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Dennett's predecessor brings it all together

  1. Mar 5, 2004 #1
    I'm sure we all know that Dennett was not the first Materialist philosopher of the mind. His theory is unique, but it is not without precedent. One example of a previous Materialist philosopher, who (I think) may shed considerable light on the issues that have been discussed in many previous threads, to do with consciousness and subjective experience.

    The philosopher was David Hume. I think I mentioned him briefly before, on another thread.

    Hume's ideas on consciousness seem integral to Dennett's philosophy, yet I don't think Dennett ever mentioned Hume in his books...this is perhaps because Dennett came up with his theory on his own, and certain parts just happened to have already been discovered by Hume in the 18th century.

    Anyway, there are (at least) three points that were addressed by Hume, in his writings, that I feel are relevant here. Before we get to those, I need to do some preliminary defining of terms.

    In Hume's philosophy, the term "impression" refers to those stimuli which immediately impress themselves on our sensory organs (e.g. the pain of being poked in the finger is an impression). On the other hand, there are also "ideas" (notice how he avoided the trap that Locke had fallen into, of lumping all sorts of thought and experience into "ideas"), which are either "simple" or "complex", and which are defined (basically) as those thoughts that are not impressed upon us by external reality, but which are purely subjective (produced inside the brain without external stimulus). A "simple idea", by Hume's definition, is (basically) one that is identical (except in degree) to a previous impression. A "complex idea" is one that is not identical to a previous impression, but which can be reduced into many "simple ideas" which can be traced back to some past "impression". Indeed, all thought, in Hume's paradigm, could either be traced directly back to an identical (except in degree) impression, or to a simpler "idea" - which could then be traced back to an impression.

    He put a bit of (IMO, unnecessary) effort into proving that all simple ideas are identical (except in degree - what I mean by this, btw, is that (for example) when you imagine being kicked in the gut, you don't actually feel pain (no matter how vivid the imagination); ergo, the degree is different, but you would still not be able to imagine being kicked in the gut, if it had never been "impressed" upon you) to previous impressions, and that the impression must always precede the idea, but I don't think I need to dwell on that too much, for now.

    Now to the three relevant points:

    1) From Hume's paradigm, we get that any "idea" (a subjective experience that is not equal to a previous "impression") can be reduced, and eventually traced back to some objective phenomenon. Even my use of the English language, in such a manner as to explain these things to all of you, is a complex "idea" that can be broken up into simpler "ideas", which can be traced back to impressions.

    2) From Hume's paradigm, we get that, when one strips away all "impressions" and innate behavior (i.e. nature and nurture) one does not have some naked "self" left over, but has nothing, since there is nothing more to the self or the mind than these things.

    3) (My favorite) From Hume's paradigm, we get that questions of the form "how/why did the 'impression' get comprehended as it did in the first place?" are completely moot. The famous example of different shades of blue...one might easily be convinced that the "impression" of each different shade is necessary for the "ideas" of different shades, in later life. However, some may still ask "how did the mind ever see 'blue' in the first place?" or "how did that particular wavelength translate to 'blue', when first 'impressed' in the viewer?". Hume's answer (in a nutshell), "how else should it have looked?". Think about it, if that wavelength of light didn't look that way, it would have to look some other way, and we'd still be asking the same question. So, it looks the way it does because it doesn't look any other way. Simple as that.

    The other senses are much easier to deal with than sight, which is why I chose a visual example. But it seems rather simple, that the visual cortex does what the visual cortex is supposed to do: process incoming stimulus from the retina - which has already done some processing of its own - and categorizing for future reference (whether as an "idea" or another "impression" of the same color).

    Take all of this and tie it in with all of the other philosophy and theory that I've discussed in previous threads (that of Dennett, Calvin, and Edelman to name a few), and I just don't see the "hard problem" as having any weight anymore.

    P.S. Those other threads, if you haven't been there yet, are:
    "Faulty expectations of a theory of consciousness", "'What makes a liquid liquid?' questions, and The Flaw in the Definition of Consciousness

    And those are just the ones I've started. There are plenty more of them.
  2. jcsd
  3. Mar 5, 2004 #2


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    I still think you are missing the entire point, but it's probably a lost cause anyway.
  4. Mar 5, 2004 #3
    I think he gets your point, and feels that it is irrelevant...all of this is a lost cause, but we seem to get some sort of enjoyment from it anyways.
  5. Mar 8, 2004 #4
    I think I get your point. At the heart of the matter, in your mind, is the eventual linking of all these computational processes to the workings of the brain. After all, the maple syrup I'm imagining right now doesn't look anything like synchronously-firing neurons. But what is it, exactly, that you don't think I've understood yet?
  6. Mar 8, 2004 #5
    I'm not going to take hypnagogue's spot to explain himself, but I will give my shot at the disagreement.

