It doesn’t make sense to say that I could make predictions just as well as before if I experienced all tactile sensations as degrees of being burnt alive, because such sensations would be equivalent to predictions that I would be burning alive, which would be false and therefore interfere with my functioning. You can’t separate experience from its consequences. That’s also why philosophical zombies are impossible; if you could have a body which doesn’t experience, then it’s not going to function as normal.

If I were to experience all tactile sensations as degrees of being burnt alive, I would assume something was wrong with my body and I would want to alleviate that situation by making predictions about which actions would alleviate it by wielding only concepts related to the Easy Problem. How would the Hard Problem help me in that situation?

If the concepts of romantic relationships and marriage didn’t exist, I doubt most people would pursue them in those forms. For a lot of (dare I say most) people it’s a matter of culturally induced FOMO.

A romantic relationship, let alone marriage, is not an unequivocal good. Each micromarriage can be separated into a microsuccesfulmarriage part and a larger microdivorce part. There’s a real danger of such a relationship ruining your life, including opportunity costs. Survivorship bias and the shame of failure means you’ll hear a lot more from people who are currently having good experiences. Being in love is like being on cocaine; should I listen to the drug advice of drug addicts?

Hi, please see my reply to gilch above.

To add to that reply, an explanation only ever serves one function, namely to aid in prediction; every moment of our life, we try to achieve outcomes by predicting which action will lead to which outcome. An explanation to the Hard Problem doesn’t do that. Any state of consciousness that I try to achieve I do so with concepts related to the Easy Problem. I do have experiences (I don’t know what the word “phenomenal” would add to that), such as pain, but to the extent that I can predict and control these, I do so purely with solutions to the Easy Problem. And in my book, concepts that exist only in explanations that don’t aid in prediction are by definition not real. But the Hard Problem is even worse than that; it’s set up so that we can’t tell the difference between a correct and incorrect explanation in the first place, which means literally anything could be an explanation, which is equivalent to no explanation at all. Sure, you can choose to believe that something like panpsychism is real or that it’s not real, but because neither belief adds any predictive power, you’re better off just cutting it out, as per Occam’s Razor.

Thank you for this reply, I think this helps to pin down where our disagreement comes from.

Technically I don’t disagree with your assumptions, because I think it’s equally valid to say they’re true as that they’re false, which is exactly the issue I have with them. There doesn’t seem to be a fact of the matter about them (i.e., there’s no way to experimentally distinguish a world in which any of these assumptions holds from one in which it does not), so if the existence of the Hard Problem is derived from them, then that doesn’t alleviate the issue of its unfalsifiability.

The cause of this issue is that (from my point of view) many of the words you’re using don’t have clear definitions in the domain that you’re trying to use them in. I don’t mean to be a pedant, but if we’re really trying to use language for extraordinary investigations like these, then I think precision is warranted. For now, let me just focus on the thought experiment you posed. The way I see it, it’s equivalent to the Ship of Theseus. I think what we’re ultimately trying to grapple with is how best to model reality and it seems to me that we actually already have a perfectly good model to solve the Ship of Theseus and your thought experiment, namely particle physics. If you look at the Ship of Theseus or a person’s brain or body (or a piece of text they wrote), these are collections of particles that create a causal chain to somebody saying “Hey, it’s the Ship of Theseus!” or “Hey, gilch wrote a reply!” Over time, some of those particles may get swapped for others and cause us to still use the same name or maybe not. There’s no mystery or contradiction there, it’s a bunch of particles doing their thing and names are patterns in those particles, for example in the air when we speak them or in silicon when we’re writing it on a phone.

Do we think about the world in terms of fundamental particles? No, it’s wildly impractical, so we’ve been forced to resort, through our evolution and the evolution of language, to much simpler models/heuristics. Daniel Dennett has this idea of “folk psychology”, which talks specifically about how we model other people’s behaviors, by talking about things like “belief”, “desire”, “fear” and “hope”. This model works most of the time, but it breaks down when you try to use it to model, for example, the behavior of a schizophrenic person, or the behavior of a dead person. You can extend this idea to a kind of “folk reality”, where we model the world in terms of “people”, “alive”, “dead”, “conscious”, “justice”, “love” and pretty much all other words, which can similarly break down when trying to use them to communicate about things that they’re not normally used to communicate about.

