The Society of Mind

1. Prologue

"Much of the power of the mind seems to stem from just the messy ways its agents cross-connect. If so, that complication [of the structure of this book] can't be helped; it's only what we must expect from evolution's countless tricks."

• The Agents of the Mind - Minds are built from mindless agents, parts that are much smaller and simpler than anything we'd consider smart. Our theory must span three scales of time:
  • Slow - for the billion years in which our brains have evolved.
  • Fast - for the fleeting weeks and months of infancy and childhood
  • In-Between - for the centuries of growth of our ideas through history
• The Mind and the Brain - Psychologists, like Freud and Piaget, and mathematicians, like Kurt Gödel and Alan Turing contributed ideas that were brought together in the 1940s to show how machines might be made to see, reason, and remember
• The Society of Mind - Many many processes are going on in our minds and bodies all the time to allow us to walk, drink a cup of tea and hold conversations. These things seem so natural that we take them for granted, but they all take vasts amounts of machinery
• The World of Blocks - Though all adults know how to build a tower of blocks, no one understands how we learn to do them! This amnesia of infancy makes us think that all our abilities were always there inside our minds, and we don't take time to ask how they began and grew.
• Common Sense - Is not a simple thing. Instead, it is an immense society of hard-earned practical ideas - of multitudes of life-learned rules and exceptions, dispositions and tendencies, balances, and check
  • As each new group of skills matures, we build more layers on top of them. As time goes on, the layers below become increasingly remote until, when we try to speak of them in later life, we find ourselves with little more to say than "I don't know".
• Agents and Agencies - Block Builder and other agents have "agency" in that they seem to know how to do their jobs, but as "agents" cannot know anything at all. Every time we seem to find an agent with intelligence, we must look inside it to break it down smaller
  • When you drive a car, you don't care how it works, but when something goes wrong you have to look inside it to see. But you can't be thinking about the detailed interior when you are driving, or you will crash
  • Knowing how is not the same as knowing why
  • We'll constantly switch between the viewpoints of agents and agencies.

2. Wholes and Parts

• Components and Connections - First we must know how each separate part works. Second, we must know how each part interacts with those to which it is connected. And third, we have to understand how all these local interactions combine to accomplish what that system does - as seen from the outside.
• Novelists and Reductionists :
  • Reductionists - Are people who prefer to build on old ideas. They are usually right - at least at science's cautious core, where novelties rarely survive for long.
  • Novelists - are people who like to champion new hypotheses. Outside science's core, older ideas have had more time to show their flaws
  • We need to approach our descriptions at various different levels and each higher level of description must add to our knowledge about lower levels.
  • Physics has only a dozen basic principles that are combined into explanations, while psychology may need to combine hundreds of smaller theories.
• Parts and Wholes - It's hard to explain what it happening in our brains, but talking about "more than the sum of its parts" won't help us.
• Holes and Parts - We can't use words like life and mind to describe the smallest components of living things because these words were invented to describe how larger assemblies interact.
• Easy Things are Hard - In general, we're least aware of what our minds do best. It's mainly when our other systems start to fail that we engage the special agencies involved with what we call consciousness. We'"re more aware of simple processes that don't work well than of complex ones that work flawlessly.
• Are People Machines? - Let's put aside this argument for now. We're certainly not trivial machines, but we are getting better and better at making highly sophisticated machines with millions of parts.

3. Conflict and Compromise

• Conflict - Agencies like "Play" must compete with other agencies like "Eat" and "Sleep". Conflicts within agencies tend to migrate to higher levels.
• Noncompromise - The Principle of Noncompromise: The longer an internal conflict persists among an agent's subordinates, the weaker becomes that agent's status among its own competitors. If such internal problems aren't settles soon, other agents will take control and the agents formerly involved will be "dismissed".
  • We sometimes settle disputes by appealing to superiors, but other conflicts never end and never cease to trouble us.
  • Tiny mental agents don't know enough to negotiate with each other. Only larger agencies could be resourceful enough to do such things.
• Hierarchies - The relations between agents are hierarchical with "Builder" being like a high-level executive, far removed from those subordinates who actually produce the final product. But there is no real planning or assignments happening or ways to deal with unexpected events.
• Heterarchies - But there are also heterarchies where agents require cooperation and no one is legitimately in charge of the other.
• Destructiveness - Destructive acts can serve constructive goals by leaving fewer problems to be solved. There are no simple causes for destructive acts, and no need for zero-sum games. When Sleep starts, Play can still run, with the child building towers in its dreams.
• Pain and Pleasure Simplified - They both make it hard to think of other things, thus simplifying your point of view.

