How is it that we experience the world? How is it possible that the environment we live in, the objects we use and see, touch and taste, hear and smell, are both patently out there and simultaneously, it seems, in our heads? After four long conversations, considering the positions of philosophers and neuroscientists, those who assume that experience is an amalgam of neuron-generated representations in the brain and those who have looked for it in our interaction with the environment, Riccardo Manzotti and I are no nearer to establishing what consciousness is or where it resides. Today, then, we have set ourselves a simple task: to review all the ways philosophers have supposed a subject might relate to and become conscious of an object, setting aside once and for all those hypotheses that have clearly failed and asking, is there one approach which has not yet been given due attention? Riccardo believes there is.
Tim Parks: Riccardo, to talk us through this I know you want to propose something you call “the metaphysical switchboard.” Can you explain?
Riccardo Manzotti: Well, at the beginning of any discussion of consciousness there are some fundamental premises to be established that will constrain everything that follows. The metaphysical switchboard will help us get a grasp of those premises and the various directions they lead in.
Parks: I’m all ears.
Manzotti: So, imagine an old-fashioned switchboard with just two toggle switches. Each time you flick one of those switches you open a path that sends the debate in a different direction. Let’s say the first switch determines whether or not subject and object are to be considered separate, the second whether or not the subject is to be supposed physical.
Parks: This should be fairly straightforward: two toggle switches means just four available pathways. Let’s start by turning our first switch in favor of a separation of subject and object, since I’m sure most of us think of our minds as separate from the objects they perceive.
Manzotti: Fine. With the first switch on separate, we now have to set the second. If we set it for a subject that is non-physical then we get Descartes’s immaterial, or spiritual subject. That is, in the Cartesian model, we have immaterial souls, or just selves if you like, separate from the physical objects we experience and even, ultimately, from our bodies. It’s a solution that has occupied a huge space in modern history and that many religions endorse, but scientifically it’s a non-starter, since it’s based on the notion that the subject cannot be an object of scientific enquiry. So we can be forgiven, I think, for paying it no further attention.
Parks: No souls flying up to heaven, freed from their material prison.
Manzotti: Alas no. All the same, assuming we now flick that second switch to physical, things hardly get much easier. This is the territory, I should say, of modern science from Galileo right up to today’s neuroscientists. They left the first switch set to keep subject and object separate, but placed the subject in a predetermined place in the physical world, namely the brain, and hence made consciousness a neural process that is inside the head and separate from the physical world it perceives. Unfortunately, since all available empirical findings have shown that the properties of neurons are nothing like the properties of our minds or our experience, this shows every sign of being another dead end.
Parks: We discussed the brain-based solution in our first dialogues. But did setting our second switch to physical mean we had to place the subject in the brain? Couldn’t it have been the whole body?
Manzotti: Some philosophers and scientists—Francisco Varela, Maurice Merleau-Ponty, and Rodney Brooks, for example—take the whole body and what the body does to be the basis for the mind, but, at least as far as regards consciousness, they’ve had no more success than those focusing on the brain. You can look at muscles, blood cells, and nerve endings for as long as you like without finding anything that remotely resembles consciousness.
Parks: Time to go back to the first switch then and set it for a subject and object that are not separate. Is this, perhaps, what the enactivists we discussed in our last conversation are doing? Is this what they mean when they suggest that consciousness is not contained inside the head but constituted by our interaction with the world?
Manzotti: The enactivists toy with the first switch, without actually turning it all the way to not separate. They see that consciousness can’t be reduced to a property of the goings-on in the brain, so they start to look outside. But instead of considering the external object as such, they look at our dealings with the object, our handling the object, our manipulating the object, believing that consciousness is a product of the actions we perform. At the end of the day, though, the object remains doggedly separate from the subject who experiences it. And unfortunately, as we said last time, actions, whether they be eye movements, or touch, or chewing, are no better than neural firings when it comes to accounting for experience. How can my actions explain why the sky is blue or sugar sweet?
Parks: Okay, let’s stop playing with that switch and set it determinedly on subject and object not separate. As for the second switch, let’s again start with a subject that is not physical, since I suspect you are going to give that position short shrift.
Manzotti: Yes. This is the territory of Bishop Berkeley and Leibniz in the late seventeenth and early eighteenth centuries. Crudely speaking, they proposed that subject and object become identical, the same thing, but both in a completely non-physical world.
Parks: What exactly do we mean by identical? How can different things be the same thing?
Manzotti: Well, identical the same way that Bruce Wayne and Batman are identical. Bruce Wayne is Batman. For a true idealist—that’s what this approach is called—the object of perception is nothing but a modification of a part of the subject who experiences mental representations or ideas, which are not physical. The world is all idea. Actually, you could say that this position has recently been revived by techno-enthusiasts like Elon Musk who wonder whether we live in a giant computer simulation concocting the illusory objects we erroneously imagine reality is made of. These are intriguing ideas, but again they are scientific non-starters since they depend on a non-substance which no one can track down or verify. You can’t even begin to prove them wrong.
