The Mind is Flat

Prologue: Literary Depth, Mental Shallows

The inner, mental world, and the beliefs, motives, and fears it is supposed to contain is, itself, a work of the imagination. We invent interpretations of ourselves and other people in the flow of experience, just as we conjure up interpretations of fictional characters from a flow of written text.
There is no pre-existing "inner world of thought" from which our thoughts issue. Thoughts, like fiction, come into existence in the instant that they are invented, and not a moment before.
Introspection is a process not of perception but of invention: the real-time generation of interpretations and explanations to make sense of our own words and actions. The inner world is a mirage.
The very task of our improvising mind is to make our thoughts and behavior as coherent as possible - to stay "in character" as well as we are able. To do so, our brains must strive continually to think and act in the current moment in a way that aligns as well as possible with our prior thoughts and actions. We are like judges deciding each new legal case by referring to, and reinterpreting, an ever-growing body of previous cases. So the secret of our minds lies not in supposed hidden depths, but in our remarkable ability to creatively improvise our present, on the theme of our past.
There is no inner world. Our flow of momentary conscious experience is not the sparkling surface of a vast sea of thought - it is all there is.
Our brain creates new momentary thoughts and experiences by drawing not on a hidden inner world of knowledge, beliefs, and motives, but on memory traces of previous momentary thoughts and experiences.
Our brain is an engine that creates momentary conscious interpretations not be drawing on hidden inner depths, but by linking the present with the past, just as writing a novel involves linking its sentences together coherently, rather than creating an entire world.
The whole of thought, whether chess-playing, abstract mathematical reasoning, or artistic and literary creation, is really no more than an extension of perception.
Our freedom consists not in the ability magically to transform ourselves in a single jump, but to reshape our thoughts and behaviors, one step at a time: our current thoughts and actions are continually, if slowly, reprogramming our minds.
Common-sense psychology sees our thought and behavior as rooted in reasoning, but a lot of human intelligence seems to be a matter of finding complex patterns.

Part One: The Illusion of Mental Depth

1. The Power of Invention

The attempt to draw a map, or build a model, of Gormenghast Castle leads to inconsistency and confusion - the descriptions of great hallways and battlements, libraries and kitchens, networks of passages and vast, almost deserted wings can't be reconciled. They are as tangled and self-contradictory as the inhabitants of the castle itself.
Creating a fictional place is a bit like setting a crossword. Each description provides another clue to the layout of the castle, city, or country being imagined. But as the number of clues increases, knitting them together successfully soon becomes extraordinarily difficult - indeed it rapidly becomes impossible, both for Gormenghast's readers and for Peake himself.
Stories have to make sense in so many ways: through consistency of plot, character, and a myriad of details.
With fictional worlds, avoiding inconsistency requires incredible vigilance.
Even the fictional worlds of Tolkien and Peake are notable too for their sparseness. In real life, everyone has a specific birthday, fingerprint and an exact number of teeth. In fictional worlds, most characters have none of these properties, or any of a million others, whether significant or trivial.
Anna Karenina's mind is just as vaguely sketched as her body.
The two characteristics of fiction: Inconsistency and sparseness.
Whereas the fictional Anna is a sketchy and contradictory character created by Tolstoy's brain, a real Anna would be an equally sketchy and contradictory character, created by her own brain.
Our beliefs, values, emotions, and other mental traits are, I suggest, as tangled, self-contradictory and incompletely spelled out as the labyrinths of Gormenghast Castle. It is in this very concrete sense that characters are all fictional, including our own. Inconsistency and sparseness are not just characteristics of fiction. They are also the hallmarks of mental life.
In the work on AI mental systems, at no stage have human beliefs been successfully mined or common-sense theories reconstructed.
People can fluently generate verbal explanations and justifications of their thoughts and actions; and, whenever parts of those explanations are queried, out will tumble further verbal explanation or justification. But analysis of these streams, however long they continue, shows that they are little more than a series of loosely connected fragments:
- Chess grandmasters can't really explain how they play chess.
- Doctors can't explain how they diagnose patients
- None of us can remotely explain how we understand the everyday world of people and objects. What we say sounds like explanation - but really it is a terrible jumble that we are making up as we go along.
As we try to explain a natural phenomenon or social situation, each explanation seems to be new, different and typically incompatible with the last one, rather then following from a single set of underlying principles - the explanations of every new scenario just seem to run off on all directions, apparently without limit. Moreover, each step in each explanation can itself be queried. Why does water tend to find a level? Why do ballbearings bounce off each other? Why does sugar change consistency as it enters the bucket of water? And so on.
Our explanations have holes everywhere and inconsistencies abound. Psychologists talk of the "illusion of explanatory depth" for the bizarre contrast between our feeling of understanding and our inability to produce cogent explanations.
Whether explaining how a freidge works, how to steer a bicycle, or the origin of tides, we have a feeling of understanding which seems wildly out of balance with the mangles and self-contradictory explanations we actually come up with.
Our verbal explanations of the physical world - but equally of the social, economic worlds or our moral or aesthetic judgements - turn out not to be a confused description of inner clarity, but a confused description of inner confusion.
Our verbal explanations and justifications are not reports of stable, pre-formed building blocks of knowledge, coherent theories over which we reason, deep in an inner mental world. They are ad hoc, provisional, and invented on the spot.
We have vastly underestimated our powers of invention. Our inner oracle is such a good storyteller - so fluent and convincing - that it fools us completely. But the mental depths our mind conjures up are no more real than the world of Gormenghast or Middle Earth. The mind is flat: our mental surface, the momentary thoughts, explanations, and sensory experiences that make up our stream of consciousness is all there is to mental life.
The analytic tradition in philosophy tried to get language and meaning straight, as a crucial stepping-stone to launch an indirect attack on big philosophical questions, but it did not work.
Even the structural patterns observed in language - not just its meaning - are a jumble of inconsistent regularities, sub-regularities, and outright exceptions.
Countless experiences in psychology and behavioral economics have shown just how spectacularly ill-defined and self-contradictory our beliefs and preferences are.
People routinely supply wildly different answers to exactly the same question even within a few minutes, and their answers to different questions are often inconsistent.
We may or may not have strong opinions, but these opinions don't - and could not possibly - spring from coherent and fully spelt-out common-sense theories.
From the perspective of the arts, literature, and humanities, there is a long tradition of seeing people and their actions as the subjects of conflicting, fragmented, and endlessly recreated interpretation. But viewing psychology as part of the arts and humanities is to react to the illusion of mental depth in, I think, precisely the wrong way. A science of the mind requires understanding how the engine of improvisation that is the core of human intelligence can be constructed out of the machinery of the human brain.

