal narrative is mysteriously malfunctioning, but miraculously happens to be correctly echoing the justified thoughts of the epiphenomenal inner core", and again, in our universe, miraculously happens to be correct.

Oh, come on!

Shouldn't there come a point where you just give up on an idea?  Where, on some raw intuitive level, you just go:  What on Earth was I thinking?

Humanity has accumulated some broad experience with what correct theories of the world look like.  This is not what a correct theory looks like.

"Argument from incredulity," you say.  Fine, you want it spelled out?  The said Chalmersian theory postulates multiple unexplained complex miracles.  This drives down its prior probability, by the conjunction rule of probability and Occam's Razor.  It is therefore dominated by at least two theories which postulate fewer miracles, namely:

  • Substance dualism:
    • There is a stuff of consciousness which is not yet understood, an extraordinary super-physical stuff that visibly affects our world; and this stuff is what makes us talk about consciousness.
  • Not-quite-faith-based reductionism:
    • That-which-we-name "consciousness" happens within physics, in a way not yet understood, just like what happened the last three thousand times humanity ran into something mysterious.
    • Your intuition that no material substance can possibly add up to consciousness is incorrect.  If you actually knew exactly why you talk about consciousness, this would give you new insights, of a form you can't now anticipate; and afterward you would realize that your arguments about normal physics having no room for consciousness were flawed.

Compare to:

  • Epiphenomenal property dualism:
    • Matter has additional consciousness-properties which are not yet understood.  These properties are epiphenomenal with respect to ordinarily observable physics—they make no difference to the motion of particles.
    • Separately, there exists a not-yet-understood reason within normal physics why philosophers talk about consciousness and invent theories of dual properties.
    • Miraculously, when philosophers talk about consciousness, the bridging laws of our world are exactly right to make this talk about consciousness correct, even though it arises from a malfunction (drawing of logically unwarranted conclusions) in the causally closed cognitive system that types philosophy papers.

I know I'm speaking from limited experience, here.  But based on my limited experience, the Zombie Argument may be a candidate for the most deranged idea in all of philosophy.

There are times when, as a rationalist, you have to believe things that seem weird to you.  Relativity seems weird, quantum mechanics seems weird, natural selection seems weird.

But these weirdnesses are pinned down by massive evidence.  There's a difference between believing something weird because science has confirmed it overwhelmingly—

—versus believing a proposition that seems downright deranged, because of a great big complicated philosophical argument centered around unspecified miracles and giant blank spots not even claimed to be understood—

—in a case where even if you accept everything that has been told to you so far, afterward the phenomenon will still seem like a mystery and still have the same quality of wondrous impenetrability that it had at the start.

The correct thing for a rationalist to say at this point, if all of David Chalmers's arguments seem individually plausible, is:

"Okay... I don't know how consciousness works... I admit that... and maybe I'm approaching the whole problem wrong, or asking the wrong questions... but this zombie business can't possibly be right.  The arguments aren't nailed down enough to make me believe this—especially when accepting it won't make me feel any less confused.  On a core gut level, this just doesn't look like the way reality could really really work."

But this is not what I say, for I don't think the arguments are plausible.  "In general, all odd numbers are prime" looked "conceivable" when you had only thought about 3, 5, and 7.  It stopped seeming reasonable when you thought about 9.

Zombies looked conceivable when you looked out at a beautiful sunset and thought about the quiet inner awareness inside you watching that sunset, which seemed like it could vanish without changing the way you walked or smiled; obedient to the plausible-sounding generalization, "the inner listener has no outer effects".  That generalization should stop seeming possible when you say out loud, "But wait, I am thinking this thought right now inside my auditory cortex, and that thought can make my lips move, translating my awareness of my quiet inner listener into a motion of my lips, meaning that consciousness is part of the minimal closure of causality in this universe."  I can't think of anything else to say about the conceivability argument.  The zombies are dead.

Comments (165)

Comment author: RobbBB 03 July 2016 08:30:32PM *  16 points [-]

The "conceivability" of zombies is accepted by a substantial fraction, possibly a majority, of academic philosophers of consciousness.

This can be made precise. According to the 2009 PhilPapers Survey (sent to all faculty at the top 89 Ph.D-granting philosophy departments in the English-speaking world as ranked by the Philosophical Gourmet Report, plus 10 high-prestige non-Anglophone departments), about 2/3 of professional philosophers of mind think zombies are conceivable, though most of these think physicalism is true anyway. Specifically, 91 of the 191 respondents (47.6%) said zombies are conceivable but not metaphysically possible; 47 (24.6%) said they were inconceivable; 35 (18.3%) said they're (conceivable and) metaphysically possible; and the other 9.4% were agnostic/undecided or rejected all three options.

Looking at professional philosophers as a whole in the relevant departments, including non-philosophers-of-mind, 35.6% say zombies are conceivable, 16% say they're inconceivable, 23.3% say they're metaphysically possible, 17% say they're undecided or insufficiently familiar with the issue (or they skipped the question), and 8.2% rejected all three options. So the average top-tier Anglophone philosopher of mind is more likely to reject zombies than is the average top-tier Anglophone philosopher. (Relatedly, 22% of philosophers of mind accept or lean toward 'non-physicalism', vs. 27% of philosophers in general.)

There is a stuff of consciousness which is not yet understood, an extraordinary super-physical stuff that visibly affects our world; and this stuff is what makes us talk about consciousness.

Chalmers' core objection to interactionism, I think, is that any particular third-person story you can tell about the causal effects of consciousness could also be told without appealing to consciousness. E.g., if you think consciousness intervenes on the physical world by sometimes spontaneously causing wavefunctions to collapse (setting aside that Chalmers and most LWers reject collapse...), you could just as easily tell a story in which wavefunctions just spontaneously collapse without any mysterious redness getting involved; or a story in which they mysteriously collapse when mysterious greenness occurs rather than redness, or when an alien color occurs.

Chalmers thinks any argument for thinking that the mysterious redness of red is causally indispensable for dualist interactionism should also allow that the mysterious redness of red is an ordinary physical property that's indispensable for physical interactions. Quoting "Moving Forward on the Problem of Consciousness":

The real "epiphenomenalism" problem, I think, does not arise from the causal closure of the physical world. Rather, it arises from the causal closure of the world! Even on an interactionist picture, there will be some broader causally closed story that explains behavior, and such a story can always be told in a way that neither includes nor implies experience. Even on the interactionist picture, we can view minds as just further nodes in the causal network, like the physical nodes, and the fact that these nodes are experiential is inessential to the causal dynamics. The basic worry arises not because experience is logically independent of physics, but because it is logically independent of causal dynamics more generally.

The interactionist has a reasonable solution to this problem, I think. Presumably, the interactionist will respond that some nodes in the causal network are experiential through and through. Even though one can tell the causal story about psychons without mentioning experience, for example, psychons are intrinsically experiential all the same. Subtract experience, and there is nothing left of the psychon but an empty place-marker in a causal network, which is arguably to say there is nothing left at all. To have real causation, one needs something to do the causing; and here, what is doing the causing is experience.

I think this solution is perfectly reasonable; but once the problem is pointed out this way, it becomes clear that the same solution will work in a causally closed physical world. Just as the interactionist postulates that some nodes in the causal network are intrinsically experiential, the "epiphenomenalist" can do the same.

This brings up a terminology-ish point:

The technical term for the belief that consciousness is there, but has no effect on the physical world, is epiphenomenalism.

Chalmers denies that he's an epiphenomenalist. Rather he says (in "Panpsychism and Panprotopsychism"):

I think that substance dualism (in its epiphenomenalist and interactionist forms) and Russellian monism (in its panpsychist and panprotopsychist forms) are the two serious contenders in the metaphysics of consciousness, at least once one has given up on standard physicalism. (I divide my own credence fairly equally between them.)

Quoting "Moving Forward" again:

Here we can exploit an idea that was set out by Bertrand Russell (1926), and which has been developed in recent years by Grover Maxwell (1978) and Michael Lockwood (1989). This is the idea that physics characterizes its basic entities only extrinsically, in terms of their causes and effects, and leaves their intrinsic nature unspecified. For everything that physics tells us about a particle, for example, it might as well just be a bundle of causal dispositions; we know nothing of the entity that carries those dispositions. The same goes for fundamental properties, such as mass and charge: ultimately, these are complex dispositional properties (to have mass is to resist acceleration in a certain way, and so on). But whenever one has a causal disposition, one can ask about the categorical basis of that disposition: that is, what is the entity that is doing the causing?

One might try to resist this question by saying that the world contains only dispositions. But this leads to a very odd view of the world indeed, with a vast amount of causation and no entities for all this causation to relate! It seems to make the fundamental properties and particles into empty placeholders, in the same way as the psychon above, and thus seems to free the world of any substance at all. It is easy to overlook this problem in the way we think about physics from day to day, given all the rich details of the mathematical structure that physical theory provides; but as Stephen Hawking (1988) has noted, physical theory says nothing about what puts the "fire" into the equations and grounds the reality that these structures describe. The idea of a world of "pure structure" or of "pure causation" has a certain attraction, but it is not at all clear that it is coherent.

So we have two questions: (1) what are the intrinsic properties underlying physical reality?; and (2) where do the intrinsic properties of experience fit into the natural order? Russell's insight, developed by Maxwell and Lockwood, is that these two questions fit with each other remarkably well. Perhaps the intrinsic properties underlying physical dispositions are themselves experiential properties, or perhaps they are some sort of proto-experiential properties that together constitute conscious experience. This way, we locate experience inside the causal network that physics describes, rather than outside it as a dangler; and we locate it in a role that one might argue urgently needed to be filled. And importantly, we do this without violating the causal closure of the physical. The causal network itself has the same shape as ever; we have just colored in its nodes.

This ideas smacks of the grandest metaphysics, of course, and I do not know that it has to be true. But if the idea is true, it lets us hold on to irreducibility and causal closure and nevertheless deny epiphenomenalism. By placing experience inside the causal network, it now carries a causal role. Indeed, fundamental experiences or proto-experiences will be the basis of causation at the lowest levels, and high-level experiences such as ours will presumably inherit causal relevance from the (proto)-experiences from which they are constituted. So we will have a much more integrated picture of the place of consciousness in the natural order.

This is also (a more honest name for) the non-physicalist view that sometimes gets called "Strawsonian physicalism." But this view seems to be exactly as vulnerable to your criticisms as traditional epiphenomenalism, because the "causal role" in question doesn't seem to be a difference-making role -- it's maybe "causal" in some metaphysical sense, but it's not causal in a Bayesian or information-theoretic sense, a sense that would allow a brain to nonrandomly update in the direction of Strawsonian physicalism / Russellian monism by computing evidence.

I'm not sure what Chalmers would say to your argument in detail, though he's responded to the terminological point about epiphenomenalism. If he thinks Russellian monism is a good response, then either I'm misunderstanding how weird Russellian monism is (in particular, how well it can do interactionism-like things), or Chalmers is misunderstanding how general your argument is. The latter is suggested by the fact that Chalmers thinks your argument weighs against epiphenomenalism but not against Russellian monism in this old LessWrong comment.

It might be worth e-mailing him this updated "Zombies" post, with this comment highlighted so that we don't get into the weeds of debating whose definition of "epiphenomenalism" is better.

Comment author: ike 03 July 2016 02:23:29AM 8 points [-]

Are you planning on doing this for more of the sequences? I think that would be great.

Comment author: Furcas 02 July 2016 10:20:24PM *  7 points [-]

Nice.

So, when are you going to tell us your solution to the hard problem of consciousness?

Edited to add: The above wasn't meant as a sarcastic objection to Eliezer's post. I'm totally convinced by his arguments, and even if I wasn't I don't think not having a solution to the hard problem is a greater problem for reductionism than for dualism (of any kind). I was seriously asking Eliezer to share his solution, because he seems to think he has one.

Comment author: kilobug 05 July 2016 12:22:15PM 4 points [-]

Not having a solution doesn't prevent from criticizing an hypothesis or theory on the subject. I don't know what are the prime factors of 4567613486214 but I know that "5" is not a valid answer (numbers having 5 among their prime factors end up with 5 or 0) and that "blue" doesn't have the shape of a valid answer. So saying p-zombism and epiphenomenalism aren't valid answers to the "hard problem of consciousness" doesn't require having a solution to it.

