10 Mysteries of Consciousness

Consciousness abounds with unusually deep mysteries. I think most people realise there's something inexplicable about the mind, but not many know how utterly strange it all is. The mysteries put together leave gaping holes in our understanding of reality. That might sound like trouble to physicists but physicists have by and large not paid much attention to it, and at least tacitly assume that consciousness doesn't fall under their purview; they believe it is a matter to be dealt with by the brain sciences. 

I would say that insofar as physicists are attempting to explain reality at its most fundamental level, they cannot finish their job without a theory of consciousness. This is because, as I hope to show, consciousness does not reduce to mere brain processes. Instead it appears to be an entity of its own special kind that may or may not have causal effects on the physical world. 

I understand that this is an outlandish claim (though not an uncommon one) and that I have all the work ahead of me to argue for this case. 

But before we start, we should define what consciousness is. We're accustomed to thinking of the world in a particular way: most of us believe that everything in the universe is built up of atoms and other sub-atomic particles. All higher level structures in the universe, like stars and human beings, are composed of the activities of these tiny particles being pushed and pulled by the laws of physics. 

Then we see matter organised in special ways so that the whole has properties that its parts don't have. We call these emergent phenomenon. Life itself is one such case. All living creatures are composed of simple molecules like proteins, lipids, and nucleic acids that are not themselves alive, but are organised in such a way that they can metabolise, reproduce, and adapt, or in other words, come alive. Life emerges from the underlying complexity of dead matter.

Or consider water: an individual water molecule is not a fluid but a collection of water molecules sitting at room temperature is one. Though it's hopeless to predict where any molecule in a stream of water might end up, its higher-level dynamics can be described very accurately using the Navier Stokes equation. That it can be described this way is an emergent property of water molecules. Simple fluid dynamics emerges from the chaos of a large stream of water molecules.  

Or now consider a termite colony: you must have seen the tall termite mounds that look eerily like Gaudi's architectural genius, the Sagrada Família. Though in that case it's a top-down wielding of intellectual power, in the case of termites, there's no central director, no grand orchestrator. The termites simply react to chemical cues, having no conception of why it's doing what it's doing. Intelligence emerges from the dumb acts of dumb creatures.  

Consciousness, in this line of stories, must also be such an emergent phenomenon of individual neurons firing in particular patterns. 

There are a few intuitions that compel us to think this: (1) consciousness is a complex phenomenon (with vision, memory, thoughts, emotions, senses, all unified into one) and (2) it is correlated with brain activity. When parts of the brain are damaged, say the visual cortex, people report loss of vision; and when the brain stops altogether, so does our consciousness (or so we imagine). 

This view, while containing some truth, is dangerously incomplete and therefore wrong. Consciousness is not complex, only its contents are. And this view doesn't contend with the most puzzling features of consciousness: its irreducibility, its ineffability, and its privateness. We will get to those later. 

Now let's get precise about what consciousness really is. 

Imagine what it is like to be a bat. A bat uses ultrasonic sound waves to map out its physical space, something we featherless bipeds  know little about. Though it’s hard to imagine (impossible really) I hope you agree that there’s something it is like to be a bat – a bat, like humans, are conscious. On the other hand, there is (presumably) nothing it is like to be a rock, it has no inner movie, no felt sense of anything – a rock is unconscious. It is this what-it-is-like-ness that I’m calling consciousness. Or in other words, a system is conscious if there is something it is like to be that system. 

Observe what it is like to be you: there's a visual field of colours and shapes; there's an auditory field, a field of taste, of smell, of tactile sensation; you have internal versions of some of them, what you might call your mind's eye, internal images - try to imagine a pink cow to see what i mean here - you have emotions, a sense of self, a sense of free will, and a few more things. A snapshot of all of these together is your consciousness. It's a rich collection of mental features that make up what it is like to be you, and this complexity gives us a false sense that consciousness itself is complex, but it is not. 

