Nagel's Batty Explanation of the Mind-Body Problem

[Copernicus]

In 1974, Philosopher Thomas Nagel published his classic 17-page explanation of why it is so difficult to understand the physical basis of consciousness: What is it Like to Be a Bat?

In internet discussion forums, people love to argue over the nature of consciousness. Most people seem to believe that brains cause consciousness, and I will not try to argue otherwise. That goes without saying. But how? How can there be an objective explanation of subjective experience? People believe that there must be some explanation that reduces to physical activity, but reductionism never seems to get us anywhere. People who wish to discuss this question intelligently really need to start by reading Nagel's brilliant essay, because Nagel nails it. And, no, the paper is not mostly about bats. That is just the  intuition pump that Nagel uses to make his argument about why reductionist claims are so unsatisfying.

One can come away from Nagel's essay with the rather unsatisfying answer that What it is Like to Be a Bat is just What it Feels Like to be a Bat. But that is just as unsatisfying as saying that the bat's consciousness is some kind of physical phenomenon. Sure, the bat has a brain, but it doesn't experience reality in the same way a human brain does. So what is consciousness in a bat? You can come up with all sorts of thoughts on what you imagine it to be like, but you don't sense reality in the same way that a bat does. You don't use echolocation to paint a 3D picture of reality (although some blind folks do develop a more limited ability to detect objects and distances through sound and other senses). And bats are more like us than snakes or worms or plants. At what point does consciousness of our sort go away? Worms have very rudimentary nervous systems. Are they conscious at all? We like to say that robots are not conscious, yet they behave in ways that give the illusion of conscious behavior. Is it possible for a robot to be conscious? In my opinion, it is. And robots quite often rely on echolocation to map out their local space.

The answer to the mind-body problem is grounded in the nature of experience. Brains have experiences, but what is an experience from a physical perspective? That's all I want to say for now--to point people at Nagel's explanation, if they have not already read this seminal paper. I will give my thoughts later on the way to think about the objective side of subjective experience.

 

[rousseau]

It's a hard problem to solve in part because this ability has evolved over literally billions of years. The nervous systems of animals are unfathomably complex, the brain is difficult to study, and science is pretty young.

For my part I'm satisfied with saying it works and moving on to more interesting problems. When it comes to pragmatics how consciousness works physically really isn't that important. But I think it's worth noting that we seem to frame consciousness as a thing we have, rather than a thing that's happening. This is worth noting, because a lot of philosophy has been preoccupied with confirming that humans are somehow special, and not just like every other animal.

Most of what we call 'conscious' experience is just parts of our physiology sensing and reacting to the environment across time, just like any other animal. How does it work? Billions of years of iterations.

 

[Treedbear]

In 1974, Philosopher Thomas Nagel published his classic 17-page explanation of why it is so difficult to understand the physical basis of consciousness: What is it Like to Be a Bat?
...
The answer to the mind-body problem is grounded in the nature of experience. Brains have experiences, but what is an experience from a physical perspective? That's all I want to say for now--to point people at Nagel's explanation, if they have not already read this seminal paper. I will give my thoughts later on the way to think about the objective side of subjective experience.

Thanks for the reference to the article, which I haven't had time to read yet but look forward to. I went right to the last paragraph though and found this which subscribes to my own views on understanding the subject of conscious experience (my bolding):

Apart from its own interest, a phenomenology that is in this sense objective may permit questions about the physical basis of experience to assume a more intelligible form. Aspects of subjective experience that admitted this kind of objective description might be better candidates for objective explanations of a more familiar sort. But whether or not this guess is correct, it seems unlikely that any physical theory of mind can be contemplated until more thought has been given to the general problem of subjective and objective. Otherwise we cannot even pose the mind-body problem without sidestepping it.

As is often the case when dealing with paradox it might be a matter of not addressing the right question. Also a more objective point of view requires adopting a broader perspective.

... At what point does consciousness of our sort go away? Worms have very rudimentary nervous systems. Are they conscious at all? ...

What if an extremely advanced space-traveling race visited Earth? People like to worry about whether human would be bred like cattle for food. But would they look at us as lower on the consciousness scale? Perhaps barely conscious at all? We likely would be, compared to their level of understanding and general awareness.