Comment author: gjm 05 July 2016 02:33:08PM -1 points [-]

Quite true, but if you follow the link in Furcas's last paragraph (which may not have been there when you wrote your comment) you will see Eliezer more or less explicitly claiming to have a solution.

Comment author: Furcas 05 July 2016 06:58:52PM 1 point [-]

Yeah, I edited my comment after reading kilobug's.

Comment author: TheAncientGeek 04 July 2016 01:57:21PM *  0 points [-]

Snarky, but pertinent.

This re-posting was prompted by a Sean Carroll article, that argued along similar lines...epiphenomenalism (one of a number of possible alternatives to physicalism) is incredible, therefore no zombies.

There are a number of problems with this kind of thinking.

One is that there may be better dualisms than epiphenomenalism.

Another is that criticising epi. doesn't show that there is a workable physical explanation of consciousness. There is no see-saw (titter-totter) effect whereby the wrongness of one theory implies the correctness of another. For one thing,there are more than two theories (see above). For another, an explanation has to explain...there are positive, absolute standards for explanation..you cannot say some Y is an an explanation, that it actually explains, just because some X is wrong, and Y is different to X. (The idea that physicalism is correct as an incomprehensible brute fact is known as the "new mysterianism" and probably isn't what reductionists physicalists and rationalists are aiming at).

Carroll and others have put forward a philosophical version of a physical account of consciousness, one stating in general terms that consciousness is a high-level, emergent outcome, of fine-grained neurological activity. The zombie argument (Mary's room, etc) are intended as handwaving philosophical arguments against that sort of argument. If the physicalist side had a scientific version of a physical account of consciousness, there would be no point in arguing against them philosophically, any more than there is a point in arguing philosophically against gravity. Scientific, as opposed to philosophical, theories are detailed and predictive, which allows them to be disproven or confirmed and not merely argued for or against.

And, given that there is no detailed, predictive explanation of consciousness, zombies are still imaginable, in a sense. If someone claims they can imagine (in the sense of picturing) a hovering rock, you can show that it is not possible by writing down some high school physics. Zombies are imaginable in a stronger sense: not only can they be pictuured, but the picture cannot be refuted.

Comment author: Houshalter 05 July 2016 05:43:10PM *  1 point [-]

Another is that criticising epi. doesn't show that there is a workable physical explanation of consciousness.

I feel like it's gets halfway there though. Once you accept epiphenomenalism is nonsense, you are left with something like nonmaterial "souls" at best. That there is some real force that actually interacts with the world, and could be, in principle, observed, experimented with, and modelled in something like a computer simulation. Some chain of causes and effects lead you to say you "feel conscious", and that chain could be, in principle, understood.

That seems to take all the magic out of it though. It's no longer something that's "beyond science". It's some set of laws that could be understood just like physics, just not the physics we know currently. If you are uncomfortable with the idea that we are "just atoms", and don't feel like that explains qualia or experience, just getting new laws of physics isn't going to help. Then you have to confront the idea that maybe physics can explain experience.

Comment author: TheAncientGeek 05 July 2016 06:25:55PM *  -2 points [-]

. Once you accept epiphenomenalism is nonsense, you are left with something like nonmaterial "souls" at best

Perhaps, so long as you have also refuted physicalist monism.

That seems to take all the magic out of it though. It's no longer something that's "beyond science". It's some set of laws that could be understood just like physics, just not the physics we know currently. If you are uncomfortable with the idea that we are "just atoms", and don't feel like that explains qualia or experience, just getting new laws of physics isn't going to help.

If you have a reason for thinking that no physics can possibly explain consciousness, then you would reject the Extra Physics family of theories, but if you beef is just with the present state of physics, then you might not.

Comment author: Furcas 04 July 2016 02:48:57PM 1 point [-]

Ahh, it wasn't meant to be snarky. I saw an opportunity to try and get Eliezer to fess up, that's all. :)

Comment author: MockTurtle 04 July 2016 12:17:58PM *  5 points [-]

I wonder what probability epiphenomenalists assign to the theory that they are themselves conscious, if they admit that belief in consciousness isn't caused by the experiences that consciousness brings.

The more I think about it, the more absurdly self-defeating it sounds, and I have trouble believing that ANYONE could hold such views after having thought about it for a few minutes. The only reason I continue to think about it is because it's very easy to believe that some people, no matter how an AI acted and for how long, would never believe the AI to be conscious. And that bothers me a lot, if it affects their moral stance on that AI.

Comment author: kilobug 05 July 2016 11:50:40AM 3 points [-]

Another more directly worrying question, is why or if the p-zombie philosopher postulate that other persons have consciousness.

After all, if you can speak about consciousness exactly like we do and yet be a p-zombie, why doesn't Chalmer assume he's the only not being a zombie, and therefore letting go of all forms of caring for others and all morality ?

The fact that Chalmer and people like him still behave like they consider other people to be as conscious as they are probably points to the fact they have belief-in-belief, more than actual belief, in the possibility of zombieness.

Comment author: buybuydandavis 09 July 2016 12:09:43PM 1 point [-]

Another more directly worrying question, is why or if the p-zombie philosopher postulate that other persons have consciousness.

A wonderful way to dehumanize.

therefore letting go of all forms of caring for others and all morality ?

The meat bag you ride will let go of caring, or not.

Under the theory, the observer chooses nothing in the physical world. The meatbag produces experiences of caring for you, or not, according to his meatbag reasons for action in the world.

Comment author: UmamiSalami 06 July 2016 08:33:35PM -1 points [-]

is why or if the p-zombie philosopher postulate that other persons have consciousness.

Because consciousness supervenes upon physical states, and other brains have similar physical states.

Comment author: kilobug 07 July 2016 07:20:11AM 1 point [-]

Because consciousness supervenes upon physical states, and other brains have similar physical states.

But why, how ? If consciousness is not a direct product of physical states, if p-zombies are possible, how can you tell apart the hypothesis "every other human is conscious" from "only some humans are conscious" from "I'm the only one conscious by luck" from "everything including rocks are conscious" ?

Comment author: UmamiSalami 07 July 2016 03:21:14PM *  0 points [-]

Chalmers does believe that consciousness is a direct product of physical states. The dispute is about whether consciousness is identical to physical states.

Chalmers does not believe that p-zombies are possible in the sense that you could make one in the universe. He only believes it's possible that under a different set of psychophysical laws, they could exist.

Comment author: dxu 18 July 2016 04:30:54AM *  0 points [-]

I claim that it is "conceivable" for there to be a universe whose psychophysical laws are such that only the collection of physical states comprising my brainstates are conscious, and the rest of you are all p-zombies. Note that this argument is exactly as plausible as the standard Zombie World argument (which is to say, not very) since it relies on the exact same logic; as such, if you accept the standard Zombie World argument, you must accept mine as well. Now then: I claim that by sheer miraculous coincidence, this universe that we are living in possesses the exact psychophysical laws described above (even though there is no way for my body typing this right now to know that), and hence I am the only one in the universe who actually experiences qualia. Also, I would say this even if we didn't live in such a universe.

Prove me wrong.

Comment author: UmamiSalami 22 July 2016 05:07:20PM *  -1 points [-]

I claim that it is "conceivable" for there to be a universe whose psychophysical laws are such that only the collection of physical states comprising my brainstates are conscious, and the rest of you are all p-zombies.

Yes. I agree that it is conceivable.

Now then: I claim that by sheer miraculous coincidence, this universe that we are living in possesses the exact psychophysical laws described above (even though there is no way for my body typing this right now to know that), and hence I am the only one in the universe who actually experiences qualia. Also, I would say this even if we didn't live in such a universe.

Sure, and I claim that there is a teapot orbiting the sun. You're just being silly.

Comment author: entirelyuseless 18 July 2016 01:35:53PM 0 points [-]

No one can prove you wrong. But your pretended belief is unreasonable, in the same way that it is unreasonable to believe that the sun will not rise tomorrow, even though no one can prove that it will.

It is also for the same reasons; the argument that the sun will rise tomorrow is inductive, and similarly the argument that others are conscious.

It may even be the case that infants originally believe your argument, and then come to the opposite conclusion through induction. I know someone who says that he clearly remembers that when he was three years old, he believed that he alone was conscious, because the behavior of others was too dissimilar to his own, e.g. his parents did not go and eat the ice cream in the freezer, even though there was no one to stop them.

Comment author: dxu 18 July 2016 03:49:39PM 0 points [-]

No one can prove you wrong. But your pretended belief is unreasonable, in the same way that it is unreasonable to believe that the sun will not rise tomorrow, even though no one can prove that it will.

In that case, the Zombie World argument is just as unreasonable--which is what I was getting at in the first place.

Comment author: entirelyuseless 19 July 2016 04:50:45AM -1 points [-]

I don't know what you mean by the "Zombie World argument." No thinks that the real world is a zombie world.

Comment author: dxu 19 July 2016 07:55:26PM *  0 points [-]

Okay, here's the Zombie World argument, paraphrased:

  1. It is "conceivable" (whatever that means) for there to be a universe with physical laws exactly identical to ours, but without the "bridging psychophysical laws" that cause certain physical configurations of atoms to produce subjective awareness, i.e. "consciousness".
  2. By assumption, the universe described above is physically identical to ours, right down to the last quark. As a result, there is a planet called "Earth" in this universe, and this planet is populated by humans identical to ourselves; each of us has a counterpart in this other universe. Moreover, each of those counterparts behaves exactly like you or I would, talking to each other, laughing at jokes, and even falling in love.
  3. However, since this hypothetical "conceivable" universe lacks the "bridging psychophysical laws" that are necessary for true consciousness to exist, each of those people in that universe, despite acting exactly like you'd expect a conscious being to act, aren't actually conscious, i.e. they don't experience qualia or possess any sense of self-awareness at all. They are, for all intents and purposes, automatons.
  4. Since by definition, there is no physical experiment you can perform to distinguish our universe from the Zombie Universe, any observer would have be told, as a separate and independent fact, that "yes, this universe is not the Zombie World--there is actually consciousness in this universe". This is then taken as proof that consciousness must be extra-physical, i.e. epiphenomenal.
  5. In both the Zombie World and our universe, people write philosophy papers about consciousness, since (again) the Zombie World and our universe are stipulated to be physically identical, and the act of writing a philosophy paper is a physical act. Incidentally, by the way, this means that the philosophers in the Zombie World are being absolutely crazy, since they're talking about a phenomenon that they have no way of knowing exists, by definition.
  6. However, it turns out that our universe's philosophers (whose beliefs about consciousness are no more justified than the Zombie World's philosopher's beliefs) actually are correct about consciousness, because by sheer miraculous coincidence, they happen to be living in a universe with the correct "psychophysical laws" that produce consciousness. They are correct, not because of any logical reasoning on their part (indeed, the reasoning they used must be flawed, since they somehow deduced the existence of a phenomenon they literally have no way of knowing about), but because they just happen to be living in a universe where their statements are true. Yay for them (and us)!
  7. Oh, and by the way, we really are living in a universe with consciousness, not the Zombie World. I know that there's literally no way for me to prove this to you (in fact, there's no way for me to know this myself), but just trust me on this one.