    I think, maybe——you are forgetting to consider the experience of the consciousness argument. I'll define it this way. You are imaging maple syrup, so naturally you know what maple syrup smells and tastes like, even if you never had it, you still subjectively allow your firing neurons from the neural brain signals to do the computational methods for you. This is experience. This is what is the heart of the matter. If you can see it in your mind, you can taste it, you can feel it, then, afterall this must be the experience that your brains tells you that experience happened before. And those same synchronously-firing neurons are their to match up the unidentified object to the object that you are imagining. So, in conclusion what I'm saying is: experience is its own individual experience and those neurons are their own individual experience on how subjectively define that object——imaginatively.
  7. Mar 9, 2004 #6
    One problem: there is no "maple syrup" in my mind. It isn't an object, it's a collection of previous "impressions" (or, to go without Hume for a second, it's a collection of previous memories, which happen to fire together to produce almost exactly the same effect as if I were eating maple syrup (I say "almost exactly" because it can never reach the same degree as the actual "impression")).
  8. Mar 9, 2004 #7
    Just wanted to add...

    I just wanted to add a bit of reasoning that I thought would be obvious from what I posted originally, but I think I was mistaken...

    The philosophies of Hume and Dennett (and their followers) lead to a logical framework which allows us to get rid of the idea that there are neural firings, and then there is an experience. After all, the synchronous firings never meet up at any one place (thus the experience is "smeared" out among different parts of the brain (as Dennett would put it)) and one perceives one coherent picture, while the firings occur at different times (thus the experience is "smeared" out temporally as well as spacially). So, trying to explain how the experience eventually comes to be (evolves) is like trying to explain how a natural disaster evolves...there is no one point in time or space wherein the whole disaster occurs, it takes a long time, and the end result (when the catastrophe subsides) is not a disaster, but is a world that has been ravaged by that disaster. Yet, one can't say that the disaster didn't happen, just because there was no exact place, nor any exact time, when/where it occured, you simply look back and lump all the events together so that, in retrospect, the whole set of occurances = a natural disaster.
  9. Mar 9, 2004 #8
    Ok. But saying brain states are distribited in time and space is not contentious. It is precisely what gives rise to the binding problem. That is, it is part of the problem, part of what needs explaining, not the solution. It is a statement of fact and explains nothing.
  10. Mar 9, 2004 #9
    Well, you would be 110% right (extra 10% for eloquency in presentation...something I'm trying to learn from your example) if there was an eventuality to these brain states, as so many philosophers have assumed. But, if they just keep going on, and re-stimulating themselves, without ever meeting up, then there is no "hard problem" of how they ever form a complete picture, they just don't.
  11. Mar 9, 2004 #10


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    I don't think you have a good grasp on what the hard problem is-- or at least, you are misrepresenting it here. Brain processes never meeting up-- that's still the binding problem, which asks how perceptual experiences are tied together to form the perception of single, coherent objects.

    The hard problem deals with how it is that subjective experiences exist at all, and need not invoke the binding problem. Someone in a ganzfeld setup, for example, visually experiences only a uniform (say) red field; in this scenario, there are no diverse visual experiences to bind together, so the binding problem is irrelevant. But we still may ask why the person experiences redness at all (in the sense that a blindsighted person does not). Why shouldn't the person just be a zombie, with no experience of redness, yet still be able to process information from the visual stimulus? That's the hard problem. I hope the difference is clear.
  12. Mar 9, 2004 #11

    you report information very well and grasp heavy concepts.

    what i don't understand is your 'point'. what have you learned studing these philosophers and what can you add?

    who and what is Mentat?? when you go outside on a clear spring day, do you smell the air? can you feel the natural renewal of life?

    what do you believe? not what hume or dennett wrote.

    do you believe in sunny days and baseball?

  13. Mar 9, 2004 #12


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    In Consciousness Explained Dennett has a beautiful passage where he's sitting on a patio under rustling trees, immersed in the balmy air and the birdsong -- and he brings it all home with his account of his own consciousness, with nothing of what he calls "skyhooks" and I call "magic" . Let me be clear about that; I don't mean ritual magick or literal magic, but rather appeals to something that is beyond empiricism and analysis.
  14. Mar 9, 2004 #13
    I don't understand why more people don't see the elegance and beauty of a "machine"( the human body, including the brain) working in glorious harmony to engage the natural world of which it is a small part.
  15. Mar 9, 2004 #14


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    That might be elegant and beautiful, but it fails to explain all the phenomena that need explaining.
  16. Mar 10, 2004 #15
    But they never do...that's the only reason Dennett thinks the Materialistic paradigm can work: The perceptual experiences (whatever those are) never have to meet up and become a singular, coherent experience (whatever that is) because it works just as well for the information to be integrated (as in a computer) such that, in retrospect, it seems like a coherent experience (and "seems like" can be replaced with "is processed as").

    How do you know that they do exist at all, if they aren't even defined?

    A blind-sighted person does experience the color, otherwise they wouldn't know what the color was later. But then, I don't know anything about blindsight studies, and don't pretend to...I just know what you've told me so far, and it seems as though the subject can report the color that they saw, later, while not having experienced it at the time...is that right?

    Yes, it is. You're better at this explaining than I am, and I appreciate your ability as well as your use thereof to teach me.