Consciousness is not changed by its contents. Consciousness is the capacity to have all of the things we listed (and more). This capacity itself is not diminished or elevated by the things it carries. This means that consciousness is a discrete on-off phenomenon; unlike most other biological phenomena, it doesn't appear in degrees. Either you have it or you don't. Of course the contents of consciousness - the images, the sounds, the emotions - do come in degrees, and simpler organisms would have simpler versions of them, but do not confuse that with consciousness itself being a spectrum. 

Now that we've defined consciousness, let's go over the 10 gnarly problems that resist a full explanation. 

(1) The Hard Problem of Consciousness

We grow up learning that reality is, at bottom, just a bunch of particles following the laws of nature. All the rich complexities of the universe - the bacteria, the bats, or even Bach himself -  are all reducible to a tightly choreographed dance of tiny dots in the grand stage of the space-time continuum. There's nothing more to it; no immaterial souls, no magic, and certainly no miracles. 

There's an unmistakable trend in science of relentless conquest. Everything sacred is cut down, measured, logged, and explained. Though to their credit often what's revealed is more beautiful than what it replaced. In any case, the mysteries that eluded the brightest minds of a few centuries ago are now known to even little children. We came, not from Gods that fashioned us in his image, but through a process of evolution by natural selection over billions of years. Our position in the universe is not at its centre as the holy books described, but in the outskirts of a typical galaxy, revolving around a mid-sized star, out in a minuscule corner of an incomprehensibly vast cosmic space. 

So it is believed that consciousness, too, in due time, will fall to the power of science. Yes, it is a mystery today, but so was all of physics a few hundred years ago. For now we can just say that it's some type of emergent phenomenon. You take a brain, have it perform the right sort of computation and out will pop consciousness, emerging from the underlying complexity and character of its information processing. 

It couldn't be anything else for brains are made of atoms and we know fully well how atoms behave. We can even write the equations down on a piece of paper. It's like fluidity: individual water molecules are not fluid, just like individual neurons are not conscious. But if you gather enough water molecules together you find fluidity, and in the same way, a right network of neurons should produce consciousness. 

This is the consensus in most scientific circles. And it's a false confidence in the face of a fundamental misunderstanding of the subject matter. 

Every emergent phenomenon can be explained through a story of how its parts interact. Water molecules are loosely held using weak intermolecular forces such that they easily slide between each other. This is what appears to us as fluidity. Life itself is nothing more than an impressively designed collection of proteins and tissues that captures energy it main itself; with sufficient complexity, it becomes manifestly alive. No mystery here. 

Consciousness, on the other hand, cannot be broken down this way. The redness you see, unlike water or creatures, has the strange quality of not being composed of anything smaller. Indeed, if you try to describe it, you'll be at a loss for words. In the end all you can muster would be that it's redness itself. And those of you who'd understand it will do so only by virtue of seeing redness in your own visual field and calling it by the same name. This is quite strange; for nothing else can you say such a thing. You couldn't say this about apples, horses, or even atoms, they are all composed of simpler entities which when put together explain the whole's behaviours and character, but no such reduction is possible for redness. 

Of course a story can be told about photons reflecting off of a red apple, which hit your retina, stimulate the rod and cone cells, and send electrical signals up to your visual cortex, which then... what exactly? Which produces a redness in your consciousness? How? How does it suddenly jump from informational structures composed by wet neurons to this magical, ineffable, irreducible, appearance of redness? That is the Hard Problem of consciousness. No story, however complex you make it, about neurons doing neuron things, can ever explain why all those neuron businesses produce subjective experience. Indeed it looks like a miracle happened, for no amount of resemblance in structure between neural circuitry and experience of redness can cause there to be a real redness. 

This is the Hard Problem. The question of how brains can produce consciousness. The seemingly unbridgeable gap between matter and mind. At best you can say that so and so neural circuitry maps to such and such experiences; why it happens is a mystery. 

(2) The Qualia Mapping Problem

In your conscious experience, there are distinct individual components, the redness, the sound of birds, the taste of chocolate, and they are called qualia (singular: quale). Consciousness and qualia relate to each other a bit like how space relates to matter. Matter is contained within space; qualia is contained within consciousness. 

Whereas the Hard Problem is about why consciousness - and qualia - exists at all when brains do things, the Qualia-Mapping problem is about why particular brain states produce particular qualia. Suppose we find that a certain  pattern of neural circuitry is responsible for redness, we can ask, then, why is it that it's this pattern and not some other pattern which corresponds to redness. 