If you like, I could go into detail how this applies to each of your assumptions, but I’ll do so just for your last assumption for now. Consciousness in normal usage is a word that evolved to mean something like “able to respond appropriately to its surroundings”, so a person who is sleeping or knocked out is basically unconscious; that’s enough for practical, daily usage. Similarly, we say humans normally are conscious, other primates and mammals maybe a little less, insects maybe and plants not really, i.e., the fewer traits it has that we recognize in humans the less conscious it is; this is already a bit less practical and more academic, but it affects how we behave. (For example, vegans claim eating animals is bad, while eating plants is okay, even though they’re absurdly glossing over whether plants can feel pain, which is not clear at all.) Over time, the evolution of language (which is a product of both chance and deliberate human decisions) adapted the meaning of words like consciousness to remain a useful part of folk reality. Our intuitions about the meanings of words and in turn about reality depend on how we see these words being used as we grow up, even if they don’t model reality correctly; we always end up with somewhat mistaken intuitions, because folk reality does not model reality exactly. And now, quite suddenly, we’ve ended up in a situation where there are machines that can behave in a way that we’re only used to recognizing in humans and so there’s a lot of confusion over whether they are conscious. Again, from a particle physics perspective it’s clear what’s going on; it’s particles doing their thing like they always have. Some particles are arranged in a structure we haven’t seen before, so what? However, our folk reality model breaks down because it’s imprecise and not adapted to this new situation. That’s also not an issue in itself; language and intuitions just have to adapt. Maybe we’ll come to a consensus that they are just as conscious as we are, or maybe we’ll see them as inferior and therefore treat them with greater indifference, even though how we describe them doesn’t actually change their nature, just our perception and treatment of them.

The real problems begin when people assume that their intuitions are true and fail to recognize that our intuitions and language are models of reality (largely inherited from cultures before us who had much less experience with the world) and that they frequently don’t generalize well. So when I encounter something like the Hard Problem, I throw my intuitions about how “I really feel like I’m experiencing things, so I can’t just be an automaton” out the window, because going down that road just leads to a bunch of useless contradictions and I conclude that whatever is going on must be made possible by particles doing their thing and nothing else, at least until I encounter a better model.

As for whether I would choose to undergo the procedure, I probably would. I don’t see any meaningful difference between my brain being replaced by new synthetic or biological material. In fact, according to my intuition (perhaps mistaken), my future counterpart with a 100% biological brain would be just as much a different person from me as my alternative future counterpart with a 100% synthetic brain.

The burden of proof is on those who assert that the Hard Problem is real. You can say what consciousness is not, but can you say what it is? As it stands, no explanation of the Hard Problem is possible, because the Hard Problem has no criteria for what would comprise a satisfying explanation; no way to distinguish a correct explanation from an incorrect one. All real science has such criteria, yet even David Chalmers has none. Until those criteria are established, the existence of the Hard Problem will forever remain unfalsifiable, unscientific and belief in it irrational.

Unfortunately, proper criteria for explanations always involve (physical) observations and their predictions. Therefore any attempt to establish criteria for explanations of the Hard Problem is met with the criticism that, because it refers to physical aspects of consciousness, it ignores the Hard Problem. Evidently, proponents of the Hard Problem have backed themselves into a contradictory corner; the Hard Problem is unfalsifiable and any attempt to make it falsifiable makes it not the Hard Problem.

If the Hard Problem is “above” science (i.e., not science), as it seems to be, then it is above inquiry and if it’s above inquiry, why inquire?

The naked truth is that belief in the existence of the Hard Problem fetishizes mystery; it abhors actual explanation and therefore scrambles to keep its suppositions immune to it.

Belief in the Hard Problem, being unscientific and therefore not real, begs the question why such beliefs can nonetheless take root in the face of overwhelming contrary evidence, which is what my earlier post attempted to explain.

I’m experiencing just like you, but the Hard Problem doesn’t jive at all with the rest of my beliefs (and I have seen many attempts to reconcile them, all unsuccessful). Therefore I choose to accept the benefits of the sensation of experience and accept the Easy Problem of consciousness as the overwhelmingly likely Only Problem of consciousness.

The Hard Problem doesn’t exist.

Do you believe that all your beliefs are represented only in the structure of your brain? Then changing the structure of your brain changes your beliefs; this way you could theoretically be made to believe anything, including, of course, things that are false. Some false beliefs are useful, such as some optical illusions and illusions in general, such as the belief that “you” are “experiencing” things. (I once interviewed a man who had had a stroke and reported feeling like “he wasn’t there” anymore and he would look at his own hand and say, “it’s like it’s not mine”. This caused difficulties with locomotion and knowing when “he” had to go to the bathroom, because it was hard for him to realize it was actually “his” bladder being full and “him” having to make a decision to relieve it.) It’s a useful, evolved structure in your brain that makes you believe that. But it’s technically still false.

Similarly, you could hallucinate that a dragon is standing in front of you; some people actually have such hallucinations. The rational thing to do at such a moment is to disbelieve your direct experience, based on all the other things you know about the world; you know that the evidence against the existence of dragons is overwhelming and you know hallucinations happen. However, disbelieving that what you’re experiencing is real doesn’t make you suddenly not experience it, that’s why hallucinations can be so debilitating.