And now here's my argument, paraphrased:

  1. It is "conceivable" (whatever that means) for there to be a universe with physical laws exactly identical to ours, but whose "bridging psychophysical laws" are such that only those physical configurations of atoms corresponding to my (dxu's) brainstates produce consciousness; nothing else is or can ever be conscious.
  2. By assumption, the universe described above is physically identical to ours, right down to the last quark. As a result, there is a planet called "Earth" in this universe, and this planet is populated by humans identical to ourselves; each of us has a counterpart in this other universe. Moreover, each of those counterparts behaves exactly like you or I would, talking to each other, laughing at jokes, and even falling in love. One of those people is a counterpart to me; we'll call him "dxu-2".
  3. However, since this hypothetical "conceivable" universe has a different set of "bridging psychophysical laws", each of those people in that universe (with one exception), despite acting exactly like you'd expect a conscious being to act, aren't actually conscious, i.e. they don't experience qualia or possess any sense of self-awareness at all. They are, for all intents and purposes, automatons. Of course, I said there was one exception, and that exception should be obvious: dxu-2 is the only person in this universe who possess consciousness.
  4. Since by definition, there is no physical experiment you can perform to distinguish our universe from the Modified Zombie Universe, any observer would have be told, as a separate and independent fact, that "yes, this universe is not the Modified Zombie World--everyone here is conscious, not just dxu-2". This is then taken as proof that consciousness must be extra-physical, i.e. epiphenomenal.
  5. In both the Modified Zombie World and our universe, people write philosophy papers about consciousness, since (again) the Modified Zombie World and our universe are stipulated to be physically identical, and the act of writing a philosophy paper is a physical act. Incidentally, by the way, this means that the philosophers in the Modified Zombie World are being absolutely crazy, since they're talking about a phenomenon that they have no way of knowing exists, by definition.
  6. Dxu-2, by the way, isn't a professional philosopher, but he's fond of making comments on the Internet that assert he's conscious and that no one else is. Of course, when he makes these comments, his physical self is being exactly as crazy as the other philosophers in the Modified Zombie World, but luckily for dxu-2, the drivel that his physical self types just happens to be exactly right, because by sheer miraculous coincidence, he lives in a universe with the correct "psychophysical laws" that cause him to be conscous.
  7. Oh, and by the way, the Modified Zombie World is our universe, and "dxu-2" is actually me. I know I can't prove this to you, but just trust me on this one.

If you accept the Zombie World argument, you have to accept my argument; the two are exactly analogous. Of course, the contrapositive of the above statement is also true: if you reject my argument, you must reject the Zombie World argument. In effect, my argument is a reductio ad absurdum of the Zombie World argument; it shows that given the right motivation, you can twist the Zombie World argument to include/exclude anything you want as conscious. Just say [insert-universe-here] is "conceivable" (whatever that means), and the rest of the logic plays out identically.

P. S. One last thing--this part of your comment here?

No [one] thinks that the real world is a zombie world.

If the Zombie World exists (which I don't believe it does--but if it did), all of the people in that universe (who don't think their world is a zombie world) are dead wrong.

Comment author: turchin 03 July 2016 12:58:21PM *  4 points [-]

I know people who claim that they don't have qualia. I doubt that it is true, but based on their words they should be considered zombies. ))

I would like to suggest zombies of second kind. This is a person with inverted spectrum. It even could be my copy, which speaks all the same philosophical nonsense as me, but any time I see green, he sees red, but names it green. Is he possible? I could imagine such atom-exact copy of me, but with inverted spectrum. And if such second type zombies are possible, it is argument for epiphenomenalism. Now I will explain why.

Phenomenological judgments (PJ) about own consciousness, that is the ability to say something about your own consciousness, will be the same in me and my zombie of the second type.

But there are two types of PJ: quantitative (like "I have consciousness") and qualitative which describes exactly what type of qualia I experience now.

The qualitative type of PJ is impossible. I can't transfer my knowing about "green" in the words.

It means that the fact of existence of phenomenological judgments doesn't help in case of second type zombies.

So, after some upgrade, zombie argument still works as an argument for epiphenomenalism.

I would also recommend the following article with introduce "PJ" term and many problems about it (but I do not agree with it completely) "Experimental Methods for Unraveling the Mind-body Problem: The Phenomenal Judgment Approach" Victor Argonov http://philpapers.org/rec/ARGMAA-2

Comment author: Houshalter 05 July 2016 05:27:49PM 2 points [-]

I don't believe that I experience qualia. But I recall that in my childhood, I was really fascinated by the question "is my blue your blue?" Apparently this is a really common thing.

But I think it can be resolved by imagining our brains work sort of like artificial neural networks. In a neural network, we can train it to recognize objects from raw pixel data. There is nothing special about red or blue, they are just different numbers. And there is nothing magic going on in the NN, it's just a bunch of multiplications and additions.

But what happens is, those weights change to recognize features useful in identifying objects. It will build a complicated internal model of the world of objects. This model will associate "blue" with objects that are commonly blue, like water and bleggs.

From inside the neural network, blue doesn't feel like it's just a number in it's input, or that it's thoughts are just a bunch of multiplications and additions. Blue would feel like, well, an indescribable phenomenon. Where it lights up it's "blue" neurons, and everything associated with them. It could list those associations, or maybe recall memories of blue things it has seen in the past. But it wouldn't be able to articulate what blue "feels" like.

People raised in a similar environment should learn similar associations. But different cultures could have entirely different associations, and so really do have different blues than you. Notably many cultures don't even have a word for blue, and lump it together with green.

Comment author: UmamiSalami 06 July 2016 08:22:54PM 0 points [-]

I don't believe that I experience qualia.

Wait, what?

Comment author: TheAncientGeek 05 July 2016 06:29:51PM *  0 points [-]

I don't believe that I experience qualia.

Meaning you have no experiences, or your experiences have no particular character or flavour?

From inside the neural network, blue doesn't feel like it's just a number in it's input, or that it's thoughts are just a bunch of multiplications and additions. Blue would feel like, well, an indescribable phenomenon. Where it lights up it's "blue" neurons, and everything associated with them. It could list those associations, or maybe recall memories of blue things it has seen in the past. But it wouldn't be able to articulate what blue "feels" like.

Which experiences would you expect to be easier to describe..novel ones, or familiar ones?

Comment author: VAuroch 04 July 2016 10:10:13PM 2 points [-]

I don't see any difference between me and other people who claim to have consciousness, but I have never understood what they mean by consciousness or qualia to an extent that lets me conclude that I have them. So I am sometimes fond of asserting that I have neither, mostly to get an interesting response.

Comment author: turchin 04 July 2016 10:41:23PM *  1 point [-]

Maybe your are phlizombie))

I think we should add new type p-zombies: epistemic p-zombies: The ones, who claim that they don't have qualia, and we don't know why they claim it.

You are not only one who claimed absence of qualia. I think there are 3 possible solutions.

a) You are p-zombie

b) You don't know where to look

с) You are troll. "So I am sometimes fond of asserting that I have neither, mostly to get an interesting response."

Comment author: kilobug 05 July 2016 12:03:08PM 4 points [-]

Or more likely :

d) the term "qualia" isn't very properly defined, and what turchin means with "qualia" isn't exactly what VAuroch means with "qualia" - basically an illusion of transparecny/distance of inference issue.

Comment author: VAuroch 09 July 2016 11:18:57PM *  1 point [-]

No one defines qualia clearly. If they did, I'd have a conclusion one way or the other.

Comment author: entirelyuseless 10 July 2016 03:48:34PM -1 points [-]

Do you have a clear definition of clear definition? Or of anything, for that matter?

Comment author: VAuroch 14 July 2016 11:02:30PM 1 point [-]

In this case, "description of how my experience will be different in the future if I have or do not have qualia" covers it. There are probably cases where that's too simplistic.

Comment author: entirelyuseless 15 July 2016 12:58:05PM -2 points [-]

That's easy to describe. If I have any experience in the future, I have qualia. If I have no experience in the future, I have no qualia. That's the difference.

Comment author: dxu 18 July 2016 04:34:35AM *  1 point [-]

Taboo "qualia", "experience", "consciousness", "awareness", and any synonyms. Now try to provide a clear definition.

Comment author: entirelyuseless 18 July 2016 01:30:47PM -1 points [-]

Please stop commenting. Now try to present your argument.

But more importantly, VAuroch defined clear definition as describing how experience would be different. Experience cannot be tabooed if that is what clear definition means.

Comment author: VAuroch 30 July 2016 12:57:31AM 0 points [-]

How are qualia different from experiences? If experiences are no different, why use 'qualia' rather than 'experiences'?

Comment author: entirelyuseless 30 July 2016 05:35:08AM *  0 points [-]

Qualia means the specific way that you experience something. And if you don't experience something in any way at all, then you don't experience it. So if there are no qualia, there are no experiences. But they don't mean the same thing, since qualia means "the ways things are experienced", not "experiences."

Comment author: kilobug 05 July 2016 12:01:27PM 1 point [-]

I would like to suggest zombies of second kind. This is a person with inverted spectrum. It even could be my copy, which speaks all the same philosophical nonsense as me, but any time I see green, he sees red, but names it green. Is he possible? I could imagine such atom-exact copy of me, but with inverted spectrum.

I can't.

As a reductionist and materialist, it doesn't make sense - the feeling of "red" and "green" is a consequence of the way your brain is wired and structured, an atom-exact copy would have the same feelings.

But letting aside the reductionist/materialist view (which after all is part of the debate), it still wouldn't make sense. The special quality that "red" has in my consciousness, the emotions it call upon, the analogies it triggers, has consequences on how I would invoke the "red" color in poetry, or use the "red" color in a drawing. And on how I would feel about a poetry or drawing using "red".

If seeing #ff0000 triggers exactly all the same emotions, feelings, analogies in the consciousness of your clone, then he's getting the same experience than you do, and he's seeing "red", not "green".

Comment author: TheAncientGeek 05 July 2016 06:31:45PM -1 points [-]

But letting aside the reductionist/materialist view (which after all is part of the debate), it still wouldn't make sense

Is "it" zombies, or epiphenomenalism?

Comment author: kilobug 06 July 2016 07:19:45AM 1 point [-]

Is "it" zombies, or epiphenomenalism?

The hypothesis I was answering to, the "person with inverted spectrum".

Comment author: DefectiveAlgorithm 03 July 2016 06:31:56PM 1 point [-]

I would like to suggest zombies of second kind. This is a person with inverted spectrum. It even could be my copy, which speaks all the same philosophical nonsense as me, but any time I see green, he sees red, but names it green. Is he possible?

Such an entity is possible, but would not be an atom-exact copy of you.

Comment author: turchin 03 July 2016 07:11:29PM 0 points [-]

We don't know how qualia are encoded in the brain. And how to distinguish a person and his copy with inverted spectrum.

Comment author: DefectiveAlgorithm 03 July 2016 09:51:20PM 0 points [-]

I didn't say I knew which parts of the brain would differ, but to conclude therefore that it wouldn't is to confuse the map with the territory.

Comment author: turchin 03 July 2016 10:32:21PM 0 points [-]

We can't conclude that they would not differ. We could postulate it and then ask: could we measure if equal copies have equal qualia. And we can't measure it. And here we return to "hard question": we don't know if different qualia imply different atom's combinations.

Comment author: gjm 06 July 2016 11:25:43AM *  -2 points [-]

we don't know if different qualia imply different atom's combinations

Either (1) your saying "this looks red to me" versus "this looks green to me" is completely unaffected by the red/green qualia you are experiencing;

or (2) your brain works by magic instead of (or as well as) physics;

or (3) different qualia imply different physical states.

For me #1 is kinda-imaginable but would take away all actual reasons for believing in qualia; #2 is kinda-imaginable but the evidence against seems extremely strong; which leaves #3 a clear enough winner that saying "we don't know" about it is in the same sort of territory as "we don't know whether there are ghosts" or "we don't know whether the world has been secretly taken over by alien lizardmen".

[EDITED to add: Of course my argument here is basically Eliezer's argument in the OP. Perhaps turchin has a compelling refutation of that argument, but I haven't seen it yet.]

Comment author: turchin 06 July 2016 01:26:45PM 0 points [-]

My point was to show that using possibility of phenomenological judgments as an argument against epiphenomenalism is not working as intended.

Because more subtle form of epiphenomenalism is still possible. It is conceivable, but I don't know if it is true.

But your appeal to "alien lizardmen" as an argument against "don't know" is unfair as we have large prior knowledge against lizardmen, but we don't have any priors of experiences of other people.

No one in all history was able to feel the feeling of other being (maybe one-cranial siam twins will be able), so we have no any prior knowledge about if this qualia all similar or all disimilar in different beings.

Your (1) point also could be true in my opinion, or, more exact, we don't have instruments to show that it is true.

Imagine, that I met exact my copy and could ask him any questions, and want to know if he has inverted spectrum... More here: http://plato.stanford.edu/entries/qualia-inverted/

Comment author: gjm 06 July 2016 02:34:59PM -2 points [-]

The alien lizardmen aren't intended as an argument against "don't know", just as an example of something else about which in some sense we "don't know" but where there's not much scope for doubt.