4. The Self

• The Self - We don't know what we mean by "self". We'll use the following terms:
  • Self-Images - Beliefs about what we are, are capable of, and may be disposed to do. We use these beliefs when we solve problems or make plans.
  • Self-Ideals - Ideas about what we'd like to be and what we ought to be, which have guided our growth from infancy. May be hard to express, because they are (can be?) inaccessible to consciousness.
• One Self or Many? - We all sometimes have feelings of disunity, conflicting motives, compulsions, internal tensions and dissensions. Perhaps, paradoxically, it is because there are no persons in our heads, that we construct the myth that we're inside ourselves.
• The Soul - Beliefs in souls are insinuations that we're helpless to improve ourselves. But the value of a human self is not in some small precious core, but in its vast, constructed crust.
• The Conservative Self - One function of the self is to keep us from changing too rapidly. If we changed our minds too recklessly, we could never know what we might want next. We'd never get much done because we could never depend on ourselves.
• Exploitation - If work could simply turn off sleep, we'd quickly wear our bodies out. If work could simply switch anger on, we'd be fighting all the time. Directness is too dangerous. We'd die. If self-control were easy to obtain, we'd end up accomplishing nothing at all.
• Self-Control - Willpower, activity, expression, chemistry, emotion, attachment - so many schemes for self-control! How do we choose which ones to use? There isn't any easy way. Self-discipline takes years to learn. It grows inside us stage by stage.
• Long-Range Plans - The easiest path to "self-control" is doing only what one is already disposed to do.
  • Which are our slowest-changing agencies of all? Later we'll see that these must include the silent, hidden agencies that shape what we call character. These are the systems that are concerned no merely with the things we want, but with what we want ourselves to be - that is the ideals that we set for ourselves.
• Ideals - Without enduring self-ideals, our lives would lack coherence. As individuals, we'd never be able to trust ourselves to carry out our personal plans. In a social group no one person would be able to trust the others. A working society must evolve mechanisms that stabilize ideals - and many of the social principles that each of us regards as personal are really "long-term memories" in which our cultures stores what they have learned across the centuries.

5. Individuality

• Circular Causality - We often speak of "straightening things out" when we're involved in situations that seem too complicated. It seems to me that this metaphor reflects how hard it is to find one's way through a maze that has complicated loops in it. In such a situation, we always try to find a path through it by seeking causal explanations that go in only one direction, and we can apply the vary same types of reasoning to everything that we can represent in terms of chains of causes and effects.
• Unanswerable Questions - All human cultures evolve institutions of law, religion, and philosophy, and these institutions both adopt specific answers to circular questions and establish authority-schemes to indoctrinate people with those beliefs. Does this to substitute dogma for reason and truth? Maybe, but in exchange, they spare whole populations from wasting time in fruitless reason loops. Minds can lead more productive lives when working on problems that can be solved.
• The Remote-Control Self - The idea of a single, central Self doesn't explain anything. Maybe we believe it because so much of what our minds do is hidden from the parts of us that are involved with verbal consciousness.
• Personal Identity - In order to keep control, we simplify how we represent what's happening and then, when that complicated mental scene is straightened out it seems as though a single pipeline of ideas were flowing through the mind. Thinking of ourselves as a single thing helps with:
  • The Physical World - We can base our plans on having a single body.
  • Personal Privacy - We must remember to whom we have told something, and individuals give us a sense of responsibility.
  • Mental Activity - Thinking two different thoughts from different agencies is confusing
• Fashion and Style - Fredkin's paradox: The more equally attractive two alternatives seem, the harder it can be to choose between them. Aesthetics are useful for:
  • Recognisibility - Familiar styles make it easier for us to recognize and classify the things we see.
  • Uniformity - Uniform styles protect us from useless distractions
  • Predictability - Societies need rules that make sense for individuals
• Traits - We try to be consistent and to think that others are consistent, because this is easier.
• Permanent Identity - We all experience that sense of changelessness in spite of change.