2. The Feeling of Reality

Invented stories are notoriously difficult to distinguish from true stories - both feel real.
The mind-as-mirror metaphor can't possibly be right - we need a very different viewpoint, that perception requires inference.
Our brain glimpses, and conceives of, the world fragment by fragment.
Illusions of depth, which can be both literal and metaphorical are everywhere.
Outside of where we are attending, the visual periphery is colorless and extremely fuzzy.
Our attention is in short supply and where we are not attending, things disappear.
A gaze-contingent screen can track where you are looking at provide meaningful content only there. The window that we read in can be shrunk to just 10-15 charcters, shifted somewhat to the right of the fixation point, because the brain is thinking ahead slightly.
What happens when the retinal image is suddenly made almost perfectly still?
- The image begins to disappear, either piece by piece, or in its entirety; all that is left is a uniform grey field which sometimes darkens into black. Then, without warning, the whole image or parts of it spontaneously reappear typically to disintegrate, reorganize, or entirely disappear again.
- Now and again, the brain re-engages with the only available meaningful signal, and the straight line pops back into view. But not for long - our whirring imagination is continually straining to find new material onto which an interpretation can be imposed.
- The visible material retained at any moment tends to correspond to continuous regions of the image (ag the upper, lower, or left side) or meaniful units rather than a set of arbitrary fragments.
- The fragments that the brain locks onto are meaningful patterns, rather than random parts.
Principles of the operation of perception (and, by extension, thought):
- We see only meaningful organizations (or, at least, the most meaningful organization the brain can find): visual chunks, patterns and whole letters, numbers, words, rather than a random scatter of fragments.
- We see just one meaningful organization at a time
- Other sensory information that is not part of this meaningful organization is largely or even entirely ignored, to the point of becoming invisible.
- The brain is continually churning: despite the unaccustomed lack of new input, the brain is desperately attempting to disengage from the current organization, and to find another. When it cannot, the image entirely disappears.
Perceiving is a type of thinking and perhaps the most important type, with all other types of thought being just powerful extensions of perception.
We think we see a detailed multicolored world, but we don't. This hoax is so astonishing and all-encompassing that it is sometimes known in philosophy and psychology as the "grand illusion".
The mind itself is an impossible object - it has only the superficial appearance of solidity.

3. Anatomy of a Hoax

Our perceptual experience is like a narrator who wishes to remain as unobtrusive as possible - we want to know about the story, not the viewpoint of the storyteller.
While it si possible, not surprisingly, to perceive multiple locations at once, it appears not to be possible to see two colors at once: indeed, it seems that we must switch back and forth between seeing one colored region and another, but hat we do this so quickly and effortlessly that we have the illusion that we are "grasping" two or more colors at the same time.
A patient with simultagnosia is able to see objects of different distances and sizes - but has no sense of the continuing existence of the rest of the visual world.