Think of an analogy; imperfect though it is, I hope it conveys the point clearly: the picture of a cat that you see on your computer screen is represented as 1s and 0s in your computer memory. A string of bits fully represents the cat's image. This is similar to how the brain circuitry encodes the image of a cat you see in your consciousness. In both cases, there's an image, and it's represented in a different form; in one case as 1s and 0s of a computer's memory, and in the other, as the excitations and communications between neurons. 

In the case of the image of a cat on the screen, however, it is no mystery why the bit stream gets represented as the cat, for we understand fully well how it is that the 1s and 0s get transformed through different layers of the software stack, and then gets converted to electrical signals which get transmitted through the wires which connect to the monitor, where the electronics board of the monitor interprets it and determines how to colour each pixel, so that what we see is a cat. The whole process is visible, inspectable, and comprehensible. 

What analogous process exists for the relationship between brain states and qualia? It seems there's nothing there; there is some representation of a cat in your brain, and then through a magical process that we cannot see or detect, a process interprets it as a cat's image in consciousness. But what is this process? What is it that tells the universe that a certain brain state must map to certain other qualia state? 

Information is subject; observer-dependent. A minor change in the code, nothing to do with how the cat's image's bitstream is represented, can be flipped to invert the colours of the cat on the screen, so that the reds become blue, the greens become yellow, and so on. There's no inherent meaning to any bitstream, it all depends on how you choose to interpret it. In which case, why does the brain's neural patterns get interpreted the way it does? What process does it take? Why is it invisible? and how does it tell consciousness, that this is how it is to be shown? All of that seems utterly mysterious and without an explanation; that's the Qualia-Mapping problem. 

(3) The Evolution Problem

In the physicalist conception of the universe, it is causally-closed. Consciousness, for that reason, cannot have any causal effect in it. Whatever it is that we do, how we behave, how we act, can all be explained quite satisfactorily through a third-person account of how the brain interacts with the body. No reason to invoke consciousness in any of those explanations. If so, this means consciousness is inert, it has no causal power, and it has no function. It is an ephiphenomenon. 

Which then begs the question: how did we evolve to have consciousness? How do creatures come into the world, and how can those creatures have conscious experiences? And specifically, how would it possess the complex richness that we have? 

For the case of creatures, the problem of its design was a mystery until Darwin solved it. A process of random mutation and natural selection gradually produces stunning designs in nature. But how can we explain something for consciousness?

There are two distinct sub-problems here: first, asking why creatures have consciousness at all, if it has no function; but suppose it did have it (suppose physicalism is wrong and consciousness has causal influence on the brain) you still have no explanation for how this particularly rich design was created from the primitive consciousness of simpler creatures. The genes only encode how brains evolved, not how consciousness evolved. This is intimately related to the qualia-mapping problem; if indeed it's true that the actual feeling of pain has something to do with why we flinch, then how is this feeling designed? What process designs it? Or think of something more interesting like music - no doubt it's richly designed, a song, its magical experience, the first-person view, of what it sounds like - how does that get designed? Mere brain patterns reacting to patterns vibrating air says nothing at all about its quality. 

First of all, why are these modalities the way they are: the visual field, the olfactory, the sound, the tactile sensation; they are all independent, distinct, and ineffable; they have some structural similarities, in a way, and that's why it's often possible to explain one modality in terms of another modality, in poems and prose, and have it be intelligible.  

How could complex qualia evolve? Darwinian evolution happens because the replicator (genes) code for how creatures look and function; it's the blueprint for its atomic construction. But how could any process possibly design what qualia looks like? How do you even conceivably put together atoms so that it has an intricately designed privately-only accessible dashboard of sorts.  

(4) The Self-Report Problem 

How is it possible for the brain to know that it's conscious? If the physical universe is causally-closed, then how is your mouth speaking words like "I am conscious. I see redness" - how does a physical system spontaneously start uttering these strange words, and how is it, coincidentally, exactly what's going on in its conscious experience? 

