METAPHYSICS OF THE MATRIX

This is Chapter 1 from a book-in-progress by Peter B. Lloyd.

This book explains the technological and philosophical concepts of the film The Matrix, and the related film eXistenZ, and expands these ideas into bigger metaphysical issues. I wrote this chapter last year, after the film was released, naively thinking it would be easy to find a publisher. My intention now is to go ahead and write the book on the basis of self-publication, using Ingrams' new computerised short-run digital printing service.

Still, if you are a publisher interested in commissioning this work, do please contact me! (See also, the synopsis.htm

This work is copyright. Please do not copy it without my permission!  

CHAPTER 1: INTRODUCTION

1. Virtual reality

Some recent films have explored the same theme in a new arena: the genre of science fiction. It is illuminating to examine how these ideas hang together in this new medium, and to what extent they still relate to the religious and traditional doctrines that have been passed down over generations. There is also light to be found in their connection with modern philosophical trends, where academic philosophers are beginning to grapple with these ideas again.

The films we will focus on here are eXistenZ by David Cronenberg and The Matrix by Andy and Larry Wachowski (both released in 1999). Two other, older films that we can usefully compare are Andrei Tarkovski's STALKER and Wim Wenders' WINGS OF DESIRE, which represent two other genres of film. The latter two are concerned not with virtual reality as such, but with human contact with an underworld and an overworld, respectively.

In Cronenberg's film eXistenZ, players are plunged into a game of virtual reality that is driven by a biological computer. The players' sensory experience of the virtual reality is every bit as vivid and pressing as their experience of the mundane world - or even more so, because their sensory acuity is heightened. Nonetheless, they do know that it is only a virtual world. They are reminded of this often enough by the odd behaviour of the people they meet. The most common form of oddness is that of the other characters' habit of getting into a mental loop in which they do not know what to say or do next. They are waiting for a cue, or something to snap them out of their mental cycle. Apart from that, the virtual reality feels like mundane reality.

In the Wachowski brothers' Matrix, on the other hand, the virtual reality is global. The world as we know it has been destroyed by a nuclear catastrophe, and robots have taken over. The robots now farm human beings for energy. Humans are kept imprisoned, naked and alone, in vast arrays of vats, immersed in gelatinous fluid and plugged into some unseen computer system, the Matrix. The computer feeds electrical signals into the nervous system of each human, creating the sensory experience of a virtual reality. Unlike the players of the game eXistenZ, these people are oblivious of their true situation. They are plugged into the computer at birth and remain in it throughout their lives, and they regard the world that they see and feel to be the ultimate reality. The plot revolves around a group of individuals who somehow break out of the Matrix, and escape to the true reality outside the clutches of the Matrix.

(In what follows, I will use the word 'Matrix' for the virtual reality system of the film The Matrix, and 'matrix' for the supra-physical system that is claimed to underpin the temporal world that you and I inhabit.)

Cinematically, eXistenZ and The Matrix are very different films and will appeal to different audiences. Their thematic content, however, has many points of contact, and both serve as an entr‚e into a large and important subject. As we will see, Cronenberg has a firmer grasp of the technology of virtual reality, but the Wachowski brothers take us further into the philosophical depths. Or, in the words of Morpheus, the guru of The Matrix, they take us further down the rabbit hole. Analysing science fiction films in the light of philosophy is not the most common response that moviegoers have. Some films, though, are so heavily steeped in philosophical ideas that they beg us to consider them in this way. These two films fall into this category. There is also, in some blinkered quarters, a disinclination to take science fiction seriously at all. This, I feel, is a big mistake, and I would like to answer it by quoting J.G. Ballard's' introduction to his novel, Crash (1974):

I firmly believe that science fiction, far from being an unimportant minor offshoot, in fact represents the main literary tradition of the 20th century, and certainly its oldest - a tradition that runs in an intact line through H.G. Wells, Aldous Huxley, the writers of modern American science fiction, to such present-day innovators as William Burroughs. Information and consciousness

What separates you from the real-life matrix are your ideas. There is no distance, there is no barrier, that separates you from the matrix. You are already in it, and it already penetrates you. Nevertheless your ideas have created an apparent, subjective separation that is every bit as effective as any real, objective separation could be.

Ideas are not as malleable as they appear to be. When someone realises that they are separated from the matrix by their own ideas, then their first reaction is: well, let's change those ideas - let's re-engineer the mental software and hack into the matrix. Ideas, however, have their own mental mass, and when they are dynamic thoughts they have their own mental momentum. To change ideas by merely intending to change them is the stuff of fantasy: it is literally wishful thinking. It cannot be done. The momentum of an idea is as recalcitrant as the momentum of a solid object. To move massive objects in physical space, you need to deliver controlled power to the object you want to move. Let us follow up with this comparison to see where it takes us. For you, as a human organism, to move heavy masses, you need an engine of some sort. Engineering, as the name suggests, is the art of using engines to move stuff around. Our first engines were social: the institution of slavery enabled a few individuals to move very massive objects by whim, and they threw up such surreal shapes as Stonehenge and such profound shapes as the Pyramid of Cheops. But when the thermal power of steam was controlled in hands of a new kind of engineer, we took a long leap up in the business of moving stuff round. Enlarging that basic technique to encompass combustible fossil fuels, humankind became able to engineer craft that travelled to the Moon and to the depths of the oceans. And, as in physical space, so it is also in informatic space. To move information, to rearrange it, to build it up and break it down, you need information engines to deliver the controlled power. Babbage rightly called his contraption a calculating engine, but the insipid misnomer of 'computer' has spread like a fungus across the human comprehension of what informatic machinery is about. Computation is actually a very small part of what 'computers' do. What they are actually for is to engineer information. They are informatic engines, just as turbines are physical engines. They drive information through conduits: they pump bits of data around circuits and networks in order to do work. Now, let us return to ideas. We have seen that mankind has created physical engines to shift matter around, and informatic engines to shift data around. What do we have to shift ideas? Nothing. We are still in the cottage-industry stage of ideational technology.

Ideas are not data. Consciousness is not information. Computers have no mental life. A computer, or informatic engine as we would like to have called it, drives information through lifeless, mindless electronic machinery. A computer has no experience of colour, or sound, or smell or taste. It can never 'know' what it is like, for instance, to eat Camembert cheese, simply because the experience of smell and taste is not a knowing of data, but a having of an experience. For all their power, electronic computers can never directly serve as engines of consciousness. They are limited to the informatic domain.

Computers can indirectly affect conscious experience, of course. But so can a jet turbine. If you get on an aeroplane at Heathrow, bound for Bombay, then you will soon be immersed in a very different sea of experiences. Your eyes will blaze with colours, your nasal cavity will be awash with new aromas, and your ears will hum with sounds. So, in a crude sort of way, even physical engines can change your consciousness. Electronic machines can do it slightly less crudely. Radio and television, stereophonic hi-fi, big-screen cinemas can all rearrange your auditory and visual perception. So-called virtual reality systems nudge the technology a notch further. Miniature screens in your goggles, stereophonic sound in your headphones, a pressure-sensitive glove around your hand or even your whole body, together can create an illusion that you are immersed in another three-dimensional space. But all these informatic technologies are struggling through the bottleneck of the human sense organs. They present stimuli to the external interfaces of the human nervous system, and then they must hand over control to the body's own physiology. Virtual-reality goggles display moving imagery to the retinae at the back of the eyes, but that information must then be transported along the optic nerve into the visual cortex of the brain in precisely the normal manner as when you look at this page. Only inside the brain is that bio-information rendered into conscious experience. Virtual reality is about engineering information, not engineering consciousness itself. Its site of action is in the informatic domain: it fails to deliver controlled power to consciousness itself, it fails to drive the ideas directly.

The final frontier for informatic engineering will be the electrochemical interface of man-made machinery with the human nervous system. In Cronenberg's film eXistenZ, the computer is itself built of biological tissue - the nervous system of a mutated amphibian. In Wachowskis' film The Matrix, the network of computers is electronic. Either way, the principle is the same. The external sense organs are bypassed and information is fed into the nerve fibres. This method skips over the outer bottleneck of the normal external bodily interface, the organs of perception - eyes, ears, tongue, and so on. Nevertheless, this machinery is still only engineering information. It is applying controlled power to data, not to ideas. A machine can induce arbitrary patterns of signals in the optic nerve, to make you see anything that is seeable. Faster, smoother, more fine-grained than any virtual reality that you could ever see through goggles, neuro-stimulated vision would be the apogee of informatically engineered experiences. In principle, it could be made to be indistinguishable from so-called real life. Likewise, every other sensory faculty could be driven by electrical stimulation of nerve fibres. You could be immersed in a full-speed multi-channel synchronised simulacrum of the physical world. And you would probably never know the difference.

I said that this kind of technology is the final frontier for informatic engineering: total simulation of a physical world by neural stimulation. But we can go beyond that frontier. In all the computing machinery that has ever been or will ever be built - from Babbage's computing engine to the most advanced neuro-stimulating virtual-reality systems that the next century will bring - we remain within a single paradigm. It is the paradigm of informatic engineering. All we are doing is running a plumbing system with bits of data instead of streams of water. Beyond the frontier there is another paradigm: consciousness engineering.

Consciousness engineering is the art of applying controlled power directly to conscious experience in order to do work on it: to create and destroy experiences, to manipulate them, transport and communicate them, to spin them out and draw them back in. Western civilisation has not yet engaged with this technology. In fact, it does not even know it exists. Tunnel-visioned by the blinkers of materialism, it has almost completely missed the bigger picture. Focusing exclusively on the engineering of physical matter and information, it has got itself caught up in the limiting delusion that we are merely biological machines: that we are live meat. Western science has imprisoned itself in a cage of ideas. This cage tells us that we have no souls, that we are survival mechanisms produced by blind evolution, and that the human mind is nothing but the information processing of the brain tissue. Future generations will mock at this prison of ideas just as we mock at the belief of our ancestors that the terrestrial world is flat.

So, what is the bigger picture? What is the real matrix? As Morpheus says in the film, "Unfortunately, no one can be told what the matrix is. You have to see it for yourself." You are certainly not going to find out what the matrix is by watching a film or by reading a book. It is not the kind of thing you can know by knowing facts. The nature of matrix can be known only by experiencing it directly, at first hand. Well, that should not be so surprising. There are lots of things in your mental life that nobody could have told you. If you had never seen the colour red, could anyone have told you what it was like? To be sure, someone could have told you the wavelength of the radiative energy that is called 'red', and could have given you a detailed description of what happens in the retina at the back of the eye, and in the visual cortex at the back of the brain when the eyes receive optical energy of the wavelength called 'red'. You could absorb and comprehend all that information, and still be completely ignorant of what it is like actually to see the colour red, to have that conscious visual experience. Nor is it just colour that eludes informatic analysis. Everything in your mental life is irreducibly experiential. Every sound you hear has a quality that nobody could have told you about: the timbre of a ringing bell, or the whine of an electric guitar, or the howl of the wind. Even if someone were to give you a comprehensive account of sound waves and their reception by the ears, that would not tell what it was like to hear something if you had been born deaf. And every smell and every taste: you need to have them to know what they are like. The sensual feeling of having a body, the weight of your backside resting on the chair, the pressure of your feet against the floor, the tension in your shoulders, your awareness of the angle at which your head is tilted: your whole stream of consciousness is comprised of what philosophers call 'qualia'. Qualia are the purely qualitative aspects of what your mind experiences - the qualities that you know about because you have directly experienced them, and nobody could ever have told you about them without your having had that experience. Underpinning this richly textured sensorium, or manifold of sensations, is the matrix. Holding together the tapestry of experientiae is the living, active matrix. As we shall see later, however, although the matrix normally seems invisible, it is itself made of the same stuff as the sensorium itself. That is to say, the matrix is internally composed of experientiae. Consequently, the matrix can be known only through direct experience for precisely the same reason that the colour red can be known only through direct experience. Because the matrix is experiential in nature, it can be known only by experiencing it, not by reading about it or being told things about it.

