This question has always brought up fascinating implications about the seemingly private nature of our consciousness. Such a thorough understanding of the mechanics of perception really seems to undermine the idea that your conscious perception is completely personal and ineffable. It can be broken down piece-by-piece and examined — compared against the larger backdrop of human mental experience.
And, as you say, this ought to grant us quite a bit of empathy, knowing that so much of our experience is shared and explainable. Something that feels so personal and private and indescribable is actually quite universal.
I think the details of how my brain processes sensations is a little different from yours. We probably don't see red and green differently but I have a brain tumour and I do smell scents that you don't smell and vice versa. Ronaldo and Messi are able to track a football in ways that I am not able. Da Vinci sees the world a little differently too. There's probably no one that sees the world exactly the way that I do but there's also no one that sees it completely differently. It's a spectrum.
Bats too.
Most bats have sight that is worse than ours. Some a little, some a lot. None are completely blind though. It's a spectrum. This American Life has an episode about a blind man, Daniel Kish, who has learned to echolocate by clicking. He's blind like a bat but he echolocates like a bat too. Is he completely the same as a bat? Or completely different? Or are they both on the same spectrum that we are on?
I think we're not so different from bats and we could all learn to echolocate if we practiced a bit more. It's a mistake to say that we are completely unlike bats. I don't know exactly what it's like to be a bat but I don't know exactly what it's like to be you either.
Perhaps it’s not possible for me to see your red when you see green given that this difference would be reflected in the external structural relations between colours. But I think it is possible that our phenomenal colours share the same external structural relations while differing in their internal structural characteristics. Maybe when you see red, I see red* and maybe your red relates to your other colour perceptions in the same way that my red* relates to my other colour* perceptions.
At the level of the brain, this might be reflected by us using different brain states to represent colours, with these different brain states acting as placeholders in a broadly similar higher level neural network. We know that human brains are quite similar at the level of morphology and high level neural activation patterns (e.g. processes you can detect on an EEG), but also individually variant at the level of lower level structure like neural weights and small scale neural networks.
This is an empirical question, but I find it entirely plausible that the neural realizers for colour might exist at the lower level of scale which is individually variant, in which case different people might actually have different experiences of colour.
Brain states aside, we have plenty of behavioral evidence that we have differences in how we represent color--some people can discriminate more colors than others, and there are situations where people will disagree about color classifications. So it's absolutely true that there are differences in their internal structural characteristics in that sense!
Holeeee shiiiiit. I thought it was only me ever in the history of all humanity that had wondered if everyone saw the “same colors as me”. Have wondered this since I was a kid. And I’m not even stoned.
Same here. My father was color blind. He can't see red. Red to him, he says, is Grey. He had no problem with traffic lights. In fact, if he had not told me he was colorblind, I would not have known.
I went through the article twice and found no reference to the electromagnetic spectrum and the spectrometer that can look into deep space and determine elements based on uniform color wave lengths. Could you comment on the scientific determination of colors, based on wave length, from the visible light spectrum?
You're right that I don't explicitly mention it, but the x-axis in the plot of the absorption of the different cones is light frequency wavelengths.
Obviously our perception of color is very closely tied to the wave lengths in the visual spectrum, but the story of what we perceive is more complex than that--it seems to depend on the environment in which we see things as well, for example with color constancy: https://en.wikipedia.org/wiki/Color_constancy
Tommy, I was just thinking like a Forensic Scientist giving testimony in a Civil or Criminal Courtroom. If a jury was told by a defense attorney who made a claim that any color/hue is a toss-up - and no expert was presented to counter that testimony- then injustice would occur. Expert testimony and scientific instrumentation can precisely determine colors, in the visible spectrum, that would be uniform around the globe & on celestial bodies. My Japanese wife sometimes calls me “shikimo” (Japanese for color-blind) when she and I do not agree on color, I have told her that there are instruments that can precisely settle our differences. Blessings.
