10 ms·

What Is It Like to Be a Bat? (1974) [pdf]

132 points by miobrien 10y ago

ForrestN 10y ago
TLDR: please read every word, because this work is that brilliant and that important.
woodruffw 10y ago
I have a suspicion that future generations of philosophers will be taught Nagel's is like-be problem in the fashion that Hume's is-ought problem [1] is now taught. Although they concern completely different subjects, the similarities between the two are striking: 1. On what grounds can we make statements about what ought to be based on what is? 2. On what grounds can we make statements about what it is to be something based on what it is like to think about the experiences of that thing? Edit: In case there's any confusion, I called it the is like-be problem to draw a similarity to Hume, not because anybody else calls it that. [1]: https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem
- smithkl42 10y ago
  That's a great point about the similarity of the two problems. If we didn't already know from intimate personal experience that there is such a thing as consciousness, no amount of physical observation could ever be sufficient to prove to us that it exists. Similarly, if we weren't well prepared (on other grounds entirely) to assert that certain things ought or ought not to be done, no amount of observing the actual state of things could be sufficient to show that there is actually good or evil in the world.
- andkon 10y ago
  Yeah, I think this is probably true. Hume was trying to argue that normative statements can't be reduced to or derived from natural statements about how the world is; Nagel's fighting the reduction of consciousness to positive, objective statements about consciousness, because of the existence of phenomenal character. There's a certain way to be a bat that's wrapped up in the very fact of its being a conscious being with a specific biology and neurology, but which is still irreducible to those features. If you wanna link this up to an older philosopher, this is basically what Kant's on about in his Critique of Pure Reason. Our special human brain stuff is responsible for providing us with the faculties (e.g. understanding of things like causation) we have for understanding the world. We are always trapped in our experience of the world, and though that shouldn't preclude us from experiencing the world, you can't separate how we experience objective reality from the fact that we experience it as humans, with human brains and faculties.
  - woodruffw 10y ago
    Absolutely, and you've said it better than I did. As a nit, wasn't Kant's Critique of Pure Reason written in part as a response to Hume?
    - andkon 10y ago
      ooooh totally was. He was deeply affected by Hume's attack on causation, so tried to come up with a coherent response. Ended up positing a whole bunch of wacky and (I think) true things about our embedded cognition, so I think it's probably fair to say that Critique of Pure Reason is the result of his beef with Hume.
      - miobrien 10y ago
        In the CPR, Kant proposes a synthesis of both rationalism and empiricism: although some knowledge comes from sensory experience, there are some things that we just know -- e.g., pure mathematics. So I'd say it's the result of his beef with everyone!
        goatlover 10y ago
        Doesn't this all go back to Plato, where Plato thought knowledge depended on the forms, because the flux of particulars cannot provide knowledge?
    - Gormisdomai 10y ago
      In CPR here is what Kant says about Hume: "David Hume, who among all philosophers came closest to this problem, still did not conceive of it anywhere near determinately enough and in its universality ... believing himself to have brought out that such an a priori proposition is entirely impossible, and according to his inferences everything that we call metaphysics would come down to a mere delusion of an alleged insight of reason into that which has in fact merely been borrowed from experience and from habit has taken on the appearance of necessity." The "problem" Kant is referring to is how metaphysics can be possible in spite of what Hume proved. Kant says in the same breath, that this is the central problem of the critique - so i guess you can nearly say that it's written almost entirely as a response to Hume.
dghughes 10y ago
I just found out yesterday about how amazing the immune system of bats is they are practically immortal almost nothing makes them sick! But then it's confusing that bats in my region are being killed off by white nose syndrome. Fungus on their nose wakes them from hibernation and causes them such stress it eventually kills them. Which actually does make sense since the theory is bats do so well immunity-wise because of the large swing in their body temperature range. A bat's temperature drops very low when hibernating then when they fly it shoots up very high. http://www.popsci.com/bats-immune-systems-are-totally-unique http://www.popsci.com/bats-immune-systems-are-totally-unique
KingMob 10y ago
I went to grad school to study the neuroscientific basis of consciousness, and this paper is a classic. It inspired one of the weirder conference sessions I've ever been to at ASSC, called "Is a fish conscious?" Imagine a room full of philosophers and scientists arguing vociferously to determine where (or even if) to draw the line between conscious/unconscious organisms. (E.g., fish=probably, bacteria, probably not?)
- ilugaslifg 10y ago