    The problem still remains, as stated in my little quote (at the end of each post): How else do you expect a visual cortex to process visual stimuli? It doesn't "know" any other way, besides visual experience. If you get a silicon machine that does the same things as a visual cortex, it will experience visual stimuli also, that's what they're made to do.
  17. Mar 10, 2004 #16
    What phenomenon does it leave out (note: please do not include any undefined terms in your answer)?
  18. Mar 10, 2004 #17
    Re: Mentat

    Thank you.

    I don't have a "point", except to "report information well and grasp heavy concepts". I have learned nothing conclusive from these philosophers and can add nothing conclusive to them, and I like it better that way (viz a viz changing primary belief with each new philosophy).

    I prefer rainy days and reading...but I understand what you mean. You're wondering how I can maintain the joi de vive if I see reality only through the eyes of materialistic philosophers, right? The truth is, I have a set of core beliefs that have no entered the picture here. I right down what Dennett and Hume say, because what I believe myself is both irrelevant to the conversation and a potential obstruction of logical discussion.
  19. Mar 10, 2004 #18


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    I think everything else you addressed in this post of yours is being addressed elsewhere, and this may be too, but I'll reply again anyway.

    Here is your explanatory method as applied to H2O molecules and water fluidity:

    Say we have a set X of H2O molecules under certain circumstances. Such a set is always observed to correspond to macroscopic fluidity. How else do you expect it to be? That is just the way it is.

    This is an impoverished explanation because it has not yet made explicit any a priori logical ties between the properties of H2O molecules and the fluidity of water. It has no bridge principle. To have a good explanation, we must provide a bridge principle that makes explicit the logical ties, such that one could predict a priori from the description of X its macroscopic properties. Such a bridge principle is easy enough to construct in this case, but it is not so obvious in the case of the relationship between brain processes and subjective experience. Until we find such a bridge principle we can't be satisfied with brute correlation as an explanatory mechanism.
  20. Mar 10, 2004 #19
    That previous colletion of images, nonetheless, would form the object in your mind imaginatively to make that memory of what maple syrup is. And how do you know it isn't in your mind? What does that mean exactly to your reference of the imaginary effect on the degree of actual impression of maple syrup?
  21. Mar 10, 2004 #20
    Re: Re: Mentat

    why cheat the universe of your unique views?? if you can undersatand these concepts, you must have an opinion on what is realy happening in our reality. i would rather discuss views and ideas, not debate what someone else said or wrote.

    to each his own, peace!
  22. Mar 11, 2004 #21
    Complete answers have to undefined terms in them otherwise they will be trivially self-referential. This is the mathematical equivalent of the hard problem. It's worth understanding why this is so because it is directly relevant.

    A theory is equivalently a set of definitions. Any non self-referential set of definitions must contain an undefined term. Consciousness is science's ultimate undefined term, the final term in its theory that cannot be defined. This is what Max Planck was implying in that quote I posted to you.

    It does not take a Sherlock Holmes to interpret the evidence. Ex hyothesis science cannot explain subjective experience or ultimate reality, and we know any theory of everything must have an undefined term in it. This is the hard problem from a mathematical perspective.

    BTW this is why it is incorrect to take Buddhism as being based on theory. If it was it would suffer from the same problem. This issue is what led Einstein to make his well known comment that insofar as as a mathematical system describes reality it is not provable, and vice versa.

    It is arrogant of you, IMHO, to dismiss all these arguments as if their proponents were stupid philosophers rather than infallible scientists. I do not feel that as yet you have grasped the issues.

    I thought that you were trying to this, but I'm becoming less and less certain. If the problem was as simple as you assert it to be then we would have solved it, in outline at least, in the 18th Century, and probably much earlier.
    Last edited: Mar 11, 2004
  23. Mar 11, 2004 #22
    "Subjective experience" and "ultimate reality" are null phrases, from my standpoint. There is no reason to assume the existance of either as being somehow "apart" from the mechanistic operation of the human brain, and the universe as a whole. The desire to believe there is something beyond the mechanistic and material is an emotional stance, not a logical one.
  24. Mar 11, 2004 #23


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    How's this for logic:
    1) All mechanistic processes are objectively observable.
    2) Subjective experience is a mechanistic process.
    3) Subjective experience is not objectively observable.

  25. Mar 11, 2004 #24
    Are you sure about #3? I'll admit that our ability to track the operation of the mind is at its infancy, but already we can see how certain parts of the brain produce certain "subjective experiences", and can even use electrodes to create those experiences directly.
  26. Mar 11, 2004 #25


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    Those things might be something like the objective footprints of subjective experience, but they are not subjective experience itself. Surely this is a useful tool for getting a better understanding of consciousness, but the fact remains that I cannot literally see what you see-- I cannot observe your subjective experience. If what you see literally is a mechanistic process, I should be able to literally see it in your brain. If you propose rather that subjective experience is some kind of 'aspect' of your brain processes, the fact remains that this aspect is completely hidden from my objective observation of you.
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