4. The Inconstant Imagination

Our sense of the vividness of the tiger in a picture stems from the fluency with which we can answer any question we wish about its appearance - but the information is created on demand, not loaded into our brains in a single visual gulp.
We don't "load" vast quantities of information about an object or a scene simultaneously into our memory - but we can have the answer to any question about visual experience available just when we need it.
Mental imagery, too, is both sparse and contradictory.
Aren't the realms of fiction, fantasy, and dreams illustrations of the richness of the inner worlds that our minds can construct?
Our imagination, like visual experience, is a narrow window of lucidity, and what we see through that window is invented - creatively, subtly, intelligently - not merely reported from some fully specified, entirely coherent inner world.
The "world" of dreams is a fiction, a jumble of fragments and contradictions. Indeed, it is a particularly inchoate fiction: there is no careful author painstakingly attempting to bring the story into some kind of order - merely a succession of capricious imaginative leaps.
Dreams are improvised stories, with few details sketched in. When our minds create them, we lock onto some specific fragments of information; almost everything else is left utterly blank.
The inconsistent, sketchy flow of thought is not a projection of a rich and deep inner mental world. Our thoughts are not shadows of an alternative inner reality, to be charted and discovered; they are fictions of our own devising, created moment by moment.
Graf and Freud's mistake was to confuse literary creation with psychology. They were able to invent a story about Herbert/Hans and his phobia; and they could equally easily have invented a variety of alternative stories. They believed psychology should be science, they practised it as a literary art form.
We may feel rather unsure exactly about the nature of the inhabitants of our inner world, but plausible candidates would seem to te beliefs, desires, hopes, fears, mental images, logical arguments, justifications, feelings of anxiety, delight, excitement, gloom, contentment, resignation or enthusiasm, flashes of anger or surges of empathy. Our vagueness about quite what our minds contain is by no means accidental - the solidity of our mental furniture is liable to dissolve as soon as we reach out and touch it.

5. Inventing Feelings

The Kuleshov effect - inserting still images evoking emotions in between images that are part of the action, and seeing these images change the interpretation of the scene.
The brain interprets each piece of the perceptual input (each face, symbol, object, or whatever) to make as much sense as possible in the light of the wider context.
Isn't our bodily state just another set of highly ambiguous clues that need to be interpreted, which can be explained in many different ways depending on the situation we are in? Perhaps emotions - including our own emotions, are just fiction too.
The brain receives rather crude perceptual signals from your own body, indicating that your hear is pumping, and a certain amount of adrenaline is flowing, you are breathing rapidly, etc. But what does it all mean?
Our feelings do not burst unbidden from within - they do not pre-exist at all. Instead, they are our brain's best momentary interpretation of feedback about our current bodily state, in the light of the situation we are in. We "read" our own bodily states to interpret our own emotions, in much the same way as we read the facial expressions of other people to interpret their emotions.
Maybe just two physiological dimensions will suffice: one indicating level of arousal and the other indicating like-dislike.
Plato sees reason and emotion as two horses pulling in opposite directions. But this goes astray from the outset - having an emotion at all is a paradigmatic act of interpretation, and hence of reasoning.
The two forces are just two different types of reason, with both carrying positive and negative reasons and feelings.
Far from knowing our own minds, we are endlessly struggling to make sense of our own experiences - and we can often jump to the wrong conclusions. Even attraction, it seems, does not well up from within from some primal source. We feel a surge of adrenaline as attraction rather than experiencing it as fear or anger, because of the circumstances that confront us - our brains, are, moment by moment, attempting to interpret the minimal physiological feedback from our body.
Emotions have their meaning not through some elementary properties of raw experience, but through their role in our thoughts, our social interactions and our culture.

6. Manufacturing Choice

The corpus callosum - a massive bundle of more than 200 m nerve fibres, whose role it is to exchange messages between the two hemispheres of the brain.
Michael Gazzaniga and the "interpreter" - a master of speculation.
The very ability of the interpreter to create such stories may be crucial to maintaining the sense of the mental unity for the split-brain patient. But for people with normal brains, choices are also naturally and fluently explained after the fact.
Deciding what to say is a creative act, rather than a read-out from a comprehensive database of my beliefs, attitudes, and values.
Our beliefs, desires, hopes, and fears do not wait pre-formed in a vast mental antechamber, until they are ushered one by one into the bright light of verbal expression. The left-brain interpreter constructs our thoughts and feelings at the very moment that we think and feel them.
In a Swedish study, people's responses to a survey were reversed. People are able to effortlessly cook up a perfectly plausible story to justify an opinion that they did not express, just as easily as they are able to justify opinions that they did express. And we are blithely unaware of the difference between the two.
The interpreter can argue either side of any case; it is like a helpful lawyer happy to defend your words or actions whatever they happen to be at a moment's notice. So our values and beliefs are by no means as stable as we imagine.
The story-spinning interpreter is not entirely amnesic; and it attempts to build a compelling narrative based on whatever it can remember. It works by referring back to, and transforming, memories of past behavior - we stay in character by following our memories of what we have done before.
The interpreter does not merely describe our past actions, but helps shape what we do next.
Even more important than explaining a decision is the aim of being consistent - to make choices that the interpreter can justify and defend. It is so much easier, and so much more convincing to be consistent.
We attempt continuously to construct our preferences to fit the thoughts that happen to be splashing through our stream of consciousness.
The brief presence of an American flag in an internet survey had significantly shifter actual voting behavior, a full eight months later! To the extent that I later recall that, when contemplating my political views, I previously found myself leaning to the right, I am a little more likely to lean to the right in the future. To make the most sense of my own behavior, I will aim to think and act as I did before.
When we make choices, we are not expressing a pre-existing preference at all. What we are doing instead is improvising - making up our preferences as we go along:
- If we are asked to choose an option, we mostly focus on positive reasons.
- If we are asked to reject an option, we mostly focus on negative reasons.