6. Insight and Introspection

• Consciousness - Turning our bodies and walking in a direction is much like turning a car and driving - in both cases we are aware only of a general intention and all the rest takes care of itself. Our conscious thoughts use signal-signs to steer the engines in our minds, controlling countless processes of which we're never much aware. Not understanding how it's done, we learn to gain our ends by sending signals to those great machines, much as the sorcerers of older times used rituals to cast spells.
• Signals and Signs - How do we understand anything? Almost always, I think, by using one or another kind of analogy - that is by representing each new thing as though it resembles something we already know. Whenever a new thing's internal workings are too strange or complicated to deal with directly, we represent whatever parts of it we can in terms of more familiar signs:
  • To overstate the case a bit, what we call consciousness consists of little more than menu lists that flash, from time to time, on mental screen displays that other systems use. Like computer game players using symbols to invoke complicated processes of which they know nothing.
  • You can scarcely see a hammer except as something to hit with, or see a ball except as something to throw and catch. Why do we see things less as they are and more in view of how they can be used? It is because our minds did not evolve to serve as instruments for science or philosophy, but to solve practical problems of nutrition, defense, procreation, and the like. We tend to think of knowledge as good in itself, but knowledge is useful only when we can exploit it to help us reach our goals.
• Thought Experiments - Why is it so hard to explain the results of experiments of imagining things in our minds? Because we get confused. Our thoughts about our mind-experiments are mind-experiments themselves - and therefore interfere with one another:
  • Thinking affects our thoughts.
• B-Brains - The only way to get a brain to keep track of itself is to split it into two parts, A and B. Connect A to the world and connect B only to A. Then A is the B-Brain's world.
• Frozen Reflection - When introspection seems to work, it's not because we've found a magic way to see inside ourselves. Instead, it means that we've done some well-designed experiment.
• Momentary Mental Time - No portion of a mind can ever know everything that is happening at the same time in all the other agencies. Because of this, each agency must have at least a slightly different sense both of what has happened in the past - and of what is happening "now". Each different agent of the mind lives in a slightly different world of time.
• The Causal Now - Our everyday ideas about the progression of mental time are wrong: they leave no room for the fact that every agent has a different causal history. To be sure, those different pasts are intermixed over longer spans of time, and every agent is eventually influenced by what has happened in the common, remote history of its society. But that's not one means by "now". The problem is with the connections between the moment-to-moment activities of largely separate agencies.
• Thinking Without Thinking - If we're aware of anything at all, it is that "I'm aware - hence I'm aware." yet what do such convictions really mean? If self-awareness means to know what's happening inside one's mind, no realist could maintain for long that people have much insight in the literal sense of seeing-in.
• Heads in the Clouds - Even in your own mind, you can never know precisely what you mean! How useless any thought would be if, afterward, your mind return to the selfsame state. But that never happens, because every time we think about a certain thing, our thoughts go off in different ways:
  • The secret of what anything means to us depends on how we've connected it to all the other things we know. It's almost always wrong to seek the "real meaning" of anything. A thing with just one meaning has scarcely any meaning at all.