To see the matrix, you have to knock out some of the bricks from prison of ideas that you are inside. Sometimes this happens to people by chance. Occasionally, a brick just falls out and you get a glimpse of the matrix: a sudden insight that seems to come from nowhere. Psychotropic chemicals can also reveal the matrix. In the 1960s, Stanislav Grof and other researchers used lysergic acid diethylamide (LSD) to squeeze minds through cracks in the prison wall and into the raw matrix. Undisciplined use of what can be compared to a psychological power drill led inevitably to bad trips, bad reactions, and the authoritarian clampdown on all psychedelic experimentation - which is only now being lifted. Although it stole the limelight and captured the popular imagination, LSD was only a modern postscript to a very long history that encompasses the use of psychotropic substances to break through to the matrix. It is a history that spans thousands of years in most non-westernised cultures. Part of the reason for the magnitude of LSD's impact was that Western culture has for at least three centuries been locked into the materialist mind-set. When LSD punched a whole through the wall mental prison, there was no safety rope. There were no established institutions for guiding people into the matrix and safely home again. No tradition of shamanism existed in the modern world that could give psychic travellers the structures of consciousness with which to sail in a controlled manner through the matrix. People did not even have the necessary terms of reference with which to articulate what was 'out there' (or 'in there', which turned out to be the same place as 'out there'). Other cultures, which have not yet passed through the meat-grinder of modernism, still retain the mental equipment that is need to function in the domain beyond the physical world. For instance, in the tradition of ritually using ayahuasco in Brazil, we can discern a primitive but effective psychic technology.

Western science is slowly dragging itself into a position where it must encounter consciousness as the essential component of reality, instead of brushing it away as a vestige of pre-modern folk psychology. It is zeroing in on a confrontation with the matrix. Throughout the broader community that exists outside the closed world of scientific academia, there is a growing realisation of the presence of the matrix. There is a storm gathering in the intellectual climate of the West. When it breaks, when the scientific community discovers not only the matrix but the forces and entities that are already operating in the matrix, it will have the biggest cultural rupture in its three-hundred year old history.

The term 'consciousness engineering' describes what the matrix is built with. It is a form of engineering that has existed since the beginning of time but Western civilisation has yet to drill into it. Whereas the industrial revolution of the nineteenth century pivoted on the invention of engines for handling physical power, and the information revolution of the second half of the twentieth century pivoted on computers, the twenty-first century will be dominated by a psychotechnic revolution which will pivot on leveraging the technology of the real matrix. Rather than diving straight into a serious discussion of the matrix and consciousness engineering, I think it would be useful to approach the matter gradually by tracking through a discussion of what happens in the films eXistenZ and The Matrix. These details will help to build up a general picture of virtual realism, and to put consciousness engineering into perspective. Limits to virtual realism?

Whenever the topic of virtual reality comes up, a lot of people polarise into two camps: the gung-ho enthusiasts who have total conviction that man-made virtual-reality systems that are based on neuro-stimulation can yield a level of one hundred per cent realism, which is utterly indistinguishable from what our ordinary waking experiences; and the sceptics, who say that, as a matter of principle, that degree of realism is impossible and it will therefore be forever unattainable.

There are two lines of thought that lead people to scepticism about virtual realism. First, the belief that the human mind has a direct connection with the human body, and possibly other bodies - a connection that can never be reproduced with electrodes attached to nerve fibres. For instance, people say that if you look into your lover's eyes, you can see his or her soul, and so you can know that this is not a virtual reality that we are in now. On the other hand, the second line of thought that equally leads to scepticism is the claim that to simulate the external world to the level of detail that is required for perfect realism would involve such vast computational power that it would be impracticable. These people typically claim that full realism would need the computer to simulate every particle of the universe, and therefore the computer that is running the simulation would need to be bigger than the universe - an obvious absurdity.

Strictly speaking, science fiction does not need to address these questions. It is in the business of making internally consistent assumptions about possible worlds, and looking at the implications. So, a science fiction author could rightly say, "Well, let us just assume that a fully realistic level of virtuality is, in principle, possible, and let us explore what the ramifications of this would be." That, however, is not very satisfying. There is an ugly laxity and laziness about it, and one might even say a certain intellectual sterility. It is better to adopt the more challenging and rigorous approach of seeking to base the science fiction on genuine possibilities, not just fantasies.

Therefore, I believe we should spend a little time considering these doubts the envisaged quality of virtual reality. Even if we cannot refute them, we can at least get a feel for how credible they are.

First, let us take a look at the claim that you have such a strong connection with your body that you just know that you are really in a solid, three-dimensional world, and not a virtual reality. For instance, if I press my index finger against the top of my desk, then it seems that I can feel the pressure actually in my finger. That sensation is not, seemingly, in my brain or in my mind: it is out there, inside my physical finger, in a specific, visible location in three-dimensional space. This argument, however, begins to look weak as soon as we consider other instances, where we seem to have a sensation in some part of the body, but we know that the sensation is not really out there, in physical space. 'Pins and needles' is a universal occurrence. When you sit or lie awkwardly on a leg or an arm for a long time, you may find that part of your arm or leg has become numb; when you get up and move around, you will experience a tingling sensation along the area of flesh that was numb, which children call 'pins and needles'. Although this numbness and then tingling seems to be in the arm or leg, in fact it is caused by compression of a nerve further up the arm or leg. This is therefore a paradoxical situation. When I pressed my finger against my desk top, then the stimulus, or cause of the sensation, was at the point of contact between my finger and the desk; and the sensation itself seemed to be in the same place. Yet, with pins and needles, the cause of the sensation might be situated in the elbow or the knee, while the sensations seem to be spread out down toward the hand or foot. We want to say, "I just know that the tingling sensation is in my hand", but we hesitate because we know that its cause is upstream. What seems to happen, then, is that the brain receives signals from a particular nerve fibre and imaginatively projects the resulting sensation back to where the nerve ending is. If you think about what the brain actually receives, it is inevitable that this should be so. All that the brain gets from, say, your arm is a bundle of nerve fibres with pulsed signals on them. The signals are a bit like the clicks of a Geiger counter: lots of clicks signifies a strong sensation, a few clicks a weak one. The brain gets no information about where these signals originated. So, it assumes that they originated in the nerve ending in the arm. Hence the sensation is projected out to that site.

Neuralgia is a more severe example of the same principle. In this disorder, a nerve is mechanically damaged or compressed, or is diseased, and the person suffers pain in the area of the body that is served by the nerve. Often, the pain follows the path of the nerve. One particular form of neuralgic pain, sciatica, results from damage to a nerve called the 'sciatic nerve' where it passes through the hip, or damage to one of the spinal nerves that feeds into the sciatic nerve. Subjectively, the pain is indisputably experienced as being in the part of the body where the nerve terminates, in the leg, but objectively the cause of the sensation is further upstream, in the hip. In experimental neuropsychology, artificial stimulation of the brain with electrodes can likewise induce sensations that appear to be in the corresponding part of the body. This is just the same principle as in neuralgia: electrical activity at an 'upstream' site causes a sensation that the mind projects onto a 'downstream' site.

Phantom limbs provide a rarer, but more dramatic illustration of the same process of projection. Where a limb has been amputated, the nerves still exist from the stump to the brain, and random electrical noise in those nerves is interpreted by the brain as sensations lying in the limb. Those sensations may be very painful. Yet, in this case, it is plainly nonsense to assert that the sensation is literally in the limb, for the limb no longer exists. Clearly, what is happening here is that the mind is projecting the sensation into the space where it expects the limb to be. In this sense, a phantom limb can be thought of nature's own virtual reality. It is important to bear in mind that the sense of location in experiences such as neuralgia and phantom limbs is very real. We are not dealing with some vague, illusory impression of location. As far as the person's subjective experience is concerned, a neuralgic pain is in the body in precisely the same way as any other sensation is.

Now, one way of looking at these examples is to say that the mind can sometimes be fooled into thinking that a sensation is in some part of the body where it does not really lie. That, in fact, provides a sort of weak justification for the virtual reality technologies that are assumed in eXistenZ and The Matrix. There is, however, a deeper realisation that you need to get: your subjective experience of your own body is already, in some sense, a phantom, a virtual reality. Let us return to the case of phantom limbs experienced by amputees. As we noted earlier, the brain has a certain number of input channels, or 'afferent nerves', leading into it from all parts of the body. The signals carried on those nerves comprise the only source of information that the brain has about the rest of the body. This is a crucial point, and I would ask you to try hard and imagine what it is like to be a brain stuck inside the skull, knowing nothing about the external world except for the pulses coming in on those nerve fibres. How does the brain know where the legs are, for instance, or where the arms are? It has to work it all out from those minute trains of electrical pulses arriving on nerve signals.

What the mind does is to create a complete, subjective body image. All bodily sensations are then assigned to locations within that body image. When I press my finger against my desk, that sensation of pressure is assigned to a particular site within that body image. That is what is meant by saying that I project it out into the physical world: I do not literally send it out into my physical, bodily space. Rather, I attach it to the relevant site in my body image. When an amputee loses a limb, the physical body is changed but not the body image. In the body image, the limb is still there. So, when random electrical noise comes in from the arm nerve, its resulting sensation can be slotted into the arm part of the body image. Thus the pain is 'in the limb', but it is in the subjective limb, not the objective limb. That, however, is where all sensations are. No sensation is ever in the objective space of the physical body, it is only in the subjective space of the body image. No feeling of touch is ever literally in your finger, it is only in the part of your body image that represents your finger.

In the neuro-stimulated virtual reality of eXistenZ and The Matrix, the virtual reality system simply takes over that natural projection. Players of the game eXistenZ will feel their bodies to be exactly the same as when they are in everyday life. A player can run her fingers through her hair, bite her tongue, chew and swallow food, and scratch an itch on her nose - and it will all feel as if these sensations are located in her body. Indeed, they are 'in her body' - but they are in her subjective body, not her objective body.

