The Nature of Consciousness

Philosophical Reflections XXXVII

At the dawn of Philosophical Reflections I identified the two absolutes for each of us, that exist beyond the possibility of question: our own existence as a conscious entity, and some kind of external reality outside our own consciousness. Each of us knows we exist because we are conscious of ourselves and things outside ourselves; each of us knows something else exists outside our consciousness, precisely because we are conscious of things: we most definitely do not bring them into being by our own conscious will. I can make my arm move by willing it, and can imagine something by thinking about it: but the contents of a new book I am reading or the next words of the person I am talking to are things independent of my conscious control, that present themselves to me according to their own natures, not my decisions or will. Boo! See what I mean?

As for what external reality is, fundamentally that is something every child learns, and it generally takes a cleverly corrupt education to unlearn it. The external world is an objective one where things are what they are, a world of trees and rocks, air and sunlight. What it is in detail is the subject of science, whose existence and efficacy is dependent on and proof of that objective reality.

But what is consciousness? Philosophical Reflections has spent a lot of time on various aspects of reality, and on the relation between reality and consciousness (which is the core of the nature of objectivity), but little on consciousness as such. As some writers have claimed that recent scientific investigations show consciousness is an “illusion”, now is a good time to revisit the question of what consciousness is.

Science and Consciousness

The scientific study of consciousness is difficult but over the past few years has been generating more interest, or at least more press. Some investigators have explained this as science formerly “shunning” the topic, with comments like this from David Chalmers:

Consciousness remained off-limits, fit only for late-night discussion over drinks. Over the past several years, however, an increasing number of neuroscientists, psychologists and philosophers have been rejecting the idea that consciousness cannot be studied and are attempting to delve into its secrets. (Scientific American, Dec 1995)

However, while this charge might apply to the more materialistic behaviourists who pretend they have no minds, there is a simpler and obvious reason why consciousness has been little studied: it is too hard. Until recently, there was very little one could do to study consciousness with any precision, though tellingly, what could be done (e.g. the effects of drugs or damage) was done. Chalmers himself admits that in the same article:

The overall assessment one must make of consciousness is quite simple in concept: it is a function of the brain. But therein lies the difficulty. Brains are staggeringly complex, especially human brains – which are the only ones we know of that are sophisticated enough to ponder these questions. Other animals are certainly conscious, but only we possess a rational consciousness. It is only recently that tools that can probe brain function at moderate resolution (such as positron emission tomography and magnetic resonance imaging) or that can probe the individual and collective firing of individual nerves have become available – and even they are woefully inadequate, covering too much or too little brain tissue for anything approaching complete data.

Not that there is much to be surprised by in that. As noted in early Philosophical Reflections, it is quite clear that consciousness is a function of the brain, from such readily observable phenomena as the effects of chemicals or illness on the mind, to less common but still common enough phenomena like the effects of local or general brain injury. The staggering complexity of the brain and, concomitantly, the inadequacy of our current instruments for any kind of thorough investigation of its functions, is likewise plain to see.

So should we then just give up for now, and go back to the now perhaps more understandable “reluctance” of scientists to study consciousness? That would be to commit the fallacy of “if we can’t know everything we know nothing.” There is much we can learn about consciousness with present tools, whose increasing precision has given us new windows into what goes on inside our brains. But before we look more into that, it is worth identifying what questions we might want to answer.

Easy or Hard?

Chalmers divides the “problem” of consciousness into two basic questions, “easy” and “hard.” The easy question is identifying where and how abilities such as identification, discrimination, recollection and attention arise. These are (relatively) easy because they just involve identification of the neural mechanisms that enable them, a simple enough thing in principle whatever the complexities in practice. The “hard” problem is explaining how and why we have qualitative, subjective conscious experience. The difference may be illustrated by what happens when we see a blue butterfly. How we discriminate between blue and other colours and how we identify the butterfly as a discrete moving object are not essentially problematic: and by scientific investigation of these questions, we know that different types of retinal cells respond differently to different wavelengths of light, and we know a lot about how our brains process movement, edges etc. to extract percepts from our sensations. But how that ends up as the subjective experience of “blueness�, let alone what emotions we might experience as we watch the butterfly dance among flowers on a summer’s day, are not so obviously amenable to analysis. There are also related questions to ponder: is my experience of “blue” the same as yours?