Ever had déjà vu? When I have déjà vu, I get an overwhelming sense of having experienced something before and my mind starts racing, trying to explain it. I usually recognize rationally that this is probably a déjà vu, but that explanation feels very unsatisfying in the moment because the feeling of recognition is so convincing. It’s only when this sensation subsides about ten seconds later that I can put the matter to rest, assured that it was just a glitch in my brain. But what if it never subsided? What if you had a déjà vu that lasted the rest of your life? It would be very hard to ignore the constant sensation of recognition. This is exactly the kind of thing that “believing you are experiencing” (and many associated beliefs) is. In both cases it’s false, but in the latter it’s there because it’s useful.

The point is that sometimes the structure of our brains can reach a state in which certain things seem to be true, even though rationally we should disbelieve it based on all the other things we know. The evidence for the existence of the Hard Problem is extremely thin. In fact, it’s unfalsifiable—not even wrong. Everything we know about science, truth and knowledge points to the Hard Problem not existing. What actually needs to be explained is not why we experience things, but why we think that we experience things and we have perfectly good (physical) explanations for that.

Whether or not one’s beliefs are correct is similar to whether one’s genes are correct, because, fundamentally, one’s beliefs are determined by an evolutionary algorithm; the ideas that are best at spreading and keeping their hosts alive survive and are in that sense “correct”. Some of these ideas involve heuristics and elements of what we call critical thinking or rationality, but they are limited.

We talk about rationality a lot on here, obviously, but I dare say it doesn’t help to pay the rent in almost any case for anyone here at LessWrong, and in some cases is actively harmful, so I’m not sure that it’s helpful on average.

One could write a microcontroller program that makes some signal if it's circuit is damaged.

People are not fundamentally different from such a microcontroller. It’s signals all the way down.

One can try to do suffering calculus like in the original post, based on certain axioms, but these are unfalsifiable. Realistically, suffering calculus is based on a political and sociological consensus, e.g., the Overton window. Humans have political representation and Western civilization has human equality as a kind of axiom, at least nominally, so in the Western world there is a lot of incentive to reduce all human suffering (unlike in China, for example, where Uyghurs are marginalized). Animals have far less representation, so there is less incentive to reduce suffering. In my country, there is a Party for Animals with a few seats in Parliament, voted in by people (because axiomatically animals don’t have the right to vote) who do it to perhaps virtue signal, or because the human brain is wired to empathize more with similar beings, or for unfalsifiable philosophical considerations, or for some other reason which for other voting blocs is not in their Overton window. For plants the situation is far more dire. It is in principle possible that for large swaths of the public the Overton window shifts such that they will refuse to support the “slaughter” of plants. But what’s in the Overton window is separate from the facts and there are no facts of the matter about suffering.

I can’t really be persuaded by this kind of argument, because suffering (and pain) is not coherent enough for this kind of calculus. Why couldn’t plants suffer? What about one-celled organisms? It’s arbitrary.

I really liked this post; it puts modern computing into an interesting perspective.

I think the perspective of physics is also interesting to add, because I think it really shows how fundamental the idea of computation is. According to modern physics, everything is computation; every physical interaction, whether it’s between two elementary particles, or between two people shaking hands, is computation. As you mentioned, it was mathematically proven by Alan Turing that there is a type of machine, now called a Turing machine, which can compute anything that can in principle be computed, which therefore supposedly includes all of physics. All our laptops and other modern computers are Turing machines, so our laptops, in principle, are capable of computing anything physical, including a human brain. The question is, how practical is it to do a given computation?

Computing the movements that a grain of sand makes over the course of one second would take a laptop aeons to compute, let alone computing in real time what goes on in a human brain. However, in practice you don’t usually need to do an exhaustive computation to get the result you want. For example, you can program your laptop to calculate the result of 1+1, but you can also simulate your physical laptop while it is computing 1+1 to get the same result (hopefully 2). However, the latter would waste an extreme amount of computation you don’t need to do. Similarly, the relevant outputs of the human brain might be calculated with much less computation than it takes to simulate an entire physical human brain. In fact, artificial neural networks appear to do just that, meaning that the physical brain appears to “merely” physically implement the virtual equivalent of our artificial neural networks.

Some people have countered by saying that many important processes in the human brain have been abstracted away in artificial neural networks, but it is not clear that these processes are part of the fundamental computations that lead to the results we care about, instead of simply supporting the physical implementation of these fundamental computations. Some other people, such as Roger Penrose, have even claimed that human brains do processing that is not computable and therefore cannot be computed even using a Turing machine, in turn implying that such uncomputable processes are possible in nature, which is counter to modern physics’ understanding of nature.