So, when you press your finger against the desk and think, "I can't believe this sensation isn't really in my finger", ask yourself which finger you are talking about. Do you mean your physical finger or do you mean your body-image finger? Surely it is your body-image finger, for this is the only finger that your brain really knows about.

Identifying the body-image with the physical body is an example of what the ancient Hindu doctrine of Vedanta calls 'maya'. This Sanskrit word is often translated as 'illusion', but it is more accurately rendered as 'delusion'. It does not, however, just mean 'delusion' in general. Rather, it refers to a specific sort of delusion: the delusion that consists in projecting qualities onto something that does not genuinely possess those qualities. A standard example that is discussed at length in Vedantic scriptures and commentaries is that of someone who sees a rope in the twilight and thinks it is a snake: the concept of the snake is projected onto the rope, and the person imagines that he sees the flesh-and-bone body of the snake move sinuously before him. When he realises it is only a rope, the snake is annihilated. In essentially the same way, when we conflate the subjective body-image with the objective physical body, we are projecting experiential qualities onto mindless matter. Thus the modern understanding of virtual reality on the one hand, and the Hindu path to enlightenment on the other hand, share the same realisation that the experienced body is not the physical body.

As I mentioned earlier, besides our seeming embodiment in physical matter, we also seem to have a direct connection with other human beings, who appear to be located 'out there' in physical space. Some people are adamant that the virtual reality of The Matrix could not be happening now, because they feel an immediate connection of love with their spouses, which could not possibly be mediated through the Matrix computer system; or they can feel the presence of other people in the dark even they cannot see them; or they feel a togetherness with others in a group, especially when in engaged in some team effort, such as collective meditation or playing football. None of this, however, counts against the fundamental realisation that the world we experience exists inside our minds and is projected out into the physical world. Let us take each of these examples. When you physically look into the eyes of your lover or spouse, light is reflected from his or her eyes, it is focused onto the retinae of your eyes, and coded electrical signals are transmitted from your eyeballs into your brain. Thus even in this simple case, there is no direct and unmediated connection: the connection is mediated by electrical signals, albeit biological ones. Would it make any difference if you had bionic eyes instead of normal biological tissue? No. What matters is the person behind the eyes, not the mere visual apprehension of the eyes. If two lovers are immersed in the virtual reality of The Matrix, they can still look into each others' eyes and it will be just as significant as if they were physically facing each other eyeball to eyeball. The claim that it is 'not real' is only a reflection of the delusion of maya, a result of vacuous sentimentality: it is as real as it gets. Again, sensing the presence of other people, or having a feeling of togetherness with other people, is mediated through one or more of our sense organs, and is experienced only as a result of electrical pulses arriving on nerves entering your brain. The same signals can be induced artificially. For people caught up in the virtual reality of the Matrix, people can have precisely the same sense of bonding and togetherness. It makes no difference whether we are embodied in actual bodies that are walking around in a physical world, or whether we are in a virtual world. In short, the first argument against virtual reality turns out to be false. It is an articulation of a delusion, which the ancient Indian rishis called 'maya', the delusion that identifies the mental body-image with the physical body. Seeing through this argument is also part of the Vedantic path to enlightenment.

Let us move on to the second argument for scepticism. Enormous strides forward have been taken in the software that drives modern virtual reality systems. Using parallel processing to perform ray-tracing computations in real time yields amazing levels of visual realism. Finite-element simulation of soft tissues and fluids can produce uncannily life-like dynamics. Virtuality is become more and more realistic at a breakneck speed. Yet, the sceptics claim that there are intrinsic limits to how good a simulation can be. Let us grant, for the sake of argument, that any given static scene can be reproduced perfectly. Even this is an enormous technical feat that will take many decades to achieve. But most researchers in this field would agree that there is no deep question of principle that stands in the way. Now, what about interactive scenes? What about chopping wood in the garden, and watching the splintering wood? What about making a bonfire of the branches, and watching all the leaves shrivel up and burn, with a myriad sparks and flames. These are complex scenes, each tiny part of which involves complex biological, chemical, and physical processes. The computational power required to model it all is enormous. If you then consider that we are part of an infinite but interconnected universe, where for instance the gravitational pull of the Moon affects the tides and even the fluids of the body. To carry out a detailed simulation of all this would seem to be pushing us toward a simulation of the whole universe. That, however, is an absurdity because the computer itself is part of the universe. The computer would have to be bigger than the universe.

There are, however, two factors that this sceptical argument ignore. The first factor is the tunnel-like focus of our attention, the narrow range of energies that our sense organs can register, and the low resolution of most of our perceptions. According to an Arab proverb, "The mind sleeps until the mind asks it a question". Normally, we see only what we are looking for, and what we are able to recognise and categorise. We scan the environment with mental templates, looking for incoming data that fits the templates. An illustration of this is Hermann Rorschach's famous ink-blot test, where the subject sees the ink-blot as an object or creature of some sort, not as the random blot of ink that it really is. We remain oblivious of most of the physical processes that impinge upon our bodies. This probably offers significant scope for the virtual reality system to reduce its work load. Consider again the bonfire of tree branches: although there seems to be a lot of detail present, if you were asked to draw an accurate picture of it afterwards then you would find that you had perceived only fragments of it. To what extent this fact could reduce the work load of the computer would depend on the site at which the sensory data is delivered to the brain. For instance, inducing the artificial signals in the optic nerve after it has left the eyeball will skip over the first level of edge-detection and therefore simplify the picture that the computer must render.

Likewise, the facts that we can see only visible light - which occupies a narrow section of the electromagnetic spectrum - and that we hear only a certain range of sound frequencies, means that the computer need render only one portion of the spectrum of energies that we are physically surrounded by.

Most importantly, though, all our sense organs are severely limited in resolution. There are a finite number of sensory nerve endings around the body. So there are a finite number of sense-data pixels that the computer needs to render. That our encounter with the world seems more detailed that is due to the clever technique of having a mobile area of enhanced resolution. On the retina of your eye, only the fovea has a high density of light-sensitive cells: the rest of the retina is only sparsely populated, thinning to zero at the edge of the visual field. When you look at something, such as your fingertip, your eyes automatically swivel so as to slide the fovea of each eye under the relevant part of the optical image that has formed on the surface of the retina. So, whatever you are looking at appears visually detailed. You do not normally notice that most of your visual field is much less detailed. (The reason you do not notice this fact is precisely because you are not looking at it.) The tips of your fingers have a high density of nerve endings, and you can move them around and touch and feel any object. This gives the impression that you are immersed in a tactually detailed world. Most of the body's skin, however, is very thinly populated with nerve endings, with a correspondingly less detailed tactile image. Again, the tip of the tongue has a concentration of nerve endings while the rest of the tongue and the mouth is sparsely innervated. What all of this implies that the seeming infinitude of sensory data with which we appear to be bombarded turns out to be a finite set, focused in a few concentrated clusters.

The second factor that we must confront the sceptic with is that the world is 'chaotic', in the mathematical sense of chaos theory. In everyday speech, the word 'chaotic' is synonymous with being random or haphazard. There is, however, a tradition in mathematics and physics of hi-jacking common words and assigning them new, technical meanings. In this case, the word 'chaotic' now has a mathematical sense in which it denotes a system of such acute delicacy that any arbitrarily small change to its initial conditions can yield major outcomes. The classic example is the Earth's atmosphere: as a result of its being 'chaotic', the flapping of a butterfly's wings could cause a hurricane on the other side of the world. This may well seem astonishing at first, but when you look at the thermodynamics of the atmosphere in the genesis of a storm, you will see that it is profoundly unstable, and that even the tiniest eddy might trigger a hurricane. You can compare it to a cone with an infinitely sharp cone, balanced upside on its point. Obviously, any cone in real life that is balanced on its point will be unstable, and a light tap will topple it. For an infinitely sharp cone, however, even an infinitely small puff of air can knock it over: no matter how small the puff of air, it will be enough to disturb the centre of gravity and make the cone fall over. So, in fact, it is not just the flapping of the butterfly's wings but even the tweaking of a single hair on its body that could trigger the storm. Crucial to the concept of a chaotic system is that no matter how small the change in initial conditions, it can be amplified to produce major effects. Chaos is all around us: in the atmosphere, in the rivers and oceans, in living things.

What does this have to do with virtual reality? Well, the sceptic's argument is that, since everything in the universe is interconnected, you cannot realistically simulate any part of the universe in a virtual reality without simulating the whole universe. Because of chaos, however, this is not so. Let us suppose, for instance, that inside the virtual reality of The Matrix, a hurricane blows up. The sceptics will argue that the computer will need to perform a detailed simulation of every parcel of air, of every raindrop, even of every molecule of the atmosphere and the underlying land and water. Not so. Since the atmosphere is chaotic, the precise movements of air and water vapour inside the hurricane do not matter: an infinite variety of movements will do just as well. The computer's simulation can proceed at a broad-brush level, and will need to fill in the details only when some human inside the virtual reality decides to take some meteorological measurement. Likewise, the sceptics will tell you that every star and planet in the universe will have some gravitational pull on you, and a realistic simulation will therefore need to model every lump of matter in existence. This is not so: distant celestial objects are so far away that their gravitational pull on us is swamped by random differences in the material concentration of the Earth. Chaos thus draws a fine cloak over the detail of the universe. It thus becomes possible for a computer to carry out a comparatively large-scale simulation of the world and nonetheless render an utterly realistic virtual reality. To be sure, the amount of computing power needed is still enormous, and vastly beyond present capabilities. With future developments in massively parallel quantum computers, however, this strength of computing power may not be too far away. In any case, the sceptics are not justified in saying that the simulation computers would need to be bigger than the universe.

The films eXistenZ and The Matrix reflect different levels of simulation and, correspondingly, different degrees of computing power. In eXistenZ, players enter a comparatively small world for the duration of a game; and this virtual world is simulated in the brain of a mutated amphibian. By contrast, in The Matrix, the world of the whole human race is simulated throughout the lives of all the individuals. In that case, it is clear that a computer system of stupendous power and resource is needed.

The simulation work of the metaflesh pod in eXistenZ is comparable to that carried out every day by ordinary human brains several times each night, in dreams. Sometimes dreams are vague, and sometimes they are vivid and detailed. In lucid dreams, they can be uncannily detailed. Evidently, a brain of standard size has enough computing power to do the job. We are told nothing about the mutations that have been applied to the metaflesh pods or about the programming of their nervous system, but it seems entirely plausible that they could generate realistic dreams, or virtual reality simulations, for the purposes of the eXistenZ game.