As Chalmers encapsulated it:

It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does. (Journal of Consciousness Studies 2:200-219 (1995))

Of course without the “hard problem” there would be no problems at all. If we were not conscious of things in that manner, then we would not be asking the easy question either. We would not be asking any questions at all, as there would be nothing to do the wondering – there would be “nobody at home”.

Illusions of Self

The hard problem is hard, if only in the sense that we have no tools yet capable of investigating consciousness at that level. Thus doubts as to the actual reality of consciousness stem from studies into the easy problem.

Such doubts are, of course, nonsensical. That we exist as conscious beings is an absolute: you cannot even think about the question without both experiencing and proving the fact that you are conscious.

It is certain that consciousness is not the primary driver that a naive view might imagine. First, consciousness is not continuous: there are gaps, lapses, missing bits filled in later by guesswork and patchwork. Second, consciousness is a consequence not the driver of attention. For example, you might feel that you noticed a branch move then focused on it to see why: but in fact, the neural activity to bring your attention to the movement happens before you are consciously aware of that movement. Whereas the first is hardly news, as a moment of reflection on what happens on long car trips should suggest, the latter is perhaps more surprising, as the subjective experience is “I became aware then did something about it”, not “my brain started doing something about it then I became aware.” Similar delays have been demonstrated between the decision to move and awareness of that decision.

However, if one looks more deeply, there is nothing surprising about it. It would only be surprising if one held a mystical view that consciousness is some kind of ineffable soul inhabiting your body and driving it as first cause. But as soon as you realise that consciousness is a physicalphenomenon caused by neural activity: then of course there must be neural activity preceding consciousness. Causes always precede effects. Nor is it surprising that the cause precedes the effect by a measurable interval. It is plain by examining our brains and those of animals that show more or less outward signs of consciousness, that consciousness requires very complex and heavy neural processing and consequently is relatively slow. For example, if you are walking along a trail and see a snakelike shape, you will already have jumped before your consciousness “catches up” enough to actually identify whether it is really a snake, whether it might be dangerous, and if it is alive.

Thus, there is nothing in science which would indicate that consciousness is an “illusion.” Certain impressions one might get about consciousness, such as continuity and priority, might be illusions: but not consciousness itself.

Yesterday, Today & Tomorrow

As noted, consciousness is not continuous. In what sense, then, do we possess continuity as a person?

Clearly, we are not the same person as yesterday or last year in any exact sense. I am not speaking of the molecular level here. Yes, the atoms in our body are continually turning over, but it is the structures of our body that underlie what we are, not the interchangeable atoms that make them up. Just as our bones continue to support us while their structural integrity lasts, despite continual molecular turnover, so all our other functions continue while the structures performing them remain intact.

What is more significant is that the content of our mind changes: we learn new things, forget old things, change opinions, change friends, even change major beliefs. Yet we feel that despite all that, we are in some way “the same person” as that little boy or girl playing in a field years or decades ago. Similarly, our consciousness might cease every night, but this does not worry us. Rather, we spend effort and expense on comfortable beds. We are not so sanguine about someone murdering us in that bed as we sleep. Why? Because we want to wake up tomorrow, we expect to wake up tomorrow – and it is we who we think will be waking up.

Is that all just an illusion?

To see why it is not, it helps to broaden our perspective a little. We are not a mere consciousness floating around somewhere. Like everything else, each of us is a distinct entity existing among but separate from all other entities. So what gives continuity to any entity? Plainly, it is the same as with our bones: the continuance through time of the bound structures defining the entity. This might be more obvious with a table or a rock, which are fairly stable even at the molecular level (though of course, still not absolutely). But the same is true of living entities, whether the tree in your backyard, your pet dog or yourself. The structure of your body changes over time, but itchanges, with the emphasis on both those words. The whole concept and meaning of “change” is dependent on the concept and existence of entities that change. You as an entity, albeit an evolving one, can be traced back in time through your continuous existence, back to before the day you were born.