Part Two: The Improvised Mind

7. The Cycle of Thought

Despite being a pudgy bundle of fibres powered by a modest 20 watts of energy, the human brain is by far the most powerful computer in the known universe It can interpret a bafflingly complex sensory worlf, perform a hubes variety of skilled actions, and communicate and navigate a vastly complex physical and social world.
A PC has one or at most a few processing chips, processing at a phenomenal rate, while the human brain has roughly 100 bn sluggish neurons, linked by roughly 100 tn connections.
Brain-style computation must result from cooperation across the highly interconnected, but slow, neural processing units, leading to coordinated patterns of neural activity across whole networks or perhaps entire regions of the brain.
The brain seems to be pretty close to one giant, highly interconnected network (although the connections between different regions of the brain are not equally dense).
The brain's slow neural units split up the problem into myriad tiny fragments and share their tentative solutions in parallel across the entire, densely interconnected network.
What is important is that the very fact that the brain uses cooperative computation across vast networks of neurons implies that these networks make one giant, coordinated step at a time rather than, as in a conventional computer, through a myriad of almost infinitesimally tiny information-processing steps. This sequence of giant, cooperative steps, running at an irregular pulse of several "beats" per second, is the "cycle of thought".
Whatever object or task is engaging our conscious attention will typically engage large swathes of the brain. Accordingly, there will typically be severe interference between any two tasks or problems that engage our conscious attention.
The entrainment in epilepsy typically starts in a specific region of the cortex, as if the inhabitants of one district are particularly prone to spontaneously launching into Mexican waves - and the nearby neighborhoods are then drawn in, and the wave spreads inexorably across the city.
Most information from our senses passes through the thalamus before projecting onto the cortex; and information passes in the opposite direction from the cortex through to deep sub-cortical structures to drive our actions.
The deep brain serves as a relay station between the sensory world and the cortex, and from the cortex back to the world of action. Here, perhaps, somewhere in these deep brain structures, is the crucial bottleneck of attention; and whatever passes through the bottleneck is consciously experienced.
A "petit mal" episode involves a person, during everyday activity, suddenly adopting a vacant stare and becoming completely unresponsive to their surroundings. Unlike epilepsy, this doesn't spread across the brain but seems to impact the whole brain simultaneously, and leaves no memory after consciousness spontaneously returns.
No electrical stimulation of the cortex itself could trigger the crisp, immediate, total shutdown of the cortical system, because, Penfold suggested, the "switch" of consciousness lies not in the cortical surface but deep within the brain.
Our brain is fully engaged with making sense of the information it is confronted with at each moment. Consciousness, and indeed the entire activity of thought, appears to be guided, sequentially, through the narrow bottleneck: deep sub-cortical structures search for, and coordinate, patterns in sensory input, memory and motor output, one at a time. The brain's task is, moment by moment, to link together different pieces of information, and to integrate and act on them right away. Our brain will, of course, lay down fresh memories as this processing proceeds; and draw on the richness of memories of past processing.
While the cortex is crucial in processing visual information, planning movements and drawing on memories, we are aware of the results of the vast cooperative enterprise across the brain only in so far as the results of such computations reach the sub-cortical gateway structures - these, and not the cortex itself, are the locus of conscious experience.
Four proposal:
- Attention is a process of interpretation - The target might be aspects of sensory experience, a fragment of language, or a memory
- Our only conscious experience is our interpretation of sensory information - All we experience is the stable and meaningful world: we experience the result, not the process.
- We are conscious of nothing else - Sensory information need not necessarily be gather by our sense, but may be invented in our dreams or by active imagery. and much sensory information comes, of course, not from the external world but from our own bodies - including many of our pains, pleasures, and sensations of effort or boredom. We are conscious of the sounds or shapes of the words we use to encode abstract ideas; or the imagery that accompanies them. But we are not conscious of the abstract ideas themselves, whatever that might mean. Words and images are the objects of consciousness - not the abstract belief.
- The stream of consciousness is nothing more than a succession of thoughts, an irregular cycle of experiences which are the results of sequential organization of different aspects of sensory input.