I hope I have shown you that, as far as basic principles are concerned, eXistenZ and The Matrix cannot be thrown out for being totally absurd. For the purposes of science fiction, there is enough plausibility in their respective views of possible futures that it is credible to explore them further. In the next two sections, I will discuss what can be said about the technology of neurally stimulated virtual reality in the two films. The technology of eXistenZ

In the plot of David Cronenberg's film, eXistenZ, a new interactive game is released to a group of volunteers to test-drive. Unlike present-day games, which are programmed in electronic circuits and burnt onto silicon chips, the game eXistenZ is programmed into the nervous system of a mutated amphibian. The body of this genetically engineered organism is in the form of a pod of metaflesh, with external nipples that are sensitive to touch. True to Cronenberg's adventurous and idiosyncratic sexual symbolism, the pod is activated by sensually caressing and plucking its nipples. Communication between the pod and the human players is achieved through umbilical cords that reach out of the pod and are each plugged through a 'bioport' directly into each player's spine. Anyone who wants to play games of this sort needs to have a permanent bioport fitted - a somewhat brutal operation in which the port interface is fired into one of the lumber vertebrae with what is essentially a bioport gun.

One of the tests of good science fiction is how far it goes in developing a consistent picture of a possible future. As I suggested earlier, science fantasy throws ideas around with carefree abandon, without bothering to tie them together: science fiction tries to weave the ideas together into a tapestry. Cronenberg's basic thesis of games programmed into biocomputers raises many questions. At a rather mechanical level, the question of hygiene is raised in the film: how can it be safe to have a permanent open wound in the spine? It is a question that provides a useful methodological clue. The question is left somewhat up in the air, with the suggestion that the bioport is no more dangerous than other orifices such as the mouth. What those orifices have in common is that, anatomically, they are not 'holes' in the sense that wounds are holes. They do not break through the body's outer, protective layer. Covering the external surface of the human body is a tough screen of semi-permeable tissue called skin that restricts the evaporation of water, prevents the ingress of micro-organisms, and to some extent helps to the hold the internal organs in place. Skin is continuous with the mucous membrane that forms the wall of a digestive tunnel running through the core of the body - beginning with the mouth, proceeding downward in the form of the gullet, stomach, and small and large intestines, and rejoining the skin at the anus. Throughout the length of this alimentary canal, there is a tough physical barrier between what is genuinely 'inside' the body, where the body fluids such as blood are located, and 'outside' the body, where the bolus of food being digested slowly flows. The surface of this long tube is selectively permeable: it allows digestive juices to be secreted into the food, and it allows basic nutritional substances such as proteins and sugars to be absorbed. Likewise in the other apparent holes of the body: the mucous membrane of the lungs is again continuous with the skin, but is specially adapted to enable an exchange of gases: to allow oxygen to be absorbed into the bloodstream, and carbon dioxide to leave. Finally, the uterus is constructed with a mucous membrane, again continuous with the skin, which is able to allow a fertilised egg-cell to embed in it. An intact layer of skin or mucous membrane never allows the passage of entities as large as cells into the body - be they bacterial cells, or the nerve cells of the game pod's metaflesh. So, how does Cronenberg's bioport fit in with this scheme of safe orifices in the body? We must assume that the bioport does not involve a permanent break in the skin, otherwise it would breach the body's defences against micro-organisms.

The problem we are looking at here is one that arises only with biological interfaces. It does not arise with merely electronic hardware. If you plug your telephone line into the modem of a personal computer, you are making a direct metal-to-metal connection between the wiring of your computer on the one hand, and the wiring of the telephone network on the other. You do not need to worry about anything like micro-organisms penetrating the circuitry of your computer through the open port. The question of 'viruses' entering your computer from the internet arises only at a higher level, the level of software, not at the level of the physical port. Infection by small, hostile antagonists is an invention only of biological evolution.

How, then, does the bioport allow entry of the information from the pod, if it does not permit the ingress of foreign cells? One possibility is that, inside the protected space of the bioport, the skin has been reduced to a very thin covering over the exposed nervous tissue of the spinal cord. This then enables the nerve fibres of the pod to induce signals in the nerve fibres of the human nervous tissue. A similar technique is used in present-day 'subcutaneous induction' of nerve signals by electrodes in experimental research. Maybe. A variation of this arrangement would have the bioport itself serving as an electrical interface: it would detect the incoming signals from the pod's nerve fibres and relay them to the human nerve fibres, in order to convey sensory inputs to the human. The same interface would also operate in the opposite direction, and convey the human brain's intended muscle movements to the pod's brain.

An important conclusion that we can draw from these thoughts is that the terminus of the pod's umbilical cord can have only a small, local point of contact with the human spine, and that still through a thin covering of membrane. The risk of infection makes a permanent opening prohibitively dangerous, so the metaflesh cannot penetrate the spine and reach the brain.

Unfortunately, there is a major technical difficulty that is entailed by this arrangement: namely, that the spinal cord is just the wrong part of the body at which to access most of the sensory input into the brain. How does the input for those sense organs that are physically located in the head - such as the eyes and the ears - make its way from the bioport into the relevant part of the brain's cortex? For instance, each optic nerve, which carries visual perception from one eye, goes straight from the back of the eye through a hole in the front of the skull into the brain; likewise the auditory nerve goes straight from the inner ear through a hole in the side of the skull, into a nearby part of the brain. Similarly for taste and smell. None of these sensory inputs passes through the spinal cord. The spinal cord in the lumbar section, where the bioport is inserted, will be carrying afferent nerve fibres from the legs only. So, how could the pod ever induce sound and vision in the virtual reality? Conversely, the nerves that control facial expression and speech will pass from the brain to the face, mouth, and throat - they will not pass through the lower reaches of the spine. So, how would the pod ever know about what the human is saying inside the virtual reality of the game?

The only solution would be to assume that when the bioport is installed, extra cabling is also installed, leading from the bioport up to the main nerve centres in the brain itself. These extra cables would be able to ferry incoming signals, which have been fed in by the pod, from the bioport and up the spine, into the sensory cortex of the brain. So, the pod could deliver visual data, auditory data, and indeed data for all senses, into the bioport, whence the new cables would deliver it directly to the relevant part of the brain's cortex.

How does the cabling get put in? Certainly it is not inserted manually. There is a scene in the film where the protagonist Ted Pikul (played by Jude Law) has a bioport installed. The process is fast and rough. There is no long, involved procedure of opening up the brain and spine and fitting new fibres. Indeed, the bioport is installed by a redneck garage mechanic (played by Willem Dafoe), with no expertise in neurosurgery. So, the cables must get into place automatically. Also, we can tell that the process must be triggered by the bioport insertion itself. For, when Ted Pikul first comes to use the pod, the functionality of his bioport is there immediately: there is no delay while we wait for the cabling to get laid along the length of the spine. The spinal cables are laid when the bioport is implanted.

The only way to reconcile these facts is to suppose that when the bioport is inserted, the operator also injects into the human spinal tissue some embryonic cells of 'meta' nervous tissue, and that those cells grow into fibres that will link the bioport to the relevant nerve centres of the brain. Such implanted meta-tissue might even have the same genes as the pod itself. Thus the correct wiring up of the bioport is achieved by an automatic biological process that neither the bioport fitter nor the subject need be aware of. It is difficult to say how quickly these biological cables could be grown into place. Obviously, they would use the existing human nerve fibres as a scaffold, probably twining themselves up the spinal cord like ivy climbing a tree. Infiltrating the brain would also be easy, although navigating through the mass of brain tissue would be tricky. For instance, how would it know which section of brain tissue is the visual cortex and which section is auditory cortex? After all, brain cells are very much alike wherever they are. If you look at a brain cell under a microscope you can tell which layer of the cortex it comes from, but not from which area of the brain. And it is by area, not depth, that the brain's architecture separates different functions. Nevertheless, it is conceivable that the pod fibres would work it out somehow, perhaps by monitoring the activity of the human's brain and recognising characteristic patterns. For instance, visual perception has a two-dimensional structure that auditory perception lacks. It could well be that the implanted meta-tissue will comprehensively report the activity of all areas of the human's brain, and transmit the information through the bioport back to the game pod - where the pod's brain will work out which area of the complete manifold of data corresponds to the visual cortex is, which to the auditory cortex, and so on.

In a similar fashion, we may suppose that the pod nerve fibres will wrap themselves around the human nerve cells in the motor centres of the brain. There, they would be able to detect the person's intentions to move any muscle of the body. That information would be fed into the long fibres that would now pass down the spine, and be picked up at the bioport. This would, of course, encompass all kinds of voluntary muscular movements, including those of the speech organs - the lips, the tongue, the vocal cords, the rib cage, and the diaphragm. From that stream of data, the pod would know all the human's intended utterances.

As we see in the film, it is inevitable that the human's body will be paralysed while the game is in play. Just as in normal sleep, the intention to carry out a voluntary movement must be stopped before its resulting neural signal reaches the muscles. It would obviously be too hazardous to allow the human subject to walk around, enacting the events that are happening in the virtual-reality game. Again, this paralysis cannot be achieved in situ in the spinal cord, but would require cables running up to the brainstem.

Before we move on from considering the basic technology of biocomputer interfaces, there is another detail that a fully worked-out science fiction would need to explicate. As we saw above, the human body is a rigorously contained system that allows only tiny particles of very specific substances to enter the body proper: oxygen is allowed in through the air sacs of the lungs, nutritional molecules are allowed in through the absorptive villae of the stomach lining. When the skin or mucous membrane is broken and foreign bodies penetrate the internal body space, they trigger a cascade of defensive mechanisms. Under the general rubric of the 'immune system', these protective measures are led by the white blood cells, which seek to engulf and destroy the foreign bodies. They are able to recognise the foreign bodies because every cell of the body has a distinctive pattern of knobs on its surface, called 'antigens'. These are based on the individual's genetic make-up, and are therefore unique for each person (with the exception of identical twins). When the white blood cells come across anything that lacks the antigens, they designate it as a foreign body and seek to destroy it. If it is small enough, such as a bacterium, it will simply be engulfed and digested by a white cell. If it is larger, it will be wrapped up with a clot of small cells called 'platelets', which are strung out on a net of 'fibrin': on the surface of a graze or cut, this is the familiar scab. So, what would this interlocking army of defences make of the implanted nerve cells that climb up the spinal cord and wrap themselves around the brain cells? They are obviously foreign bodies, as they possess the genetic make-up of the pod, not the human. They would lack the human antigens. Therefore, the body's natural reaction would be to reject the meta-tissue, in much the same way that the body rejects transplanted organs. To disable this immediate response, the installation of the bioport must also be accompanied by an injection of an immunosuppressant drug, which will shut down the immune system for a period of time, until the body adjusts to having the foreign tissue inside it. (Presumably, this immunosuppressant would be injected along with the anaesthetic drug that is mentioned in the film.)

This, by the way, would explain why we see so little inflammation around the installed bioport in the film. Not only does the flesh around the bioport entry point not become red and filled with pus, as we might have expect, but is actually appealing enough for Allegra Geller (played by Jennifer Jason Leigh) to insert her tongue sexily into Ted Pikul's fresh bioport. (This is another display of Cronenberg's playful treatment of novel erogenous orifices, which follows on from his film adaptation of J.G. Ballard's CRASH.)

We now have a fairly clear picture of the basic technology implied by Cronenberg's eXistenZ. What implications does it have for the potentialities and limitations of the virtual reality that it can produce?