  Even having that argument in the first place is basically crypto-dualism. The idea that there is objectively such a distinction is 100% reducible to any other attempt to assert that some definitional dichotomy "actually exists". It's exactly isomorphic to any other argument about taste. What is a sandwich, what is a car. An argument about whether a fetish is hot, between a person who has it and a person who doesn't. It's all the same damn thing. Shit like that is why I hadn't stop taking philosophy courses in university. It was just rehashing what always came down to this exact same essentially platonist theory of forms bullshit, over and over and over.
- CuriouslyC 10y ago
  A large part of the problem is that people don't all agree on the definition of consciousness. It ranges anywhere from the property of having an internal experience (which I subscribe to) all the way to self awareness, and even to the ability for rational thought. This - and arguments over the definition of "is" - were the reason I stopped reading philosophy of mind papers.
stabbles 10y ago
What I like about Thomas Nagel is that he is one of the few atheists who steps up against darwinism and materialism as an explanation for almost everything. Quoting from The Last Word (1997): "[...] I don't want here to be a God; I don't want the universe to be like that. My guess is that this cosmic authority problem is not a rare condition and that it is responsible for much of the scientism and reductionism of our time. One of the tendencies it supports in the ludicrous overuse of evolutionary biology to explain everything about life, including everything about the human mind." Of course his book Mind & Cosmos is the best example of this
- ue_ 10y ago
  I think it's rather refreshing to have someone speak out against scientism, thank you for the book.
- amasad 10y ago
  I agree that darwinism is overused to explain everything but materialism seems inescapable -- especially for atheists. I think even Nagel agrees with "Inference to the Best Explanation" and so far I've never seen a single case of anything better explained than the materialist explanation.
  - goatlover 10y ago
    Materialism is not inescapable for atheists in philosophy at all. You can be anti-realist or an idealist sans God. You can also be a platonist. Or you could be a dualist like Chalmers. There's plenty of room for different views than materialism without committing to a belief in the supernatural.
    - ilugaslifg 10y ago
      How would you distinguish between "dualism" and "the supernatural"?
      - goatlover 10y ago
RockyMcNuts 10y ago
Humans can actually get pretty good at echolocation http://www.faculty.ucr.edu/~eschwitz/SchwitzPapers/Echo.pdf http://www.faculty.ucr.edu/~eschwitz/SchwitzPapers/Echo.pdf https://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_navigate_the_world https://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_nav...
- larsiusprime 10y ago
  Nagel acknowledges this in the article, for what it's worth: Footnote 8, page 9: > 8 It may be easier than I suppose to transcend inter-species barriers with the aid of the imagination. For example, blind people are able to detect objects near them by a form of sonar, using vocal clicks or taps of a cane. Perhaps if one knew what that was like, one could by extension imagine roughly what it was like to possess the much more refined sonar of a bat. The distance between oneself and other persons and other species can fall anywhere on a continuum. Even for other persons the understanding of what it is like to be them is only partial, and when one moves to species very different from oneself, a lesser degree of partial understanding may still be available. The imagination is remarkably flexible. My point, however, is not that we cannot know what it is like to be a bat. I am not raising that epistemological problem. My point is rather that even to form a conception of what it is like to be a bat (and a fortiori to know what it is like to be a bat) one must take up the bat's point of view. If one can take it up roughly, or partially, then one's conception will also be rough or partial. Or so it seems in our present state of understanding.
sahadeva 10y ago
This is a great essay, and I would highly recommend this as a counterpoint to Nagel in terms of explaining consciousness ("qualia") if you want to get the most out of Nagel's argument: http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts-science-of-the-soul http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts... If Nagel things materialists can't explain consciousness Dennett thinks they can. E.g. "The obvious answer to the question of whether animals have selves is that they sort of have them. [Dennett] loves the phrase 'sort of.' Picture the brain, he often says, as a collection of subsystems that 'sort of' know, think, decide, and feel. These layers build up, incrementally, to the real thing. Animals have fewer mental layers than people—in particular, they lack language, which Dennett believes endows human mental life with its complexity and texture—but this doesn’t make them zombies. It just means that they 'sort of' have consciousness, as measured by human standards." Joshua Rothman, New Yorker, MARCH 27, 2017 - http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts-science-of-the-soul http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts... More detailed counterargument by Dennett: https://www.amazon.com/DARWINS-DANGEROUS-IDEA-EVOLUTION-MEANINGS/dp/068482471X https://www.amazon.com/DARWINS-DANGEROUS-IDEA-EVOLUTION-MEAN...
- danbruc 10y ago