8. The Narrow Channel of Consciousness

Our perceptual system is continually ready to raise the alarm - and to drag our limited attentional resources away from their current task in order to lock onto a surprising new stimulus; But these alarms systems don't themselves involve the interpretation and organization of sensory input; instead they help direct our attempts to organize and interpret sensory input. So we do not know what it is that has attracted our attention until we have locked onto the unexpected information and attempted to make sense of it.
This means that we are sometimes oblivious to information to which we are not attending, even though it may be in plain view - inattentional blindness.
Focusing on a tricky visual judgement can lead not only to inattentional blindness (even for a stimulus we are looking at directly), but also to inattentional deafness.
Our brains lock onto fragments of sensory information, and work to impose meaning on those fragments. But we can only lock onto and impose meaning on one set of fragments at a time. If our brains are busy organizing the lines on a heads-up display, we may miss the large aircraft turning onto the runway in front of us, in the same way that, peering through a lighted window into the garden, we can be utterly oblivious of our own reflection.
As the brain's processing proceeds, the effort of interpretation will narrow ever more precisely on the scraps of information that helped form whatever pattern is of interest, and the processing of other scraps of information will be reduced and, indeed, abandoned.
There is a characteristic frisson of brain activity associated with reading a word in contrast merely to a meaningless string of letters.
Without attention, there is no interpretation, analysis, or understanding.
The brain is densely interconnected - and almost any moderately complex problem, from understanding a sentence to recognizing a face or seeing a constellation in the night sky, will typically involve activity across vast swathes of the cortex. So our ability to carry out several mental activities in parallel will be severely limited.

9. The Myth of Unconscious Thought

When a solution suddenly pops out, we have a sense of sudden insight, but no idea how to explain where it came from. Without warning, order emerges from chaos. We have no sense of getting warmer or colder before insight suddenly hits us - we have a sense of floundering aimlessly, followed, if we are lucky, by what feels like a bolt from the blue of understanding. The problem is solved not by a sequence of steps, getting ever closer to the answer. Quite the opposite: the cycle of thought churns on and on, exploring different possible organizations with no sign of progress until, suddenly, and within a single step, it chances upon the solution.
The phenomenon of sudden insight stems not from unconscious thought, but from the nature of the problem: searching for a meaningful interpretation with few helpful and unambiguous clues.
Solving difficult problems, whether mathematical, musical or of any other kind, is the very antithesis of a routine, specialized problem with a dedicated brain network: on the contrary, thinking about such problems will need to engage most of the brain.
What is special about such problems is that you can't solve them through a routine set of steps. You have to look at the problem in the right way before you can make progress.
Breaking out of mental cul-de-sacs is precisely what a break will give us. Starting afresh with a relatively clear mind is more likely to succeed than a mind filled with partial solutions and suggestions which, after an increasingly frustrating struggle, have clearly failed.
Unconscious problem-solving and unconscious thought of all kinds is a myth.
The flash of inspiration represents no more than the revelation of a new and promising direction to explore - it is the starting point for a long period of creation, perhaps even creative struggle.
Though you believe you can hold a conversation, listen to the radio, and drive at the same time, in fact you are rapidly switching back and forth between each task, and multitasking in this way will necessarily slow down your reactions to unexpected events on the road.
Now and again, thoughts do pop into our minds - names we have struggled to remember, things we have forgotten to do, and occasionally even insights into tricky problems with which we have been struggling. But this isn't the product of unconscious, background thought. It arises when we flip back to thinking about an old problem for a moment and, now free of the unhelpful mental loops which got us stuck in the first place, we see a solution that had evaded us before - or, in some cases, dimly suspect where such a solution might lie.
The flash of inspiration is perhaps better termed a flash of suspicion.