First of all, we must recognise that the pod can completely reproduce whatever sensory impressions we might have in 'real life'. Whatever you see with your eyes, whatever you hear with your ears, or smell with your nose, or taste, and whatever feelings your skin may give you, of pressure, of heat and cold, of roughness and smoothness, it can all be reproduced by the game pod. We have seen that the bioport gives access to the full spectrum of the human sense organs: the pod only needs to deliver the requisite sequence of electrical signals to the bioport, and the human subject can be wholly immersed in a sensual world every bit as solid and tangible as the 'real' one. 'Solidity', which is often mistakenly thought of as a touchstone for reality, consist of no more than the perceived impression of resistance to movement. You press your finger against the table, and experience the compression of your finger's tissue. That experience of compression, however, is evoked by a stream of electrical signals from pressure sensors in your finger. As we have seen, any such signals will be re-created by the pod. So, inside the virtual reality, you can press your (virtual) finger against a (virtual) table, and it will seem solid, because the experience will be the same.

We can also see that, as stated in the film, a single bioport installation can serve for all pod games. You do not need a new kind of bioport to take new advantage of the latest version of the game. The bioport already gives complete coverage of the complete range of human senses and voluntary actions. There is nothing more that a new bioport could offer. Whatever is new lies in the programming of the game pod itself, not in the bioport.

Moreover, the scope of the pod's information about the subject is not limited to voluntary muscular actions, such as walking and talking. As we saw above, when the bioport is installed, a seed of pod nervous tissue is also inserted, which quickly grows along the human's spinal cord and into the brain. Once in the brain, it would probably have to wrap itself around every cell of the cortex: not just the perception areas, such as the visual cortex at the back the head, which handles vision; not just the motion areas, which control bodily movements; but also the emotional and thought centres. This has interesting implications for how much information will be available to the pod and therefore the possible dynamics of the game.

It seems that at the data terminal inside the bioport there would be a complete map of the electrical activity going on inside the cortex of the human's brain. The pod need only pick and choose whatever information it wishes to utilise from that wealth of detail. We know that it must pick up and use a comprehensive picture of bodily movements, in order to represent those actions inside the virtual reality and feed back the correct imagery to both players into whom the pod is plugged. For instance, if a player intends to raise her hand, then the game pod detects this and transmits the visual and kinaesthetic imagery back to the perception areas of the brain. What the pod could also pick up and use are the private thoughts and feelings of the players.

There is no evidence in the film that that extra range of information is being used. Since the pod controls both the environment and all the characters, other than the avatars of the players themselves, we need to look for occasions when either the environment or the characters respond to a player's private thoughts. This does not happen. Perhaps in a sequel, we might see the next version of the game pod with this functionality added in. In Allegra Geller's current version of eXistenZ, there is no mind reading.

What we do see, though, is the converse. There are some very good scenes where Ted Pikul suddenly finds that he knows exactly what to do with some kit, although he is in an entirely new situation and nobody has told him what to do. It might be more accurate to say that his body knows what to do, rather than to say that he knows what to do. It is almost as if his body were acting by itself and he himself is a bemused witness, and is passively observing his own body. And yet that description is not quite right either. Cronenberg has actually devised a more subtle situation, in which the game pod is force-feeding thoughts into Pikul's mind.

Consider the scene in which Pikul pulls apart the bones of the Special Dish that he has ordered and eaten at the Chinese restaurant. Without being told, and without evening deliberating on it, he starts putting the skeletal remains together to make a 'tooth gun'. This device is a virtuoso piece of creativity (which also featured on the advertising posters for the film). Loaded with separate human teeth instead of bullets, the gun uses the natural elasticity of cartilage, within a rigid framework of bone, to impart an impulse of kinetic energy to individual teeth, firing the teeth through the air - just like firing a bullet from a pistol.

Allegra Geller asks Pikul what he is doing: but, although Pikul is building the gun through a series of voluntary actions, he does not have any conceptual knowledge of what he is about, nor any recollection of how he acquired this skill. It is instinctual. Earlier, working on a conveyor belt at the metaflesh farm, he instinctually knows how to cut up the amphibians, pick out the required organs and sort them. It is like breathing, walking, and running: we know how to do it without having concepts about it. When you run, you do so under voluntary control, yet you do not deliberate on which muscles to contract or relax, or how to maintain your body's centre of gravity so that you do not fall over. Your intention to run somewhere is at a higher level of information processing. If you carry out higher-level activities, such as playing tennis or riding a bicycle, then a further layer of information processing is absorbed into the instinctual level. When we go to a still higher level, we find automaticity coming into play in a lot of social activity. For instance, one of the difficulties in combating sexism and racism is that sexual harassment and racial abuse often take place in the instinctual realm. A labourer at a building site wolf-whistles at every passing woman because it is part of a learned pattern of behaviour, an acquired instinct. These are instincts that are programmed into us by a supra-personal social organisation. In military service, other kinds of instinctual behaviour are burnt into the mind's repertoire of automatic actions by repeated drills - including the assembly and disassembly of weapons.

Thus Pikul's instinctive construction of the tooth gun is consonant with what we know of the human mind's capacity for complex acquired patterns of behaviour. What is interesting is that, in order to have plugged this skill into Pikul's mind, the game pod must have accessed quite a high tier of his motor control. The pod was not engaging in the muscle-by-muscle control of Pikul's fingers. It was placing somatic goals into his motor control centre, and then letting his brain figure out for itself what precise finger movements are needed to accomplish those goals. Thus it would tell him that a bone of a certain shape must be inserted at a certain angle into another bone of such-and-such shape. His mind would then recognise the necessary bones on his dinner plate, and feel the urge to pick them up and push them together.

After instinctively assembling the gun, Pikul has the intuition that he must shoot the Chinese cook. The dividing line between instinct and intuition is an important one, albeit not always sharply delineated. They are processes of the same kind, but intuition works at the level of thought, and instinct at the level of action.

The fact that the game pod was able to give Pikul the intuitive urge to shoot the cook shows that it had 'write access' to the highest level of information processing in Pikul's mind. Yet there was nothing in the film to suggest that the game pod also had 'read access' at that level. It appears that the pod could write suggestions into the mind, but not read thoughts out of it. If only we could interview Allegra Keller, the software - or 'wetware' - developer who programmed the pods, we could find out why. What technical obstacle was it that barred the pod from reading the player's minds?

We will return to consider other aspects of eXistenZ later. Now, we need to look at The Matrix and compare its technology of virtual reality with that of eXistenZ. The Technology of The Matrix

The Wachowski brothers have stuck to the somewhat unadventurous technology of the electronic digital computer as the engine that drives the virtual reality in which the human race has been immersed. Indeed, very little is said about the nature of the robots, except that the contrast is emphasised between their electronic machinery and living creatures.

The assumption of an electronic future is a bad move. It speaks of too close an attachment to established motifs of the science fiction genre, and a reluctance to follow the latest trends in technology to their natural conclusion. Electronics is an ingenious but crude and inelegant first step for mankind's progress into informatic engineering. Already, experimental computers use photonics - circuits of light rather than electric current - to achieve new orders of speed and miniaturisation. On the technological horizon, we can discern that the future of informatic engineering will be in the shape of molecular manipulation, in the discipline of nanotechnology. Nanotechnology involves using individual molecules to build macromolecular machines. This is the ultimate limit in miniaturisation of computing machinery. It will probably also make it easier to use the principles of quantum computing, which will touch the ultimate limit in speed of computation. These technologies are already the focus of intense research activity. They are also natural destinations for the two trends that have shaped the progress of computing over the second half the twentieth century: the relentless march toward smaller and faster computations. Undoubtedly, the harnessing of living tissue in bio-computers offers a short cut to these new peaks of engineering. Every living cell is, in effect, a natural nanotechnological powerhouse. Moreover, the massively parallel architecture of the brain offers the only known practicable method for utilising the immensely fast nano-switching power of individual cells, and combing those switches in a flexible, intelligent network. In fractions of a second, a human brain can execute complex and subtle computations that surpass anything that we have any hope of achieving with electronics. Yet, those qualities are precisely what would be needed in any computing system that is going to yield a full-scale simulation of reality. The most likely form of a future virtual reality system offering fully credible immersion is a bio-computer.

Therefore, Cronenberg is much more on target with his metaflesh pods that the Wachowski brothers are with their robots.

As in eXistenZ, the humans in The Matrix have a single, spinal bioport. There, however, the similarity ends. The Matrix bioport is located at the back of the neck, at the very top of the spinal column. Its precise anatomical location is not clear. It may be implanted into the occipital bone that forms the base of the skull, or it could be implanted in the first cervical vertebra. With either site of attachment, though, the electronic wires of the bioport would best be taken into the brain through the soft cartilage that provides a cushion between the skull and the top of the vertebral column. They could then pass directly into the brain through the same aperture in the occipital bone that the spinal cord itself passes through. Adopting this pragmatic approach to wiring the human brain avoids the need to drill any holes through bone, and maintains the mechanical and biological integrity of the protection that the skull offers to something as vital as the central nervous system. Since the bioport reaches directly into the brain, it obviates the extra obstacle that Cronenberg's scheme faces, of conveying neural data from the brain to a bioport near the bottom end of the spine.

Inside the brain, the Matrix's bioport would terminate in a dense forest of electrodes, distributed throughout the volume of the brain. When a neonate is first fitted with the bioport, the sheathed mass of wire filaments would be pushed into the baby's head through the bioport. On reaching the skull cavity, the sheath would be released, and the filaments would spread out in a hemisphere, rather like a dandelion seed. Being gently pushed in, these wires would gradually reach every area of the developing cortex. Nested sheaths would allow a branching structure to be built into the tree of filamentary electrodes: as each tiny, sheathed wire approaches the surface of the brain, it would release hundreds of thousands of even tinier electrodes to cover the circumjacent area of cortex. At this early stage of development, there is very little synaptic connection between cells in the human brain, so that these slender electrodes could penetrate every part of the brain without wreaking any damage. Once in place, they would probably remain static.

If necessary, however, adjustments could be made later. We could certainly imagine that, along with the data cables that are passed into the brain, there is also a fibre optic surgical line. The optical fibre could transmit a minute laser beam to provide the power to make and break connections between electrodes and nerve fibres. Navigating the micro-surgical device around the brain would probably be achieved by sub-microscopic propellers, perhaps in the form of rotating helical structures only a few molecules wide. This could propel the micro-surgical device in much the same way as flagellae or 'hairs' propel such micro-organisms as the paramecium. Once again, at the micro level, the next steps of our technological progression are foreshadowed by nature's own evolved techniques.

These surgical interventions after installation of the bio-port are, however, pure speculation on my part. After all, they might be completely unnecessary if the electrodes are well placed to begin with.