Having established that, the rest follows. As a living being, your existence continues as long as the structures that support your life continue, and again, your existence as a living thing can be traced back and forward through time. And your continuity as a personality, as the conscious being with mind and thoughts and ideals that is you in the mental sense, is based on sufficient continuity of the physical structure of your brain that you actually know that the entity and life you are was around yesterday, last year and last decade.

If we had no memories, we would be a new person every day, if not every second. Memories are a function of the structures in the brain, and a consequence of your continuance as an entity through time: you could have no memories without that continuity to hold them. Your memories are the consequence, requirement and proof of your continuity as a person.

Philosophy & Consciousness

We also need to distinguish between different meanings or levels of consciousness. The aspect of consciousness studied in the above experiments is the level we share with other mammals – immediate, reactive, moment to moment awareness, interpretation and decision. We can call this “attention, identification and response.” It is largely reactive: it identifies what is in the environment and decides what to do about it. I shall call it tactical consciousness because its purpose is to make decisions in a short time frame according to short-range conditions.

What philosophy is mainly concerned with, in contrast, is what I will call strategic consciousness. This is the consciousness that does not react to movement or other immediate circumstances, but which thinks, reflects and plans. For obvious reasons – philosophy arising from and being about thinking not reflexes – this is the aspect of consciousness most relevant to philosophy. While partly reactive, its peculiar feature is being proactive, the long term driver of what we do, not the short term handler of immediate events. Your short term consciousness might move like a puppet in reaction to neural firings prompted by a windblown branch: but your strategic consciousness sets the course of your life decades hence – including whether there is a tree with a branch outside your window to wave and catch your future attention.

As I noted before, our existence as conscious beings is an absolute, beyond even the possibility of meaningful doubt. Does this refer to its tactical or its strategic aspect? Clearly both, as we have only the one consciousness: it simply possesses both tactical and strategic aspects. Our tactical consciousness – our awareness – is clearly an absolute, proven by awareness itself. But so is our strategic consciousness – our thinking – proven by thinking itself. Indeed, without it, we could not even identify our tactical consciousness as absolute, as we would neither know there was an issue nor be able to think about it and identify it.

Why Be Conscious?

Before we look into how we can have a subjective conscious experience (the “hard” question), it is worth looking at why animals are conscious at all.

If we look at it in reverse, it is clear that consciousness serves a very important purpose. As I have noted, consciousness is a much slower process than more basic neural activity and reflexes. This is because it takes a lot of complex neural activity to achieve. Consequently, it is also an expensive asset in terms of the resources needed to grow and maintain the tissue required: the human brain, for example, while comprising only 2% of body weight consumes 20% of the body’s energy. In the struggle for survival, pointless extravagance is the first thing to go: hence the universal loss of eyes in species that have been restricted to lightless caves for relatively few generations. This gives us a simple equation. Whatever consciousness costs, and it costs quite a lot, is worth it.

The value of a rational consciousness is quite clear. It is what has brought us from obscure tropical ape to the species that dominates the planet from pole to pole and has sent machines to other planets and beyond the solar system. But this is a much later development, dependent on the earlier evolution of tactical consciousness.

The value of tactical consciousness is suggested by the name itself. It allows tactical response. Without it, an organism is restricted to relatively simple and inflexible responses, based on immediate reflexes coupled with, at best, a degree of longer-term enhancement or reduction of those responses according to more chronic environmental conditions. Consciousness provides a far more sophisticated decision-making process, based not only on immediate circumstances but also on a host of other factors both sensory and remembered. The more sophisticated the consciousness, the more broad and flexible its decision-making capacity. How much advantage this gives and whether it is worth its cost depends on an organism’s particular lifestyle. Thus, most animals do not have as sophisticated a consciousness as mammals (indeed, most are not conscious at all); carnivores who have to outwit their prey are generally larger brained than herbivores who just have to sneak up on a leaf and run away from danger; and only we have a thinking consciousness.

To illustrate this, consider a cat dozing on a window sill. The occasional touch to its tail will cause the tail to twitch, apparently without the conscious awareness of the cat. But do it too much and something may be wrong, so the cat is made aware of the annoyance, in order to initiate a more sophisticated identification of the cause and the appropriate response. Or consider the autonomic actions of your own body, mostly unconscious unless something starts going wrong such as getting hungry or out of breath.