So, anyway, you're proposing that perhaps turchinA and turchinB have different qualia but the same behaviour because the connection between qualia and behaviour is wired differently; so for turchinA seeing red things produces red qualia which provoke saying "red", while for turchinB seeing red things produces green qualia which provoke saying "green".

So, what is the actual difference between turchinA's red qualia and turchinB's so-called green qualia? They produce the exact same behaviour. In particular, turchinB's so-called green qualia lead turchinB to say things like "that looks red to me". And they are provoked by the exact same stimuli that give turchinA red qualia. So, er, what reason is there for calling them green qualia?

I don't know about you, but my red qualia call up all kinds of specific associations. Blood, stop-signs, lipstick, sunsets. And these are, or at least are indirectly observable via, external questioning. "What does this colour make you think of?", etc. And red, in particular, produces lower-level effects that also feed into the experience of seeing red -- IIRC, people looking at bright red things have elevated pulse rate, for instance. So turchinB's so-called green qualia have to produce these same results. Similarly, my green qualia call up associations -- grass, sickness, emeralds, etc. -- and turchinB's so-called green qualia had better not remind turchinB of those things, at least not in any way that spills over into turchinB's actions, responses to questions, etc.

Do you find it reasonable to say that these qualia of turchinB's -- evoked by seeing blood and tomatoes and the like, calling up memories of blood and tomatoes and the like, increasing arousal in the autonomic nervous system, etc., etc., etc. -- can be subjectively identical to turchinA's green qualia (calling up memories of grass, not increasing autonomic nervous system arousal, etc.)? Because I don't. What would that even mean?

Comment author: turchin 06 July 2016 03:19:54PM 0 points [-]

I see it simple: Turchin A sees red object - feels red qualia - associates it with blood - calls it "red". TurchinB - sees red object - feels green qualia - associates it with blood - calls it "red".

So all associations and behavior are the same, only the qualia is different. From objective point of view there is no difference. From my-subjective point of view there is a difference.

Comment author: gjm 06 July 2016 04:14:28PM -2 points [-]

To my mind the following

all associations and behavior are the same, only the qualia is different

is incoherent. The associations are part of how seeing something red or green feels. So if turchinB sees something and associates it with blood, then turchinB's subjective experience is not the same as that of turchinA seeing something green.

Now, it looks as if you've retreated a bit from the full "inverted spectrum" scenario and are maybe now just saying that maybe turchinA and turchinB experience different qualia on seeing red, even though their behaviour is the same. That's not so obviously incoherent. Or is it?

Any way of probing turchinB's experience of seeing a tomato has to produce exactly the same result as for turchinA. Any question I might ask turchinB about that experience will produce the same answer. If I hook turchinB up to a polygraph machine while asking the questions, the readings will be the same as turchinA's. If I present turchinB with the tomato and then ask other questions in the hope that the answers will be subtly biased by whatever not-so-conscious influences the tomato may have had -- same results, again.

So whatever differences there are between turchinA's subjective experiences and turchinB's, they have to be absolutely undetectable by turchins A and B: any attempt at describing those experiences will produce the exact same effects; any effect of the experience on their mood will have no detectable consequences; and so on and so forth.

The situation still seems to me the way I described it before. If turchinA's and turchinB's brains run on physics rather than magic, and if their physical states are the same, then everything we can see of their subjective states by asking them questions, or attaching electrodes to them, or having sex with them, or showing them kitten pictures and seeing whether they smile, or any other kind of observation we can make, matches exactly; which means that any differences in their qualia are so subtle that they have no causal influence on turchinA's and turchinB's behaviour, mood, unconscious physiological reactions, etc.

I see no reason to believe in such subtle differences of qualia; I see no reason to think that asking about them is even meaningful; and they seem to me a violation of Ockham's razor. What am I missing? Why should we take this idea more seriously than lizardmen in the White House?

Comment author: Gurkenglas 05 July 2016 11:05:07PM 0 points [-]

If the copies are different, the question is not interesting. If the copies aren't different, what causes you to label what he sees as red? It can't be the wavelength of the light that actually goes in his eye, because his identical brain would treat red's wavelength as red.

Comment author: Riothamus 08 July 2016 06:58:58PM 0 points [-]

I do not think we need to go as far as i-zombies. We can take two people, show them the same object under arbitrarily close conditions, and get the answer of 'green' out of both of them while one does not experience green on account of being color-blind.

Comment author: gjm 08 July 2016 08:56:04PM -2 points [-]

What do you infer from being able to do this?

(Surely not that qualia are nonphysical, which is the moral Chalmers draws from thinking about p-zombies; colour-blindness involves identifiable physical differences.)

Comment author: Riothamus 12 July 2016 03:40:11PM *  0 points [-]

This gives us these options under the Chalmers scheme:

Same input -> same output & same qualia

Same input -> same output & different qualia

Same input -> same output & no qualia

I infer the ineffable green-ness of green is not even wrong. We have no grounds for thinking there is such a thing.

Comment author: CronoDAS 02 July 2016 09:04:32PM 4 points [-]

Can you make "something" with the same input-output behavior as a human, and have that thing not be conscious? It doesn't have to be atom-by-atom identical.

Comment author: Eliezer_Yudkowsky 02 July 2016 09:08:53PM 8 points [-]

Sure. Measure a human's input and output. Play back the recording. Or did you mean across all possible cases? In the latter case see http://lesswrong.com/lw/pa/gazp_vs_glut/

Comment author: CronoDAS 03 July 2016 12:33:17AM 3 points [-]

Yeah, I meant in all possible cases. Start with a Brain In A Vat. Scan that brain and implement a GLUT in Platospace, then hook up the Brain-In-A-Vat and the GLUT to identical robots, and you'll have one robot that's conscious and one that isn't, right?

Comment author: kilobug 05 July 2016 02:03:21PM 1 point [-]

Did you read the GAZP vs GLUT article ? In the GLUT setup, the conscious entity is the conscious human (or actually, more like googolplex of conscious humans) that produced the GLUT, and the robot replaying the GLUT is no more conscious than a phone transmitting the answer from a conscious human to another - which is basically what it is doing, replaying the answer given by a previous, conscious, human from the same input.

Comment author: Houshalter 05 July 2016 05:55:20PM 0 points [-]

I don't think the origin of the GLUT matters at all. It could have sprung up out of pure randomness. The point is that it exists, and appears to be conscious by every outward measure, but isn't.

Comment author: kilobug 05 July 2016 09:34:37PM *  4 points [-]

It definitely does matter.

If you build a human-like robot, remotely controlled by a living human (or by a brain-in-a-vat), and interact with the robot, it'll appear to be conscious but isn't, and yet it wouldn't be a zombie in any way, what actually produces the response about being conscious would be the human (or the brain), not the robot.

If the GLUT was produced by a conscious human (or conscious human simulation), then it's akin to a telepresence robot, only slightly more remote (like the telepresence robot is only slightly more remote than a phone).

And if it "sprung up of pure randomness"... if you are ready to accept such level of improbability, you can accept anything - like the hypothesis that no human actually wrote what I'm replying to, but it's just the product of cosmic rays hitting my computers in the exact pattern for such a text to be displayed on my browser. Or the Shakespear was actually written by monkeys typing at random. If you start accepting such ridiculous levels of improbability, something even below than one chance in a googolplex, you are just accepting everything and anything making all attempt to reason or discuss pointless.

Comment author: Houshalter 09 July 2016 06:23:00AM *  0 points [-]

The question is whether the GLUT is conscious. I don't believe that it is.

Perhaps it was created by a conscious process. But that process is gone now. I don't believe that torturing the GLUT is wrong, for example, because the conscious entity has already been tortured. Nothing I do to the GLUT can causally interact with the conscious process that created it.

This is why I say the origin of the GLUT doesn't matter. I'm not saying that I believe GLUTs are actually likely to exist, let alone appear from randomness. But the origin of a thing shouldn't matter to the question of whether or not it is conscious.

If we can observe every part of the GLUT, but know nothing about it's origin, we should still be able to determine if it's conscious or not. The question shouldn't depend on its past history, but only it's current state.

I believe it might be possible for a non conscious entity to create a GLUT, or at least fake consciousness. Like a simple machine learning algorithm that imitates human speech or text. Or AIXI with it's unlimited computing power, that doesn't do anything other than brute force. I wouldn't feel bad about deleting an artificial neural network, or destroying an AIXI.

The question that bothers me is what about a bigger, more human like neural network? Or a more approximate, less brute force version of AIXI? When does an intelligence algorithm gain moral weight? This question bothers me a lot, and I think it's what people are trying to get at when they talk about GLUTs.

Comment author: dxu 18 July 2016 04:21:21PM *  1 point [-]

So, the question being asked here appears to be, "Can a GLUT be considered conscious?" I claim that this question is actually a stand-in for multiple different questions, each of which I will address individually.

1) Do the processes that underlie the GLUT's behavior (input/output) cause it to possess subjective awareness?

Without a good understanding of what exactly "subjective awareness" is and how it arises, this question is extremely difficult to answer. At a glance, however, it seems intuitively plausible (indeed, probable) that whatever processes underlie "subjective awareness", they need to be more complex than simply looking things up in an (admittedly enormous) database. So, I'm going to answer this one with a tentative "no".

2) Does the GLUT's existence imply the presence of consciousness (subjective awareness) elsewhere in the universe?

To answer this question, let's consider the size of a GLUT that contains all possible inputs and outputs for a conscious being. Now consider the set of all possible GLUTs of that size. Of those possible GLUTs, only a vanishingly minuscule fraction encode anything even remotely resembling the behavior of a conscious being. The probability of such a GLUT being produced by accident is virtually 0. (I think the actual probability should be on the order of 1 / K, where K is the Kolmogorov complexity of the brain of the being in question, but I could be wrong.)

As such, it's more or less impossible for the GLUT to have been produced by chance; it's indescribably more likely that there exists some other conscious process in the universe from which the GLUT's specifications were taken. In other words, if you ever encounter a GLUT that seems to behave like a conscious being, you can deduce with probability ~1 that consciousness exists somewhere in that universe. Thus, the answer to this question is "yes" with probability ~1.

3) Assuming that the GLUT was produced by chance and that the conscious being whose behavior it emulates does not and will not ever physically exist, can it still be claimed that the GLUT's existence implies the presence of consciousness somewhere?

This is the most ill-defined question of the lot, but hopefully I at least managed to render it into something comprehensible (if not easily answered!). To answer it, first we have to understand that while a GLUT may not be conscious itself, it certainly encodes a conscious process, i.e. you could theoretically specify a conscious process embedded in a physical medium (say, a brain, or maybe a computer) that, when run with a certain input, will produce the exact output that the GLUT produces given that input. (This is not a trivial statement, by the way; the set of GLUTs that fulfill this condition is tiny relative to the space of possible GLUTs.)

However, suppose we don't have that process available to us, only the GLUT itself. Then the question above is simply asking, "In what sense can the process encoded by the GLUT be said to 'exist'?" This is still a hard question, but it has one major advantage over the old phrasing: we can draw a direct parallel between this question and the debate over mathematical realism. In other words: if you accept mathematical realism, you should also be fine with accepting that the conscious process encoded by the GLUT exists in a Platonic sense, and if you reject it, you should likewise reject the existence of said process. Now, like most debates in philosophy, this one is unsettled--but at least now you know that your answer to the original question regarding GLUTs concretely depends on your answer to another question--namely, "Do you accept mathematical realism?", rather than nebulously floating out there in the void. (Note that since I consider myself a mathematical realist, I would answer "yes" to both questions. Your answer may differ.)

4) Under standard human values (e.g. the murder of a conscious being is generally considered immoral, etc.), should the destruction of a GLUT be considered immoral?

In my opinion, this question is actually fairly simple to answer. Recall that a GLUT, while not being conscious itself, encodes a conscious process. This means (among other things) that we could theoretically use the information contained in the look-up table to construct that conscious being, even if that being never existed before hand. Since destroying the GLUT would remove our ability to construct said being, we can clearly classify it as an immoral act (though whether it should be considered as immoral as the murder of a preexisting conscious being is still up for debate).

