This is where my ‘brain linkage’ thought experiment comes in. If two or more minds can be linked artificially so that they share experiences, then each individual that is connected in this way would be able to confirm that the others are capable of experiencing qualia. Admittedly, this experiment requires technology that does not yet exist and may never exist, but it seems that there is nothing unphysical about the concept (unlike, for instance, the philosophical zombie thought experiment).
Of course, there are some counterarguments;
…even if we could build such a linkage channel, the internal activity of another mind might be completely incomprehensible to another mind, since they have developed from scratch in separate bodies (unlike the twin hemispheres of our own brain). I expect, and hope, that the differences encountered in such an experiment could be overcome by ‘sufficiently advanced’ translation software - but I suppose it may be possible that sufficiently advanced translation software itself might create qualia where none existed before.
…even if we could link an arbitrary number of minds together, and they all experienced some form of qualia, that would not necessarily prove that all minds of all human-level beings are capable of experiencing qualia, or that they are all self-aware. To establish that, it would be necessary to link every mind sufficiently well to establish that consciousness exists in all of them. A long and fairly pointless process.
…qualia may be an illusion, produced by the logical processes in the mind that need to analyse data somehow. Qualia may just be a convenient and quick way to display quantitative data in an easily accessible form. In which case we would just be sharing an illusion - something that humans seem to be quite good at.
I’m always fascinated by the illusory experiences that occur during dreams. Certainly there are certain qualia associated with dreams, although they don’t always have the same quality as waking experiences. If we are all somehow daydreaming our way through life, then everything about our existence may be illusory.
It’s not something that’s blandly asserted, not something you need to have faith in; it’s the conclusion of an argument in the form of a thought experiment that notes that everything in the causal chain between stimuli and reactions can coherently be imagined without any accompanying subjective experience, and that indeed a complete explanation of any given behavior down to the microphysical picture seems possible without ever appealing to experiential notions.
You’re welcome to refute this argument, but this requires showing its logic or assumptions to be erroneous, or casting doubt on it by other means—such as explaining how subjective experience arises from non-experiential physical facts. But just flatly rejecting it isn’t convincing.
I think that’s pretty clearly the case. For example, every color you’ve ever seen is a hallucination*. And of course fire plus finger does not equal “pain”. Your brain invents that…somehow.
Color hallucinations
People are often skeptical of the claim that colors are hallucinations; it seems too intuitive that colors are really “out there”. I’ve found the best way to illustrate this is with the following example:
The wavelength of yellow light is approximately 580nm. Shine that pure wavelength of light at a human, they see yellow.
So, say you see a vivid yellow banana on TV. How many photons of wavelength 580nm are reaching your retina? The answer is: zero, because TVs don’t make yellow light. Then have RGB phosphors or LEDs, and it’s simply the case that red and green light, striking the retina close enough together, is perceived as yellow, because they are activating the cones of the retina in the same way that yellow light does.
But note then, that we are basically “hallucinating” yellow in this case; there is no real yellow “out there”. Red and green photons pass through each other without “mixing”; someone sat closer to the screen can verify that for you. Like I say, there are certainly no 580nm photons being produced or fused into existence.
And if we concede that seeing yellow on a TV screen is an illusion, then the question becomes what is the difference with “really” seeing yellow? After all, the same cones of the eye are activated; your brain has no possible way to know the difference. How does it know when to “fake” yellow and when to “really” see it?
The answer of course is that it is always fake. We have no idea what 580nm photons really look like, or even if that’s a meaningful concept. All we know is the experience that brains make when particular cones are activated.
My refutation stands; in a universe which is infinite, an infinite number of replicas of you and I exist, and every one of those replicas feel pain, since they are identical to each other and to ourselves. I can’t see any coherent alternative to that conclusion.
There’s no reason to conceive of an infinite number of replicas; one will do.
I think the point is that, yes, I do think that something about the physiology of the human brain leads to us having experiences and thus, yes, I would expect a perfect copy of me to not only feel pain but see yellow the same as I do etc.
However, that’s just an assumption while I can’t be sure how experiences are generated. Absent a model, I can’t say for sure that you feel pain, that dogs feel pain, or even a perfect to the atom copy of me; for all I know the exact specifics of how my body came to be was necessary to make a feeling entity instead of a p-zombie.
