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dxu comments on Zombies Redacted - Less Wrong Discussion

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

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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: entirelyuseless 20 July 2016 04:56:26AM -1 points [-]

While I disagree with Eliezer's post, I also disagree with the Zombie world argument as you have presented it. That said, it is not true that your argument is completely analogous with it. One difference is in number 7. In the first argument, we believe we are living in a world where everyone is conscious for inductive reasons. The fact that other human beings have similar bodies and actions with mine, gives me reason to think that others are conscious just as I am. In your argument, there is simply no reason to accept your #7, since there is no analogy that would lead you to that conclusion.

Comment author: dxu 20 July 2016 07:03:44PM *  0 points [-]

While I disagree with Eliezer's post

Where? How?

I also disagree with the Zombie world argument as you have presented it.

Well, I disagree with the Zombie World argument, period, so it's possible I may have misrepresented it somehow (though naturally, I don't believe I did). Is there something you specifically disagree with about my phrasing of the Zombie World argument, i.e. some objection that applies to my phrasing, but not to (what you consider) the original?

That said, it is not true that your argument is completely analogous with it. One difference is in number 7.

Okay, so it seems like this is the meat of your objection. This being the case, I'm going to devote a rather larger amount of effort to answering this objection than to what you wrote above. If you feel I didn't focus enough on what you wrote above, again, please feel free to expand on any objections you may have there.

In the first argument, we believe we are living in a world where everyone is conscious for inductive reasons. The fact that other human beings have similar bodies and actions with mine, gives me reason to think that others are conscious just as I am. In your argument, there is simply no reason to accept your #7, since there is no analogy that would lead you to that conclusion.

Well, first off, I personally think the Zombie World is logically impossible, since I treat consciousness as an emergent phenomenon rather than a mysterious epiphenomenal substance; in other words, I reject the argument's premise: that the Zombie World's existence is "conceivable". (That's why I believe every human on the planet is conscious--given the structure of their brains, there's no way for them not to be.)

That being said, if you do accept the Zombie World argument, then there's no reason to believe we live in a universe with any conscious beings. The Zombie World (the one that has no consciousness in it, period) is far simpler than both (1) a universe in which I'm the only conscious one, and (2) a universe in which everyone is conscious. In both of the latter cases, you're saying that there's a mysterious epiphenomenal substance called consciousness that isn't there by necessity; it just happens to be there in order to make all the philosophers of consciousness (and dxu-2) right. Let's repeat that for emphasis: there is literally no reason for consciousness to exist in our universe other than to make David Chalmers right when he writes about consciousness.

If you accept that the Zombie World is conceivable, in other words, the next logical step is not to conclude that by sheer luck, we somehow ended up in a universe with consciousness--no, the next logical step would be to conclude that we ourselves are actually living in the Zombie World. There's no reason to believe that you're conscious, or that I'm conscious, or that anyone is conscious; the Zombie World (assuming it's possible) is strictly simpler than all of those cases.

Remember how, in both arguments, step 7 contained the phrase "just trust me on this one"? That wasn't by accident. In order to accept that we live in a universe with any consciousness at all, you need an absolutely tremendous of faith. True, a universe in which I'm the only conscious being might be slightly more complicated that one where everyone is conscious, but that slight increase in complexity is nothing compared with the huge complexity penalty both hypotheses receive compared with the Zombie World hypothesis (assuming, once again, that you admit the Zombie World hypothesis as a valid hypothesis).

Quoting the last part of your comment once more:

In your argument, there is simply no reason to accept your #7, since there is no analogy that would lead you to that conclusion.

If you reject step 7 of my argument because you feel it is unjustified ("there is no analogy that would lead you to that conclusion"), then you must reject step 7 of (my phrasing of) the original Zombie World argument as well, because compared to the Zombie World itself, the latter claim is virtually just as unjustified as the former. Your objection is acknowledged, but it plays no role in determining the conclusion of the original discussion: you must either accept both arguments as I presented them, or accept neither.

TL;DR: I concede that the final steps of each argument were not exactly analogous. However, this does not change the fact that if you accept one argument, you must accept the other, and hence, my original contention remains unchallenged.

Comment author: UmamiSalami 21 July 2016 03:28:31AM 0 points [-]

Well, first off, I personally think the Zombie World is logically impossible, since I treat consciousness as an emergent phenomenon rather than a mysterious epiphenomenal substance; in other words, I reject the argument's premise: that the Zombie World's existence is "conceivable".

And yet it seems really quite easy to conceive of a p zombie. Merely claiming that consciousness is emergent doesn't change our ability to imagine the presence or absence of the phenomenon.

That being said, if you do accept the Zombie World argument, then there's no reason to believe we live in a universe with any conscious beings.

But clearly we do have such a reason: that we are conscious, and know this fact through direct experience of consciousness.