Parks: In our last conversation you reminded us of Sherlock telling Watson, “when you have eliminated the impossible, whatever remains, however improbable, must be the truth.” And I guess we’ve reached that point: three of our four pathways have been dismissed, so let’s turn to the last: first switch on not separate, second on physical; that is, subject and object are identical—the same thing—and physical. Improbable indeed! Crazy, most people would say. The only philosopher I can think of who has given a nod in this direction is Aristotle, when he says that the mind “is in a way all existing things.” But I suspect most of our readers will take that to be esoteric rambling from thousands of years ago.
Manzotti: Let’s forget the voices from the past, wipe the slate clean, and take a really ordinary situation: a person looking at some everyday object, let’s say, an apple. That’s the example I always use. So, we have a body—including a brain of course!—and an apple. Nothing esoteric or improbable there. The body, let’s say your body, on the left, the apple on the right, thin air in the middle. What could be simpler? But there’s still one piece of the jigsaw we haven’t placed yet—your experience, or simply the experience of the apple. Where is that? And what is that? We can’t account for it. So let’s consider the chief suspects, one by one. Is it the activity of your neurons?
Parks: We’ve already decided against that. There is nothing applish in the gooey brain, and anyway, we don’t experience neurons, we experience the apple.
Manzotti: So is your experience some movement you’re making in relation to the apple? Some action? Is it your movements that conjure a sort of applishness?
Parks: Again, we’ve already dismissed this, haven’t we? Movements, actions, don’t seem to have anything in themselves that we can identify with the apple we see. I can’t imagine a robot repeating exactly my movements would have the same experiences I have. I think we can let this go.
Manzotti: Okay, so could our experience of the apple be an amalgam of everything going on between subject and object? Neural processes, retina, optic nerve, molecules of apple, atoms in the molecules, electrons in the atoms, everything?
Parks: You’re trying to treat me like a performing dog, Riccardo. You want me to say no, obviously. Instead I’m tempted to say yes. Why can’t consciousness be the whole process?
Manzotti: Because just as we don’t experience neurons, so we don’t experience retinas or photons either. Obviously they’re necessary to the experience of seeing an apple, all the elements of the process are necessary, but they’re not it, are they?
Parks. Not convinced. Just because we don’t experience the constituent parts of a system, it doesn’t mean that they aren’t together what we are experiencing.
Manzotti: The constituent parts are causally necessary the way a pot is necessary to boil pasta, but the pot is not the cooked spaghetti. Nor is the heat source, nor is the water. In the case of the apple, if you list the properties of the process as a whole, they just don’t match the properties of the experience. Photons are not applish. The rhodopsin your retina secretes is not applish. And so on.
Parks: I need to think more about this. All I’m going to concede for the moment is that when I experience the apple, I’m not aware of experiencing the other various elements of the process.
Manzotti: Okay. By all means think it over. But meantime what if someone said that the experience was the apple itself? After all, the apple is definitely the most applish thing around. And the only thing that has the properties of an experience of an apple. It’s round, it’s red, it’s shiny. So why can’t the subject, consciousness (but not the body, notice), be identical with the apple, out there where the apple is? Consciousness is not about the apple, consciousness is the apple.
Parks: Of course, I’ve heard you come up with this argument before, Riccardo. So I’m not going to pretend to be amazed. But it’s still extremely difficult for me, and for most of our readers it will seem quite mad. Essentially, you’re proposing that my experience of the apple, or any “external object” is outside my body—out there where the object is.
Manzotti: Exactly. But did you ever really imagine the apple was in your brain? That it somehow got smuggled in among your neurons? Of course you didn’t. You always thought the apple was out there. And so it is. And with it your experience.
Parks: Again—because I still find this a huge conceptual struggle—you’re saying that my experience is literally the object. So my consciousness, the me, the subject, or at least the part of me that is the experience of the apple, is identical with it.
Manzotti: Right. Experience is physical—what else could it be?—only it is not the physical object that it is usually assumed to be, our neurons, but another physical object, the apple.
Parks: But in that case, what would be the relation between my body, my brain, and this apple experience that is halfway across the room? And what is the apple when it’s not identical with my experience? Does it disappear with Bishop Berkeley’s trees in the woods when no one’s looking at them?
Manzotti: One objection at a time! But first, please note that there is nothing here that contradicts the findings of neuroscience or, indeed, physics. All that we know about what goes on in the brain, all the correlations between neural activity and specific kinds of perception, all the physics of photons and sound waves, all the chemistry of retina and taste buds, all the mechanics of the ear and the nose, remain absolutely in place. Everything is physical, verifiable. We just have this one, admittedly enormous, conceptual shift: instead of supposing that the senses receive “input” and somehow create a second, inner mental world reflecting the outer world, we say that your experience is in the outer world: it is not separate from the physical object you perceive, it is the object.