At first, you might assume that the resulting functionality of the Matrix's bioport, and its complement of electrodes inside the brain, would be much the same as that envisaged by Cronenberg for the eXistenZ pod. The Matrix would, in effect, have comprehensive read and write access to the human subject's brain. In fact, this does not seem to be so. And the reason probably lies in the robots' use of electronic hardware instead of employing the alternative of 'wetware' or biocomputers. A key element in the plot of the film is that Neo is able, ultimately, to challenge and overcome the Matrix. If the bioports were wired to give total control of the thoughts and actions of the human subject, then than opportunity for rebellion could never arise. The human mind would be wholly subjugated and enslaved. That the possibility of freedom exists shows that there are functional elements of the human mind that remain outside even the massively invasive intervention of a life-long bioport.

Examining the nature of that ultimate freedom will take us right into the middle of a vitally important but very subtle question that lies at the core of what philosophers call the mind-body problem. We need to cover some more ground before deal with that question in the right context. For the time being, let us continue filling in our picture of the basic technology of the Matrix. With its electrodes placed well inside the human brain, the Matrix has a range of options about the precise level at which to deliver its sensory signals. For instance, vision could be simulated by inducing the requisite trains of signals in the optic nerve, using electrodes attached to optic nerve fibres just as they enter the brain. The induced electrochemical signals would then arrive at the visual cortex at the back of the brain, and be interpreted precisely as if they had come from normal vision in the eyes. Likewise, all the other incoming nerves could have micro-electrodes attached at the point of entry into the skull. Correspondingly, the outgoing motor nerves would also have micro-electrodes attached to them at their points of exit. This scheme has the merit of mirroring the natural state of the brain most closely, and would undoubtedly require the simplest design concepts. It is not, however, the only possibility. Instead of clamping the electrodes to the optic nerve, they could insert them further into the depths of the brain. These electrodes could be attached to the output nerves that arise out of the visual cortex and stimulate the visual perception from that position. This would be technically more difficult to achieve, if only because the locations of the electrodes would be subject to a greater number of factors - but it would yield a corresponding simplification of the central data processing. For, whenever you perceive the world through your eyes or ears, or any sense organ, you ignore most of the data that are available to you. Your mind filters whatever is irrelevant to what you actually want to attend to. For instance, if there is a clock ticking in your lounge, or a refrigerator humming in your kitchen, you will normally be completely oblivious of it. As you walk down a busy street, you do not register the number plates of the cars that pass you. So, if the Matrix were to deliver perceptions to the output cells from the sensory cortex - as opposed to the output from the eyes - then it would save itself the job of filling-in all those details. It would need to deliver only the key elements of your perceptual field: just the things you are specifically attending to.

Which method does the Matrix actually use? There is a scene in the film that tells the answer. When Neo wakes up from the virtual reality and finds himself in one of the vast array of vats, he pulls out the oxygen and food tubes, drags himself out of the gelatine fluid, and - perceives the world. The fact that he can see and hear proves that the visual and auditory cortices of his brain are developed and functioning. This could not have happened if the Matrix had been transmitting its sensory data into the deeper centres of his brain. If that had been done, then his sensory cortex would never have received any electrical stimulation, and it would have atrophied, wasted away to nothing. If that were the case, then Neo would wake from his vat and find himself blind and deaf, with no sense of smell or taste, no feeling of touch or heat in his skin, no awareness of whether he was vertical or horizontal, or where his arms or legs were. He would find himself in a state of complete anaesthesia, utterly insensible to the world. The fact that this is clearly not what he finds, the fact that he can see and hear and move around, tells us that his sensory cortex is alive and well. Therefore, we can infer that the Matrix had been sending its sensory data in a fully rendered form into his afferent nerves just where they enter the brain. That is, the Matrix must have injected its visual data just where the optic nerve leaves the eyeball, rather than in the midst of the brain's vision processing. Likewise, ENO's ability to walk and use his arms shows that the motor cortex is also developed and functioning. Indeed, even the cerebellum, which controls balance, must be working. So, the Matrix must be capturing its motor signals from the brain's efferent nerves after they finished with the last stage of cortical processing, but before the nerves exit the skull. This interesting conclusion might lead us to suppose that when the bioport is installed, the electrodes are physically inserted only on the major incoming and outgoing nerve bundles. And, to simplify the installation, we might expect the site of attachment of the electrodes to be the very points where the nerves enter or exit the skull. For example, where the two optic nerves pass through the two holes at the back of the eye sockets, and into the cavity of the skull - that would seem a logical place to clamp the electrodes. After all, those are the only electrode sites in use, so why should there be any others installed? As we shall now see, however, this is not so. The Matrix has opted for a different method, with important implications.

The idea of portable skills has been in circulation on the science fiction circuit for some time. It is, of course, based firmly on the analogy of loading programs into conventional digital computers. In the Wachowski brothers' hands, however, it represents a new twist to the functionality of the Matrix. Recall that the two primary functions of the infrastructure of the Matrix are to deliver sensory data to the human brain's input channels, and capture motor impulses from the output channels. Now, delivering sensory data would involve writing to particular areas of the brain, where the incoming nerve fibres terminate. As we saw above, the Matrix must induce the sensory data in the incoming nerve fibres before any cortical processing begins. But the job of implanting new skills in the human mind would involve writing to quite different areas of the brain, where active programs are held in permanent memory. Why would the Matrix's infrastructure offer that capability? After all, the Matrix does not implant skills as part of its normal activity. People learn things in the normal manner, within the virtual reality of the Matrix, by reading books and going to college, or attending evening classes. The only reason for this capacity to implant skills to be wired into the Matrix infrastructure is that it is a spin-off from a more general, comprehensive function for writing anything anywhere in the brain.

This is a standard technique in the design of modern systems for informatic engineering. It is often easier and more efficient to build a completely general all-purpose system than to build special-purpose systems, which are capable of performing only a narrowly circumscribed range of functions. The picture that is emerging is that the Matrix has inserted a carpet of electrodes over the whole surface of the brain, but it uses only those electrodes that are attached to the main input and output data channels, such as the optic nerve. So, it would seem that when the robots designed the Matrix they simply built a comprehensive mechanism for writing any data to any part of the brain, or at least to any area of the cortex. In practice, the Matrix itself uses that mechanism exclusively for delivering sensory data. But the capability remains there for anyone to employ for their own ends. And, in the film, the crew of the Nebuchadnazzer have exploited this loophole in order to write programs into the brain. For instance, they use it to download Kung-Fu skills into Neo's brain, and to download helicopter piloting skills into Trinity's.

We can contrast this technique with what we saw in eXistenZ. There, instinctual skills, as well as intuitive urges, were made available to the players in the game. Yet, these skills were probably not permanent additions to the player's brain. Rather, the skills resided in the metaflesh pod, which fed signals in real time into the player's brain. My reason for saying this is that there was no time-lag before the skills became available. Even before Pikul had finished eating his cooked amphibian, he was picking at the bones and slotting them together to make the tooth gun. In contrast, Neo was subjected to ten hours of downloading in order to learn Kung-Fu. Admittedly, Kung-Fu is a vastly more complex skill than building a gun out of bones, but the comparison is valid as a matter of principle.

There is an implication of this, which is not explored in the film, but should be of concern in any sequel. Now that Morpheus' crew have demonstrated the feasibility of writing information to arbitrary parts of the brain, not just the sensory input areas, there is a risk that the Matrix itself will pick up on this trick and start using itself. Previously, it probably was not too interested in spending its resources investigating the methods of the errant humans, as it believed that the Agents would be able to deal with them. Now that Neo has initiated a major campaign against the Matrix, however, the robots are likely to monitor what they are up to, and may well discover this new weapon. Maybe, for instance, they would use this technique to write into Neo's brain an irresistible urge to kill Trinity, instead of having to rely on such clumsy methods as bribing a member of the crew.

We have carried out a brief, general tour of the technology that is implied in the films eXistenZ and The Matrix. Now, we need to start looking more closely at the nature of consciousness. That will give us a framework in which we can begin to appreciate the deeper philosophical allusions of The Matrix.

2. Consciousness

All this is because consciousness is something very different from information. The importance of this insight cannot be over-estimated. In fact, this seemingly innocuous remark at the mess table takes us down a very deep rabbit hole of philosophical thinking. We are, however, going only a short way down it before coming back up for air.

That consciousness is not informatic is still news to many scientists. Orthodox opinion in many of the bastions of neuroscience holds that the conscious mind comprises nothing over and above the processing of information by nervous tissue. Unorthodox opinion, as it has been expressed at the fringes of conferences and journals for some years, maintains a different position. It says two key things: that consciousness is a fundamental constituent of the universe; and that it is radically different in nature from what we conceive either physical matter or information to be. We need to be clear about the nature of consciousness in order to begin to understand the nature of the matrix that we are in.

Witnessing consciousness

What is consciousness? This may seem a straightforward question but is actually an unanswerable question. That is not because consciousness is such a mysterious thing that we cannot understand it. On the contrary, consciousness is a very ordinary thing that we experience and use all day, every day. Rather, it is unanswerable because it is a trick question. It conceals assumptions that seem to make the question possible, but those assumptions are wrong. So we cannot arrive at an answer to this question as long as we hold on to those assumptions. As in the proverbial answer, "You can't get there from here".

There are two kinds of answer that may be given to any question of the form, "What is such-and-such?" These are 'analytic' answers and 'ostensive' answers. The word 'analytic' means 'to break down', and an analytic answer to the question "What is X?" involves analysing, or breaking down, X into its constituents. For example, if you ask, "What is a square?", I can answer by saying that a square is a closed figure drawn in a flat plane, made of four equal lines at right angles. That answer is analytic because it breaks the concept of a square down into its constituents. An analytic answer need not literally break something down into parts, as I did with the square. It can also analyse something partly or wholly into relationships with other things. For example, to answer the question "What is the crest of a wave?", we cannot break down the crest into the parts it is made out of, but only say that the crest is the top part of a wave, as opposed to the trough, which is the bottom part. That is still an analytic answer, because we are still breaking the concept down. The other kind of answer is ostensive, which literally means a 'showing answer'. If you ask, "What is red?", then I can show you what it is like to see red, but I cannot tell you what it is: nobody can break the idea of red down into its constituents and give an analytic definition of it. It is true that I cannot give a comprehensive answer to the question, "What is red?", but that does not stop us from using the word meaningfully in everyday life. I can show you redness by holding up a red thing in front of, such as a ripe tomato, or some lipstick. Or I can use a filtered lamp to shine light of any wavelength from 620 to 740 nanometres into your eyes, and again you will experience the colour that we call 'red'. Some people mistakenly think that the light within that range of wavelength actually is red. But that is not so. The light merely acts as a stimulus to the eyes and induces an experience of red. You can equally well experience the colour red when you are asleep with your eyes closed, but dreaming of my shining that light into your eyes. Clearly, redness itself is in the mind. Correspondingly, I could in principle insert electrodes into your brain and apply a voltage to the correct part of the visual cortex of your brain and thereby create a sensation of redness in your visual field, just as if so-called 'red light' had been shone into your eyes. What all these methods have in common is that they are ostensive answers to the question, "What is red?" In each case, I am doing something to you that causes a red sensation to appear in your visual field, and then I am saying, "There! What you are seeing is what we call red!"