The inverted spectrum argument has long struck me as circular, just presupposing some type of dualism or other non-physicalism. It seems to ignore the structural and causal relationships involved. Once we take those into account, it becomes a logically incoherent conjecture, unless we posit something extra happening in addition to the brain's functionality, something non-causal, that makes no difference to behavior. It means that even our discussions about it wouldn't be caused by it. In my mind, it's just not a productive way to conceptualize experience.
Excellent essay, Tommy. I have to disagree, I think there is something mysterious about private, conscious experience; at least, something that cannot be captured linguistically or described scientifically. This is not because I'm a Cartesian (who emphasizes the cognitive, private life versus outer world), but rather, because phenomenal experience is prior to, or more fundamental than, scientific inquiry. I concur with the phenomenologists that a “view from nowhere” appears, ultimately, impossible. And science, especially physics, is aimed at this useful impossibility. I doubt that necessarily makes me an anti-realist about science, but it does make me an anti-reductionist. The phenomenal, conscious experience seems to me to be irreducible to the brain, and there are arguments to this effect (e.g., multiple realizability). Nagel's "what it's like to be a bat" is using an intuitive example that shows (but does not prove) this point (as I recount in this essay). https://agapesophia.substack.com/p/a-reflection-on-reductionism-art
Your well-put argument makes me think of the late Daniel Dennett, who bemoans "intuition pumps" in philosophy of mind. I'll need to write an essay on this, but I think he mistakes the intuitive examples as the final word, when in fact, the primordial, prior nature of phenomenology is at the crux of the problem. While I can't address all your points, I think I simply wanted to comment about the most likely way, in my estimation, your very good essay might be wrong.
Why would subjective experience being "prior" mean we can't investigate it? How do you reconcile the "impossibility" of studying subjective experience (and the physical world more generally) with the success of fields that study experience, like psychophysics or psychology/neuroscience of attention, or fields that study the world, like physics?
I think we can definitely investigate these things. I'm a believer in physics, neuroscience, psychology (my wife and father are counselors), etc. Rather, there's a stronger claim that *everything that exists can be described in terms of fundamental physics* (one flavor of naturalism) that I disagree with. “Can” there does not mean it “can” be described that way at the moment, with our current theories, but that it hypothetically *could* be described--all reality is intelligible to physics. Therefore, while I don't doubt the intelligibility of reality, I rather doubt that physics could provide a 100% complete picture of reality. Your point that the success of science lends it credence is well taken, and I agree to an extent. However, I don't think science's success entails the stronger claim that physics could describe all reality, including consciousness. This is because science is an abstraction of reality, not reality itself. The reason phenomenology being prior matters is that, to me, if science undercuts the foundation of phenomenology, then it cuts itself off from reality.
You could go Nagel's way, and say consciousness is just another set of facts about the world apart from what is describable by physics (he's still a soft naturalist). I think I go a different way, just ditching naturalism altogether.
There's another problem as food for thought: How do you account for science's theories being continually replaced by better theories? Doesn't that suggest that our current theories are probably substantially false? I think this isn't detrimental, just a curious question that has me thinking at the moment. Hope you're having a good week!
I think different levels of description are good and valid so I don't see the conflict between explaining things in terms of physics vs other higher level descriptions.
"How do you account for science's theories being continually replaced by better theories? Doesn't that suggest that our current theories are probably substantially false?"
I'm not clear on how this connects to the rest of your comment. But my answer to why our theories get replaced is "we learn stuff".
Of course our current theories are wrong in various ways. The ways in which they are wrong is important. We can have a fuzzy picture that gradually becomes more clear, that doesn't mean the fuzzy picture didn't tell us anything.
Fair enough. And I agree, the various levels of analysis are good! As to the science thing, I agree with you. It’s not an existential problem for science, per se. I’m thinking on both of these questions more philosophically in line with arguments against Reductionism, which is ultimately what Nagel is trying to communicate in “what it’s like to be a bat.”
Regardless, I look forward to reading more. Cheers!
I like the statement: "I think there's something to this tension."
I think so too!