  If Nagel things materialists can't explain consciousness [...] I do not think he makes this statement. He seems perfectly open to the possibility of explaining subjective experiences in physical terms but he is convinced that we are at least very far away from being able to do it. In consequence he obviously considers all current attempts flawed and lacking.
  - sahadeva 10y ago
    I appreciate the pushback. Here is what Nagel says in his essay (emphasis mine). I wonder if you still disagree? "It is impossible to exclude the phenomenological features of experience from a reduction in the same way that one excludes the phenomenal features of an ordinary substance from a physical or chemical reduction of it--namely, by explaining them as effects on the minds of human observers. If physicalism is to be defended, the phenomenological features must themselves be given a physical account. But when we examine their subjective character it seems that such a result is impossible. The reason is that every subjective phenomenon is essentially connected with a single point of view, and it seems inevitable that an objective, physical theory will abandon that point of view."
pixelmonkey 10y ago
Not sure why this ended up on HN today, but this is a classic text read in many introductory courses focused on philosophy of mind and consciousness. I quite like the paper. I once wrote a follow-up paper about how one might interpret it now that we know about neuroplasticity. That was fun to ponder. I looked at a specific experiment where researchers managed to map visual impulses from a camera to an electrode "pixel grid" physically placed on the tongue, such that the visual inputs were "mapped" to corresponding locations on your tongue. It was shown, in the research, that people could catch balls thrown at them blindfolded using this setup, and after a relatively short period of sensory adjustment. They would actually "see with their tongue". You can read about that research in this 2003 article from Discover Magazine: http://discovermagazine.com/2003/jun/feattongue http://discovermagazine.com/2003/jun/feattongue The Nagel question then, is the fact that I experience vision a certain way really an essential aspect of "what it's like to be me?" Or is my consciousness a "further fact"... something running in the background of all my senses, no matter how they are wired (or rewired) over time? This is sometimes referred to as the "hard problem" of consciousness, summarized nicely in Wikipedia here: https://en.wikipedia.org/wiki/Hard_problem_of_consciousness https://en.wikipedia.org/wiki/Hard_problem_of_consciousness
- miobrien 10y ago
  Cool, thanks for the links. It ended up on HN because philosophy is what I studied in college/grad school, and I like the fact that HN seems to be a very intellectually omnivorous community -- sans the annoying dilettantism you find elsewhere.
- larsiusprime 10y ago
  Interestingly, Nagel actually seems to acknowledge/anticipate this point on page 9, see reply to sibling: https://news.ycombinator.com/item?id=13999907 https://news.ycombinator.com/item?id=13999907
- danbruc 10y ago
  Now I would be interested in the following experiment. Teach someone blind from birth to see with this tongue device, then restore eyesight with a surgery and test if they can recognize shapes. Why? I once read about an experiment where they restored eyesight of a person blind from birth and the person was unable to identify shapes by looking at them. The subject could easily identify the shapes by touching them, knew how a round ball or the corners of a cube felt, but that was obviously not enough to figure out what a corner looks like. I wonder if the tongue device would be sufficient to provide such an understanding.
username223 10y ago
Whoa, time warp to a previous life... Whatever you decide about his beliefs, Nagel is a wonderful writer. Pick up a copy of Mortal Questions if you get a chance.
goatlover 10y ago
It really comes down to objectivity vs subjectivity. What properties are objective features of the world, if any, and which ones are either individual or creature specific? And if science is our best attempt at creating an objective account of the world, how do we include the subjectivity of creatures different than us in that account? If we can't, then science is incomplete, because the world isn't entirely objective. Also, if the objective (shape, extension, number, etc) is created by abstracting away from the subjective (color, smell, feel, etc), then you can't use the objective to explain the subjective, although you can correlate the two (certain brain processes result in certain subjective experiences).
- visarga 10y ago
  In our days we learned how to do seemingly "subjective" feats with objective means (neural nets). It's not such a big, insurmountable divide any more.
  - goatlover 10y ago
    You mean the neural nets reported being puzzled by consciousness? Otherwise, I think you're conflating subjectivity with cognitive abilities, which need not be subjective at all.
visarga 10y ago
To be a bat, or a woman, or man, means to be an agent that exists as part of an environment, learning to select the best actions that maximize rewards. Of course for a bat the list of possible sensations, actions and rewards is different than for men or women. But what doesn't change is that they are all agents acting by reinforcement learning, trying to survive. I'm wondering why philosophy doesn't take this stance. Is it because it sounds too similar to behaviorism? Does it seem reductionist? Instead of using the parsimonious concept of reinforcement learning agent, they use hard to define words such as consciousness and self. Instead of looking at what matters - reward maximization, survival - they analyze qualia and Chinese Rooms. Philosophers, why are you ignoring recent AI research? Isn't it a waste of time to use such intuitive concepts as consciousness, free will and self? If only you could have come to a definition of consciousness you agree upon, but you can't, because it's a reification, a suitcase concept.