 

[Copernicus]

Nagel was writing at a time when computer technology was leading to a revolution in our understanding of chaos theory, although the concept of  emergence was very old, going back at least to Aristotle. The point is that an entity interacting with other entities in a system can exhibit properties or behaviors that its parts do not have. Those properties emerge only when there is systemic interaction. Nagel does not speak of emergence, but it seems clear that subjective experience emerges from objective interactions in a running neural system. Generally speaking, we can analyze chaotic interactions in a system by reducing the system to simpler interactions between entities within the system. Cellular automata are one way of formally capturing simple emergent behaviors, so it is possible to achieve a kind of reductionist explanation that seems almost intractable by other methods. We just need to identify the major components of the system that are interacting with each other and discover how they interact. The people who are building such systems from the bottom up are roboticists--the creators of autonomous systems that interact with the same environmental factors that human beings interact with, including especially other human beings.

 

[bilby]

Consciousness doesn't exist.

I am only able to observe a single instance of it, amongst billions of human brains and trillions of brains with varying degrees of difference from human brains. Therefore that single datum is clearly an outlier and can be discarded from the dataset.

Problem solved.

 

[fromderinside]

Did you check your sub vocalizations or visual reenactments while you were making that statement? Whatever it is it is physical and, for you and those around you, an illusion. There is no 'You' to bring it forth.

 

[rousseau]

it seems clear that subjective experience emerges from objective interactions in a running neural system.

I hesitate to say much about subjective experience based on what philosophy has said. We need to open up the brain and understand the mechanics, then the mechanics are what can be said. It seems like a trivial point, but I think what I mentioned earlier about consciousness as something that happens is important.

Classically we've phrased experience as something that happens to 'us', where I'd argue that it just happens. We're a material system that senses and responds to the environment. We don't experience, the body has an interface with the environment that allows it to respond. So when our foot touches the ground, a sensation that the ground is there happens. In some way the brain processes and interprets that information.

 

[Copernicus]

it seems clear that subjective experience emerges from objective interactions in a running neural system.

I hesitate to say much about subjective experience based on what philosophy has said. We need to open up the brain and understand the mechanics, then the mechanics are what can be said. It seems like a trivial point, but I think what I mentioned earlier about consciousness as something that happens is important.

Classically we've phrased experience as something that happens to 'us', where I'd argue that it just happens. We're a material system that senses and responds to the environment. We don't experience, the body has an interface with the environment that allows it to respond. So when our foot touches the ground, a sensation that the ground is there happens. In some way the brain processes and interprets that information.

I am thinking along the same lines that you are, but I disagree that we "don't experience". Of course we do, and we even have a name for what we do. That's exactly what the nervous system does for us. And I would stop just referring to "the brain". It is the entire nervous system, including the peripheral nervous system. Our ability to model reality and predict future events is entirely constructed out of experiences that we can reconstruct every time we remember something. Just "opening up" the brain isn't really going to help us solve the mind-body problem, and Nagel explained why, in my opinion.

 

[rousseau]

it seems clear that subjective experience emerges from objective interactions in a running neural system.

I hesitate to say much about subjective experience based on what philosophy has said. We need to open up the brain and understand the mechanics, then the mechanics are what can be said. It seems like a trivial point, but I think what I mentioned earlier about consciousness as something that happens is important.

Classically we've phrased experience as something that happens to 'us', where I'd argue that it just happens. We're a material system that senses and responds to the environment. We don't experience, the body has an interface with the environment that allows it to respond. So when our foot touches the ground, a sensation that the ground is there happens. In some way the brain processes and interprets that information.

I am thinking along the same lines that you are, but I disagree that we "don't experience". Of course we do, and we even have a name for what we do. That's exactly what the nervous system does for us. And I would stop just referring to "the brain". It is the entire nervous system, including the peripheral nervous system. Our ability to model reality and predict future events is entirely constructed out of experiences that we can reconstruct every time we remember something. Just "opening up" the brain isn't really going to help us solve the mind-body problem, and Nagel explained why, in my opinion.

My claim isn't that we don't experience, it's that there is no central experiencer. I think it's more accurate to say that the body 'senses' the environment by various means, and what is stored in memory is our 'experience'.

IOW there is nothing called 'mind' that experiences. There is a body that senses. We imagine ourselves as a 'something' that senses, where in reality we're a body of disparate sensory organs that interact with the environment in conjunction with each other.

I tried reading your article but had trouble really gleaning the central message. But overall I'm skeptical of the role of philosophy in understanding neuroscience. Certainly the brain is a physical system and in theory the phenomena it projects can be modeled. So until we have the means to model it I don't know what value there is in thinking or writing about it.

Perhaps if you explained the paper it would help those that don't have the time to really commit to it.

Sent from my SM-A520W using Tapatalk

 

[bilby]

it seems clear that subjective experience emerges from objective interactions in a running neural system.