Private Eyes

An intriguing speculation related to the question of how we can have subjective experiences is whether our subjective experiences are the same. Does blue look the same to you as it does to me? Does pain feel the same? Heat? Or does blue in your mind look like red in mine, and pain feel like pleasure? Or more confusing, does red look like middle C, in some kind of cross-person synaesthesia?

We do know that not everyone experiences things the same. For example, there is a lot of genetic variability in our sense of smell – so our subjective experience of food flavours must vary. As a starker example, partly or fully colour blind people do not see colours the same as people with normal vision. Indeed, a colour blind person cannot really conceive of how the world looks with normal vision – and while the use of filters can simulate colour blindness, the reverse is also true at least for two-colour vision (what do red and green look like to a red-green colour blind person?). And what subjective sights do birds see, with four colour receptors to our three?

There is no way to know.

And that is the basic answer. There is no way to know. There is no way to get into another person’s head and experience what they experience: it is completely private.

So in a real sense, the question is unanswerable and may well not be answerable in principle. But we can make a reasonable guess. We do know that consciousness, in all its aspects, derives from neural functioning. And we know that we are all the same kind of thing: while we have no window into each other’s subjective experience, we can readily agree on our objective experience. So we can expect that to the degree that our objective equipment is the same (e.g., excluding differences in colour perception), our subjective experiences are also the same, as identical causes produce identical effects.

Magical Mystical Tours

Of course some would dispute claims like Chalmers’ that experience and mind arise from a physical basis, or if there is a physical basis that it can be the “mere” mechanistic operation of neural networks.

The personal experience of consciousness historically has led to concepts such as the soul or spirit, which in philosophy have spawned ideas like the Platonic and Kantian separations of mind from reality. There is truth in the identification of “soul” or “spirit”, but that truth is no more than the recognition that we do in fact have conscious minds – itself one of the absolute pillars that support an objective philosophy.

I will not discuss mystical notions of the soul – that the mind is something more or other than a function of our physical brains – beyond pointing out that there is nothing in our objective orsubjective experience that upon analysis supports such theories. The intimate link between our brains and our minds; the total dependence of the function and integrity of our minds on the function and integrity of our brains; the total inability of the mind to escape the constraints of the brain; and the identification of physical, brain-based mechanisms behind compelling soul-mystical experiences from peyote to near-death: are sufficient to demonstrate that the mind has its physical basis in the brain. Beliefs to the contrary are the product of faith in ancient religious beliefs or taking subjective experience at face value, not reason applied to reality.

Of course to the extent that consciousness is mysterious it could not escape being linked to everyone’s science mystery favourite, quantum mechanics. Especially when the “Copenhagen Interpretation” explicitly does the linking by alleging that conscious observers determine the outcome of quantum events. Physicist Roger Penrose, for one, has made much noise about quantum mechanics as the basis of consciousness.

I have dealt with the sordid love affair between mystics and quantum mechanics at length before, so will restrict my answer to two observations. First, even if it is true that quantum states are indeterminate until they are “observed”, it is not the observer causing it but the quantum-level events they use to do their observing – events that would happen equally in their absence (e.g., the absorption of a photon’s-worth of energy by an atom). Second, the mystery of quantum mechanics is self inflicted, stemming from nothing more than an insistence on labeling quantum entities as particles then expressing mystified amazement when they behave as waves. If one recognises that entities such as light and electrons are in fact waves whose particle-like behaviour is due to how their energy is absorbed (e.g. the wave’s energy must be absorbed one photon’s-worth at a time at discrete atoms, because light of a given frequency can only be absorbed by raising the energy level of an electron in proportion to that frequency) and how they interact as bound entities (e.g. atoms bounce off each other because their bound shells of electron waves cannot interpenetrate), then the mystery vanishes. We may be left with some hard problems to solve (e.g. why is light absorbed this way?) but no self-contradictory imponderables.

We have, therefore, no reason to doubt that our consciousness, our mind, does indeed derive from the purely mechanistic operation of the neural networks of our brain. Purely mechanistic, but by no means simple. The average human brain contains 100 billion nerve cells, each of which can make contact with thousands or tens of thousands of their fellows, each connection varying in strength, type and direction, subject to change, and each nerve’s response depending on all the inputs it receives. There is wonder enough there without invoking the mystical.