Similar to that color perception thought experiment, thinking about and experiencing illusions (like visual or cognitive) evokes the same tension in me. I notice, that there is some reality 'out there' and there is a perception of that reality is not in line with that reality 'out there', noticed by my own reasoning mind. This creates the tension for me between experience and reality. Sometimes my mind flips like in a figure ground reversal between two states of paying attention to reality and then to experience and in optical illusions you can often actually see the flipping.
Another subject that evokes similar tension is contemplating death for me. There is an asymmetry between me dying as observed from the outside and me dying as observed from the insight.
@Tommy Blanchard, do you see the notion of tension that you mentioned in my descriptions as well? And I wonder if there is a larger theory (of consciousness) behind this notion of tension, if anybodies knows I would be highly interested.
Yeah, I definitely get what you're saying with those "tensions". I think this is related to a lot of the intuitions at the heart of many of the arguments about consciousness--the idea that consciousness can't be explained because any objective third-party explanation wouldn't seem to speak to the first-person nature. I think this is one of those "sort of right but also sort of wrong" ideas. I think it's hard to wrap our heads around what it would mean to explain consciousness, but that that doesn't imply it isn't possible.
A bit more sober of a question: why is it that people group colors into different categories? For instance, if I showed 10 people a chatrtruese shirt and asked each whether it was more yellow or more green, I would likely get conflicting answers (often very opinionated answers, from experience).
Some cultures categorize colors differently (e.g. cultures that have the same label for blue and green), but why do individuals in the same culture categorize ambiguous colors differently?
Good question! If I had to hazard a guess, it would be a combination of three factors: 1) There are individual differences in our visual systems--some people have better ability to discriminate colors, etc, so some of the difference might come down to a difference between people in what they are able to detect; 2) We aren't exposed a lot to colors "on the edge" and asked to categorize them. It might simply be we have slightly different experiences with what we've seen labeled as yellow or green at the edges, and that leads to us giving different labels when asked; or 3) asking people in slightly different lumination conditions. Color can change a lot depending on the light!
These are just guesses though (and I had to look up chartreuse, which is definitely green)
This is a question that’s fascinated me since I was very young, probably in my early teens. Really interesting to read about the neuroscience involved!
On a lighter note, this is what’s been behind the fascinating, if sometimes interminable, discussions about paint, wallpaper and general decor choice I have had with my family over some forty or so years now. Who knew?
You sort of speed by the fact that colours are not out there in the world but I think that this fact would blow most people’s minds if they really absorbed it. I’d hazard that most people have a strong sense of naive realism and that that’s the source of much of our impatience when it comes to active empathy and understanding our many differences with others.
I have this theory that if we adopted a Many Worlds Approach to Interpersonal Conflict that started with the (correct) assumption that we all occupy different psychosocial worlds (albeit overlapping to large but varying extents) we would put more effort and patience into building bridges of mutual understanding. I’d love to see psychologists put this to the test.
The asymmetric shape of this Munsell color solid is really interesting stuff. I’ve got to see if I understand here. So if I wanted to try to argue that it is possible to perceive different colors, I would need to find a smooth one-to-one map of the color solid onto itself that doesn’t radically change local gradients? With the latter imposed to ensure that no one is surprised by colors appearing so abruptly. Would that be enough? It don’t have strong intuition that this is impossible, although maybe I am missing some constraints on the map here?
One constraint you might be missing is the mapping needs to be a transform along the hue-dimension. A change that some people perceive as a change of hue but you see as a change in saturation would be deeply weird and, again, noticeable behaviorally when you describe the color change.
To preserve the relationships between hues, you're left with rotating or flipping the hue dimension, but those aren't possible because of the asymmetries in the three-dimensional space.
This question has always brought up fascinating implications about the seemingly private nature of our consciousness. Such a thorough understanding of the mechanics of perception really seems to undermine the idea that your conscious perception is completely personal and ineffable. It can be broken down piece-by-piece and examined — compared against the larger backdrop of human mental experience.