I hesitate to say much about subjective experience based on what philosophy has said. We need to open up the brain and understand the mechanics, then the mechanics are what can be said. It seems like a trivial point, but I think what I mentioned earlier about consciousness as something that happens is important.

Classically we've phrased experience as something that happens to 'us', where I'd argue that it just happens. We're a material system that senses and responds to the environment. We don't experience, the body has an interface with the environment that allows it to respond. So when our foot touches the ground, a sensation that the ground is there happens. In some way the brain processes and interprets that information.

I am thinking along the same lines that you are, but I disagree that we "don't experience". Of course we do, and we even have a name for what we do. That's exactly what the nervous system does for us. And I would stop just referring to "the brain". It is the entire nervous system, including the peripheral nervous system. Our ability to model reality and predict future events is entirely constructed out of experiences that we can reconstruct every time we remember something. Just "opening up" the brain isn't really going to help us solve the mind-body problem, and Nagel explained why, in my opinion.

It's worse than that, Jim. There's the endocrine system to consider as well.

It tends to get ignored, but it's much more complex than the nervous system, it's much more influential in many circumstances, and its effects tend to be systemic, while nervous system effects are more localised.

If you ignore the endocrine system, you are ignoring a very large part of the question, and if you don't, you need to consider pretty much every cell in the body - including many that are not even human, or eukaryotic for that matter.

 

[rousseau]

I am thinking along the same lines that you are, but I disagree that we "don't experience". Of course we do, and we even have a name for what we do. That's exactly what the nervous system does for us. And I would stop just referring to "the brain". It is the entire nervous system, including the peripheral nervous system. Our ability to model reality and predict future events is entirely constructed out of experiences that we can reconstruct every time we remember something. Just "opening up" the brain isn't really going to help us solve the mind-body problem, and Nagel explained why, in my opinion.

It's worse than that, Jim. There's the endocrine system to consider as well.

It tends to get ignored, but it's much more complex than the nervous system, it's much more influential in many circumstances, and its effects tend to be systemic, while nervous system effects are more localised.

If you ignore the endocrine system, you are ignoring a very large part of the question, and if you don't, you need to consider pretty much every cell in the body - including many that are not even human, or eukaryotic for that matter.

Yea. I'd add that the reason I'm referring to the brain and not the entire nervous system, is because from my cursory understanding a lot of the magic happens in the brain, where the greater nervous system is understood a little more clearly.

On the whole, when you consider how small a single cell is, and you consider how many atoms make up a single cell, the brain (and body) is overwhelmingly complex, and it's no wonder that we don't completely understand it when it wasn't even two centuries ago that we figured out evolution was a thing. When I hear of papers like that of Nagel's it's very reminiscent of Greek philosophers waxing poetic about how 'atoms' must be a thing, but having absolutely no clue how they work in practice.

It's been 13 years since I studied anything remotely resembling neuroscience, and at the undergrad level, so I have no idea where the field is now, but I get the sense that understanding the brain fully is a tough one.

 

[untermensche]

My claim isn't that we don't experience, it's that there is no central experiencer.

What is this "my" that has claims?

Could it be the same "my" that experiences vision and sound and pain and depression?

 

[fromderinside]

Well there you go. He did make a claim. That does not make it so that he has experience or consciousness or has an internal self. The individual typed a claim IAC with his knowledge of language and use of a keyboard. Its fair that it wasn't another person. He did it. It's his product.

 

[untermensche]

Well there you go. He did make a claim. That does not make it so that he has experience or consciousness or has an internal self. The individual typed a claim IAC with his knowledge of language and use of a keyboard. Its fair that it wasn't another person. He did it. It's his product.

What made the claim?

His foot?

His brain?

His mind? The singular thing that experiences all.

 

[Copernicus]

This discussion is taking shape along the lines that it usually does, but I just wanted to focus on the main question that Nagel raised. He is really asking how it is possible to explain the way in which the subjective emerges out of an objective substrate, i.e. neural activity. That is the central question. Of course, he spends a lot of time comparing human experience to the experience that a bat or some other animal might have, because that seems to be more insightful than, say, explaining cognition in purely physical terms. Nevertheless, I would maintain that subjective experience produced by a neural system is just as physical as any systemic behavior that emerges from a physical substrate. In fact, I would go further and say that we can, in principle, build machines that do not have neurons but still produce subjective experiences. I would maintain that, because I think it is only necessary to produce a system that functions like our brains function. The physical substrate that produces the function can vary.