It is important to remember that this is not materialism in the sense it is often used. That would be another fallacy we have encountered before: that an explanation denies the existence of what it explains. It is undeniable that we are conscious and have a mind, and more, that our mind determines the course of our life. It is merely a question of where that mind comes from. That it comes from the physical operation of our brain in no way diminishes its wonder or its power.

The Gordian Knot

Previously I quoted Chalmers’ “hard question”: “Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does.”

If we take Chalmers at his word, there is a simple answer, though not necessarily a satisfying one. We have already seen why tactical consciousness arose: it confers a survival advantage on the animals that possess it. Perhaps subjective consciousness is an accidental but automatic consequence of tactical decision-making systems built from the type of nervous systems that evolved on Earth (perhaps even just in vertebrate brains). That is, we can invoke the “Anthropic Principle”: it didn’t have to be that way, but if it wasn’t, we wouldn’t be asking the question. In other words, if there is no particular reason why all that physical processing should give rise to subjective experience, still that’s how it happened here on Earth, and it had to happen that way for us to be talking about it.

However, I think there is a better answer, and that is not to accept the question on its own terms. It has smuggled in an assertion that there is a mystery, that it is “objectively unreasonable.” What if we question that assumption?

First, let us look at what goes on inside our heads. Consider colour vision. What does it mean to have colour vision? It means that the nerves activated in our brains differ for different wavelengths of light striking our eyes. It means the response of our brain is altered according to colour. And it means our tactical systems are hooked into those differences. Is it even meaningful to propose that that can happen without “awareness” of those differences? What is being hooked into those things, if it is not awareness?

Go one further. A far more important function than identifying colour is identifying objects. Our visual system does a lot of preconscious processing so that what we see are percepts, objects we perceive as discrete things separate from others, moving or stationary. How could one ever perceive an object at that level of identification, in the absence of awareness?

Then consider what it might mean to have such a tactical system without conscious awareness. Pain is a response to injury, and fear is a response to danger. We can envisage skipping all the unpleasantness and having aversion and escape without them. But that is what a jellyfish has. It seems clear that the experience of pain and fear, of hunger and desire, add a distinct piquancy to things, a most definite motivator of any tactical system. Again, does it make any sense to consider a flexible, tactical neural system, evolved to survive in a dangerous world, where injury and danger are not “unpleasant”? And does that not imply awareness?

Perhaps this overstates the case. Consider the ant, to take Solomon’s advice. Insects see colour and movement and respond to injury and danger, but are they conscious? To me, insects do appear to lie on the other side of the divide. Their behaviours are too rigid, too fixed, to be compatible with conscious awareness. To adapt the argument, what would it mean, to be aware but have no control over one’s responses, as they are hardwired by one’s genetics with maybe a bit of automatic neural adjustment?

So my conclusion is this. Things can survive and prosper, at a certain level, completely unconsciously. This is cheap, but limited, and is the lot of most life on earth. Sense organs processed by a central nervous system allow a much richer interpretation of the environment, and can be coupled with instinctive behaviours (more or less hardwired) to give a broad range of effective behaviours without conscious awareness. While still relatively cheap (consider the size of an ant’s brain), this is more expensive but can achieve far more sophistication. I propose this is the lot of insects and the like. But beyond that is a level of mental sophistication where behaviours are less hardwired and more under the control of central nervous system decisions. And to do that, requires a tactical decision making system fed by all the richness of sensory input at its disposal and motivated by what we feel as pleasure, desire and pain. This is the level achieved by mammals, birds and perhaps lower vertebrates and other relatively sophisticated creatures such as squid. At an even higher level is a rational consciousness which can also think about itself and about the meaning of the world around it, the level our species alone has reached on this planet, though perhaps not alone in the universe.

So I would turn Chalmers” question on its head. It is not that it is objectively unreasonable that we should have subjective awareness. It is objectively unreasonable that any level of mental ability beyond that of an insect would not automatically involve and require subjective awareness of what it perceives – and not only perceives, but must perceive to fulfil its function. And that is certainly true of us, of a rational not merely perceptual consciousness. For how could one think – yet be unaware of thinking?

© 2009 Robin Craig: first published in TableAus.