> I believe it's fundamentally impossible to test for consciousness.
You are talking about "phenomenal consciousness", which is sometimes also referred to as "the hard problem of consciousness". (Though not all philosophers would equate these two terms.) There are quite a few other useful definitions of consciousness, and consequently, all of the different notions of consciousness should not all be lumped together.
I actually have a Philosophy degree from MIT, and I spent almost all my philosophical time worrying about and studying this issue. It still keeps me up at night sometimes to this day.
I agree with you that the hard problem of consciousness is not amenable to scientific study, and consequently, I don't think that we can ever understand it, unfortunately.
I also agree that it is the deepest and most important question about the nature of reality that we could ever have, and it is quite frustrating that we will never know the answer.
Back to other notions of consciousness, though: Many of them are interesting, and I think amenable to scientific inquiry. So we shouldn't let the hard problem of consciousness deter us from studying easier problems of consciousness.
A perfect brain simulator could answer many questions, but it could not answer the hard problem of consciousness. Science is all about objectivity, but there's an element of consciousness that is inherently subjective, and that part - the part the hard problem deals with - is not objectively measurable.
> Science is all about objectivity, but there's an element of consciousness that is inherently subjective
Yes, that is exactly right. Science is all about that which can be studied objectively and the "hard problem of consciousness" is specifically about the component of consciousness that is purely subjective.
How can you study something that is purely subjective using objective methods?
A. You can't!
Here's another question that science can't answer:
The Many Worlds interpretation of quantum mechanics and the Bohm interpretation of quantum mechanics posit vastly different things about the nature of reality. Unfortunately, they are experimentally indistinguishable from each other.
So, if somehow we could narrow QM down to either MW or Bohm, at this point we are stuck. We can never know which interpretation is the right one, even though the answer to this question is up there in importance with the hard problem of consciousness!
It's interesting how "subjectivity" has been reintroduced into physics and mathematics in the 20th century: Relativity and its frames of reference, Quantum Mechanics and its necessity of entangling yourself with what you want to observe, Statistical Physics showing that entropy was the lack of information that you have about the system, Mathematics - that you were forced to choose a set of postulates that you then wouldn't be able to prove...
So that's interesting. Behaviorism, for instance, was actually an oppressive "science" of the 20th century because it was ideologically opposed to even acknowledging the existence of subjective mental states. The proponents of Behaviorism felt that subjective mental states were inherently unscientific and they wanted to turn Psychology into a respectable science.
Behaviorists were operating under the misconception that something can't be both subjective and objective at the same time. It took Cognitive Psychology to rescue us from this sorry state of affairs. But for years, those who wanted to do Cognitive Psychology academically were blocked from publishing and getting tenure, etc., by the entrenched Behaviorist establishment.
These days we know that via using FMRI, for instance, psychologists and neuroscientists can often determine objectively more about some of your own thoughts than you yourself might know. Or they can sometimes know what you will come to decide before you believe yourself to have decided. Etc.
But certain mental states (i.e., phenomenal ones) seem to have an inherently subjective component that cannot be studied objectively at all. Or at least that's what someone who believes in the "hard problem of consciousness" will say. Others will say, "Pshaw!"
I'd say that too many people still seem to equate "objective" with "real"/"physical"...
(P.S.: Assuming that a "God's view" of the problem has to exist?)
I'm suspecting that physics might end up in a similar situation than mathematics, where we find out that we can't objectively prove everything - and either we'll have an epistemological breakthrough allowing us to deal with subjectivity in a framework that has still some resemblance to a scientific method, or... we won't.
(Personally, I'm hopeful that the Hard Problem can be "dissolved" - and this "philosophical zombie" concept just seems to me to be misguided, just like the concept of aether was.)
I skimmed the article very quickly. It doesn't even mention the Bohm interpretation. It has long been considered that the Bohm interpretation and MWI are experimentally indistinguishable. Since the article doesn't specifically mention this issue, I'm not sure that it's worth the slog (if all you care about is the philosophical worry that we can never distinguish whether we're in an MWI world vs a Bohm world.)
As for MWI/Bohm being distinguishable from other interpretations, it is certainly the case that this is true. Though actually doing so in practice would be extremely difficult. My guess is that this article is really on how me might approach trying to narrow the field down to MWI/Bohm, or exclude them, as the evidence may ultimately show.
> But is there anything subjective left if all information is accessible and available to observation, study and even replay on other simulated brains?
It's impossible to objectively study what it feels like to be another being. One of the canonical examples from the philosophy literature is on what it feels like to be a bat.
We can't ever observe what it feels like to be a bat because the only way to know for sure what it feels like to be a bat is to actually BE a bat. But you can't be a bat. Consequently, you cannot know for sure what it feels like to be a bat.