Bat brains create subjective experiences, but those experiences are very different from ours. Normal human beings rely a lot on vision to produce their models of reality, but bat brains rely more on hearing. Those models are necessary for the types of complex animal bodies that we possess, because both bats and humans need to navigate safely within their environmental niches. Brains are guidance systems for bodies. What humans and bats have in common, besides being mammals, is that they integrate their visual/auditory sensations with other kinds of sensations--touch, taste, smell, etc. Emotions guide their goals and choices. Volition controls their motor behaviors. How does all of that emerge from a physical machine whose parts are not conscious per se? We have some understanding of the environmental forces that influence the behavior of physical objects--gravity, electromagnetism, strong nuclear, weak nuclear. Are the mental forces that influence human and bat behaviors also physical forces in some sense? I think that it is possible to answer that question positively or negatively, depending on how you frame it.

Where I am headed with this is a discussion of the nature of emergent properties of physical systems. That is, I want to make the case that physical reality as we construe it is built up out of layers of emergent systems, where each system can be framed in two different ways--the mechanical functions of the substrate and the systemic functions that emerge from it. Both layers are real and have very different properties, so it makes no sense to say that the systemic layer doesn't exist when one is talking about the mechanics or the mechanical layer doesn't exist when one is talking about the systemic layer. Both layers coexist, but in their different conceptual frames. Those who claim that thoughts don't exist because they are not material things and that only material things can exist are wrong. The problem is that the words "material" and "mental" are presupposed to exist independently of each other, but one is just another systemic functional layer that emerges from the mechanical layer that serves as its substrate.

In the physical sciences, atoms, molecules, and solutions are very different objects with different properties. H2O molecules have systemic properties that are very different from the systemic properties of hydrogen and oxygen atoms. And water has very different systemic properties that are not derivable from just the behavior of H2O molecules. When talking about the cognitive system of a human being, one necessarily talks about the same two system-of-system layers, where each entity has properties that can be very different from the properties of the entities in their substrates. Robots have bodies with sensors and actuators, just like biological animals. They also have guidance systems that operate without neurons, although the programs that drive them can in some sense mimic the behavior of neurons. In principle, we could build a robot with enough complexity to have cognitive experiences that are as similar to ours as perhaps a bat's experiences are. I'm not saying that our species will survive long enough to achieve it, but I think that there may exist intelligent animal species on other planets that may have achieved that feat.

 

[untermensche]

Where I am headed with this is a discussion of the nature of emergent properties of physical systems. That is, I want to make the case that reality as we construe it is built up out of layers of emergent systems, where each system can be framed in two different ways--the mechanical functions of the substrate and the systemic functions that emerge from it. Both layers are real and have very different properties, so it makes no sense to say that the systemic layer doesn't exist when one is talking about the mechanics or the mechanical layer doesn't exist when one is talking about the systemic layer. Both layers coexist, but in their different conceptual frames. Those who claim that thoughts don't exist because they are not material things and that only material things can exist are wrong. The problem is that the words "material" and "mental" are presupposed to exist independently of each other, but one is just another systemic functional layer that emerges from the mechanical layer that serves as its substrate.

Unfortunately all these discussion about the nature of consciousness and the nature of a mind experiencing don't really go anywhere because the phenomena of a mind experiencing a thought is not understood in any way. Saying it happens in the brain is not an understanding.

Mental and material ARE two separate things.

Color is a mental experience.

It is not made up of any material.

It does not exist in any way except as a mental experience.

 

[Copernicus]

Untermensche, I think that these discussions go somewhere for those of us who are open to looking at the subject from different angles, but I'm not sure that you are. For example, you responded to a paragraph about emergence without making any reference to the concept or showing that you understood the difference between a system description and a description of its substrate. I'm not saying that I disagree with anything that you said in your post. I'm just saying that it doesn't really address the point I was trying to make. You appear to disagree with what I posted, but AFAICT you don't agree or disagree, because you aren't talking about what I actually posted.

Lets consider the difference between two cars--one powered by a gasoline engine and one powered by an electrical engine. That fact alone does not make one an automobile and the other something else. They both perform exactly the same functions from the perspective of a driver, although the operating instructions may be a bit different. Start thinking of different ways to alter those cars, taking away some components and adding others. At what point do they cease to be automobiles? I think you'll find that it is easier to describe their differences when their functions change rather than the physical components. That is, you can describe an automobile in terms of its mechanical components and how they interact to produce an operational product. However, what really defines something as an automobile is the way in which we interact with it--its functional properties. Automobiles emerge from physical components, but they are not just the sum of their physical parts. They exist as functional objects, too.