The confusion in your post is grounded in the idea that Chalmers or I would claim that the proof for consciousness is people's claims that they are conscious. We don't (although it could be evidence for it, if we had prior expectations against p-zombie universes which talked about consciousness). The claim is that we know consciousness is real due to our experience of it. The fact that this knowledge is causally inefficacious does not change its epistemic value.

Comment author: dxu 21 July 2016 05:37:02AM 0 points [-]

And yet it seems really quite easy to conceive of a p zombie. Merely claiming that consciousness is emergent doesn't change our ability to imagine the presence or absence of the phenomenon.

Not too long ago, it would also have been quite easy to conceive of a world in which heat and motion were two separate things. Today, this is no longer conceivable. If something seems conceivable to you now, that might just be because you don't yet understand how it's actually impossible. To make the jump from "conceivability" (a fact about your bounded mind) to "logically possible" (a fact about reality) is a misstep, and a rather enormous one at that.

But clearly we do have such a reason: that we are conscious, and know this fact through direct experience of consciousness.

By stipulation, you would have typed the above sentence regardless of whether or not you were actually conscious, and hence your statement does not provide evidence either for or against the existence of consciousness. If we accept the Zombie World as a logical possibility, our priors remain unaltered by the quoted sentence, and continue to be heavily weighted toward the Zombie World. (Again, we can easily get out of this conundrum by refusing to accept the logical possibility of the Zombie World, but this seems to be something you refuse to do.)

The claim is that we know consciousness is real due to our experience of it.

This exact statement could have been emitted by a p-zombie. Without direct access to your qualia, I have no way of distinguishing the difference based on anything you say or do, and as such this sentence provides just as much evidence that you are conscious as the earlier quoted statement does--that is to say, no evidence at all.

The fact that this knowledge is causally inefficacious does not change its epistemic value.

Oh, but it does. In particular, for a piece of knowledge to have epistemic value to me (or anyone else, for that matter), I need to have some way of acquiring that knowledge. For me to acquire that knowledge, I must causally interact with it in some manner. If that knowledge is "causally inefficacious", as you put it, by definition I have no way of knowing about it, and it can hardly be called "knowledge" at all, much less have any epistemic value.

Allow me to spell things out for you. Your claims, interpreted literally, would imply the following statements:

  1. There exists a mysterious substance called "consciousness" that does not causally interact with anything in the physical universe.
  2. Since this substance does not causally interact with anything in the physical universe, and you are part of the physical universe, said substance does not causally interact with you.
  3. This means, among other things, that when you use your physical fingers to type on your physical keyboard the words, "we are conscious, and know this fact through direct experience of consciousness", the cause of that series of physical actions cannot be the mysterious substance called "consciousness", since (again) that substance is causally inactive. Instead, some other mysterious process in your physical brain is occurring and causing you to type those words, operating completely independently of this mysterious substance. Moreover, this physical process would occur and cause you to type those same words regardless of whether the mysterious epiphenomenal substance called "consciousness" was actually present.
  4. Nevertheless, for some reason you appear to expect me to treat the words you type as evidence of this mysterious, causally inactive substance's existence. This, despite the fact that those words and that substance are, by stipulation, completely uncorrelated.

...Yeah, no. Not buying it, sorry. If you can't seeing the massive improbabilities you're incurring here, there's really not much left for me to say.

Comment author: UmamiSalami 22 July 2016 05:21:13PM *  -2 points [-]

Not too long ago, it would also have been quite easy to conceive of a world in which heat and motion were two separate things. Today, this is no longer conceivable.

But it is conceivable for thermodynamics to be caused by molecular motion. No part of that is (or ever was, really) inconceivable. It is inconceivable for the sense qualia of heat to be reducible to motion, but that's just another reason to believe that physicalism is wrong. The blog post you linked doesn't actually address the idea of inconceivability.

If something seems conceivable to you now, that might just be because you don't yet understand how it's actually impossible.

No, it's because there is no possible physical explanation for consciousness (whereas there are possible kinetic explanations for heat, as well as possible sonic explanations for heat, and possible magnetic explanations for heat, and so on. All these nonexistent explanations are conceivable in ways that a physical description of sense datum is not).

By stipulation, you would have typed the above sentence regardless of whether or not you were actually conscious, and hence your statement does not provide evidence either for or against the existence of consciousness.

And I do not claim that my statement is evidence that I have qualia.

This exact statement could have been emitted by a p-zombie.

See above. No one is claiming that claims of qualia prove the existence of qualia. People are claiming that the experience of qualia proves the existence of qualia.

In particular, for a piece of knowledge to have epistemic value to me (or anyone else, for that matter), I need to have some way of acquiring that knowledge.

We're not talking about whether a statement has "epistemic value to [you]" or not. We're talking about whether it's epistemically justified or not - whether it's true or not.