Another example from the philosophy literature is the "inverted spectrum hypothesis". Let's say that we make a robot duplicate of you. The robot duplicate of you behaves exactly as you would in all situations. Now let's say that we show the robot a ripe tomato. When you look at this ripe tomato, you will experience a feeling of redness. But for all we know, the robot duplicate of you might feel blueness instead. I.e., it might feel what you feel when you look at the sky on a beautiful summer day.
There's no way for us to know the answer to this question.
There are also philosophers who argue that a robot duplicate of you would feel nothing at all. E.g., no redness, no blueness. If you want to know more about why someone would believe this, look up Searle's Chinese Room argument.
Philosophers who take this point of view believe that any robot will be a "zombie". I.e., it will have all the other sorts of consciousness that we might talk about, but it wouldn't have phenomenal consciousness.
This is also sometimes referred to as the "absent spectrum hypothesis".
All those things you mention represent information. Information encoded in matter. Information that can be compared. We could hypothetically compare two neural circuits that respond to red and thus see if they have the same activation profiles for redness.
Batness could similarly be simulated and then made available to a human brain as read-only stream, perhaps as a dream-like experience.
This is entirely speculative, handwavy and would take fantastic levels of technology, but it does not seem information-theoretically impossible unless you assume that there is something immaterial, at which point things just turn into religion.
Thus it is within the realm of scientific study, albeit it requiring currently hypothetical instruments. But so does the study of quantum mechanics in strongly curved spacetime.
> If you want to know more about why someone would believe this lookup Searle's Chinese Room argument.
I am familiar with it and agree with the position that the (turing-complete) chinese room is simply a way to describe an AGI which speaks chinese and the operator of the room is the computational substrate of the AI and thus a red herring. It's really just an anachronistic analogy.
You're arguing that there is no "hard problem of consciousness". You're wrong. But at least you have plenty of company. Philosophers have been debating this issue rabidly for decades. Huge tomes have been written on the subject, arguing both for and against the "hard problem" being real.
We are not going to settle this issue here. I suggest that we come back in a millennium and see if any progress has been made. I don't have high hopes.
> You're making it sound more and more like that problem is an invisible pink unicorn.
You might have a point if philosophers had been arguing for decades and written huge tomes on whether or not there is an invisible pink unicorn. But they haven't.
The academic philosophy community isn't made up of dimwits. You don't do anyone a service by implying that they are.
I'm not calling anyone a dimwit. Great minds can erect complex thought edifices containing clever arguments but ultimately rest on shaky foundations. E.g. methodically respectable, rigorous studies are made on parapsychology. Newton was studying the occult, european scientists were chasing N-rays.
To me qualia, subjective experience, p-zombies and so on either appear to be arguments from insufficient information or require non-material (read: supernatural) phenomena. The former would crumble under sufficiently advanced study, the latter are invisible pink unicorns with people arguing over the exact spectral distribution of pink.
(1) You are being extremely dismissive, indicating that your mind is closed on the topic, so there is really no point in any further discussion.
(2) As I mentioned previously, we are not going to settle this debate here anyway. There's a huge amount of literature on the issue. And even just "getting" what the issues are often requires attending a Philosophy of Mind class for weeks or months and doing lots of reading and discussing and philosophizing with an open mind.
(3) If your mind is less closed than it seems, and you don't have access to a good Philosophy of Mind class, you might read this book by David Chalmers:
I'm guessing it'll be kind of a slog, though. And I don't agree with much of what he says, but it's a start at least. He's also the most famous proponent of "the hard problem" (or at least he was when I was actively studying Philosophy of Mind). He's also the person who coined the term "hard problem of consciousness".
Or you could start with the Wikipedia page, but I doubt that anyone would be convinced by it:
I am dismissive because you make absolute statements as if there were formal proof and dismiss doubt with "you are wrong" and "attend class for weeks", the latter reminding me of climate change skeptic and creationist retorts.
I am also dismissive because I don't see a succinct motivating example, paradox etc.
A similarly speculative, philosophical field is the simulation hypothesis. At first glance it's metaphysical, untestable and indistinguishable from base reality and thus not very informative. But then people throw up questions how simulation fidelity might show up in high energy physics or what it would mean if the simulation had bugs/were hackable. It's still far out there but at least there is a direct aim to get away from metaphysics, instead finding ways to subject it to scientific inquiry. This drive is what I am missing in your replies. Claiming that something is categorically unknowable and yet an important field of study is inconsistent.
So this is something for you to think about if you really want to have a discussion: I mentioned this issue briefly in my longer response, but it might serve our interests to just jump into the debate in bite-sized bits.
The famous cosmologist Max Tegmark has written an entire book (and published several papers) arguing that there is no difference between mathematical existence and physical existence and therefore all worlds that can be described mathematically and consistently are just as "real" as our world. Consequently, physical existence of a world is due to nothing more than that such a world can be described mathematically.