I will grant you that you don't understand thought "in any way", just don't include others in your generalization. People understand a great deal about what thought is, and those who make their living by studying it and things related to it must certainly know a great deal more than you do. I don't believe that you understand what "we" understand about thought.

 

[untermensche]

OK

I want to make the case that physical reality as we construe it is built up out of layers of emergent systems, where each system can be framed in two different ways--the mechanical functions of the substrate and the systemic functions that emerge from it.

Are you saying?

Our ability to experience and our experiences of reality are constructed by various subsystems. These subsystems have an activity associated with them and this activity results in the emergent phenomena of subjective experience.

 

[abaddon]

Copernicus,

I think your idea of a systemic layer is an intriguing idea. But I don't think it explains the emergence of mind. To me, it seems a more complicated way of asserting that "mind" (as the systemic layer with emergent traits differing from the mechanical parts) is "created by" those mechanical parts.

A little time back I read a couple articles about panpsychism that are also very intriguing to me. In panpsychism, the mental emergent traits aren't "created" by matter. In this view, "emergent" wouldn't be synonymous with "create". Rather, consciousness is there all along, just in a super-simple form, in the particles or atoms. When configured in a mechanical system, they form your "systemic layer".

This way there's no "when complex enough, mind pops into existence" implied. Rather, "when complex enough, then from particle-consciousnesses emerges a bat-consciousness" (or a human-consciousness, or an AI-consciousness, or whatever the neural and bodily configuration is).

In this view, mind and matter are the same thing all along, just the mental trait of everything is not recognizable to us until it's a neural system.

Pretty much everything you say still applies. Just, I guess some of us are allergic to the notion of "create". Matter "creates" mind... hm, even when that notion is reframed as complex systems of stimulus-response, it sounds a little "magical". That is, not explanatory.

Is "wateriness" there in H2O? No. But then the proposition of panpsychism is not the feeling quality that you and I experience as our "minds" is there in molecules or atoms or particles either. It's still talk of a variety of emergence. Just, it's not an emergence that involves "creating" something that's utterly new in the universe.

 

[Treedbear]

This discussion is taking shape along the lines that it usually does, but I just wanted to focus on the main question that Nagel raised. He is really asking how it is possible to explain the way in which the subjective emerges out of an objective substrate, i.e. neural activity. That is the central question. ...

I like to reduce problems into their most basic components to understand things. Conscious experiences seem to come in two forms: thoughts and feelings. Thoughts seem to be the product of the model-creating ability of brains. Whether we are conscious of it or when we are not our brain is processing information based on perceptions and learned behavior in order to model its environment. That environment includes everything we encounter in the external world as well as everything that arises within our personal sense of awareness. The latter is usually our most continuously stimulated and intimate source of input, and we identify it as the "Self". So how models are built would be a great place to begin to analyze the functionality of the objective substrate. Frankly I don't have a clue. As far as I'm aware computer science doesn't either.

Feelings cover a wide range of experiences from touch sensations to emotions. They frequently serve as an input for thought processes and often provide a necessary motivation for it. But the word is normally used to describe something that is not the result of thought. In fact we tend to use the term when we describe what we think of some matter when in actuality we don't really understand why. "This is what I feel about it" rather than "what I think about it." So it can be inferred that some connection exists there.

At any rate I find that reducing something to its most basic level is often helpful in discovering what it is. I think there's an explanation for feelings in general, which is that all feelings are associated with some level of arousal that varies on a scale from serenity to anxiety. Arousal translates in the substrate as the level of neural activity, requiring that energy resources be managed. Indeed as the brain evolves in size and complexity this becomes a critical, and so an integral function in order that the brain functions efficiently and avoids the buildup of excess heat. Energy requirements and heat buildup determine the upper limit of brain size, just as with electronic microprocessors. There are many types of cells that support and moderate neuron activity. Those subsystems naturally effect a wider region of brain cells than would signals between neurons. Therefore the effect can be either more localized or generalized as required in order to influence specific processes.

What I'm thinking here is that this paradigm of energy management is integral to the evolution of brains in general. And since it has been so from the earliest times there is quite possibly some integral ability to sense (if that's the right word) that level of arousal and identify it as either good (serenity) or bad (anxiety). And if that is so then the rest of our so called feelings can be characterized accordingly and "colored" (so to speak) with whatever type of experience the brain's thought processes associate with it. Whether it's love, hate, joy, sadness, compassion, etc., there are various combinations of experience that we associate with them. So I can't say how exactly arousal is sensed but I can rationalize how all feeling can be simplified as an expression of that one faculty.