10. The Boundary of Consciousness

Consciousness is, then, analogous to the read-out of a pocket calculator, a search engine, or an intelligent computer database.
Behind that read-out is a welter of electrical signals sparking across rich and complex networks of neurons, responding to current sensory input and past memory traces. This is the real nature of the unconscious: the vastly complex patterns of nervous activity that create and support our slow, conscious experience.
The neural processes within each cycle of thought are, crucially, not the kind of thing that could be conscious. They are, after all, hugely complex patterns of cooperative neural activity, searching for possible meanings in the current sensory input by reference to our capacious memories of past experience.
Consciousness if limited to awareness of our interpretation of the sensory world; and these interpretations are the result of each cycle of thought, not its inner workings.
Our consciousness experience is determined by what the brain thinks is present - the output of the cycle of thought, not its input.
When trying to work out the interpretation that best fits the web of inferences, the ideal approach is to consider all the constraints simultaneously - and continue to jiggle the interpretation unitl it fits this full set of constraints as well as possible.
The task of simultaneously matching a huge number of clues and constraints is just what the brain's cooperative style of computation is wonderfully good at.
It is tempting to imagine that the brain must have found some clever shortcut to avoid all these complex calculations. But the current consensus in AI, machine vision and perceptual psychology is that no such shortcut exists. Computer vision systems, from recognizing faces, scenes, or even handwriting typically work using roughly the "web of inference" method.
Perception is a process of incredibly rich and subtle inference - the brain is carefully piecing together the best story it can about how the world might be, to explain the agitations of its sense organs. Indeed, attempts to interpret sensory input, language or our own memories typically involve inference of great subtlety to figure out which story weaves together the data most compellingly.
Perception is not merely inference - it is, of course, unconscious inference.
Consider, when deep in a novel, how our flow of experience is taken over by the story - while we have no awareness at all of the mysterious process by which the brain transforms sequences of printed letters into images and emotions.
Mental processes are always unconscious - consciousness reports answers, but not their origins.
During a typical eye movement, the eye will be in motion for between 20-200 ms, depending on the angle through which the eyes "jump". During this period, we are in effect, almost completely blind. And each time our eyes "land on" and stick to a new spot, the image projected onto our retina, and hence onwards to our brain, is a fresh snapshot, abruptly discontinuous with what we have seen before.
So our visual input is a sequence of distinct "snaps" of the of the scene or page, rather than a continuous flow - and when the eye lands on a target, a new cycle of thought begins, locking onto elements of the snapshot and making sense of it (recognizing an object, reading a facial expression, identifying a word).
Your eyes never rove smoothly, except when you're tracking a moving object such as a passing car; aside from these specialized "smooth pursuit" eye movements, your eyes always move in discontinuous jumps).
Indeed, it is surprisingly difficult even to tell exactly where one is looking at any given moment - such is the power of the grand illusion that the entire visual field is simultaneously present in all its richness.
From the inside, the flow of thought feels entirely seamless.
The brain's goal is to inform us about the world around us, not about the workings of its own mechanisms.
We're like military officers reading a message in a cipher that has been broken: in order to decide our next move in battle, all we care about is what the message says, the process by which the code was broken, with whatever teams of brilliant analysts and banks of computers, is entirely invisible and irrelevant.
Our sense that seeing and hearing seem continuous arises because the brain is informing us that the visual and auditory world are continuous; and subjective experience reflects the world around us, not the operations of our own minds.
Our internal narrator wants us to focus on the story and to remain as unobtrusive as possible.
Hume: "For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception."
When we think of a number, what we are conscious of is not the number itself, but sensory impressions pertaining indirectly to the number, such as sensory impressions of the sound of things we might say about the number. We know lots of facts about seven, of course, surely what we are conscious of are nto the facts themselves, but sensory impressions - most notably of rather abbreviated snippets of English, running through our minds.
The same is true of supposed higher-order consciousness. I can hear myself "saying" internally: "I know I'm conscious" and "I must be conscious of being conscious" and I may have a vague visual image floating through my mind. But it is these sensory impressions, and their meaningful organization into images and snippets of language that I am conscious of - and no more.
Consciousness is necessarily superficial: it is defined by the interpretations through which we organize sensory experience.
We aren't really conscious of numbers, apples, people, or anything else - we're conscious of our interpretations of sensory experience (including inner speech) and nothing more.
Psychologists have often suspected there may be two (or more) different types of mental system fighting for control of our behavior:
- One or perhaps many unconscious mental systems that are fast, reflexive and automatic
- One deliberative system that is conscious, reflective, and slow.
Neuroscientists have suggested there may be multiple decision-making systems in the brain, at most one of which operates consciously, and which can generate conflicting recommendations concerning how we should think and act.
But the division between the conscious and the unconscious does not distinguish between different types of thought. Instead, it is a division within individual thoughts themselves: between the conscious result of our thinking and the unconscious processes that create it.
There are no conscious thoughts and unconscious thoughts; and there are certainly no thoughts slipping in and out of consciousness. There is just one type of thought, and each such thought has two aspects:
- A conscious read-out
- Unconscious processes generating the read-out
And we can have no more conscious access to these brain processes than we can have conscious awareness of the chemistry of digestion or the biophysics of our muscles.
We can't introspect how our lungs or stomachs work - why should it be any different for the brain?
Novelists exploit the chatter and imagery running through our head, but the stream of consciousness in To the Lighthouse or Ulysses is hardly an exploration of the innermost workings of the mind. The technique displays, at best, a sequence of partial results, workings, intermediate steps - the outputs of successful cycles of thought.
We engage in introspection to a limited degree, not about the operation of the cycle of thought, but about its successive outputs.
Ask yourself what you are thinking, and you cease to think it.
Of course, our attempt to makes sense of a movie or symphony will proceed in many sequential steps, following the flow of dramatic or musical events as they occur, but also stepping back to ponder their interrelationships and significance.
It is interesting to ponder what is happening when we are in this type of reflective mode, exploring and critically analyzing.
We can debate endlessly and reconsider not just our own lives, but our analysis and evaluations of our lives.
As with art and literature, such evaluations are about meaning, how best to make sense of our lives, and how to make our lives more meaningful in the future. Meaning, in this broad sense, is about fitting together, finding patterns, seeking coherence.
We do not merely live our lives, but frequently step back to comment on what happens and why, and we also wonder about the validity of our commentary, and so on, without any definite limit. But at each of these moments, the cycle of thought has a single task: to lock onto sensory (including crucially, linguistic) information and organize and interpret that information as far as possible.
We can, or course, debate art, literature, and life endlessly - and each turn of the cycle of thought attempts to impose meaning on those fragments that have gone before.
The search for meaning is the object of each cycle of thought; and meaning is about organizing, arranging, creating patterns in and making sense of thoughts, actions, stories, works of art, games, and sports.
Finding meaning is about finding coherence. And coherence is created step by step, one thought at a time; it is never complete, but is continually open to challenge and debate. And thi is how it should be; surely no novel, poem or painting, however profound, can be as rich, complex, challenging and as endlessly open to re-evaluation as an individual human life.