If physicalism is true, and consequently epiphenomenalism is true, then consciousness is inert and has no purpose, yet we somehow know we're conscious - how is such knowledge possible? In the picture we were forced to believe, consciousness is a separate substance, and has causal powers, but without such power, it would be impossible for the brain to know it's conscious. 

But even if you think there's some causal influence, it's still a bit mysterious how it can work, for consciousness itself has no features, no forms, no abilities at all; it is merely a screen on which things are projected, a blank canvas of sorts, but a canvas with no frames and no thickness; a featureless frame, containing only what's in it, and nothing more. What's shown in it, comes from the brain, and this includes all the desires, the intentions, the wills, the will about the will, and every other mental content. They are all but a stream.

Within this stream, there's an knowing, that the knowing is happening within an experience. We can't account for a physical mechanism by which this knowledge is possible, yet we utter things like "I see redness", and when they say it, there's really a red there, not inside your brain, where you can't see, but there's no doubt a redness. 

(6) The Location Problem

Where is consciousness? It's not in space, indeed space is only perceivable via consciousness. There's a feeling that it's somehow in your head, but if you were to remove your brain but somehow maintain its connection with the rest of the nervous system, you'd continue to feel like consciousness is in your head even as your brain is being moved out. 

The feeling of having a head is within consciousness. It's not an invisible overlay on top of the brain, undetectable by physics. There's no central point in the brain where all the information comes together, meaning, the correlates of the contents of consciousness are spread about in space, and don't collapse into a single point. 

But it feels like consciousness doesn't even have to be part of the universe. Imagine you wear a VR headset and enter an alien world in a video game. Is the headset itself part of the world? No, the headset is part of a different world, through which you can see the alien world.

(6) The Subjectless Subject Problem

Everything we experience is within consciousness, including space, time, matter, our bodies, and crucially, the self - the "I" - the feeling of being a thing at the centre of consciousness. Perhaps a witness to consciousness itself. After all, if we conceive it as something of a screen, it is intelligible to ask to whom this screen is presented, and it appears the answer is no one. There is no thing that's viewing it, there's only the  view itself. 

The feeling that there's a self, an I, that is the author of your thoughts, the recipient of conscious experience, the ephemeral, unclear, yet strong feeling, that you are in your head, is itself an illusion, and these feelings are yet more appearances in consciousness. But these feelings warp our sense of consciousness so strongly that we get confused into thinking there's a subject. 

But then, what is the alternative - how can there be only the view and no viewer?  Though perhaps, if we ask how a viewer can see the view, you have to posit, in the internal consciousness of this viewer, yet another viewing without the viewer, which causes an infinite regress. 

Having a view without a viewer and having a view with a viewer are equally nonsensical. Yet one of them has to be true, and since the latter leads to an infinite regress, we're forced to pick the former. 

(7) The Value Problem 

How is consciousness the seat of all value? I don't even understand what type of philosophical problem it is, it's somehow more baffling than all the other baffling questions. How is it that caring about anything only makes sense if it reduces to some conscious experiences somewhere? If we kick a rock, nobody cares; if they ever do, it's because there's a person (a consciousness) who prefers the rock to be not kicked. Why? How is consciousness the only reason to value things? 

(8) The Purposelessness Problem 

What is the purpose of consciousness? Naively it looks like it’s some high-level control centre, but it’s not, it’s a structureless, featureless capacity for occupying its contents; it’s analogous to space itself, and the different qualia, (colours, tastes, sensations etc.) are like matter within space. Neither is there a self (an “I”), nor is there free will (an “I” making decisions). Thoughts, intentions, decisions, they all appear in consciousness fully formed. So what’s the point of it all?

(9) The Valuable Purposelessness Paradox 

How can (8) and (7) be true together? 

(10) The Ineliminable Observer Problem 

It’s impossible to imagine a world without consciousness. Even when you try, you’re invariably imagining it through a conscious point of view. When I imagine something, say a chair that no one's looking at, in my imagination a conscious agent (imaginary me) is looking at it, and indeed, there's no way of conceiving things without an imaginary conscious point of view. Why? Why is a space that's not lit by consciousness not even conceivable?**