It seems to me that the four questions listed above suffice to describe all of the disguised queries the original question ("Can a GLUT be considered conscious?") stood for. Assuming I answered each of them in a sufficiently thorough manner, the original question should be resolved as well--and ideally, there shouldn't even be the feeling that there's a question left. Of course, that's if I did this thing correctly.

So, did I miss anything?

Comment author: MrMind 04 July 2016 10:14:40AM 0 points [-]

Hmm... is that true?
The only difference is that they were conscious at different time.
Also, creating a GLUT out of a person is an extremely immoral thing to do.

Comment author: Piecewise 04 July 2016 04:27:44PM 3 points [-]

"a being that is exactly like you in every respect—identical behavior, identical speech, identical brain; every atom and quark in exactly the same position, moving according to the same causal laws of motion—except that your zombie is not conscious."

As someone with a medical background, I find it very hard to believe this is possible. Not unless Consciousness is reduced to something so abstract and disconnected from what we consider our "Selves" as to render it almost meaningless. After all, traumatic brain injury can alter every aspect of your personality, capacity to reason, and ability to perceive. And if "consciousness" isn't bound up in any of these things, if it exists as some sort of super disconnected "Thinking thing" like Descartes seemed to think, I really can't see the value of it. It's like the Greek interpretation of the afterlife where your soul exists as a senseless shadow, lacking any concept of self or any memory of your past life. What good is an existence that lacks all the things which make it unique?

Then again, as a somewhat brutal pragmatist, I cease to see the meaning in having an argument when it seems to devolve beyond any connection to observable reality.

Comment author: kilobug 05 July 2016 11:47:44AM 1 point [-]

I agree with your point in general, and it does speak against an immaterial soul surviving death, but I don't think it necessarily apply to p-zombies. The p-zombie hypothesis is that the consciousness "property" has no causality over the physical world, but it doesn't say that there is no causality the other way around: that the state of the physical brain can't affect the consciousness. So a traumatic brain injury would (under some unexplained mysterious mechanism) reflect into that immaterial consciousness.

But sure, it's yet more epicycles.

Comment author: buybuydandavis 09 July 2016 11:58:41AM 0 points [-]

You're watching a POV movie of a meat bag living out it's life. When the meat bag falls apart, the movie gets crapped up.

Comment author: Gram_Stone 03 July 2016 03:02:41PM 3 points [-]

I skipped the stuff on p-zombies when I read R:AZ because I experienced difficulty reading 'Zombies! Zombies?' and I didn't expect it to be as useful as what came later in the book.

Now I feel silly, because this time my reading experience was fluent and I had that extra processing motivation from the content's 'recency'.

Now I think it didn't have much at all to do with how useful I thought it would be at the time. It seems more like I asked "Are there minutiae on Penrose?" rather than "Will this be useful to know?"

After all, I didn't read the rest of the book via some mantra of instrumentality; not really. Instrumental value was a nice side effect like profits to the cheesecake industry is a nice side effect of consuming cheesecake. I really read it because it was enjoyable to read.

So, this content now seems accessible to at least one person to whom it did not seem accessible before. That seems like a plausible goal of someone rewriting something.

Comment author: timujin 06 July 2016 02:40:54PM 5 points [-]

This argument is not going to win over their heads and hearts. It's clearly written for a reductionist reader, who accepts concepts such as Occam's Razor and knowing-what-a-correct-theory-looks-like. But such a person would not have any problems with p-Zombies to begin with.

If you want to persuade someone who's been persuaded by Chalmers, you should debunk the argument itself, not bring it to your own epistemological ground where the argument is obviously absurd. Because you, and the Chalmers-supporter are not on the same epistemological ground, and will probably never be.

Here's how you would do that.

---- START ARGUMENT ----

Is it conceivable that the 5789312365453423234th digit of Pi is 7?

No, don't look it up just yet. Is it conceivable to you, right now, that it's 7?

For me, yes, it is. If I look it up, and it turns out to be 7, I would not be surprised at all. It's a perfectly reasonable outcome, with predictable consequences. It's not that hard for me to imagine me running a program that calculates and prints the number, and it printing out 7.

Yet, until you look it up, you don't really know if it's 7 or not. It could be 5. It would also be a reasonable, non-surprising and conceivable outcome.

Yet at least one of those outcomes is logically impossible. The exact value of Pi is logically determined, and, if you believe that purely logical conclusions apply universally, then one of those values of 5789312365453423234th digit of Pi is universally impossible.

And yet both are conceivable.

So logical impossibility does not imply inconceivability. This is logically equivalent to saying "conceivability does not imply logical possibility" (A->B => ~B->~A).

If conceivability does not imply logical possibility, then even if you can imagine a Zombie world, it does not mean that the Zombie world is logically possible. It may be the case that the Zombie world is logically impossible. Chalmer's argument does not rule that out. For example, it may be the case that certain atomic configurations necessarily imply consciousness. Or it may be any other case of logical impossibility. What matters is that consciousness as an additional nonphysical entity is not implied by its conceivability.

---- END ARGUMENT ----

Comment author: UmamiSalami 06 July 2016 08:29:09PM *  -1 points [-]

This argument is not going to win over their heads and hearts. It's clearly written for a reductionist reader, who accepts concepts such as Occam's Razor and knowing-what-a-correct-theory-looks-like.

I would suggest that people who have already studied this issue in depth would have other reasons for rejecting the above blog post. However, you are right that philosophers in general don't use Occam's Razor as a common tool and they don't seem to make assumptions about what a correct theory "looks like."

If conceivability does not imply logical possibility, then even if you can imagine a Zombie world, it does not mean that the Zombie world is logically possible.

Chalmers does not claim that p-zombies are logically possible, he claims that they are metaphysically possible. Chalmers already believes that certain atomic configurations necessarily imply consciousness, by dint of psychophysical laws.

The claim that certain atomic configurations just are consciousness is what the physicalist claims, but that is what is contested by knowledge arguments: we can't really conceive of a way for consciousness to be identical with physical states.

Comment author: timujin 07 July 2016 10:37:05AM 1 point [-]

Chalmers does not claim that p-zombies are logically possible, he claims that they are metaphysically possible. Chalmers already believes that certain atomic configurations necessarily imply consciousness, by dint of psychophysical laws.

Okay. In that case, I peg his argument as proving too much. Imagine a cookie that is exactly like an Oreo, down to the last atom, except it's raspberry flavored. This situation is semantically the same as a p-Zombie, so it's exactly as metaphysically possible, whatever that means. Does it prove that raspberry flavor is an extra, nonphysical fact about cookies?

Comment author: ChristianKl 08 July 2016 06:49:19PM 0 points [-]

Via hypnosis it's perfectly possible to let someone perceive the raspberry flavor when eating an Oreo. There's no problem to say that an Oreo has a flavor that based on the person eating it (an observer).

The flavor qualia of an Oreo is not predetermined by it's physcial makeup.

Comment author: gjm 08 July 2016 08:54:49PM -2 points [-]

In the presence of hypnosis, hallucination, olfactory damage, etc., the different flavour qualia of the Oreo are not properties of the Oreo at all. This doesn't seem to me at all analogous to the p-zombie or "inverted spectrum" thought experiments, where the point is that the people are the same and the qualia are unchanged.

Comment author: ChristianKl 09 July 2016 08:29:04AM 0 points [-]

the different flavour qualia of the Oreo are not properties of the Oreo at all.

Why isn't how the Oreo tastes a property of the Oreo? It's just not a physical property of it in the sense that you can investigate it by investigating the physical makeup of the Oreo.

It's simplier to how the qualia of conscious experience that a p-zombie might lack.

Comment author: gjm 10 July 2016 09:27:28AM -2 points [-]

Sorry, I was a little inexact. The way an Oreo tastes to someone whose tasting-system has been interfered with is a property of both the Oreo and the interference, and in some cases (e.g., someone hypnotized to think they're eating a raspberry) it may be a property of only the interference; in any case, the differences between different such tasters' experiences is largely a matter of the interference rather than the Oreo.

Something a bit like this is true even without interference, of course. Different people have different experiences on tasting the same foods. Very different, sometimes.

But, again, none of this is a good analogy for the p-zombie or inverted-spectrum experiments. The way the analogy is meant to work is:

  • Person : inverted spectrum :: Oreo : tastes of raspberries.
  • Inversion is a difference in the person :: raspberry taste is a difference in the Oreo.
  • In both cases the change is purely internal.
    • "Inverted spectra" pose no sort of difficulty for physicalism if what's actually happening is that person 1 sees red and person 2 sees green because person 1 is looking at a tomato and person 2 is looking at a cabbage.
  • In both cases the only change is supposed to be non-physical.
    • Otherwise there's no argument against physicalism here.

And timujin is suggesting that the Oreo version of this is obviously silly, and that we should apply the same intuitions to the other side of the analogy.

Your introduction of hypnosis breaks the analogy, because now (1) the change is no longer "internal": the raspberry taste is only there if a particular person is eating the Oreo, and that person has changed; and (2) the change is no longer non-physical: hypnosis involves physical processes and so far as we know is a physical process.

Comment author: UmamiSalami 07 July 2016 03:18:23PM *  -2 points [-]

Yes, this is called qualia inversion and is another common argument against physicalism. There's a detailed discussion of it here: http://plato.stanford.edu/entries/qualia-inverted/

Comment author: timujin 07 July 2016 08:01:04PM 2 points [-]

It's not about qualia. It's about any arbitrary property.

Imagine a cookie like Oreo to the last atom, except that it's deadly poisonous, weighs 100 tons and runs away when scared.

Comment author: kilobug 08 July 2016 08:42:25AM 1 point [-]

Imagine a cookie like Oreo to the last atom, except that it's deadly poisonous, weighs 100 tons and runs away when scared.

Well, I honestly can't. When you tell me that, I picture a real Oreo, and then at its side a cartoonish Oreo with all those weird property, but then trying to assume the microscopic structure of the cartoonish Oreo is the same than of a real Oreo just fails.

It's like if you tell me to imagine an equilateral triangle which is also a right triangle. Knowing non-euclidian geometry I sure can cheat around, but assuming I don't know about non-euclidian geometry or you explicitely add the constraint of keeping it, it just fails. You can hold the two sets of properties next to each other, but not reunite them.

Or if you tell me to imagine an arrangement of 7 small stones as a rectangle which isn't a line of 7x1. I can hold the image of 7 stones, the image of a 4x2 rectangle side-by-side, but reuniting the two just fails. Or leads to 4 stones in a line with 3 stones in a line below, which is no longer a rectangle.

When you multiply constraints to the point of being logically impossible, imagination just breaks - it holds the properties in two side-by-side sets, unable to re-conciliate them into a single coherent entity.

That's what your weird Oreo or zombies do to me.

Comment author: Good_Burning_Plastic 09 July 2016 09:17:47AM *  3 points [-]

Or if you tell me to imagine an arrangement of 7 small stones as a rectangle which isn't a line of 7x1.

O.O.O.O
O..O..O
Comment author: gjm 08 July 2016 12:55:05PM -2 points [-]

My impression was that this was pretty much tinujin's point: saying "imagine something atom-for-atom identical to you but with entirely different subjective experience" is like saying "imagine something atom-for-atom identical to an Oreo except that it weighs 100 tons etc.": it only seems imaginable as long as you aren't thinking about it too carefully.

Comment author: timujin 08 July 2016 01:36:09PM 2 points [-]

Confirm.

Comment author: UmamiSalami 07 July 2016 08:18:23PM *  0 points [-]

Flavor is distinctly a phenomenal property and a type of qualia.

It is metaphysically impossible for distinctly physical properties to differ between two objects which are physically identical. We can't properly conceive of a cookie that is physically identical to an Oreo yet contains different chemicals, is more massive or possessive of locomotive powers. Somewhere in our mental model of such an item, there is a contradiction.

Comment author: RobbBB 07 July 2016 04:13:57AM 0 points [-]

Chalmers doesn't think 'metaphysical possibility' is a well-specified idea. He thinks p-zombies are logically possible, but that the purely physical facts in our world do not logically entail the phenomenal facts; the phenomenal facts are 'further facts.'