11 Precedent Not Principles

After five seconds, a top chess player is able to "read" the structure of a chess position - searching out which pieces are threatening which others, noting familiar patterns of pieces, finding, in short, what the position means.
Memory is the by-product of understanding: what we cannot interpret, we cannot remember.
The superior memory skills of grandmasters evaporate as soon as they are faced with arbitrary chess position, because they can impose no meaningful interpretations on these positions in relation to their huge repertoire of past chess experience.
Perhaps expertise in any domain, however remarkable, is not based on superior mental calculating power, but on richer and deeper experience.
We layer each momentary thought on top of past momentary thoughts, tracing an ever-richer web of connections across our mental surface.
We do not interpret every sensory impression afresh, but in terms of the memory traces of past sensory impressions.
The cycle of thought should, then, create an organization of the sensory input that depends not just on the input itself, but on resonance with memory traces of past inputs.
When interpreting a new stimulus, the brain may have little idea which memories it needs to search - indeed, it seems able to draw on its entire stock of memory traces equally easily. Before the interpretation has been made, the brain can't know which memories will be relevant - so it has to search them all.
We never see the world with fresh eyes.
What are memory traces like? What information do they contain? The most natural answer is that they are nothing more than the remnants of past interpretations of past perceptual inputs. As far as we know, these remnants are not later reorganized, filtered, corrected, or generally tidied up; and there is no internal librarian to carefully file and index each memory trace into a coherent archive. The remnants of each individual episode of perceptual processing lie, as it were, where they fall; the brain is immediately busy with the next cycle of thought, and the next.
Memory traces are fragments of past processing - so that it is past interpretations that are stored in memory, rather than raw, disorganized sensory input.
Today's memories are yesterday's perceptual interpretations.
Successful perception, then, requires almost instant conjuring up, and deploying, of the "right" memory traces to make sense of the current sensory input, just when we need them. This is remarkable in the light of the sheer number of such traces, accumulated over a lifetime.
Metaphors pervade our language and our thoughts - memories of one thing are fluidly and naturally linked to our memories of another thing.
The brain operates by the routine exercise of an astonishingly exuberant imagination.
We can have the feeling of immediate and simultaneous access to a vast repository of general knowledge, autobiography, likes, and dislikes, moral and religious convictions, and more. But in truth we impose meaning on one set of memory traces at a time. And when we do lock onto those memory traces, we impose meaning on them with the same flexibility and urgency that applies in perception.
The memories themselves are not thoughts: they are not, for example, beliefs, choices, or preferences. And we cannot merely read off their contents to know what we think, what we like, or what sort of person we are. Instead, they consist of mere fragments of past thoughts, to be reused, reconstituted and transformed by the cycle of thought.
We are like corals layered polyp by polyp, into infinitely diverse forms. What makes each of us unique is our individual and particular history - our own specific trail of precedents in thought and action. We are each unique, in short, because of the endless variety of our layered history of thoughts and actions.
Each of us is a tradition, guided and shaped by our past. Like traditions in music, art, literature, language, or the law, we are capable of refinement, adjustment, reinterpretation, and whole-sale reinvention.
Thoughts are like water droplets finding their way from high ground to the sea, following the channels in the landscape, whether gullies, streams, or river valleys. And, in its passing, each droplet cut those channels just a little more deeply. The landscape, then, is partly a history of past water flow, as well as a guide for how water will flow in the future. In the same way, our mental life follows channels carved by our previous thoughts, and traces of our present thoughts and actions will shape how we think and act in the future.
Over a lifetime, the flow of thought shapes, and is shaped into, complex patterns: our habits of mind, our mental repertoire. These past patterns of thought, and their traces in memory, underpin our remarkable mental abilities, shape how we behave and make each of us unique.
So, in a sense, we do, after all, possess some inner mental landscape. But this is not an inner copy of the outer world or, for that matter, a library of beliefs, motives, hopes, or fears; it is, instead, a record of the impact of past cycles of thought - rather than, as it were, any mysterious subterranean geological forces.