  • An idea with a single sense can lead you along only one track. Then, if anything goes wrong, it just gets stuck - it sits in your mind with nowhere to go. When someone learns something by rote (ie with no sensible connections) we say they don't really understand. Rich meaning-networks, however give you many different ways to go: if you can't solve a problem one way, you can try another. Too many indiscriminate connections will turn a mind to mush. But well-connected meaning structures let you turn ideas around in your mind, to consider alternatives and envision things from many perspectives until you find one that works. And that's what we mean by thinking!
  • David Hume: "What we call a mind is nothing but a heap or collection of different perceptions, united together by certain relations and suppos'd, tho' falsely, to be endow'd with a perfect simplicity and identity."
• Worlds Out of Mind - There is no singularly real world of thought; each mind evolves its own internal universe.
  • We appear to like best worlds of thought where goals and actions mesh in regions large enough to spend our lives in - and become a Buddhist, Republican, pet, or topologist.
  • Some mental starting points grow into great, coherent continents. In certain parts of maths, science, and philosophy, a relatively few but clear ideas may lead into an endless realm of complex yet consistent new structures. Yet even in maths, a handful of seemingly innocent rules can lead to complications far beyond our grasp.
  • In mental realms we make up countless artificial schemes to force things to seem orderly, by specifying legal codes, grammar rules and traffic laws. When growing up in such a world, it all seems right and natural - and only scholars and historians recall the mass of precedents and failed experiments it took to make it work so well. These "natural" worlds are actually more complex than the technical worlds of philosophy. They're far too vast to comprehend - except where we impose on them the rules we make.
  • In some cases, an accident of mental stress has temporarily suppressed the capacity to question, doubt, or probe. The mind has found a way to simplify itself - this may lead to a sense of revelation, but perhaps no problem has been solved at all.
• In-Sight - Where do we get the ideas we need? Most of our concepts come from the communities in which we're raised. Even the ideas we "get" for ourselves come from communities - this time the ones in our heads. Brains don't manufacture thoughts in the direct ways that muscles exert forces or ovaries make estrogens; instead, to get a good idea, one must engage huge organizations of submachines that do a vast variety of jobs.
• Internal Communication - We overestimate how much we actually communicate. Instead, despite those seemingly important differences, much of what we do is based on common knowledge and experience. Although we can't express what we mean, we can often cite various example to indicate how to connect structures we're sure must already exist inside the listener's mind. In short we can often indicate which sorts of thoughts to think, even though we can't express how they operate.
  • We find it particularly hard to use our language skills to talk about the parts of the mind that learned such skills as balancing, seeing, and remembering, before we started to learn to speak.
• Self-Knowledge is Dangerous - Why do we become bored when doing the same thing over and over, even if that activity was pleasant at first? Without variety, our pleasure systems tend to satiate. Every learning system must have some such protective scheme, since otherwise it could get trapped into endlessly repeating the same activity. It's good that we have such mechanisms and that they are very hard to suppress.
• Confusion - It's mainly when our systems fail that consciousness becomes engaged. It is better to realize that one is confused as opposed to being confused without knowing it. Then we can apply our intellect to alter or repair the defective process.