There exists a mysterious substance called "consciousness" that does not causally interact with anything in the physical universe.

Neither I nor Chalmers describe consciousness as a substance.

Since this substance does not causally interact with anything in the physical universe, and you are part of the physical universe, said substance does not causally interact with you.

Only if you mean "you" in the reductive physicalist sense, which I don't.

This means, among other things, that when you use your physical fingers to type on your physical keyboard the words, "we are conscious, and know this fact through direct experience of consciousness", the cause of that series of physical actions cannot be the mysterious substance called "consciousness", since (again) that substance is causally inactive. Instead, some other mysterious process in your physical brain is occurring and causing you to type those words, operating completely independently of this mysterious substance.

Of course, although physicalists believe that the exact same "some other mysterious process in your physical brain" causes us to type, they just happen to make the assertion that consciousness is identical to that other process.

Nevertheless, for some reason you appear to expect me to treat the words you type as evidence of this mysterious, causally inactive substance's existence.

As I have stated repeatedly, I don't, and if you'd taken the time to read Chalmers you'd have known this instead of writing an entirely impotent attack on his ideas. Or you could have even read what I wrote. I literally said in the parent comment,

The confusion in your post is grounded in the idea that Chalmers or I would claim that the proof for consciousness is people's claims that they are conscious. We don't (although it could be evidence for it, if we had prior expectations against p-zombie universes which talked about consciousness). The claim is that we know consciousness is real due to our experience of it.

Honestly. How deliberately obtuse could you be to write an entire attack on an idea which I explicitly rejected in the comment to which you replied. Do not waste my time like this in the future.

Comment author: UmamiSalami 21 July 2016 03:16:55AM *  -2 points [-]

4 is not a correct summary because consciousness being extra physical doesn't imply epiphenominalism; the argument is specifically against physicalism, so it leaves other forms of dualism and panpsychism on the table.

5 and onwards is not correct, Chalmers does not believe that. Consciousness being nonphysical does not imply a lack of knowledge of it, even if our experience of consciousness is not causally efficacious (though again I note that the p zombie argument doesn't show that consciousness is not causally efficacious, Chalmers just happens to believe that for other reasons).

No part of the zombie argument really makes the claim that people or philosophers are conscious or not, so your analogous reasoning along 5-7 is not a reflection of the argument.

Comment author: entirelyuseless 21 July 2016 03:03:59AM -2 points [-]

I'm not going to respond to all of this, because I don't have the time or energy for it, and I think you are very confused here about a large number of issues; resolving them would take much, much more than a comment.

But I will point out one thing. I agree that zombies are impossible, and therefore that a zombie world is impossible. That says nothing about what is conceivable; we know what we mean by a zombie or a zombie world, so it is quite conceivable.

But the thing you are confused about is this: just because a zombie world is impossible, does not mean that we have a syllogistic proof from first principles that it is impossible. We do not. And so if someone thinks it is possible, you can never refute that. You can only give reasons, that is, non-conclusive reasons, for thinking that it is probably impossible. And the reasons for thinking that are very similar to the reason I gave for thinking that other people are conscious. Your comment confuses two different ideas, namely whether zombies are possible, and what we know about zombies and how we know it, which are two different things.

Comment author: dxu 21 July 2016 06:06:37AM 1 point [-]

just because a zombie world is impossible, does not mean that we have a syllogistic proof from first principles that it is impossible. We do not.

True.

And so if someone thinks it is possible, you can never refute that.

False.

You can only give reasons, that is, non-conclusive reasons, for thinking that it is probably impossible. And the reasons for thinking that are very similar to the reason I gave for thinking that other people are conscious. Your comment confuses two different ideas, namely whether zombies are possible, and what we know about zombies and how we know it, which are two different things.

This is not a matter of knowledge, but of expectation. Basically, the question boils down to whether I, personally, believe that consciousness will eventually be explained in reductionistic, lower level terms, just as heat was explained in reductionistic, lower level terms, even if such an explanation is currently unavailable. And the answer to that question is yes. Yes, I do.

I do not believe that consciousness is magic, and I do not believe that it will remain forever inexplicable. I believe that although we do not currently have an explanation for qualia, we will eventually discover such an explanation, just as I believe there exists a googol-th digit of pi, even if we have not yet calculated that digit. And finally, I expect that once such an explanation is discovered, it will make the entire concept of "p-zombies" seem exactly as possible as "heat" somehow being different from "motion", or biology being powered by something other than chemistry, or the third digit of pi being anything other than 4.

This is, it seems to me, the only reasonable position to take; anything else would, in my opinion, require a massive helping of faith. I have attempted to lay out my arguments for why this is so on multiple occasions, and (if you'll forgive my immodesty) I think I've done a decent job of it. I have also asked you several questions in order to help clarify your objections so that I might be able to better address said objections; so far, these questions of mine have gone unanswered, and I have instead been presented with (what appears to me to be) little more than vague hand-waving in response to my carefully worded arguments.