According to Tegmark, our world is just pure math with no extra secret sauce to make it "real" and physical. And so, of course, according to Tegmark, there are an infinite number of other worlds described by math that also exist physically. And they exist physically for no other reason than that they exist mathematically.
Do you agree with Tegmark?
And if you don't, why isn't it the case that you are postulating invisible pink unicorns to explain the difference between mathematical existence and physical existence?
(Note: I'm not aware of this approach to arguing for the hard problem to be present in the literature. This argument is my own.)
> I am dismissive because you make absolute statements as if there were formal proof
If I were writing a formal proof, you would know it. I have expressed my beliefs and explained as best I can the reasons for them with the extremely limited time that I had available to me.
As for "You are wrong", I softened that with the acknowledgement that you have plenty of company amongst philosophers, and that the subject has been a topic of vigorous debate for decades, and that reasonable people differ on this issue and that we weren't going to be able to resolve such a fraught issue in this limited forum.
You want more tip-toeing than that in a debate? Really? My Philosophy professors would just say directly to you in the middle of a class in front of everyone else, things like, "You are suffering from a profound misconception." This was just a challenge to you to either step up your argument or to ask them for more explication. They would not, however, mock you, or impute that you or half of all the Philosophers who study the topic are so ignorant that they are making an invisible unicorn argument.
As for attending classes for weeks to understand the issue: I have a Philosophy degree from MIT. I spent most of my actual work on Philosophy studying THIS particular issue. It took ME weeks in my first Philosophy of Mind class, when we got to this very topic to ultimately understand the issues involved. I wasn't slower than anyone else in the class either. In fact I'm a natural at Philosophy. I.e., I got an A on every single Philosophy paper I ever wrote. (And MIT does not have grade inflation.) As with most difficult philosophical issues, true understanding really only sets in when setting out to write a paper on the topic.
What's also somewhat unique about this particular philosophical divide is that no matter how much motivating either side does, many philosophers (e.g., even famous professional ones) cannot see the opposing viewpoint at all. No matter what is said, there is a certain contingent on both sides that basically just pounds their fists on the table in frustration that the other side won't even acknowledge that their side might have a valid point.
So what exactly am I supposed to tell you other than that I don't have the time to explain why I don't have the time to explain? (That's an inside joke from the video game Destiny, btw.)
If your point is that I wasted thousands of hours of my life studying this topic, point taken. As Wittgenstein claimed, studying Philosophy is more of a disease than anything else, since with most topics that it deals with, you can argue about the topic for hundreds of years without making much progress. But it's a disease that typically only afflicts people who are passionate and smart and who would like to understand something better, even if such understanding may be ultimately illusive.
> I am also dismissive because I don't see a succinct motivating example, paradox etc.
What makes you think that everything that's of interest can be motivated with a succinct example? Lisp is clearly the best programming language humans have ever devised and yet most programmers just dismiss it as having too many parentheses. If you can't convince people to use the best programming language no matter how much you explain the issues, why should you be able to convince a skeptic about a complex philosophical issue that is moot with respect to any practical concerns.
Though most people immediately do see why there might be a philosophical worry when you mention a robot duplicate of them, and how maybe it might feel different if you had a silicon brain rather than a meat brain. Or that it might not feel like anything at all. Most people just immediately get that there's a worry here. That's about as close as one can come to succinct motivating example. Also, most everyone who ever goes into Philosophy of Mind came up with the inverted spectrum hypothesis on their own when they were ten years old. If that doesn't describe you, then Philosophy of Mind will likely never be your cup of tea. (How can it be that they come up with this at a young age and then end up pounding the table later in life? Well, I'm not sure. I suppose that they've had an epiphany in the meantime, or they dismiss their ten-year-old philosophizing as childish musings.)
> Claiming that something is categorically unknowable and yet an important field of study is inconsistent.
You are suffering from a profound misconception. For instance, it is categorically unknowable in the general case what the morally right thing to do is. And yet ethics is still a field of the utmost importance. E.g., you can, after a whole lot of rumination and debate come up with, for instance, strategies that you might have good reason to believe will increase your likelihood of doing the morally right thing. Fingers crossed.
Also, if QM turns out to be consistent with the Many Worlds interpretation, it is categorically unknowable whether or not it is really the Bohm interpretation that is correct. On the other hand, you may come up with philosophical reasons to believe that one interpretation is more likely to be true than the other. And which is more likely might help you with other important philosophical issues.
Ultimately, this forum is just not the right place to have the sort of discussion that you seem to want to have because discussing the various arguments can be very involved and intricate. This forum is not the right place for such discussions and I don't have the free time right now anyway.
If you actually are interested, rather than just wanting to throw stones, we could move the discussion to Reddit or another forum, and I could provide better motivation for my beliefs on this issue when I have the time and inclination to do so properly.