12. The Secret of Intelligence

The holistic way we perceive Mooney faces reflects the general operation of the brain. Reading scrawled handwriting, we recognize the letters in tandem with understanding the whole word. We recognize speech sounds, word-breaks and so on at the same time as we decode the message that a person is attempting to convey.
Just like faces, metaphors are everywhere, when we stop to notice them. And, indeed, it is hard to imagine how we could talk, or think, without them.
Our entire language is a graveyard of dead or half-dead metaphors.
Battles of ideas are often fought over which metaphor is appropriate: is light made of particles or waves? Are humans "risen" apes or fallen gods? Is nature a harmonious society or a brutal war of all against all? Such metaphors are not marginal to thought, but its very essence. Our continual search for meaning is the struggle to find patterns in our present experience, in the light of the past. And so we see one thing in terms of another.
Any discipline of thought (learning to program computers, play in an orchestra, prove mathematical theorems) restricts the direction in which our imagination takes us; and the ability to work within these restrictions is learned painfully and effortfully.
I suggest such discipline is difficult precisely because it requires taming and trammeling our sometimes unruly imagination. Our natural "mode" of thinking is wildly flexible - we only think of discipline and control as the essence of thought because these require our conscious and careful attention. The sheer ubiquity of our imaginative flexibility renders it invisible.
Open-ended IQ questions are tests of mental elasticity - but also precision. Imagination is required even to make the problem meaningful at all. They are capturing our ability to search in the vast space of possible metaphorical links between words (or the ideas they bring to mind), and judging our ability to find natural, sensible mappings rather than perverse and tortured links.
Imagination - our ability to construct rich interpretations in complex, open-ended problems - seems to be just what many IQ tests are measuring. Thus the secret of intelligence is imaginative interpretation, rather than cold logic.
But intelligence requires us to harness our imagination in a disciplined way - intelligence requires more than merely blurting out the first interpretation or metaphor that comes to mind.
Carefully developed analogies are the foundation of many areas of science.
Both intelligence and analogy-making, even in science, are driven by our wonderfully elastic imagination, properly harnesses and directed.
Human intelligence is based on precedents - and the ability to stretch, mash together and re-engineer such precedents to deal with an open-ended and novel world. The secret of intelligence is the astonishing flexibility and cleverness by which the old is re-engineered to deal with the new. Yet the secret of how this is done has yet to be cracked.
It is our wild imposition of meaning upon the world by the appropriation and transformation of past experience that is the essence of human thought, from which our more sober reflections can, with difficulty, be constructed. Watching the mind at play is our best guide to its natural mode of operation. This reveals the search for interpretation that drives us - the effort to find meaning that is channelled by, rather than replaced with, step-by-step conscious deliberation.

Epilogue: Reinventing Ourselves

We are not driven by hidden, inexorable forces from a dark and subterranean mental world. Instead, our thoughts and actions are transformations of past thoughts and actions, and we often have considerable latitude, and a certain judicial discretion, regarding which precedents we consider, which transformations we allow. As today's insight or action is tomorrow's precedent, we are, quite literally, reshaping and reinventing ourselves thought by thought.
We are astonishingly inventive ad hoc reasoners, creative metaphor-machines, continually wielding together scattered scraps of information into momentarily coherent wholes.
Our culture can be viewed as a shared canon of precedents - things we do, want, say, or think - which create order in society as well as within each individual. By laying down new precedents, we incrementally and collectively create our culture.
But our new precedents are based on old, shared precedents, so that our culture also creates us. Considered in isolation, our selves turn out to be partial, fragmentary and alarmingly fragile; we are only the most lightly sketched of literary creations. Yet collectively we can construct lives, organizations and societies which can be remarkably stable and coherent.
Life is a game in which we play, invent the rules and keep the score ourselves
How then, are perceptual reorganizations, sudden insights, religious conversions, and conceptual and political revolutions possible? One answer is that memory is fragile; so that we can often end up starting again from scratch, and coming up with a different answer. We forget the old story and create a new one.
What counts as precedent can itself shift - and shift again. We hope to stumble towards better and better stories - but we can only create new stories by starting with the stories we have.