- eli_gottlieb 10y ago
  Lots of cognitive science literature models human beings as reinforcement learners, with plenty of good evidence for the hypothesis. The interesting question is: what kind of reinforcement learning?
yashksagar 10y ago
somebody show this to Nolan, about time we got another Dark Knight movie.
EGreg 10y ago
Thomas Nagel teaches at NYU, right?
- miobrien 10y ago
  Yup.
dvt 10y ago
Great paper that perfectly exemplifies what a "modern" philosopher does and thinks about on a daily basis. Unfortunately, it's also a paper that is often read only in lower-level philosophy courses. In my opinion, one needs to have a very deep understanding of the Philosophy of Mind corpus before being thrown into this paper because an uninitiated reader may be tempted to think that Nagel is obviously right on X or obviously wrong on Y, but his points are very nuanced. Nagel is also making some pretty big claims, specifically about the "private" nature of experience. Anscombe (whom I also loved reading) makes similar arguments. Philosophy of Mind was never my forte (I'm a logic and ethics guy), but reading Nagel was always a breath of fresh air in what I think is a subfield marred by unnecessary technicality and equivocation.
GeorgeKangas 10y ago
The following two sentences, from the second page of the paper, are where he really nails it: "We may call this the subjective character of experience. It is not captured by any of the familiar, recently devised reductive analyses of the mental, for all of them are logically compatible with its absence." All of today's science is logically compatible with the absence of subjective experience, because science cannot even define what subjective experience is. Every "definition" of subjective experience (SE, in what follows), is actually an ostension: the reader's attention is directed to his own SE. For example: - Perhaps nothing actually exists -- except SE. That's the one thing that MUST exist. [Descartes] - "There is such a thing, as what it's like to be..." [Nagel, in the posted paper] - There's such a thing, as what seeing red is like: a quale. - Science can't rule out that a behaviorally perfect duplicate of you, could lack SE (i.e. be a zombie). Science can't rule it out, but maybe SE does: why would a zombie vociferously assert the existence of SE? Those who claim SE is an illusion, i.e. that you actually are a zombie but don't know it, have the burden of explaining why zombies claim to have SE. All of these "definitions" require an audience that has SE and is able to recognize it. A scientific definition would not.
- cassowary 10y ago
  Well, that's precisely intrinsic to the problem of being subjective. You cannot objectively describe subjective experience, because otherwise it would cease to be subjective and become objective. It is reasonably probable that subjective experience will be outside of science for ever — unless we obtain so great a knowledge of the human brain that we can actually see some kind of physical change happening without a physical cause.
- eli_gottlieb 10y ago
  >All of today's science is logically compatible with the absence of subjective experience, because science cannot even define what subjective experience is. That just means science is incomplete and we are ignorant, not that subjective experience is metaphysically different from all other observed phenomena.
  - disconcision 10y ago
tim333 10y ago
It's interesting that we're getting fairly close (a decade or three?) to being able simulate brains and the we could combine human and bat simulations to be able to check out what it's like.
anonemouse145 10y ago
An interesting development for anyone who wants to take Nagel seriously is Mary and the colorblind room. Short version, a girl grows up in a black and white room (which is impossible in a lot of ways but just imagine) and that she is fed a database that lets her learn everything there is to know about the physical world of color (which is impossible but follow along) and then one day she exits the room and she sees a red rose. Nagel argued there's something about Mary's experience of color that she had in that moment, that she did not learn in the room. Dennett is another strong opponent here. He says Mary would retort, aha but you have a limited imagination. I know everything about color, so nothing about that experience was new to me in any non trivial way whatsoever. Because Mary knows EVERYTHING about color. It's may be impossible for us to imagine someone being omniscient about color, and that spoils the whole argument. Similarly, what if we knew every physical fact about bats. Dennett only needs to say, we have small imaginations. We have trouble imagining that what it is like to be a bat would be the sum of all physical facts about a bat. But we can't be sure of that. There is no logical certainty. Hence Nagel proved nothing. Yes you end up saying "we're all robots/zombies/unconscious animals" this way, and there's actually nothing special about being human it's just a myth we tell ourselves. But aside from some people not finding that conclusion tasteful, there's nothing wrong with it.
hit8run 10y ago
No need to read the paper. Just ask Batman. Always be yourself, unless you can be Batman. Then always be Batman! ... just kidding. Interesting read anyways.