And, as you say, this ought to grant us quite a bit of empathy, knowing that so much of our experience is shared and explainable. Something that feels so personal and private and indescribable is actually quite universal.
Fascinating piece!
Thank you!
I think the details of how my brain processes sensations is a little different from yours. We probably don't see red and green differently but I have a brain tumour and I do smell scents that you don't smell and vice versa. Ronaldo and Messi are able to track a football in ways that I am not able. Da Vinci sees the world a little differently too. There's probably no one that sees the world exactly the way that I do but there's also no one that sees it completely differently. It's a spectrum.
Bats too.
Most bats have sight that is worse than ours. Some a little, some a lot. None are completely blind though. It's a spectrum. This American Life has an episode about a blind man, Daniel Kish, who has learned to echolocate by clicking. He's blind like a bat but he echolocates like a bat too. Is he completely the same as a bat? Or completely different? Or are they both on the same spectrum that we are on?
I think we're not so different from bats and we could all learn to echolocate if we practiced a bit more. It's a mistake to say that we are completely unlike bats. I don't know exactly what it's like to be a bat but I don't know exactly what it's like to be you either.
I agree with all that!
Perhaps it’s not possible for me to see your red when you see green given that this difference would be reflected in the external structural relations between colours. But I think it is possible that our phenomenal colours share the same external structural relations while differing in their internal structural characteristics. Maybe when you see red, I see red* and maybe your red relates to your other colour perceptions in the same way that my red* relates to my other colour* perceptions.
At the level of the brain, this might be reflected by us using different brain states to represent colours, with these different brain states acting as placeholders in a broadly similar higher level neural network. We know that human brains are quite similar at the level of morphology and high level neural activation patterns (e.g. processes you can detect on an EEG), but also individually variant at the level of lower level structure like neural weights and small scale neural networks.
This is an empirical question, but I find it entirely plausible that the neural realizers for colour might exist at the lower level of scale which is individually variant, in which case different people might actually have different experiences of colour.
Brain states aside, we have plenty of behavioral evidence that we have differences in how we represent color--some people can discriminate more colors than others, and there are situations where people will disagree about color classifications. So it's absolutely true that there are differences in their internal structural characteristics in that sense!
Holeeee shiiiiit. I thought it was only me ever in the history of all humanity that had wondered if everyone saw the “same colors as me”. Have wondered this since I was a kid. And I’m not even stoned.
Same here. My father was color blind. He can't see red. Red to him, he says, is Grey. He had no problem with traffic lights. In fact, if he had not told me he was colorblind, I would not have known.
I went through the article twice and found no reference to the electromagnetic spectrum and the spectrometer that can look into deep space and determine elements based on uniform color wave lengths. Could you comment on the scientific determination of colors, based on wave length, from the visible light spectrum?
You're right that I don't explicitly mention it, but the x-axis in the plot of the absorption of the different cones is light frequency wavelengths.
Obviously our perception of color is very closely tied to the wave lengths in the visual spectrum, but the story of what we perceive is more complex than that--it seems to depend on the environment in which we see things as well, for example with color constancy: https://en.wikipedia.org/wiki/Color_constancy
Tommy, I was just thinking like a Forensic Scientist giving testimony in a Civil or Criminal Courtroom. If a jury was told by a defense attorney who made a claim that any color/hue is a toss-up - and no expert was presented to counter that testimony- then injustice would occur. Expert testimony and scientific instrumentation can precisely determine colors, in the visible spectrum, that would be uniform around the globe & on celestial bodies. My Japanese wife sometimes calls me “shikimo” (Japanese for color-blind) when she and I do not agree on color, I have told her that there are instruments that can precisely settle our differences. Blessings.
Finally, a discussion of this topic in a way that doesn’t roll the eyes. Bravo!
Thank you!
An excellent discussion!
The inverted spectrum argument has long struck me as circular, just presupposing some type of dualism or other non-physicalism. It seems to ignore the structural and causal relationships involved. Once we take those into account, it becomes a logically incoherent conjecture, unless we posit something extra happening in addition to the brain's functionality, something non-causal, that makes no difference to behavior. It means that even our discussions about it wouldn't be caused by it. In my mind, it's just not a productive way to conceptualize experience.