Comment author: UmamiSalami 03 July 2016 08:08:09AM *  4 points [-]

This was longer than it needed to be, and in my opinion, somewhat mistaken.

The zombie argument is not an argument for epiphenomenalism, it's an argument against physicalism. It doesn't assume that interactionist dualism is false, regardless of the fact that Chalmers happens to be an epiphenomenalist.

Chalmers furthermore specifies that this true stuff of consciousness is epiphenomenal, without causal potency—but why say that?

Maybe because interactionism violates the laws of physics and is somewhat at odds with everything we (think we) know about cognition. There may be other arguments as well. It has mostly fallen out of favor. I don't know the specific reasons why Chalmers rejects it.

Once you see the collision between the general rule that consciousness has no effect, to the specific implication that consciousness has no effect on how you think about consciousness (in any way that affects your internal narrative that you could choose to say out loud), zombie-ism stops being intuitive. It starts requiring you to postulate strange things.

In the epiphenomenalist view, for whatever evolutionary reason, we developed to have discussions and beliefs in rich inner lives. Maybe those thoughts and discussions help us with being altruistic, or maybe they're a necessary part of our own activity. Maybe the illusion of interactionism is necessary for us to have complex cognition and decisionmaking.

Also in the epiphenomenalist view, psychophysical laws relate mental states to neurophysical aspects of our cognition. So for some reason there is a relation between acting/thinking of pain, and mental states which are painful. It's not arbitrary or coincidental because the mental reaction to pain (dislike/avoid) is a mirror of the physical reaction to pain (express dislike/do things to avoid it).

But Chalmers just wrote all that stuff down, in his very physical book, and so did the zombie-Chalmers.

Chalmers isn't denying that the zombie Chalmers would write that stuff down. He's denying that its beliefs would be justified. Maybe there's a version of me in a parallel universe that doesn't know anything about philosophy but is forced to type certain combinations of letters at gunpoint - that doesn't mean that I don't have reasons to believe the same things about philosophy in this universe.

Comment author: Vladimir 03 July 2016 06:48:28PM 3 points [-]

forced to type certain combinations of letters at gunpoint

Except there can't be a gunman in the zombie universe if it's the same as ours (unless... that explains everything!). This essay is trying to convince you that there's no way you can write about consciousness without something real causing you to write about consciousness. Even a mistaken belief about consciousness has to come from somewhere. Try now to imagine a zombie world with no metaphorical gunman and see what comes up.

Comment author: UmamiSalami 03 July 2016 10:32:46PM -1 points [-]

Well that's answered by what I said about psychophysical laws and the evolutionary origins of consciousness. What caused us to believe in consciousness is not (necessarily) the same issue as what reasons we have to believe it.

Comment author: Vladimir 04 July 2016 10:54:08PM *  3 points [-]

I think you're smuggling the gunman into evolution. I can come up with good evolutionary reasons why people talk about God despite him not existing, but I can't come up with good evolutionary reasons why people talk about consciousness despite it not existing. It's too verbose to go into detail, but I think if you try to distinguish the God example and the consciousness example you'll see that the one false belief is in a completely different category from the other.

Comment author: naasking 04 July 2016 07:31:54PM *  3 points [-]

This was longer than it needed to be

Indeed. The condensed argument against p-zombies:

  1. Assume consciousness has no effect upon matter, and is therefore not intrinsic to our behaviour.
  2. P-zombies that perfectly mimic our behaviour but have no conscious/subjective experience are then conceivable.
  3. Consider then a parallel Earth that was populated only by p-zombies from its inception. Would this Earth also develop philosophers that argue over consciousness/subjective experience in precisely the same ways we have, despite the fact that none of them could possibly have any knowledge of such a thing?
  4. This p-zombie world is inconceivable.
  5. Thus, p-zombies are not observationally indistinguishable from real people with consciousness.
  6. Thus, p-zombies are inconceivable.

In the epiphenomenalist view, for whatever evolutionary reason, we developed to have discussions and beliefs in rich inner lives.

Except such discussions would have no motivational impact. A "rich inner life" has no relation to any fact in a p-zombies' brain, and so in what way could this term influence their decision process? What specific sort of discussions of "inner life" do you expect in the p-zombie world? And if it has no conceivable impact, how could we have evolved this behaviour?

Comment author: UmamiSalami 05 July 2016 12:24:20AM -1 points [-]

Indeed. The condensed argument against p-zombies:

I would hope not. 3 is entirely conceivable if we grant 2, so 4 is unsupported, and nothing that EY said supports 4. 5 does not follow from 3 or 4, though it's bundled up in the definition of a p-zombie and follows from 1 and 2 anyway. In any case, 6 does not follow from 5.

What EY is saying is that it's highly implausible for all of our ideas and talk of consciousness to have come to be if subjective consciousness does not play a causal role in our thinking.

Except such discussions would have no motivational impact.

Of course they would - our considerations of other people's feelings and consciousness changes our behavior all the time. And if you knew every detail about the brain, you could give an atomic-level causal account as to why and how.

A "rich inner life" has no relation to any fact in a p-zombies' brain, and so in what way could this term influence their decision process?

The concept of a rich inner life influences decision processes.

Comment author: naasking 06 July 2016 12:39:42AM *  2 points [-]

I would hope not. 3 is entirely conceivable if we grant 2, so 4 is unsupported

It's not, and I'm surprised you find this contentious. 3 doesn't follow from 2, it follows from a contradiction between 1+2.

1 states that consciousness has no effect upon matter, and yet it's clear from observation that the concept of subjectivity only follows if consciousness can affect matter, ie. we only have knowledge of subjectivity because we observe it first-hand. P-zombies do not have first-hand knowledge of subjectivity as specified in 2.

If there were another way to infer subjectivity without first-hand knowledge, then that inference would resolve how physicalism entails consciousness and epiphenomenalism can be discarded using Occam's razor.

Of course they would - our considerations of other people's feelings and consciousness changes our behavior all the time. And if you knew every detail about the brain, you could give an atomic-level causal account as to why and how.

Except the zombie world wouldn't have feelings and consciousness, so your rebuttal doesn't apply.

The concept of a rich inner life influences decision processes.

That's an assertion, not an argument. Basically, you and epiphenominalists are merely asserting that that a) p-zombies would somehow derive the concept of subjectivity without having knowledge of subjectivity, and b) that this subjectivity would actually be meaningful to p-zombies in a way that would influence their decisions despite them having no first-hand knowledge of any such thing or its relevance to their life.

So yes, EY is saying it's implausible because it seems to multiply entities unnecessarily, I'm taking it one step further and flat out saying this position either multiplies entities unnecessarily, or it's inconsistent.

Comment author: UmamiSalami 06 July 2016 05:09:23AM *  -1 points [-]

3 doesn't follow from 2, it follows from a contradiction between 1+2.

Well, first of all, 3 isn't a statement, it's saying "consider a world where..." and then asking a question about whether philosophers would talk about consciousness. So I'm not sure what you mean by suggesting that it follows or that it is true.

1 and 2 are not contradictions. Conversely, 1 and 2 are basically saying the exact same thing.

1 states that consciousness has no effect upon matter, and yet it's clear from observation that the concept of subjectivity only follows if consciousness can affect matter,

This is essentially what epiphenomenalists deny, and I'm inclined to say that everyone else should deny it too. Regardless of what the truth of the matter is, surely the mere concept of subjectivity does not rely upon epiphenomenalism being false.

we only have knowledge of subjectivity because we observe it first-hand.

This is confusing the issue; like I said: under the epiphenomenalist viewpoint, the cause of our discussions of consciousness (physical) is different from the justification for our belief in consciousness (subjective). Epiphenomenalists do not deny that we have first-hand experience of subjectivity; they deny that those experiences are causally responsible for our statements about consciousness.

and epiphenomenalism can be discarded using Occam's razor.

There are many criteria by which theories are judged in philosophy, and parsimony is only one of them.

Except the zombie world wouldn't have feelings and consciousness, so your rebuttal doesn't apply.

Nothing in my rebuttal relies on the idea that zombies would have feelings and consciousness. My rebuttal points out that zombies would be motivated by the idea of feelings and consciousness, which is trivially true: humans are motivated by the idea of feelings and consciousness, and zombies behave in the same way that humans do, by definition.

That's an assertion, not an argument.

But it's quite obviously true, because we talk about rich inner lives as the grounding for almost all of our moral thought, and then act accordingly, and because empathy relies on being able to infer rich inner lives among other people. And as noted earlier, whatever behaviorally motivates humans also behaviorally motivates p-zombies.

Comment author: naasking 06 July 2016 03:19:43PM *  1 point [-]

Epiphenomenalists do not deny that we have first-hand experience of subjectivity; they deny that those experiences are causally responsible for our statements about consciousness.

Since this is the crux of the matter, I won't bother debating the semantics of most of the other disagreements in the interest of time.

As for whether subjectivity is causally efficacious, all knowledge would seem to derive from some set of observations. Even possibly fictitious concepts, like unicorns and abstract mathematics, are generalizations or permutations of concepts that were first observed.

Do you have even a single example of a concept that did not arise in this manner? Generalizations remove constraints on a concept, so they aren't an example, it's just another form of permutation. If no such example exists, why should I accept the claim that knowledge of subjectivity can arise without subjectivity?

Comment author: UmamiSalami 06 July 2016 08:39:33PM *  -1 points [-]

Unlike the other points which I raised above, this one is semantic. When we talk about "knowledge," we are talking about neurophysical responses, or we are talking about subjective qualia, or we are implicitly combining the two together. Epiphenomenalists, like physicalists, believe that sensory data causes the neurophysical responses in the brain which we identify with knowledge. They disagree with physicalists because they say that our subjective qualia are epiphenomenal shadows of those neurophysical responses, rather than being identical to them. There is no real world example that would prove or disprove this theory because it is a philosophical dispute. One of the main arguments for it is, well, the zombie argument.

Comment author: naasking 16 July 2016 04:31:43PM *  0 points [-]

Epiphenomenalists, like physicalists, believe that sensory data causes the neurophysical responses in the brain which we identify with knowledge. They disagree with physicalists because they say that our subjective qualia are epiphenomenal shadows of those neurophysical responses, rather than being identical to them. There is no real world example that would prove or disprove this theory because it is a philosophical dispute. One of the main arguments for it is, well, the zombie argument.

Which seems to suggest that epiphenominalism either begs the question, or multiplies entities unnecessarily by accepting unjustified intuitions.

So my original argument disproving p-zombies would seem to be on just as solid footing as the original p-zombie argument itself, modulo our disagreements over wording.

Comment author: UmamiSalami 16 July 2016 05:04:16PM *  0 points [-]

Which seems to suggest that epiphenominalism either begs the question,

Well, they do have arguments for their positions.

or multiplies entities unnecessarily by accepting unjustified intuitions.

It actually seems very intuitive to most people that subjective qualia are different from neurophysical responses. It is the key issue at stake with zombie and knowledge arguments and has made life extremely difficult for physicalists. I'm not sure in what way it's unjustified for me to have an intuition that qualia are different from physical structures, and rather than epiphenomenalism multiplying entities unnecessarily, it sure seems to me like physicalism is equivocating entities unnecessarily.

So my original argument disproving p-zombies would seem to be on just as solid footing as the original p-zombie argument itself, modulo our disagreements over wording.

Nothing you said indicates that p-zombies are inconceivable or even impossible. What you, or and EY seem to be saying is that our discussion of consciousness is a posteriori evidence that our consciousness is not epiphenomenal.

Comment author: naasking 27 July 2016 01:08:49PM 0 points [-]

I'm not sure in what way it's unjustified for me to have an intuition that qualia are different from physical structures

It's unjustified in the same way that vilalism was an unjustified explanation of life: it's purely a product of our ignorance. Our perception of subjective experience/first-hand knowledge is no more proof of accuracy than our perception that water breaks pencils.

Intuition pumps supporting the accuracy of said perception either beg the question or multiply entities unnecessarily (as detailed below).

Nothing you said indicates that p-zombies are inconceivable or even impossible.

I disagree. You've said that epiphenominalists hold that having first-hand knowledge is not causally related to our conception and discussion of first-hand knowledge. This premise has no firm justification.