132 points by miobrien 10y ago

TLDR: please read every word, because this work is that brilliant and that important.

I have a suspicion that future generations of philosophers will be taught Nagel's is like-be problem in the fashion that Hume's is-ought problem [1] is now taught. Although they concern completely different subjects, the similarities between the two are striking: 1. On what grounds can we make statements about what ought to be based on what is? 2. On what grounds can we make statements about what it is to be something based on what it is like to think about the experiences of that thing? Edit: In case there's any confusion, I called it the is like-be problem to draw a similarity to Hume, not because anybody else calls it that. [1]: https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem

smithkl42 10y ago
That's a great point about the similarity of the two problems. If we didn't already know from intimate personal experience that there is such a thing as consciousness, no amount of physical observation could ever be sufficient to prove to us that it exists. Similarly, if we weren't well prepared (on other grounds entirely) to assert that certain things ought or ought not to be done, no amount of observing the actual state of things could be sufficient to show that there is actually good or evil in the world.
andkon 10y ago
Yeah, I think this is probably true. Hume was trying to argue that normative statements can't be reduced to or derived from natural statements about how the world is; Nagel's fighting the reduction of consciousness to positive, objective statements about consciousness, because of the existence of phenomenal character. There's a certain way to be a bat that's wrapped up in the very fact of its being a conscious being with a specific biology and neurology, but which is still irreducible to those features. If you wanna link this up to an older philosopher, this is basically what Kant's on about in his Critique of Pure Reason. Our special human brain stuff is responsible for providing us with the faculties (e.g. understanding of things like causation) we have for understanding the world. We are always trapped in our experience of the world, and though that shouldn't preclude us from experiencing the world, you can't separate how we experience objective reality from the fact that we experience it as humans, with human brains and faculties.
- woodruffw 10y ago
  Absolutely, and you've said it better than I did. As a nit, wasn't Kant's Critique of Pure Reason written in part as a response to Hume?
  - andkon 10y ago
    ooooh totally was. He was deeply affected by Hume's attack on causation, so tried to come up with a coherent response. Ended up positing a whole bunch of wacky and (I think) true things about our embedded cognition, so I think it's probably fair to say that Critique of Pure Reason is the result of his beef with Hume.
    - miobrien 10y ago
      In the CPR, Kant proposes a synthesis of both rationalism and empiricism: although some knowledge comes from sensory experience, there are some things that we just know -- e.g., pure mathematics. So I'd say it's the result of his beef with everyone!
      - goatlover 10y ago
        Doesn't this all go back to Plato, where Plato thought knowledge depended on the forms, because the flux of particulars cannot provide knowledge?
  - Gormisdomai 10y ago
    In CPR here is what Kant says about Hume: "David Hume, who among all philosophers came closest to this problem, still did not conceive of it anywhere near determinately enough and in its universality ... believing himself to have brought out that such an a priori proposition is entirely impossible, and according to his inferences everything that we call metaphysics would come down to a mere delusion of an alleged insight of reason into that which has in fact merely been borrowed from experience and from habit has taken on the appearance of necessity." The "problem" Kant is referring to is how metaphysics can be possible in spite of what Hume proved. Kant says in the same breath, that this is the central problem of the critique - so i guess you can nearly say that it's written almost entirely as a response to Hume.

dghughes 10y ago

I just found out yesterday about how amazing the immune system of bats is they are practically immortal almost nothing makes them sick! But then it's confusing that bats in my region are being killed off by white nose syndrome. Fungus on their nose wakes them from hibernation and causes them such stress it eventually kills them. Which actually does make sense since the theory is bats do so well immunity-wise because of the large swing in their body temperature range. A bat's temperature drops very low when hibernating then when they fly it shoots up very high. http://www.popsci.com/bats-immune-systems-are-totally-unique http://www.popsci.com/bats-immune-systems-are-totally-unique

KingMob 10y ago

I went to grad school to study the neuroscientific basis of consciousness, and this paper is a classic. It inspired one of the weirder conference sessions I've ever been to at ASSC, called "Is a fish conscious?" Imagine a room full of philosophers and scientists arguing vociferously to determine where (or even if) to draw the line between conscious/unconscious organisms. (E.g., fish=probably, bacteria, probably not?)