7. Problems and Goals

• Intelligence - Our minds contain processes that enable us to solve problems we consider difficult. "Intelligence" is our name for whichever of those processes we don't yet understand.
• Uncommon Sense - Much of "expert" adult thinking is actually simpler than what is involved when ordinary children play!
  • What people call common sense is actually more intricate than most of the technical expertise we admire. Think of all the different kinds of things a child must know merely to build a house of blocks - shapes and colors, space and time, support and balance, and an ability to keep track of what one is doing.
  • To be considered an "expert" one needs a large amount of knowledge of only a relatively few varieties. In contrast, an ordinary person's "common sense" involves a much larger variety of different types of knowledge - and this requires more complicated management systems.
  • Each type of knowledge needs some form of "representation" and a body of skills adapted to using that style of representation. Once that investment has been made, it is relatively easy for a specialist to accumulate further knowledge, provided the additional expertise is uniform enough to suit the same style of representation. The greater variety of representations would make it much harder for a single person to learn to deal with a few diseases, law cases, architectural blueprints, and orchestral scores. It would be like learning many different languages, each with its own grammar, lexicon, and idioms.
• The Puzzle Principle - We can program a computer to solve any problem by trial and error, without knowing how to solve it in advance, provided only that we have a way to recognize when the problem is solved. Without some notion of progress toward a goal, it is hard to do better than mindless chance.
• Problem Solving - The most powerful way we know for discovering how to solve a hard problem is to find a method that splits it into several simpler ones, each of which can be solved separately.
  • The Progress Principle - Any process of exhaustive search can be greatly reduced if we possess some way to detect when "progress" has been made. Then we can trace a path toward a solution, just as a person can climb an unfamiliar hill in the dark - by feeling around, at every step, to find the direction of steepest ascent.
  • Many easy problems can be solved this way, but for a hard problem, it may be almost as difficult to recognize "progress" as to solve the problem itself. Without a larger overview, that "hill climber" may get stuck forever on some minor peak and never find the mountaintop. There is no foolproof way to avoid this.
  • The most efficient way to solve a problem is to already know how to solve it. Then one can avoid search entirely.
• Learning and Memory - Those twin ideas - reward/success and punish/failure - do not explain enough about how people learn to produce the new ideas that enable them to solve difficult problems that could not otherwise be solved without many lifetimes of ineffectual trial and error. The answer must lie in learning better ways to learn.
  • At each moment, we must keep track of what we've just done, we must somehow maintain our goals and, finally, once the problem is solved, we need access to records of how it was done, for use when similar problems arise in the future.
  • When a human brain solves a hard problem, many millions of agents and processes are involved. Which agents could be wise enough to guess what changes should then be made? Where in the mind are judgements made about which agents merit praise or blame?
• Reinforcement and Reward - We cannot learn to solve hard problems by indiscriminately reinforcing agents or their connections. Why is it that among all the animals, only the great-brained relatives of man can learn to solve problems that require many steps or involve using the same agencies for different purposes?
• Local Responsibility - Local schemes reward each agent that helps accomplish its supervisor's goal. Global schemes reward only agents that help accomplish top-level goals.
  • It is harder to implement a global learning scheme, which is much more parsimonious, and global policies lead to learning more slowly. We need to learn which learning strategies to use, depending on the circumstances.
• Difference-Engines - A goal-driven system does not seem to react directly to the stimuli or situations it encounters. Instead, it treats the things it finds as objects to exploit, avoid, or ignore, as though it were concerned with something else that doesn't yet exist. When any disturbance or obstacle diverts a goal-directed system from its course, that system seems to try to remove the interference, go around it, or turn it to some advantage.
  • A difference engine must contain a description of a desired situation.
  • It must have subagents that are aroused by various differences between the desired situation and the actual situation.
  • Each subagent must act in a way that tends to diminish the difference that aroused it.
• Intentions - The difference-engine scheme scheme remains the most useful conception of goal, purpose, or intention yet discovered. It embodies both a representation of some outcome and a mechanism to make it persist until that outcome is achieved.
• Genius - Most heroes are intensely motivated, proficient in some field, and stubborn. But genius needs unusually effective ways to learn. You must learn a lot and manage what you learn, using special knacks of higher-order expertise:
  • Such knacks could begin with early accidents when a child happens upon clever ways of arranging blocks, etc. But adults cannot necessarily see these internal strategies, which can lead to silent growth in which some better ways to learn may lead to better ways to learn to learn. Then later we'll observe an awesome, qualitative change, with no apparent cause and call it a talent, aptitude, or gift.

8. A Theory of Memory

Proust: "In truth, the person within me who was at this moment enjoying this impression enjoyed in it the qualities which it possessed that were common to both an earlier day and the present moment; and this person came into play only when, by this process of identifying past with present, he could find himself in the only environment in which he could live, that is to say, entirely outside of time."