I actually have my own novel argument on this topic. But it first relies on having some knowledge of Max Tegmark's argument that there's no difference between mathematical existence and physical existence and therefore all worlds that can be described mathematically and consistently are just as real as our world. I.e., our world is just pure math with no extra secret sauce to make it real. (Max Tegmark is a famous cosmologist, in case you don't already know.)
> This is entirely speculative, handwavy and would take fantastic levels of technology, but it does not seem information-theoretically impossible unless you assume that there is something immaterial, at which point things just turn into religion.
My position on this is that there are natural phenomena which cannot be fully described mathematically. There's nothing supernatural about such things. They are just physical things, like all other physical things, but which defy mathematical analysis.
If you don't believe what I just said, then it seems that you are forced to believe Max Tegmark's theory that there is nothing to physical existence other than mathematical existence. Is that really a theory that you buy into.
It's certainly an interesting theory, but I'd be willing to wager that most scientists would not be willing to sign on.
Interesting point. Could you recommend something to read about this topic, or maybe you have some writeups of your own? Mainly interested about the correlation between quantum mechanics and the problem of consciousness.
> Could you recommend something to read about this topic
Well, if you want to dive right in, you could read this book by David Chalmers, who is (or at least was when I actively studied such things) the most famous philosopher who has grappled with the "hard problem" of consciousness:
There are a bunch of books and published papers on the topic, of course. But most of them, including the book listed above, would be a slog if you're not taking a philosophy class on the subject. Even then, they'd likely be a slog. Philosophy arguments on this topic can quickly become extremely intricate, and laden with jargon.
I've written a number of papers on the topic myself for classes, but don't recall if any of them are accessible to someone with no prior knowledge of the debate. There might be a decent one that I wrote for Douglas Hofstadter when he was a visiting professor at MIT. I can check and send you a copy if it seems like it might be approachable.
As for a correlation between consciousness and quantum mechanics, that's not really something I buy into. The famous physicist Roger Penrose, however, wrote a couple of books arguing that computers can never be intelligent because the human brain does special quantum mechanics stuff. If you ask me, his ideas about this are a bunch of claptrap. But in case you are interested, here is one of them:
I am not an expert in either of these fields, but I wouldn’t dismiss the correlation. Quantum mechanics tackles the problem of the observer. If you put a cat in a box, it’s in an undefined state until someone looks at it. If you send your friend over to check the cat, he sees the cat but to you it’s still in an undefined state. Now the friend comes back and tells you the information about the cat, and suddenly your conciousness has indirectly “resolved” the state of the cat. You can extrapolate this to all events in the universe, basically when your consciousness came into existence you have resolved the entire history of the universe.
The "interpretation" that you are using of QM is just one of many proposed interpretations. Specifically, you are referring to an interpretation called the "Von Neumann–Wigner interpretation". It's not an interpretation that I buy into.
The only interpretations that really make sense to me are objective collapse theories and the Many Worlds interpretation. For neither of these interpretations does human consciousness cause wave function collapse.
If you want to know more about the various interpretations of QM, there's a Wikipedia page on them here:
> We can't "really" know anything about the "real" world either - yet hardly anyone takes solipsism seriously...
Philosophers generally take solipsism seriously. They just do something called "bracketing" regarding solipsism. "Bracketing" is a philosopher's way of saying, "Yes, this is a serious issue, but we can't make any progress unless we ignore the problem, so that's what we're going to do. But we'll be sure to keep it in the back of our heads as a possibility, lest it come back and bite us."
I.e., virtually every philosophical argument starts with an implicit, "For the sake of argument let's assume that solipsism isn't true." There are also probably dozens of other such worries that are typically bracketed.
Mathematicians often do something similar. There are certain mathematical conjectures (usually involving infinities in my experience) which we can prove can neither be proved nor disproved. So mathematicians will just assume some such conjectures for the sake of making progress. One example of this would be the axiom of choice.
You are talking about "phenomenal consciousness", which is sometimes also referred to as "the hard problem of consciousness". (Though not all philosophers would equate these two terms.) There are quite a few other useful definitions of consciousness, and consequently, all of the different notions of consciousness should not all be lumped together.
I actually have a Philosophy degree from MIT, and I spent almost all my philosophical time worrying about and studying this issue. It still keeps me up at night sometimes to this day.
I agree with you that the hard problem of consciousness is not amenable to scientific study, and consequently, I don't think that we can ever understand it, unfortunately.
I also agree that it is the deepest and most important question about the nature of reality that we could ever have, and it is quite frustrating that we will never know the answer.
Back to other notions of consciousness, though: Many of them are interesting, and I think amenable to scientific inquiry. So we shouldn't let the hard problem of consciousness deter us from studying easier problems of consciousness.