ilugaslifg 10y ago
Even having that argument in the first place is basically crypto-dualism. The idea that there is objectively such a distinction is 100% reducible to any other attempt to assert that some definitional dichotomy "actually exists". It's exactly isomorphic to any other argument about taste. What is a sandwich, what is a car. An argument about whether a fetish is hot, between a person who has it and a person who doesn't. It's all the same damn thing. Shit like that is why I hadn't stop taking philosophy courses in university. It was just rehashing what always came down to this exact same essentially platonist theory of forms bullshit, over and over and over.
CuriouslyC 10y ago
A large part of the problem is that people don't all agree on the definition of consciousness. It ranges anywhere from the property of having an internal experience (which I subscribe to) all the way to self awareness, and even to the ability for rational thought. This - and arguments over the definition of "is" - were the reason I stopped reading philosophy of mind papers.

stabbles 10y ago

What I like about Thomas Nagel is that he is one of the few atheists who steps up against darwinism and materialism as an explanation for almost everything. Quoting from The Last Word (1997): "[...] I don't want here to be a God; I don't want the universe to be like that. My guess is that this cosmic authority problem is not a rare condition and that it is responsible for much of the scientism and reductionism of our time. One of the tendencies it supports in the ludicrous overuse of evolutionary biology to explain everything about life, including everything about the human mind." Of course his book Mind & Cosmos is the best example of this

ue_ 10y ago
I think it's rather refreshing to have someone speak out against scientism, thank you for the book.
amasad 10y ago
I agree that darwinism is overused to explain everything but materialism seems inescapable -- especially for atheists. I think even Nagel agrees with "Inference to the Best Explanation" and so far I've never seen a single case of anything better explained than the materialist explanation.
- goatlover 10y ago
  Materialism is not inescapable for atheists in philosophy at all. You can be anti-realist or an idealist sans God. You can also be a platonist. Or you could be a dualist like Chalmers. There's plenty of room for different views than materialism without committing to a belief in the supernatural.
  - ilugaslifg 10y ago
    How would you distinguish between "dualism" and "the supernatural"?
    - goatlover 10y ago

RockyMcNuts 10y ago

Humans can actually get pretty good at echolocation http://www.faculty.ucr.edu/~eschwitz/SchwitzPapers/Echo.pdf http://www.faculty.ucr.edu/~eschwitz/SchwitzPapers/Echo.pdf https://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_navigate_the_world https://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_nav...

larsiusprime 10y ago
Nagel acknowledges this in the article, for what it's worth: Footnote 8, page 9: > 8 It may be easier than I suppose to transcend inter-species barriers with the aid of the imagination. For example, blind people are able to detect objects near them by a form of sonar, using vocal clicks or taps of a cane. Perhaps if one knew what that was like, one could by extension imagine roughly what it was like to possess the much more refined sonar of a bat. The distance between oneself and other persons and other species can fall anywhere on a continuum. Even for other persons the understanding of what it is like to be them is only partial, and when one moves to species very different from oneself, a lesser degree of partial understanding may still be available. The imagination is remarkably flexible. My point, however, is not that we cannot know what it is like to be a bat. I am not raising that epistemological problem. My point is rather that even to form a conception of what it is like to be a bat (and a fortiori to know what it is like to be a bat) one must take up the bat's point of view. If one can take it up roughly, or partially, then one's conception will also be rough or partial. Or so it seems in our present state of understanding.

sahadeva 10y ago

This is a great essay, and I would highly recommend this as a counterpoint to Nagel in terms of explaining consciousness ("qualia") if you want to get the most out of Nagel's argument: http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts-science-of-the-soul http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts... If Nagel things materialists can't explain consciousness Dennett thinks they can. E.g. "The obvious answer to the question of whether animals have selves is that they sort of have them. [Dennett] loves the phrase 'sort of.' Picture the brain, he often says, as a collection of subsystems that 'sort of' know, think, decide, and feel. These layers build up, incrementally, to the real thing. Animals have fewer mental layers than people—in particular, they lack language, which Dennett believes endows human mental life with its complexity and texture—but this doesn’t make them zombies. It just means that they 'sort of' have consciousness, as measured by human standards." Joshua Rothman, New Yorker, MARCH 27, 2017 - http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts-science-of-the-soul http://www.newyorker.com/magazine/2017/03/27/daniel-dennetts... More detailed counterargument by Dennett: https://www.amazon.com/DARWINS-DANGEROUS-IDEA-EVOLUTION-MEANINGS/dp/068482471X https://www.amazon.com/DARWINS-DANGEROUS-IDEA-EVOLUTION-MEAN...