Parks: I can see it all seems extremely simple to you, and that you’ve somehow convinced yourself it’s true. But I assure you that for most people this idea will seem bizarre and almost mystical. Please answer my previous question, what is the relation between my body and the distant object, which is also, you say, my experience?
Manzotti: Francis Bacon remarked that “Opportunity makes a thief.” Likewise, we could say that your body offers the opportunity or physical conditions—eyes, optic nerve, neurons and so on—that allow the world to take place as the object we experience.
Parks: Opportunity makes the object.
Manzotti: If you like. Of course, the apple conjured up by this opportunity that is your body, the apple you perceive—is not an absolute apple, it’s not the apple that Galileo supposed was altogether measurable and fixed, nor Kant’s noumenon, the apple in itself that can never be known; it’s not an apple in an X-ray machine, nor a slice of apple under an atomic microscope. The apple that you experience is simply a selection, or subset, of the many other things going on out there in the world; it is the selection that your body—your brain plus your sense organs—allow for.
Park: A relative apple.
Mazotti: Right. It’s relative to your body, though of course, since most humans have similar perceptive equipment we will tend to agree on shape and color, up to a point, depending on our eyesight, our position, and so on. Other animals or other devices will allow for other selections and hence other object experiences, which are equally relative and equally real. Your apple is not a snail’s apple. Or a bat’s. Your apple is made of those and only those physical features that cause effects thanks to your sensory organs, your particular body. Which is not to say that other properties do not exist. They do. It’s just they’re not part of the object that you experience; to wit, one side of a shiny red round apple.
Parks: So I am the apple.
Manzotti: Of course that sounds absurd, because you identify your conscious self, the subject, the I, with your body, and your body is clearly not the apple. But what if I were to say that the very idea of consciousness was invented to explain how you could experience an apple when there is no apple in your head. So we have to have this consciousness apple. However, if experience and apple are one and the same, there is no longer any need to talk of a consciousness separate from it. The apple is more than enough.
Parks: You’re really going to say I am the apple….
Manzotti: You are a whole range of experiences, hundreds and hundreds of things going on simultaneously, of which the apple is one. That’s why when you close your eyes, the apple disappears. Eyes closed, your body no longer offers the conditions for the apple to have certain effects. Consequently the apple with its shape and colors is no longer part of your experience.
Parks: But I know it’s still there! I could reach out and touch the apple, eyes closed.
Manzotti: You could indeed! But it will not be the same apple as your visual apple. It will be a smooth solid rotundity. A blind man’s apple. And that apple too will be in the external world and not inside your hand. This ‘touch apple,’ if I can call it that, originates in the same external conditions, but a different set of physical features is now selected. Again the object is relative to the body, or the parts of the body, involved in the experience. It’s like the difference between feeling for something inside a drawer as compared to looking inside a drawer. Different experiences, different objects. None of them in your head, but out there, where you experience them.
Parks: So, what you’re claiming if I’m not mistaken is that for every experience there must be an external object which is identical with it. And frankly that is not going to be an easy sell. People will laugh you out of town. What about memories, they will say? My memory of the apple. What about dreams? What about hallucinations? And thoughts, words, cogitation, pain, heat, and cold. Where is the external object that corresponds to these aspects of experience? Your idea is dead in the water.
Manzotti: By all means, bring the objections on. I’m ready for them. All I ask is a little time and space. You can’t turn round an oil tanker on a dime. We’ll tackle these challenges, which are substantial and serious, in our next talk. But let me just say in closing that this is not simply philosophical speculation, but a concrete empirical hypothesis. It’s a risky hypothesis, I know, but didn’t Karl Popper define scientific hypotheses as inevitably risky, daring proposals open to being proved or disproved?
Parks: Which you believe this is?
Parks: Ok. Next time, we’ll give you space to say your dime’s worth, but let me warn you that I’ll be wanting to know where exactly is the external object that corresponds to each of my experiences.
Tim Parks is Associate Professor of Literature and Translation at IULM University in Milan. He is the author of many novels, translations, and works of nonfiction. A version of his essay in this issue will appear in Drawn from Life: Selected Essays of Michel de Montaigne, which will be published by Notting Hill Editions in November. (November 2016). Riccardo Manzotti has a PhD in Robotics and degrees in The Philosophy of Mind and Computer Science. He teaches Psychology of Perception at IULM University, Milan (Italy), and has been a Fulbright Visiting Scholar at MIT. He has specialized in AI, artificial vision, perception and, most of all, the issue of consciousness. After working in the field of artificial vision, he focused his research on the nature of phenomenal experience, how it emerges from physical processes and how it is related to objected perceived.