Denying it yields my original argument of inconceivability via the p-zombie world. Accepting it requires multiplying entities unnecessarily, for if such knowledge is not causally efficacious, then it serves no more purpose than vital in vitalism and will inevitably be discarded given a proper scientific account of consciousness, somewhat like this one.

I previously asked for any example of knowledge that was not a permutation of properties previously observed. If you can provide one such an example, this would undermine my position.

Comment author: TheAncientGeek 05 July 2016 06:17:06PM -1 points [-]

What EY is saying is that it's highly implausible for all of our ideas and talk of consciousness to have come to be if subjective consciousness does not play a causal role in our thinking

Although he is also saying that our ideas about free will come about from a source other than free will.

Comment author: Vladimir 03 July 2016 12:10:40AM *  2 points [-]

I'm curious to see if this convinces Bryan Caplan & Sam Harris.

Comment author: Elo 02 July 2016 09:19:33PM -2 points [-]

Welcome back!

Comment author: ingres 02 July 2016 09:52:53PM 0 points [-]

Seconded.

Comment author: SquirrelInHell 02 July 2016 11:01:48PM *  1 point [-]

"Darn, I'm out of orange juice." The sound of these words is probably represented in your auditory cortex, as though you'd heard someone else say it.

Note for accuracy:

If something puts a significant strain on short-term memory, it does indeed end up relying on the "inner voice" for extended/improved storage.

However extending this to "Darn, I'm out of orange juice." is unfounded and depending on a particular person, false to a greater or smaller degree.

Comment author: [deleted] 04 July 2016 01:07:56AM -1 points [-]

"Is", "is." "is"—the idiocy of the word haunts me. If it were abolished, human thought might begin to make sense. I don't know what anything "is"; I only know how it seems to me at this moment.

— Robert Anton Wilson, The Historical Illuminatus Chronicles, as spoken by Sigismundo Celine.

Comment author: entirelyuseless 10 July 2016 03:12:30PM 0 points [-]

I think characterizing this discussion as being about whether zombies are conceivable, as Eliezer does here, prevents productive discussion. That is not the issue, and Eliezer basically admits that in the last paragraph. Of course they are conceivable. We all know what we are talking about here.

Eliezer's basic argument is that zombies are impossible, not that they are inconceivable. And I agree that they are impossible. But the fact that he has misrepresented the nature of the argument makes it difficult to have a productive discussion of the issue.

Suppose we have a grid of pixels, with pixel #1 located at position 2,1 ; pixel #2 located at position 2,2; pixel #3 located at position 2,3; pixel #4 located at position 2,4; and pixel #5 located at position 2,5.

The pixels are in a straight line on the grid. Now suppose someone says, "Could there be a series of pixels, all in exactly those positions mentioned, but in such a way that the pixels are not in straight line?"

In this case, asking whether or not the situation is conceivable is not a helpful question here. But we do know that the situation described cannot happen. I would say that zombies are essentially the same situation -- something physically identical to a human is a human, and has all human properties, including the property of consciousness.

One difference though is this: we think we understand why the pixels must be in a straight line, but we do not think we know enough about the physical properties of humans to say why they must be conscious. We just know that humans are in fact conscious, and this is enough to tell us that zombie humans cannot actually happen.

Given the terms that physics usually uses, in fact, a deductive argument to the conclusion, "humans are conscious," is impossible, since "conscious" is not one of those terms. But in the same way, if we start from premises that only say things about the positions of individual pixels, and nothing else, we cannot formulate a deductive argument that the pixels must be in a straight line. That does not mean that the pixels might fail to be in a straight line, nor does it imply that a human could fail to be conscious. It simply means that our account, whether the physical account of the human, or the one about the positions of the pixels, is an incomplete account of reality.

And I suspect that this last point is my real disagreement with Eliezer. I think he believes that the physical account is a complete account, and likewise that an account of the pixels including nothing but the individual positions is a complete account of the pixels. If so, I think he would be mistaken in both cases.

Comment author: jkaufman 12 July 2016 07:58:08PM 1 point [-]

I was curious about the diff, specifically what sections were being removed. This is too long for a comment, so I'll post each one as a reply to this comment.

Comment author: jkaufman 12 July 2016 07:59:54PM 1 point [-]

Mind you, I am not saying this is a substitute for careful analytic refutation of Chalmers's thesis. System 1 is not a substitute for System 2, though it can help point the way. You still have to track down where the problems are specifically.

Chalmers wrote a big book, not all of which is available through free Google preview. I haven't duplicated the long chains of argument where Chalmers lays out the arguments against himself in calm detail. I've just tried to tack on a final refutation of Chalmers's last presented defense, which Chalmers has not yet countered to my knowledge. Hit the ball back into his court, as it were.

But, yes, on a core level, the sane thing to do when you see the conclusion of the zombie argument, is to say "That can't possibly be right" and start looking for a flaw.

Comment author: jkaufman 12 July 2016 07:59:47PM 1 point [-]

I have a nonstandard perspective on philosophy because I look at everything with an eye to designing an AI; specifically, a self-improving Artificial General Intelligence with stable motivational structure.

When I think about designing an AI, I ponder principles like probability theory, the Bayesian notion of evidence as differential diagnostic, and above all, reflective coherence. Any self-modifying AI that starts out in a reflectively inconsistent state won't stay that way for long.

If a self-modifying AI looks at a part of itself that concludes "B" on condition A—a part of itself that writes "B" to memory whenever condition A is true—and the AI inspects this part, determines how it (causally) operates in the context of the larger universe, and the AI decides that this part systematically tends to write false data to memory, then the AI has found what appears to be a bug, and the AI will self-modify not to write "B" to the belief pool under condition A.

Any epistemological theory that disregards reflective coherence is not a good theory to use in constructing self-improving AI. This is a knockdown argument from my perspective, considering what I intend to actually use philosophy for. So I have to invent a reflectively coherent theory anyway. And when I do, by golly, reflective coherence turns out to make intuitive sense.

So that's the unusual way in which I tend to think about these things. And now I look back at Chalmers:

The causally closed "outer Chalmers" (that is not influenced in any way by the "inner Chalmers" that has separate additional awareness and beliefs) must be carrying out some systematically unreliable, unwarranted operation which in some unexplained fashion causes the internal narrative to produce beliefs about an "inner Chalmers" that are correct for no logical reason in what happens to be our universe.

But there's no possible warrant for the outer Chalmers or any reflectively coherent self-inspecting AI to believe in this mysterious correctness. A good AI design should, I think, look like a reflectively coherent intelligence embodied in a causal system, with a testable theory of how that selfsame causal system produces systematically accurate beliefs on the way to achieving its goals.

So the AI will scan Chalmers and see a closed causal cognitive system producing an internal narrative that is uttering nonsense. Nonsense that seems to have a high impact on what Chalmers thinks should be considered a morally valuable person.

This is not a necessary problem for Friendly AI theorists. It is only a problem if you happen to be an epiphenomenalist. If you believe either the reductionists (consciousness happens within the atoms) or the substance dualists (consciousness is causally potent immaterial stuff), people talking about consciousness are talking about something real, and a reflectively consistent Bayesian AI can see this by tracing back the chain of causality for what makes people say "consciousness".

Comment author: jkaufman 12 July 2016 07:59:29PM 1 point [-]

... (Argument from career impact is not valid, but I say it to leave a line of retreat.)

Chalmers critiques substance dualism on the grounds that it's hard to see what new theory of physics, what new substance that interacts with matter, could possibly explain consciousness. But property dualism has exactly the same problem. No matter what kind of dual property you talk about, how exactly does it explain consciousness?

When Chalmers postulated an extra property that is consciousness, he took that leap across the unexplainable. How does it help his theory to further specify that this extra property has no effect? Why not just let it be causal?

If I were going to be unkind, this would be the time to drag in the dragon—to mention Carl Sagan's parable of the dragon in the garage. "I have a dragon in my garage." Great! I want to see it, let's go! "You can't see it—it's an invisible dragon." Oh, I'd like to hear it then. "Sorry, it's an inaudible dragon." I'd like to measure its carbon dioxide output. "It doesn't breathe." I'll toss a bag of flour into the air, to outline its form. "The dragon is permeable to flour."

One motive for trying to make your theory unfalsifiable, is that deep down you fear to put it to the test. Sir Roger Penrose (physicist) and Stuart Hameroff (neurologist) are substance dualists; they think that there is something mysterious going on in quantum, that Everett is wrong and that the "collapse of the wave-function" is physically real, and that this is where consciousness lives and how it exerts causal effect upon your lips when you say aloud "I think therefore I am." Believing this, they predicted that neurons would protect themselves from decoherence long enough to maintain macroscopic quantum states.

This is in the process of being tested, and so far, prospects are not looking good for Penrose—

—but Penrose's basic conduct is scientifically respectable. Not Bayesian, maybe, but still fundamentally healthy. He came up with a wacky hypothesis. He said how to test it. He went out and tried to actually test it.

As I once said to Stuart Hameroff, "I think the hypothesis you're testing is completely hopeless, and your experiments should definitely be funded. Even if you don't find exactly what you're looking for, you're looking in a place where no one else is looking, and you might find something interesting."

So a nasty dismissal of epiphenomenalism would be that zombie-ists are afraid to say the consciousness-stuff can have effects, because then scientists could go looking for the extra properties, and fail to find them.

I don't think this is actually true of Chalmers, though. If Chalmers lacked self-honesty, he could make things a lot easier on himself.

(But just in case Chalmers is reading this and does have falsification-fear, I'll point out that if epiphenomenalism is false, then there is some other explanation for that-which-we-call consciousness, and it will eventually be found, leaving Chalmers's theory in ruins; so if Chalmers cares about his place in history, he has no motive to endorse epiphenomenalism unless he really thinks it's true.)

Comment author: jkaufman 12 July 2016 07:59:08PM 1 point [-]

The zombie argument does not rest solely on the intuition of the passive listener. If this was all there was to the zombie argument, it would be dead by now, I think. The intuition that the "listener" can be eliminated without effect, would go away as soon as you realized that your internal narrative routinely seems to catch the listener in the act of listening.

Comment author: jkaufman 12 July 2016 07:58:58PM 1 point [-]

By supposition, the Zombie World is atom-by-atom identical to our own, except that the inhabitants lack consciousness. Furthermore, the atoms in the Zombie World move under the same laws of physics as in our own world. If there are "bridging laws" that govern which configurations of atoms evoke consciousness, those bridging laws are absent. But, by hypothesis, the difference is not experimentally detectable. When it comes to saying whether a quark zigs or zags or exerts a force on nearby quarks—anything experimentally measurable—the same physical laws govern.

The Zombie World has no room for a Zombie Master, because a Zombie Master has to control the zombie's lips, and that control is, in principle, experimentally detectable. The Zombie Master moves lips, therefore it has observable consequences. There would be a point where an electron zags, instead of zigging, because the Zombie Master says so. (Unless the Zombie Master is actually in the world, as a pattern of quarks—but then the Zombie World is not atom-by-atom identical to our own, unless you think this world also contains a Zombie Master.)

When a philosopher in our world types, "I think the Zombie World is possible", his fingers strike keys in sequence: Z-O-M-B-I-E. There is a chain of causality that can be traced back from these keystrokes: muscles contracting, nerves firing, commands sent down through the spinal cord, from the motor cortex—and then into less understood areas of the brain, where the philosopher's internal narrative first began talking about "consciousness".

And the philosopher's zombie twin strikes the same keys, for the same reason, causally speaking. There is no cause within the chain of explanation for why the philosopher writes the way he does, which is not also present in the zombie twin. The zombie twin also has an internal narrative about "consciousness", that a super-fMRI could read out of the auditory cortex. And whatever other thoughts, or other causes of any kind, led to that internal narrative, they are exactly the same in our own universe and in the Zombie World.

So you can't say that the philosopher is writing about consciousness because of consciousness, while the zombie twin is writing about consciousness because of a Zombie Master or AI chatbot. When you trace back the chain of causality behind the keyboard, to the internal narrative echoed in the auditory cortex, to the cause of the narrative, you must find the same physical explanation in our world as in the zombie world.