Of course, it is not just colours that must be given ostensive definition. Sounds, smells, tastes, tactile feelings, are all in the same category. Each and every mental sensation is amenable only to ostensive definition. We cannot, for instance, give an analytic answer to the question, "What is the smell of Camembert?"

Now, let us return to our original question, "What is consciousness?" What sort of question is this? By which I mean, what sort of answer do we want? Well, consciousness is essentially involved in every particular perception or mental experience. When you see red, you have consciousness of the red colour. When you smell Camembert, you have consciousness of that specific aroma. Consciousness is something that you can know about only by having it, that is to say, by having a conscious experience. So, we require an ostensive answer, not an analytic answer, to the question, "What is consciousness?"

It is not so easy to find an ostensive answer to the question, "What is consciousness?", because by focusing on any individual conscious experience we are focusing on the special qualities of that sensation, and not on consciousness in general.

Therefore, we are normally forced to approach 'consciousness in general' by abstracting it from our myriad different instances of conscious awareness. That, though, is unsatisfactory. It amounts to giving an analytic definition of consciousness, albeit in terms of what is in common between individual conscious experiences, each of which has in turn an ostensive definition. A major problem with that, rather ad hoc, approach is that it fails to establish that there is genuinely any 'thing' in common between those experiences. We may say that consciousness is the abstracted property of being conscious, but that does not carry any implication that there is any such thing. There may be no 'phenomenologically real' consciousness as such.

Instead of abstracting consciousness in this way - which we may regard as very much a Western approach to the problem - we may engage directly in an encounter with what is called 'pure conscious experience'. Eastern traditions of meditation provide us with methods for stilling the mind and allowing it to rest calmly on conceptual emptiness. There are numerous different methods in circulation, which may seem bewildering, but they all lead toward the same goal. Part of the reason for their diversity has to do with the personal dispositions of each practitioner. There are, for instance, sitting meditations, walking meditations, jumping up and down and then standing still meditations, and swirling around meditations. What works for one person may leave another person cold.

The state of mind that each of these methods can take us toward is a limiting condition of two trends. First, emptying your mind: sweeping away the mental clutter of ideas and emotions that congests your mind for most of the time, stilling the chatter of interior dialogue and narrative that is running like an inner verbal soundtrack overlaid on your daily life; and stopping the 'grasshopper' tendency to jump from one idea to another every few seconds. Second, focusing the mind: turning up your attentiveness just as you would turn up the brightness of a lamp; and, at the same time, heightening your awareness as if you were straining to see whatever is illuminated by that light of attention. There may seem to be a paradox here: you are to empty your mind but, at the same time, to intensify your attentiveness. What, then, are you to attend to when your mind is completely empty and your attention is fully focused? The answer is: your consciousness itself.

A Tibetan Buddhist method of meditation will serve to illustrate the general principle. The training initially centres on developing more and more vivid visualisation. For instance, the student may visualise a lighted candle. She may sit before a burning candle with her eyes closed visualising it, then open her eyes to refresh her image of it, and then resume visualising it with her eyes closed. In this way, through long periods of practice, the student learns to stop the mind jumping onto other ideas, and to direct an intense attention to one single thing, as well as to acquire a strong awareness of the content of consciousness. Then, the student drops the visualised candle from her mind, leaving the mind completely empty but with the attention remaining full on.

What the meditator encounters, the 'pure conscious experience', or PCE, is hard to describe. This is inevitable because we normally rely on comparing the contents of different experiences in order to describe them. In PCE, there is nothing to compare. One recurrent feature of attempts to describe it is that it involves the dissolving of the normal boundaries of the self. In fact, this begins even in the intense focusing before the mind is emptied: the self may seem to dissolve into the object being visualised, a process that is sometimes described as the merging of object and subject. The experience of the flow of time may also evaporate in the pure consciousness. These observations lead people to think in terms of a 'universal consciousness'. As we shall see later, this pure conscious experience is a gateway into the matrix, which the earliest known explorers called Brahman. Consciousness and the brain

If you have had anything like a standard scientific education, you should be feeling uneasy about what I have been saying about the nature of consciousness. This is because it is a heresy as far as the scientific establishment is concerned. Inextricably embedded in the foundations of the vast edifice of modern science is an article of faith. According to that article of faith, the physical world is the reality, the whole reality, and nothing but the reality. What increasing numbers of researchers on the edge of research into consciousness are realising is that that article of faith is wrong. There is something else, besides physical matter and energy. That is the big heresy that is gaining power as we race toward the new millennium, and it is a heresy that is now openly challenging the three-hundred year old belief system of the West.

The independent reality of consciousness is a novelty only in the culture of the West. Eastern spiritual traditions tap into a different stream of ideas. In Hinduism and its diaspora of Buddhism in the East and so-called Neoplatonism in the West, we find a recognition of the autonomous existence of mental and spiritual realms. Not only that, however. We also find the mother of all heresies, the concept of the matrix.

For now, however, let us look more closely at the connection between consciousness and the brain. As I have mentioned, the standard position is that consciousness is nothing more than the processing of information in the brain. Quite how the incessant traffic of electrical and chemical signals running along the fibres of the brain cells constitutes the rich texture of conscious experience is never explained. The advocates of physicalism just wave their hands and say that the brain is so enormously complex that we cannot yet understand the precise mechanism whereby electrical pulses in nerve cells are manifest as sensations, thoughts, and emotions. Nevertheless, they say, this must be so, because they hold the fundamental article of faith that everything is physical. This doctrine is often referred to as 'promissory physicalism' as it promises that the conscious mind will ultimately be reduced to the physical system of the brain - yet it does so without any principled reasons for believing this to be possible, nor any programme of research that we have any reason to believe will be able to achieve that reduction of mind to matter.

There is, in fact, a glaring flaw in the theory that consciousness is informatic. Information has a 'soft' reality: information is information by virtue of its being interpreted as such; conscious experiences, in contrast, have a 'hard' reality that needs no interpretation.

Suppose, for instance, I were to give you a floppy disk holding a file of columns of numerical data:

21, 250, 11, 47,
22, 250, 15, 39,
21, 252, 17, 38,
23, 252, 19, 37,
24, 256, 20, 36
24, 257, 20, 35,
etc

Conscious experience is fundamentally different. If you mischance to jam your thumb in a door, then the sharp pain you will feel is undoubtedly real and unambiguous. You do not need to interpret it as pain: it is already given to you as pain. Nor can you or anyone else re-interpret as some other sensation, such as the scent of a rose or the taste of a tomato. Conscious experiences have real, subjectively witnessed qualities that do not depend for their existence on being interpreted this way or that. That is 'hard' reality. Therefore, they are not just information. They involve something over and above the mere information.

To be sure, there is a lot of information processing going on inside your brain in parallel to at least some of your conscious experiences. These are called the 'neural correlates of consciousness'. They reflect your conscious experiences, but they are not the same things as your experiences. As we have discussed above, electrical signals arrive in the brain from all the sense organs, such as the eyes and ears. Those signals themselves are not directly correlated with conscious experiences. They feed into sensory parts of the cortex of the brain, and trigger off growing cascades of signals in the brain, which serve to process the input. Which components of this immense swirling sea of electrochemical signals actually correlate with, or reflect, your conscious experiences, is not yet known. It is the subject of intensive experimental and theoretical research at many universities. One of the most exciting theories is that the neural correlates are quantum mechanical events that occur in the 'micro-tubules' inside the brain cells themselves. The Oxford physicist Roger Penrose has detailed this theory in his books, THE EMPEROR'S NEW MIND and SHADOWS OF THE MIND.

The key point to bear in mind (which Penrose himself often tries to fudge) is that these correlates are just that: correlates. What is going on in the brain is not conscious. It is only correlated with your conscious mind, rather as the flat shadow you cast on the ground on a sunny day is correlated with your reality as a living being.

That we can systematically modify the mind by doing things to the brain has been well established at least since the 1950s. Indeed, this forms the basis of the electro-stimulated virtual reality that we discussed at length earlier. Nevertheless, that does not mean that the mind is nothing but that electrical activity in the brain. Rather, when a virtual reality computer such as the Matrix pumps signals into the brain, those signals are processed by the brain, which conveys their influence to the conscious mind.

Freedom of conscious interpretation

The matter does not end with smells and tastes, though. What about colours? The orange colour with which my study is painted is every bit as uniquely conscious a quality as the taste of fried mushrooms. A non-conscious machine could not have this experience of colour. A computer can, of course, store information about colours: I have colour photographs held in files on my personal computer, which I can display on the screen. Nevertheless, the computer is just shunting the bits of information around without possessing the slightest glimmer of awareness of the conscious experience of colour that I will have when those bits activate the monitor and the image is displayed. For similar reasons, all the other sensations that I can be conscious of will elude the digital computer. The feel of silk, the texture of the crust of a piece of toast, the feeling of nausea, or of giddiness: these are all essentially conscious experiences and therefore unavailable to insentient machines.

This being so, Mouse was rather timid in The Matrix when he speculated that the computers could not know what chicken meat should taste like. In fact, the computers would not know what anything should taste or smell like; nor would they know what anything looked or sounded or felt like. Although their virtual world may include red roses, the computers cannot know what it is like to see the colour red.

Following Mouse's reasoning, then, we might suppose that the Matrix could have been wrong about everything. For instance, all the colours that people see inside the Matrix may be the wrong colours. In fact, we shall see later that there happen to technological constraints that would, in practice, force the Matrix to get it right. For the moment, however, let us follow Mouse's claim that the Matrix computers could, in principle, be mistaken; and let us explore where it takes us. As far the computers are concerned, when people look at the (virtual) sky inside the virtual world, they may not see the same colour that we see when we look at the sky. We may both use the word "blue" to label it, but the experience of it may be different. Inside the Matrix, people could see the colour that we call "red" filling a cloudless day-time sky, and see the colour that we call "blue" on the surface of tomatoes, but nonetheless they would still talk about "blue skies" and "red tomatoes". Had the Wachowski brothers been cinematically more adventurous, they might have played around with this notion, and transposed colours in the scenes that are shot inside the Matrix. For instance, they could have transposed blue and red, or rendered the whole film in negative. There would, of course, be swings and roundabouts in doing this. On the one hand, it would emphasise that, inside the Matrix, people exist in a different perceptual world. On the other hand, it would make it harder for the audience to imagine that life inside the Matrix would seem perfectly natural to the people who are inside it. On balance, the directors were probably right to resist the temptation to indulge in such cinematographic permutations, their main duty being the clear and entertaining presentation of the ideas.

A comparison can be made, though, with other films that deal with the transgression of worlds. In Victor Fleming's The Wizard of OZ (1939), the real world is shot in monochrome, and the film shifts to colour when Dorothy enters the dream world of Oz. The same is done in Andrei Tarkovski's Stalker (1979), when the stalker, the writer, and the scientist leave the mundane world and enter the Zone. The opposite was used in Wim Wender's Wings of Desire (1987), where the angelic world is monochrome and we shift to colour when an angel drops down and enters the mundane world. Yet, in neither of these cases does the director begin to explore what we have just seen to be the arbitrary connection that happens to exist between the qualities of conscious experience and their corresponding physical stimuli - the arbitrary association of redness with light of a certain wavelength. Yet, the idea is hardly an advanced one. What child has not wondered whether other people see the same colours as she does, or whether they see permuted colours, or even completely different colours but going by the same names?