Excellent essay, Tommy. I have to disagree, I think there is something mysterious about private, conscious experience; at least, something that cannot be captured linguistically or described scientifically. This is not because I'm a Cartesian (who emphasizes the cognitive, private life versus outer world), but rather, because phenomenal experience is prior to, or more fundamental than, scientific inquiry. I concur with the phenomenologists that a “view from nowhere” appears, ultimately, impossible. And science, especially physics, is aimed at this useful impossibility. I doubt that necessarily makes me an anti-realist about science, but it does make me an anti-reductionist. The phenomenal, conscious experience seems to me to be irreducible to the brain, and there are arguments to this effect (e.g., multiple realizability). Nagel's "what it's like to be a bat" is using an intuitive example that shows (but does not prove) this point (as I recount in this essay). https://agapesophia.substack.com/p/a-reflection-on-reductionism-art
Your well-put argument makes me think of the late Daniel Dennett, who bemoans "intuition pumps" in philosophy of mind. I'll need to write an essay on this, but I think he mistakes the intuitive examples as the final word, when in fact, the primordial, prior nature of phenomenology is at the crux of the problem. While I can't address all your points, I think I simply wanted to comment about the most likely way, in my estimation, your very good essay might be wrong.
Thanks for the thoughts and kind comments!
Why would subjective experience being "prior" mean we can't investigate it? How do you reconcile the "impossibility" of studying subjective experience (and the physical world more generally) with the success of fields that study experience, like psychophysics or psychology/neuroscience of attention, or fields that study the world, like physics?
I think we can definitely investigate these things. I'm a believer in physics, neuroscience, psychology (my wife and father are counselors), etc. Rather, there's a stronger claim that *everything that exists can be described in terms of fundamental physics* (one flavor of naturalism) that I disagree with. “Can” there does not mean it “can” be described that way at the moment, with our current theories, but that it hypothetically *could* be described--all reality is intelligible to physics. Therefore, while I don't doubt the intelligibility of reality, I rather doubt that physics could provide a 100% complete picture of reality. Your point that the success of science lends it credence is well taken, and I agree to an extent. However, I don't think science's success entails the stronger claim that physics could describe all reality, including consciousness. This is because science is an abstraction of reality, not reality itself. The reason phenomenology being prior matters is that, to me, if science undercuts the foundation of phenomenology, then it cuts itself off from reality.
You could go Nagel's way, and say consciousness is just another set of facts about the world apart from what is describable by physics (he's still a soft naturalist). I think I go a different way, just ditching naturalism altogether.
There's another problem as food for thought: How do you account for science's theories being continually replaced by better theories? Doesn't that suggest that our current theories are probably substantially false? I think this isn't detrimental, just a curious question that has me thinking at the moment. Hope you're having a good week!
I think different levels of description are good and valid so I don't see the conflict between explaining things in terms of physics vs other higher level descriptions.
"How do you account for science's theories being continually replaced by better theories? Doesn't that suggest that our current theories are probably substantially false?"
I'm not clear on how this connects to the rest of your comment. But my answer to why our theories get replaced is "we learn stuff".
Of course our current theories are wrong in various ways. The ways in which they are wrong is important. We can have a fuzzy picture that gradually becomes more clear, that doesn't mean the fuzzy picture didn't tell us anything.
Fair enough. And I agree, the various levels of analysis are good! As to the science thing, I agree with you. It’s not an existential problem for science, per se. I’m thinking on both of these questions more philosophically in line with arguments against Reductionism, which is ultimately what Nagel is trying to communicate in “what it’s like to be a bat.”
Regardless, I look forward to reading more. Cheers!
Very interesting and something I have also wondered about for years after someone posed the question in school.
I like the statement: "I think there's something to this tension."
I think so too!