As this conversation has progressed, all of these things have served to foster a feeling of increasing frustration on my part. I say this, not to start an argument, but to express my feelings regarding this discussion directly in the spirit of Tell Culture. Forgive me if my tone in this comment seems a bit short, but there is only so much dancing around the point I am willing to tolerate before I deem the conversation a frustrating and fruitless pursuit. I don't mean to sound like I'm giving an ultimatum here, but to put it bluntly: unless I encounter a point I feel is worth addressing in detail, this will likely be my last reply to you on this topic. I've laid out my case; I leave the task of refuting it to others.

Comment author: entirelyuseless 21 July 2016 10:36:12AM -2 points [-]

Also, regarding the personal things here, I am not surprised that you find it hard to understand me, for two reasons. First, as I have said, I haven't been trying to lay out an entire position anyway, because it is not something that would fit into a few comments on Less Wrong. Second, you are deeply confused about a large number of things.

Of course, you suppose that I am the one who is confused. This is normal for disagreements. But I have good evidence that it is you who are confused, rather than me. You admit that you do not understand what I am saying, calling it "vague hand-waving." In contrast, I understand both what I am saying, and what you are saying. I understand your position quite well, and all of its reasons, along with the ways that you are mistaken. This is a difference that gives me a reason to think that you are the one who is confused, not me.

I agree that it would not be productive to continue a discussion along those lines, of course.

Comment author: dxu 21 July 2016 04:18:54PM *  2 points [-]

...Your comment, paraphrased:

"You think I'm wrong, but actually you're the one who's wrong. I'm not going to give any reasons you're wrong, because this margin is too narrow to contain those reasons, but rest assured I know for a fact that I'm right and you're wrong."

This is, frankly, ridiculous and a load of drivel. Sorry, but I have no intention of continuing to argue with someone who doesn't even bother to present their side of the argument and insults my intelligence on top of that. Tapping out.

Comment author: UmamiSalami 22 July 2016 07:47:28PM *  -1 points [-]

You should take a look at the last comment he made in reply to me, where he explicitly ascribed to me and then attacked (at length) a claim which I clearly stated that I didn't hold in the parent comment. It's amazing how difficult it is for the naive-eliminativist crowd to express cogent arguments or understand the positions which they attack, and a common pattern I've noticed across this forum as well as others.

Comment author: entirelyuseless 23 July 2016 03:11:02AM 0 points [-]

Yes, I noticed he overlooked the distinction between "I know I am conscious because it's my direct experience" and "I know I am conscious because I say 'I know I am conscious because it's my direct experience.'" And those are two entirely different things.

Comment author: hairyfigment 27 July 2016 01:20:45AM 2 points [-]

The first of those things is incompatible with the Zombie Universe Argument, if we take 'knowledge' to mean a probability that one could separate from the subjective experience. You can't assume that direct experience is epiphenomenal, meaning it doesn't cause any behavior or calculation directly, and then also assume, "I know I am conscious because it's my direct experience".

If it seems unfair to suggest that Chalmers doesn't know he himself is conscious, remember that to our eyes Chalmers is the one creating the problem; we say that consciousness is a major cause of our beliefs about consciousness.

Comment author: entirelyuseless 27 July 2016 03:53:14AM 0 points [-]

I don't think experience is epiphenomenal. As I said, I disagree with the Zombie world argument as proposed.

Nonetheless, it is not true that the first of those things is incompatible with the Zombie argument, even taken in that way. Because knowing I am conscious, not the saying of the words but the being, would itself be epiphenomenal, according to that theory. So direct experience could be the cause of someone knowing that he was conscious, because both of those (experience and knowing) would be epiphenonomenal, so that experience would not be the cause of anything physical (e.g. such as producing sounds that sound like someone saying "I know I am conscious because it's my direct experience.)

Comment author: entirelyuseless 21 July 2016 10:28:47AM -1 points [-]

"I do not believe etc."

That is my point. It is a question of your beliefs, not of proofs. In essence, in your earlier comment, you asserted that you do not depend on an inductive argument to tell you that other people are conscious, because zombies are impossible. But my point is that without the inductive argument, you would have no reason to believe that zombies are impossible.

Comment author: dxu 21 July 2016 04:13:58PM *  0 points [-]

No, I don't believe zombies are impossible because of some nebulously defined "inductive argument". I believe zombies are impossible because I am experiencing qualia, and I don't believe those qualia are the result of some magical consciousness substance that can be added or subtracted from a universe at will.

Comment author: entirelyuseless 22 July 2016 03:04:38AM -1 points [-]

Those are not the only possibilities (that either zombies are impossible or that qualia are the result of magic), but even if they were, your reasons for disbelieving in magic are inductive.