Don’t get me wrong, I would bet against this being the case, but I don’t know it’s not the case.
In order to accommodate the existence of an otherwise identical p-zombie we need to assume that they are different because of a non-tangible, non-physical quality that doesn’t even change behavior (elsewhere I’ve called this quality ‘wibble’, to highlight how absurd it is).
If p-zombies differ from ordinary copies only by the existence of ‘wibble’, that sounds dangerously like dualism to me.
However I am not, nor is anyone else making the claim that “wibble” exists, only pointing out that the lack of any model means even such an extreme position as that cannot be ruled out.
No one has a burden of proof that wibble exists.
Well, it is an interesting philosophical stance; wibble might exist in any or all situations, adding qualities that cannot be detected to any physical object or process without making any difference at all. Maybe rocks that contain wibble are just as conscious as we are.
Although the entertainment industry has perpetuated the notion that sociopaths are emotionless, hyperlogical evil geniuses who can think their way out of any prison and elude psychological experts and bright FBI trainees, this isn’t any more a representation of reality than million-dollar-a-hit assassins, globe-trotting spies who pursue villains with plans of world domination and throw epic parties at exotic venues carved from ice, or gangs of multimillionaire car thieves who refer to each other as “family”. Sociopaths have and are driven by affective responses (emotions) just as much as anyone else, and if anything are even more prone to outbursts and irrational beliefs as the average person. What does distinguish them from ‘normal’ people is their complete lack of compassion, empathy, or remorse, which allows them to synthesize emotional responses, ‘gaslight’, and lie effectively without the non-verbal ‘tells’ of a normal person.
Some sociopaths do learn to become highly manipulative and conceal their emotions in pursuit of longer term goals, but even they can become angry and even unhinged when caught in a trap of their own lies and self-serving behavior as anyone who has had to deal with a sociopathic spouse, family member, or colleague can attest. They are not some kind of coldly rational thinking machines that can be studied for what consciousness without affect would look like.
That’s not a refutation, that’s just begging the question: the issue is exactly whether a physically identical copy would have the same (or any) experiential states as you do. Flatly asserting that that’s the case does not an argument make.
The point remains: nothing about the physical description entails anything about our experiential reality. Either that’s because of some shortcoming in our models (as I believe), or there must be further, non-physical, distinctly experiential facts that need to be added to the bare physical world to make room for experience.
In a physicalist world, the physical facts should uniquely fix the experiential facts, in a way similar to how the pixels that make up your screen uniquely fix the displayed image. Any change in the image necessitates a change in the pixels, but changes in the pixels may not produce changes in the image. The trouble is that we can’t see how any picture at all emerges; indeed, specifying the pixels seems not to tell us anything about the image. So the result seems more like those hybrid images, where the same pixels can yield different images. There, too, further facts—relating to the distance of the viewer to the image (and the details of human vision)—are needed to actually fix the perceived image.
I think that’s actually understanding the case. It’s not that we merely can’t exclude the possibility that the physical facts fail to account for the experiential facts, it’s that with proposals like the zombie- or knowledge-argument we have a positive case that they fail to do so. Thus, to have any positive prospect for a materialist/physicalist metaphysics, these challenges have to be met.
If we just couldn’t exclude the possibility of anything extraphysical being at work in the mind, we could safely ignore it, on account of also having no reason to appeal to it.
And one thing is for certain, we will never understand consciousness by just thinking about it. To understand consciousness we need to study its physical manifestations, from nematodes to primates, from thermostats to AGI, and not by going around inventing impossible things like p-zombies as a thought experiment.
Saying that consciousness is caused by something that makes no physical difference to behaviour and cannot be detected or tested (this is implicit in the condition that p-zombies are identical to non-zombies) does not help us understand the problem at all. It is not even wrong.
Wibble could be in everything - how would we know?
Nobody is arguing anything like that. The point is that if we want to continue a commitment to a physicalist ontology, we need to understand how it is that p-zombies are not actually possible. This is the sort of conceptual work that frequently precedes scientific inquiry, in order to make sure we don’t start out by running down blind alleys.
I agree with that, although we probably won’t see it. We’ll have to work our way through understanding the consciousness of nematodes and hagfish before we get to primates. And I expect that AGI will be so different that we won’t be able to easily generalise.