danbruc 10y ago
If Nagel things materialists can't explain consciousness [...] I do not think he makes this statement. He seems perfectly open to the possibility of explaining subjective experiences in physical terms but he is convinced that we are at least very far away from being able to do it. In consequence he obviously considers all current attempts flawed and lacking.
- sahadeva 10y ago
  I appreciate the pushback. Here is what Nagel says in his essay (emphasis mine). I wonder if you still disagree? "It is impossible to exclude the phenomenological features of experience from a reduction in the same way that one excludes the phenomenal features of an ordinary substance from a physical or chemical reduction of it--namely, by explaining them as effects on the minds of human observers. If physicalism is to be defended, the phenomenological features must themselves be given a physical account. But when we examine their subjective character it seems that such a result is impossible. The reason is that every subjective phenomenon is essentially connected with a single point of view, and it seems inevitable that an objective, physical theory will abandon that point of view."

pixelmonkey 10y ago

Not sure why this ended up on HN today, but this is a classic text read in many introductory courses focused on philosophy of mind and consciousness. I quite like the paper. I once wrote a follow-up paper about how one might interpret it now that we know about neuroplasticity. That was fun to ponder. I looked at a specific experiment where researchers managed to map visual impulses from a camera to an electrode "pixel grid" physically placed on the tongue, such that the visual inputs were "mapped" to corresponding locations on your tongue. It was shown, in the research, that people could catch balls thrown at them blindfolded using this setup, and after a relatively short period of sensory adjustment. They would actually "see with their tongue". You can read about that research in this 2003 article from Discover Magazine: http://discovermagazine.com/2003/jun/feattongue http://discovermagazine.com/2003/jun/feattongue The Nagel question then, is the fact that I experience vision a certain way really an essential aspect of "what it's like to be me?" Or is my consciousness a "further fact"... something running in the background of all my senses, no matter how they are wired (or rewired) over time? This is sometimes referred to as the "hard problem" of consciousness, summarized nicely in Wikipedia here: https://en.wikipedia.org/wiki/Hard_problem_of_consciousness https://en.wikipedia.org/wiki/Hard_problem_of_consciousness

miobrien 10y ago
Cool, thanks for the links. It ended up on HN because philosophy is what I studied in college/grad school, and I like the fact that HN seems to be a very intellectually omnivorous community -- sans the annoying dilettantism you find elsewhere.
larsiusprime 10y ago
Interestingly, Nagel actually seems to acknowledge/anticipate this point on page 9, see reply to sibling: https://news.ycombinator.com/item?id=13999907 https://news.ycombinator.com/item?id=13999907
danbruc 10y ago
Now I would be interested in the following experiment. Teach someone blind from birth to see with this tongue device, then restore eyesight with a surgery and test if they can recognize shapes. Why? I once read about an experiment where they restored eyesight of a person blind from birth and the person was unable to identify shapes by looking at them. The subject could easily identify the shapes by touching them, knew how a round ball or the corners of a cube felt, but that was obviously not enough to figure out what a corner looks like. I wonder if the tongue device would be sufficient to provide such an understanding.

username223 10y ago

Whoa, time warp to a previous life... Whatever you decide about his beliefs, Nagel is a wonderful writer. Pick up a copy of Mortal Questions if you get a chance.

goatlover 10y ago

It really comes down to objectivity vs subjectivity. What properties are objective features of the world, if any, and which ones are either individual or creature specific? And if science is our best attempt at creating an objective account of the world, how do we include the subjectivity of creatures different than us in that account? If we can't, then science is incomplete, because the world isn't entirely objective. Also, if the objective (shape, extension, number, etc) is created by abstracting away from the subjective (color, smell, feel, etc), then you can't use the objective to explain the subjective, although you can correlate the two (certain brain processes result in certain subjective experiences).

visarga 10y ago
In our days we learned how to do seemingly "subjective" feats with objective means (neural nets). It's not such a big, insurmountable divide any more.
- goatlover 10y ago
  You mean the neural nets reported being puzzled by consciousness? Otherwise, I think you're conflating subjectivity with cognitive abilities, which need not be subjective at all.

visarga 10y ago

To be a bat, or a woman, or man, means to be an agent that exists as part of an environment, learning to select the best actions that maximize rewards. Of course for a bat the list of possible sensations, actions and rewards is different than for men or women. But what doesn't change is that they are all agents acting by reinforcement learning, trying to survive. I'm wondering why philosophy doesn't take this stance. Is it because it sounds too similar to behaviorism? Does it seem reductionist? Instead of using the parsimonious concept of reinforcement learning agent, they use hard to define words such as consciousness and self. Instead of looking at what matters - reward maximization, survival - they analyze qualia and Chinese Rooms. Philosophers, why are you ignoring recent AI research? Isn't it a waste of time to use such intuitive concepts as consciousness, free will and self? If only you could have come to a definition of consciousness you agree upon, but you can't, because it's a reification, a suitcase concept.

eli_gottlieb 10y ago
Lots of cognitive science literature models human beings as reinforcement learners, with plenty of good evidence for the hypothesis. The interesting question is: what kind of reinforcement learning?

yashksagar 10y ago

somebody show this to Nolan, about time we got another Dark Knight movie.