Comment author: jkaufman 12 July 2016 07:58:48PM 1 point [-]

One of the great battles in the Zombie Wars is over what, exactly, is meant by saying that zombies are "possible". Early zombie-ist philosophers (the 1970s) just thought it was obvious that zombies were "possible", and didn't bother to define what sort of possibility was meant.

Because of my reading in mathematical logic, what instantly comes into my mind is logical possibility. If you have a collection of statements like (A->B),(B->C),(C->~A) then the compound belief is logically possible if it has a model—which, in the simple case above, reduces to finding a value assignment to A, B, C that makes all of the statements (A->B),(B->C), and (C->~A) true. In this case, A=B=C=0 works, as does A=0, B=C=1 or A=B=0, C=1.

Something will seem possible—will seem "conceptually possible" or "imaginable"—if you can consider the collection of statements without seeing a contradiction. But it is, in general, a very hard problem to see contradictions or to find a full specific model! If you limit yourself to simple Boolean propositions of the form ((A or B or C) and (B or ~C or D) and (D or ~A or ~C) ...), conjunctions of disjunctions of three variables, then this is a very famous problem called 3-SAT, which is one of the first problems ever to be proven NP-complete."

So just because you don't see a contradiction in the Zombie World at first glance, it doesn't mean that no contradiction is there. It's like not seeing a contradiction in the Riemann Hypothesis at first glance. From conceptual possibility ("I don't see a problem") to logical possibility in the full technical sense, is a very great leap. It's easy to make it an NP-complete leap, and with first-order theories you can make it arbitrarily hard to compute even for finite questions. And it's logical possibility of the Zombie World, not conceptual possibility, that is needed to suppose that a logically omniscient mind could know the positions of all the atoms in the universe, and yet need to be told as an additional non-entailed fact that we have inner listeners.

Comment author: jkaufman 12 July 2016 07:58:36PM 1 point [-]

Zombie-ism is not the same as dualism. Descartes thought there was a body-substance and a wholly different kind of mind-substance, but Descartes also thought that the mind-substance was a causally active principle, interacting with the body-substance, controlling our speech and behavior. Subtracting out the mind-substance from the human would leave a traditional zombie, of the lurching and groaning sort.

And though the Hebrew word for the innermost soul is N'Shama, that-which-hears, I can't recall hearing a rabbi arguing for the possibility of zombies. Most rabbis would probably be aghast at the idea that the divine part which God breathed into Adam doesn't actually do anything.

Comment author: jkaufman 12 July 2016 07:58:28PM 1 point [-]

(Warning: Long post ahead. Very long 6,600-word post involving David Chalmers ahead. This may be taken as my demonstrative counterexample to Richard Chappell's Arguing with Eliezer Part II, in which Richard accuses me of not engaging with the complex arguments of real philosophers.)

Comment author: turchin 06 July 2016 12:56:10PM *  1 point [-]

I think that main problem of this (and similar) reasoning is its circularity. This circularity doesn't make such reasoning untrue, but weakens its evidence base.

It starts with (some version of) physicalism is true. And its conclusion is that there is nothing that is not physical.

If we take definition (one of) of the physicalism from SEP:

"(1) Physicalism is true at a possible world w iff any world which is a physical duplicate of w is a duplicate of w simpliciter." http://plato.stanford.edu/entries/physicalism/#NonModDefPhy

It means that by definition a copy has all the same qualities (including consciousness and qualia) as original.

We could see that zombies are impossible in physical world by definition of physical world.

So there is no need to prove anything.

So the only thing we need to do in order to disprove zombies - is to prove that physicalism is true. So we could go to the end of SEP article and check what kind of proves exist.

There are two:

1) Idea of casual closure of all world

2) Knowledge from science about physics and idea that philosophy should be similar to the most successful scientific explanation of the world

Both of them have some problems, some of them: What is causality? Or if we find ourself in the world which will be describe in the best possible form by existence of many small gods, should we take it as prove of their metaphysical nature?

Basically first 50 pages of SEP article is about problems with physicalism and I was surprised that there are so many of them.

These ideas penetrates in typical discussions about consciousness in subtle form. Someone starts with: "ok we know, that all out thoughts consists of atoms, neurons etc, so there is no place for qualia etc". So he used latest knowledge from science to prove his point, that is using (2). But science knowledge about where and how we have experiences are incomplete, and he also implicitly use science as a prove to physicalism

I think that we need new definition and new prove of physicalism, and in this case we will be able to solve all its puzzles.

Comment author: turchin 11 July 2016 03:17:40PM 0 points [-]

By the way, some kind of p-zombies is possible.

Its me in different modal states. For example, a "possible me" will have all the same thoughts (possible thoughts) and possible experience but will have not any subjective experiences (if we don't patch it with modal realism, but it comes with price).

For example if I am choosing between 2 ways home, one pleasant and one full of pain, I could imagine a copy of me, which will walk home with some suffering and thinking about its subjective experiences, but after I choose walk home by pleasant way, it will never come into existence. So the main difference for me of possible me from real is that possible me doesn't have any experiences. But it could think about its experiences.

It is also similar to counterfactual mugging argument, where we should think about possible me as of real.

Comment author: gjm 11 July 2016 03:55:17PM -2 points [-]

The usual point of p-zombies is to support non-physicalism. I hope it's clear that these purely-imagined possible-yous don't do that.

(Just as the fact that I can imagine disconnecting all my computer equipment from its electricity supply but having it continue to work doesn't offer any evidence that it doesn't work by electricity; it just means that my imagination is sufficiently coarse-grained that I'm often happy to imagine things that aren't actually possible.)

If you are not a modal realist, I don't think it's at all true that "the main difference for me of possible me from real is that possible me doesn't have any experiences"; a more important difference, surely, is that possible-you exists only inside your head whereas real-you exists in the actual world. And therefore, in particular, despite the "possible" in his name, possible-you is not constrained to actually be possible, unlike real-you.

It also seems to me that saying that possible-you differs from real-you mostly in not having experiences involves a sort of level-confusion. Within your imagination, possible-you has experiences (which is why it will be complaining about the pain as it takes the horrible way home, right?). In reality, possible-you has no experiences -- but also doesn't exist at all.

Comment author: turchin 11 July 2016 08:31:29PM 0 points [-]

Unfortunately even "possible me" zombies may be used against physicalism. The argument for that I read in Kant's "The critique of pure reason".

Imagine two full universes, one real and one possible, and ask a question what is the difference between them. There will be no material differences between them - energy, atoms and observers will be the same. Any difference between them will be something unobservable. For Kant it is not a problem, as its just shows absurdity of asking such questions, and I sure that in our time he would use idea of p-zombies just to demonstrate principal limits of our knowledges about metaphysics. Kant mention this very short, even shorter than I explain this here. He just said that there is no difference between the thing which is possible in all aspects and real thing.

So we need to add some kind of "vital energy" to possible world to make it actual, or to accept timeless mathematical universe model, where any possible world is actual. As LW and EY seems to accept last version, in it any possible observer must have experiences, and no possible p-zombies exist (lets call them PP-zombies). The price for it is that I can't choose between two futures, without summoning mystical idea of "measure of existence", which is the probability that I will find myself one of my future copies with one type of experience.

For example, if I have two possible futures, one normal, and one where golden meteor hit my garden, and I am modal realist, I should think about them as both real. As it results in absurd expectation, I should add that some of them are more real than others, based on their "measure of existence". Any attempts to define measure of existence result in unexpected complexity, as we need to consider numbers of different and equal copies in different worlds, quantum theory, cosmology, infinities, anthropics, non-normal predictions and ethical paradoxes. This is what I meant when said that modal realism comes with price.

In short, trying to kill one monster, p-zombies, we create another monster in form of "measure of existence".

Your counterargument is based on idea that any possible thing is only a thing which exist in my imagination. It contradicts timeless mathematical universe reality hypothesis. I think that there could be many other definitions of possibility - uncertainty, future, quantum Shroedinger cat, separated possible universes.

Counterfactual mugging thought experiment shows that I must take into account behavior of possible me (and it could be much more complex than in the experiment) https://wiki.lesswrong.com/wiki/Counterfactual_mugging

Comment author: gjm 11 July 2016 11:45:30PM -1 points [-]

Before, you were comparing a(n apparently) possible universe in which you do one thing, with an actual universe in which you do something else. These are not universes with no material differences.

But now you want me to imagine two otherwise identical worlds, one actual and one merely possible. This seems doubtfully coherent to me in two different ways. First, I am not at all sure it actually makes sense to distinguish between an imagined imaginary world and am imagined actual world: both, in fact, are merely imagined. Second and worse, if some possible world is identical to the actual world term I say it is in fact the actual world.

How you get from there to needing to choose between "vital energy" and modal realism, I don't understand; it seems to me that if any theory is in need of such "vital energy" (which I'm not at all sure if the case) then it's modal realism. And the thing you say is the "price" of modal realism seems to me obviously innocuous. Indeed, the most obvious way to try to implement something like modal realism is Everett quantum mechanics -- which comes automatically with exactly the kind of measure you're talking about.

Saying that your imagined possible-you who goes home by a different route is a figment of your imagination doesn't contradict the mathematical universe hypothesis; it just means declining to identify the constructs of your imagination with portions of the (hypothetical) mathematical universe. When you say "of course I could have gone home the other way" on the basis that it just seems obvious, you are not identifying a portion of the Tegmark universe, you're just indulging in imagination. (For the avoidance of doubt, there's nothing wrong with that.)

I'm not sure that the counterfactual mugging thought experiment exactly shows that you have to do anything in particular, but by all means take into account possible or ways you could behave -- but doing so really doesn't have the exotic metaphysical commitments you seem to be claiming it has.

Comment author: buybuydandavis 09 July 2016 11:49:36AM 0 points [-]

It is furthermore claimed that if zombies are "conceivable" (a term over which battles are still being fought), then, purely from our knowledge of this "conceivability", we can deduce a priori that consciousness is extra-physical, in a sense to be described below.

Is that really the claim? Because it seems terribly silly.

Since it is conceivable (a pun, wait for it!) that Mommy fooled around on the Daddy who raised you, and you aren't his biological son, then the identity of your "social" father and your biological father can't be true in reality?

At bottom it seems like if two concepts are different, they're denying that in reality they're referring to the same thing. It's just odd.

It is conceivable that consciousness is something beyond brain function, but it is increasingly implausible.

And how about we turn around the proposition?

It is furthermore claimed that if non-zombies are "conceivable" (a term over which battles are still being fought), then, purely from our knowledge of this "conceivability", we can deduce a priori that consciousness is extra-subjective.

Comment author: Riothamus 08 July 2016 08:21:33PM 0 points [-]

What do people in Chalmer's vein of belief think of the simulation argument?

If a person is plugged into an otherwise simulated reality, do all the simulations count as p-zombies, since they match all the input-output and lack-of-qualia criteria?

Comment author: gjm 08 July 2016 08:56:49PM -2 points [-]

Do they lack qualia? How accurate are these simulations meant to be?

Comment author: Riothamus 12 July 2016 03:23:59PM 0 points [-]

They are meant to be arbitrarily accurate, and so we would expect them to include qualia.

However, in the Chalmers vein consciousness is non-physical, which suggests it cannot be simulated through physical means. This yields a scenario very similar to the identical-yet-not-conscious p-zombie.

Comment author: TheAncientGeek 14 July 2016 03:43:08PM *  -1 points [-]

They are meant to be arbitrarily accurate, and so we would expect them to include qualia.

Whose "we"? They are only mean to be functional (input-output) duplicates, and a large chunk of the problem of qualiia is that qualia are not in any remotely obvious way functions.

However, in the Chalmers vein consciousness is non-physical, which suggests it cannot be simulated through physical means.

If you think consciousness is non physical , you would think the sims are probably zombies. You would also think that if you are a physicalist but not a computationalist. Physicalism does not guarantee anything about the nature of computational simulations.

Chalmers actual position is that consciousness supervenes on certain kinds of information processing, so that a sufficiently detailed simulation would be conscious: he's one of the "we".

Comment author: TheAncientGeek 14 July 2016 03:35:26PM -1 points [-]

They don't exactly count as p-zombie, since they are functional simulations, not atom-by-atom duplicates. I call such zombies c-zombies, for computational zombies.