We could even go a step further in imagining life in the Matrix. 'Synaesthesia' is the name given to a disorder in which people 'see sounds' or 'hear colours' - or, in general, have conscious sensations that belong to one modality, in response to a physical stimulus that belongs to another modality. It is as if some neural wires get crossed inside the brain so that, instead of just hearing sounds in the normal manner, the person also has sensations of specific colours. The colour experiences that are evoked by the sounds are thought to be genuine perceptions of the sounds, and not just associated memories, because the same sound is found to produce precisely the same colour in tests conducted years apart.

The concept of synaesthesia leads us to entertain a new world of possibilities that could arise in a neuro-stimulated virtual reality. What if the Matrix computers accidentally wired people up so that they never saw colours in response to visual input data but only heard a two-dimensional array of sounds? For the people inside the Matrix, there would be nothing odd about this at all. They would be born into a world in which information that comes from the (virtual) eyes takes the form of sounds. Strong or weak (virtual) light falling on their (virtual) eyes would produce mental experiences of loud and quiet sounds; and different wavelengths of (virtual) light would produce mental experiences of different tones of sound. Likewise, (virtual) sound waves impinging on the (virtual) ears would produce sensations of differently coloured light. It would be an internally consistent system of perception: they would see only sound waves, and hear only light waves. Nobody in the Matrix would think it amiss. Nor would it ever occur to anyone inside the Matrix that 'in reality' the sensations of sound and colour should be the other way around. Of course, the Matrix computers in a playful moment might decide to configure some individuals in such a way that they see both acoustic waves and optical waves as colours. Such people would be classed as 'synaesthetic'. Paradoxically, there might also be science fiction writers living within the Matrix who would write stories about an imaginary race of people held captive in computer-driven virtual reality, in which optical energy falling on the eyes produces sensations of colour, and acoustic energy falling on the ears produces sounds. Readers within the Matrix would then stretch their imaginations to conceive of such a world, just as we stretch our imaginations to conceive of people seeing sounds and hearing light.

Despite the vividness of the big cinema screen, the medium of the cinema could never handle such a science fiction story. Only the medium of writing has the expressive power to take us into an imaginary world where people smell colours and see sounds. This is far beyond the Wachowski brothers' territory, but they deserve credit for at least giving us a pointer to it. We have, however, not yet exhausted this line of thought: things can get stranger still. Let us go back to the popular children's question: do other people see same colours as you do? How can you ever tell? The fact is that nobody can tell whether or not we are using the same names to designate the same colours. Take the word "blue", for instance. Every person you meet could have a different mental sensation that he or she calls "blue". As long as each person consistently has the same so-called "blue" sensation when looking at the same thing, such as a cloudless sky on a sunny day, then it is impossible to tell whether those private sensations are the same or different. Likewise inside the Matrix. The computers could induce quite different sensations in each individual's mind, and nobody would notice. For (virtual) light of the wavelengths 490 to 445 nanometres, the computers could induce a completely arbitrary sensation, which each person would call "blue". Since nobody can peek into someone else's mind and check out what exactly they are experiencing, nobody would realise what the Matrix was doing. And, since the computers are mindless machines, it would probably never occur to them that humans have conscious sensations anyway, let alone worry about whether they experience the same blue or not. We need to stop for a brief digression here. If each person's blue could be different, what do words like "blue" refer to? The Cambridge philosopher Ludwig Wittgenstein famously pointed out that a public language, such as English, can never really refer to the private sensations of colour. He had the important insight that a language was like a game, and he coined the term "language-game". When people talk about blue things, such as the cloudless sky, or about the paint that is called 'Cobalt Blue', they succeed in communicating meaningfully. Yet, each person's actual experience of blue is unknown to the others and could be quite different. How is this possible? Wittgenstein realised that the word "blue" does not actually refer to the mental sensation. Rather, it is like a place-holder in the language-game. It is like the pawn in a game of chess: it plays a meaningful role in the game, but does not refer to anything outside the game. Wittgenstein wrote the following illustration:

Suppose everyone had a box with something in it: we call it a "beetle". No one can look into anyone else's box, and everyone says he knows what a beetle is only by looking at his beetle. - Here it would be quite possible for everyone to have something different in his box. One might even imagine such a thing constantly changing. - But suppose the word "beetle" had a use in these people's language? - If so it would not be used as the name of a thing. The thing in the box has no place in the language-game at all; not even as a something; for the box might even be empty. - No, one can 'divide through' by the thing in the box; it cancels out, whatever it is. (Philosophical Investigations, 293.)

We begin to see that conscious experience is ineffable in a very special sense. We discussed earlier that it is impossible to find the words to describe, say, the colour red to someone who has experienced it. Now, we see that conscious sensations are in fact completely insulated from public language. Even if someone else has had the same experience of the colour red as you have, you can never succeed in referring to it. This is because you could never peek into her mind to see what her experience of red looked like. So you could never establish what sensation it was that you meant by the word "red". The best that you can do is to refer to your own experience as "the experience of the colour red", and hope that other people have the same experience - but bearing in mind that this is a very odd expression that has a different meaning for each person. This is as far as we need to go down the philosophical rabbit hole, so let us try to get back to solid things. We have seen that Mouse's remark about the taste of chicken leads us to realise that we never really know what anyone else experiences in their mind anyway, be it in 'real life' or in the Matrix. How does this speculative philosophy mesh with what we know about the brain? In an earlier section, we concluded that the Matrix must be feeding its input signals in the afferent nerves, just as they enter the brain. It does not inject signals into the deeper nerve centres. We know this because when Neo wakes up, he finds himself fully equipped with a capacity for sense perceptions. This would be possible only if his sensory nervous tissue has been kept in working order throughout his life, which implies that the Matrix had been sending its data through the normal sensory brain tissue.

So, what happens when Neo, or anyone else, eats (virtual) fried chicken whilst living inside the Matrix? The Matrix will transmit electrical signals to the nerve fibres that enter his brain from his tongue and nose, and his brain will interpret the resulting brain activity as taste sensations. Those signals will be designed to reproduce the actual train of electrical impulses that would travel along the olfactory and gustatory nerves from the nose and mouth if that person were actually eating the chicken meat. So, in this case, it turns out that the Matrix does not possess the degree of freedom that Mouse assumed it had. How the brain interprets the input information will be just the same as in nature. The Matrix is not interfering with the interpretation circuits of the brain: it is only hi-jacking the input and output streams.

We now see that, as far as the Matrix is concerned, Mouse's worry about the taste of chicken inside the Matrix was misplaced. Provided that the computers have carried out a correct chemical analysis of chicken flesh, they can compute the chemical substances that will be in contact with the gustatory buds in the mouth and the olfactory buds in the nose. From that, they can work out which nerve fibres will fire when chicken meat is eaten, and they can therefore artificially reproduce that train of electrical impulses. The computers still have no notion of the subjective taste of chicken: but that does not stop them recreating the right input signals.

Given that Mouse's question was a false alarm, why have we spent several pages discussing this question? The answer is: because Mouse's question is in the film for a reason. It is a clue to a bigger story.

In her book, Computers as Theatre, Brenda Laurel makes some profound analyses of the relationship between theatrical performances and computer interfaces. Both involve putting on a show, which must be meaningful to, and digestible by, an audience. Her remarks also apply to films. One of the implications of being meaningful and digestible is that the film should avoid gratuitous incidents. In the pared down method of the Russian drama teacher, Konstantin Stanislavski, the actor should do nothing that does not serve a purpose in advancing the plot in some way.

Assuming that Wachowskis have followed normal conventions of dramatic construction, we may assume that Mouse's question about the taste of chicken, and the ensuing discussion around the mess table, serve a dramatic purpose in the film. And yet, we have seen that the Matrix's method of data entry removes any risk that the taste of chicken or any other perceptions will be mistaken. So, what is Mouse's question telling us? As will become clearer as we go further into the film, there is an esoteric story going on, besides the exoteric one. An 'exoteric' meaning is one that is presented openly to the audience: it is lying on the surface for you, and you do not have to dig for it. On the other hand, an esoteric meaning has to be extracted by reasoning about the contents of the film. The term 'esoteric' has acquired a bad press, because a lot of commentators have forced somewhat arbitrary meanings on ancient texts. In this year of 1999, for instance, there are a lot of works being published that extract supposed esoteric meanings from the writings of Nostradamus. Many of those works, however, are bogus, as they have projected meanings onto ambiguous texts that were not put there by the author. Proper hermeneutics relies on rigorous reasoning, and unambivalent step-by-step logic to discover esoteric significance.

Let us stop for a moment and consider who or what the author of a film really is. In separating the hermeneutical wheat from the hocus-pocus chaff, we should be careful not to be over-zealous in laying down a strict definition of what we mean by the term 'author' (which, for convenience, I shall take to include the 'auteur', or director, of a film). An author is not a creator, but a conduit for creative forces. The act of artistic creation crucially involves a letting go of deliberate control. She must train herself to be receptive to creativity, and must create a space in which creativity can manifest; but part of the discipline of authorship is the releasing the reins of power to enable the act of creation to happen. After creativity has manifested, the critical faculties are again called upon to sort, select, polish, and integrate the fruits of creation. In his inimitable style, the Spanish surrealist painter Salvador Dali described this as the 'Paranoiac-Critical Method', comprising what he called the 'Paranoiac' phase of immersion in the chaotic imagery of the subconscious, followed by the Critical phase of meticulous development.

If, therefore, I suggest that there is an esoteric significance in a film, it does not imply that the directors were fully cognisant of it, or even aware of it at all. The science-fiction writer Isaac Asimov commented that he was often surprised by the actions of his own characters in his novels. You should not reject as implausible that films such as eXistenZ and The Matrix contain an esoteric backbone that their directors may not even have been fully aware of.

This may sound somewhat mysterious and even pretentious, but it is well established in film studies that the movies, just like other works such as plays and novels, carry and express social assumptions or ideas. These are examples of esoteric, rather than exoteric, meaning. What is less well known, however, is that such works may instead carry and express psychological, philosophical, or spiritual ideas.

What this is leading up to is the claim that The Matrix carries an esoteric meaning about of the nature of reality, and that Mouse's remark about the taste of chicken is part of a series of signs directing us toward that meaning. For, if the electronic Matrix works in such a way that it does not have enough power and freedom to mix up our perceptions, then Mouse must be pointing us toward a bigger matrix that does have that power - a matrix vast enough to contain within it not only the film's computers and their Matrix but all of our reality too. That is the bigger story of The Matrix.

Bibliography

Filmography

© Peter B. Lloyd, 1999, 2000. Last modified 26 May 2000.

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