Similar to that color perception thought experiment, thinking about and experiencing illusions (like visual or cognitive) evokes the same tension in me. I notice, that there is some reality 'out there' and there is a perception of that reality is not in line with that reality 'out there', noticed by my own reasoning mind. This creates the tension for me between experience and reality. Sometimes my mind flips like in a figure ground reversal between two states of paying attention to reality and then to experience and in optical illusions you can often actually see the flipping.
Another subject that evokes similar tension is contemplating death for me. There is an asymmetry between me dying as observed from the outside and me dying as observed from the insight.
@Tommy Blanchard, do you see the notion of tension that you mentioned in my descriptions as well? And I wonder if there is a larger theory (of consciousness) behind this notion of tension, if anybodies knows I would be highly interested.
Yeah, I definitely get what you're saying with those "tensions". I think this is related to a lot of the intuitions at the heart of many of the arguments about consciousness--the idea that consciousness can't be explained because any objective third-party explanation wouldn't seem to speak to the first-person nature. I think this is one of those "sort of right but also sort of wrong" ideas. I think it's hard to wrap our heads around what it would mean to explain consciousness, but that that doesn't imply it isn't possible.
So interesting!
A bit more sober of a question: why is it that people group colors into different categories? For instance, if I showed 10 people a chatrtruese shirt and asked each whether it was more yellow or more green, I would likely get conflicting answers (often very opinionated answers, from experience).
Some cultures categorize colors differently (e.g. cultures that have the same label for blue and green), but why do individuals in the same culture categorize ambiguous colors differently?
Good question! If I had to hazard a guess, it would be a combination of three factors: 1) There are individual differences in our visual systems--some people have better ability to discriminate colors, etc, so some of the difference might come down to a difference between people in what they are able to detect; 2) We aren't exposed a lot to colors "on the edge" and asked to categorize them. It might simply be we have slightly different experiences with what we've seen labeled as yellow or green at the edges, and that leads to us giving different labels when asked; or 3) asking people in slightly different lumination conditions. Color can change a lot depending on the light!
These are just guesses though (and I had to look up chartreuse, which is definitely green)
Agreed!
This is a question that’s fascinated me since I was very young, probably in my early teens. Really interesting to read about the neuroscience involved!
Lovely article. I find your writing very lucid. Thank you.
On a lighter note, this is what’s been behind the fascinating, if sometimes interminable, discussions about paint, wallpaper and general decor choice I have had with my family over some forty or so years now. Who knew?
You sort of speed by the fact that colours are not out there in the world but I think that this fact would blow most people’s minds if they really absorbed it. I’d hazard that most people have a strong sense of naive realism and that that’s the source of much of our impatience when it comes to active empathy and understanding our many differences with others.
I have this theory that if we adopted a Many Worlds Approach to Interpersonal Conflict that started with the (correct) assumption that we all occupy different psychosocial worlds (albeit overlapping to large but varying extents) we would put more effort and patience into building bridges of mutual understanding. I’d love to see psychologists put this to the test.
The asymmetric shape of this Munsell color solid is really interesting stuff. I’ve got to see if I understand here. So if I wanted to try to argue that it is possible to perceive different colors, I would need to find a smooth one-to-one map of the color solid onto itself that doesn’t radically change local gradients? With the latter imposed to ensure that no one is surprised by colors appearing so abruptly. Would that be enough? It don’t have strong intuition that this is impossible, although maybe I am missing some constraints on the map here?
One constraint you might be missing is the mapping needs to be a transform along the hue-dimension. A change that some people perceive as a change of hue but you see as a change in saturation would be deeply weird and, again, noticeable behaviorally when you describe the color change.
To preserve the relationships between hues, you're left with rotating or flipping the hue dimension, but those aren't possible because of the asymmetries in the three-dimensional space.
If you're interested in reading about other transforms philosophers have tried, the Stanford Encyclopedia of Philosophy goes much further in depth: https://plato.stanford.edu/entries/qualia-inverted/#InvQuaSce
Ahh, very interesting! Thanks.
I will take it a step further. Colors don’t exist. I’ll leave you with this question - how does color change through time?