EGreg 10y ago

Thomas Nagel teaches at NYU, right?

miobrien 10y ago
Yup.

dvt 10y ago

Great paper that perfectly exemplifies what a "modern" philosopher does and thinks about on a daily basis. Unfortunately, it's also a paper that is often read only in lower-level philosophy courses. In my opinion, one needs to have a very deep understanding of the Philosophy of Mind corpus before being thrown into this paper because an uninitiated reader may be tempted to think that Nagel is obviously right on X or obviously wrong on Y, but his points are very nuanced. Nagel is also making some pretty big claims, specifically about the "private" nature of experience. Anscombe (whom I also loved reading) makes similar arguments. Philosophy of Mind was never my forte (I'm a logic and ethics guy), but reading Nagel was always a breath of fresh air in what I think is a subfield marred by unnecessary technicality and equivocation.

GeorgeKangas 10y ago

The following two sentences, from the second page of the paper, are where he really nails it: "We may call this the subjective character of experience. It is not captured by any of the familiar, recently devised reductive analyses of the mental, for all of them are logically compatible with its absence." All of today's science is logically compatible with the absence of subjective experience, because science cannot even define what subjective experience is. Every "definition" of subjective experience (SE, in what follows), is actually an ostension: the reader's attention is directed to his own SE. For example: - Perhaps nothing actually exists -- except SE. That's the one thing that MUST exist. [Descartes] - "There is such a thing, as what it's like to be..." [Nagel, in the posted paper] - There's such a thing, as what seeing red is like: a quale. - Science can't rule out that a behaviorally perfect duplicate of you, could lack SE (i.e. be a zombie). Science can't rule it out, but maybe SE does: why would a zombie vociferously assert the existence of SE? Those who claim SE is an illusion, i.e. that you actually are a zombie but don't know it, have the burden of explaining why zombies claim to have SE. All of these "definitions" require an audience that has SE and is able to recognize it. A scientific definition would not.

cassowary 10y ago
Well, that's precisely intrinsic to the problem of being subjective. You cannot objectively describe subjective experience, because otherwise it would cease to be subjective and become objective. It is reasonably probable that subjective experience will be outside of science for ever — unless we obtain so great a knowledge of the human brain that we can actually see some kind of physical change happening without a physical cause.
eli_gottlieb 10y ago
>All of today's science is logically compatible with the absence of subjective experience, because science cannot even define what subjective experience is. That just means science is incomplete and we are ignorant, not that subjective experience is metaphysically different from all other observed phenomena.
- disconcision 10y ago

tim333 10y ago

It's interesting that we're getting fairly close (a decade or three?) to being able simulate brains and the we could combine human and bat simulations to be able to check out what it's like.

anonemouse145 10y ago

An interesting development for anyone who wants to take Nagel seriously is Mary and the colorblind room. Short version, a girl grows up in a black and white room (which is impossible in a lot of ways but just imagine) and that she is fed a database that lets her learn everything there is to know about the physical world of color (which is impossible but follow along) and then one day she exits the room and she sees a red rose. Nagel argued there's something about Mary's experience of color that she had in that moment, that she did not learn in the room. Dennett is another strong opponent here. He says Mary would retort, aha but you have a limited imagination. I know everything about color, so nothing about that experience was new to me in any non trivial way whatsoever. Because Mary knows EVERYTHING about color. It's may be impossible for us to imagine someone being omniscient about color, and that spoils the whole argument. Similarly, what if we knew every physical fact about bats. Dennett only needs to say, we have small imaginations. We have trouble imagining that what it is like to be a bat would be the sum of all physical facts about a bat. But we can't be sure of that. There is no logical certainty. Hence Nagel proved nothing. Yes you end up saying "we're all robots/zombies/unconscious animals" this way, and there's actually nothing special about being human it's just a myth we tell ourselves. But aside from some people not finding that conclusion tasteful, there's nothing wrong with it.

hit8run 10y ago

No need to read the paper. Just ask Batman. Always be yourself, unless you can be Batman. Then always be Batman! ... just kidding. Interesting read anyways.