• K-Lines: A Theory of Memory - We keep each thing we learn close to the agents that learn it in the first place, using a type of agent called a Knowledge-line or K-line. We memorize what we're thinking about by making a list of the agents involved in that activity.
  • Whenever you get a good idea, solve a problem, or have a memorable experience, you activate a K-line to represent it. A K-line is a wirelike structure that attaches itself to whichever mental agents are active when you solve a problem or have a good idea.
  • When you activate that K-line later, the agents attached to it are aroused, putting you into a mental state much like the one you were in when you solved that problem or got that idea. This should make it relatively easy for you to solve new, similar problems.
  • Each agent can become attached to many different K-lines
  • For each familiar kind of mental job, your K-lines can refill your mind with fragments of ideas you've used before on similar jobs. In such a moment, you become in those respects more like an earlier version of yourself.
• Re-membering - When facing a new problem which is similar to an old problem, you activate an old K-line, kP, alongside your recent thoughts, Q, and both sets of agents will work together to solve today's problem. This is the simplest concept of what memories are and how they are formed.
  • If we give too much priority to the K-line's agents, we risk re-arousing old states of mind so strongly that they overwhelm our present thoughts and lost track of what we're thinking now and wipe out all the work we've done. We only want some hints, suggestion, and ideas.
  • The ideal scheme would activate exactly those P's that would be most helpful in solving the present problem, but judging that is hard.
• Mental States and Dispositions - K-lines can easily record relatively widespread and diffuse activities and, later, reactivate them all at once.
  • The experiences we find easiest to recollect are often just the kinds we find the hardest to describe.
  • In order fot a word to have a predictable effect on other persons, we must maintain strict, public discipline on how it is used - whereas each person's private, internal signals need not be so constrained.
  • The traditional view, that it is easy to understand how minds can deal with facts and propositions but hard to see how minds could have diffuse, hard-to-express dispositions, must be upside-down
• Partial Mental States:
  • A total state of mind is a list that specifies which agents are active and which are quiet at a certain moment
  • A partial state of mind merely specifies that certain agents are active but does not say which other agents are quiet
  • The "entire system" can "think several thoughts at once" because each of these thoughts is contained in a partial state of mind just like a crowd of separate people can.
• Level Bands - Understanding never ends! - we can always find more to say about a situation. We learn by attaching agents to K-lines, but we don't attach them all with equal firmness. We make strong connections at a certain level of detail, but we make weaker connections at higher and lower levels.
  • The weakly attachments are assumptions by default, which will serve unless and until they must be overridden by a specificity.
• Levels - The sorts of knowledge in mid-level bands is most broadly and generally useful, whereas uppermost and lowest-level bands are more likely to be based on aspects of the problem that are specific to an older goal or to the particular details of the original problem.
  • It is no accident that level-related ideas play many different roles in how we think.
• Fringes - Suppose some memory were so complete that it made you relive, in every detail, some perfect moment of your past. That would erase your present you - and you'd forget what you had asked your memory to do! Fringing effects make our memories more relevant to our present purposes. In order to think, we need intimate connections between things and goals - between structures and their functions. What use would thinking be at all, unless we could relate each thing's details to our plans and intentions?
  • Lower Band - Beyond a certain level of detail, increasingly complete memories of previous situations are increasingly difficult to match to new situations. The lower fringe is commonly concerned with the structure of things, and the objective details of reality
  • Upper Band - Memories that arouse agents at too high a level would tend to provide us with goals that are not appropriate to the present situation. The upper fringe is commonly involved with the functions of things and our subjective concerns with goals and intentions
• Societies of Memories - As we make new memories, we prefer to attach to existing K-lines than to individual agents.
  • Jack to Male, Young:
  • Kite to Paper, String, Red
  • Fly to Outside, Wind
  • Connecting new K-lines to old ones will not recapture so many of the scene's precise, perceptual details. Instead, the kinds of mental states that this hierarchical type of memory produces will be based more on stereotypes and default assumptions than on actual perceptions. You will tend to remember only what you recognized at the time.
• Knowledge-Trees - When making a new K-line memory, do not connect it to all the K-lines active at the time but only to those that are active within a certain level-band. Eventually all of our knowledge-structures become entangled with various sorts of exceptions, shortcuts, and cross-connections. No matter: the level-band idea will still apply in general, since most of what we know will still be mainly hierarchical because of how our knowledge grows.
• Levels and Classifications - We tend to think that our hierarchies illustrate some kind of order that exists in the world but frequently they come from the mind and merely appear to belong to the world.
  • We frequently use two or more classifications at the same time. A child can play with a porcelain duck as though it were a pretend animal but still behave in an appropriate way for a delicate china object.
  • When attempting a new task, we never like to start anew: we try to use what has worked previously. So we search around inside our minds for old ideas to use. Then, when part of any hierarchy seems to work, we drag the rest along with it.
• Layers of Societies - We can imagine an endless sequence of societies or agencies in which each new one learns to exploit the last. This is how minds develop in infancy, as layers of societies.
  • Each new layer begins as a set of K-lines, which starts by learning to exploit whatever skills have been acquired by the previous layer. Whenever a layer acquires some useful and substantial skill, it tends to stop learning and changing - and then yet another new layer can begin to learn to exploit the capabilities of the last.
  • Each new layer begins as a student, learning new ways to use what older layers can already do. Then it slows its learning rate - and starts to serve both as subject and as teacher to the layers that form afterward.

9. Summaries

• Wanting and Liking - Our reactions of pleasure or disgust are only superficial summaries of pyramids of underlying processes.
  • The surer you are that you like what you are doing, the more completely your other ambitions are being suppressed.
  • The relation between wanting and liking is not simple at all, because our preferences are the end products of so many negotiations among our agencies. To accomplish any substantial goal, we must renounce the other possibilities and engage machinery to keep ourselves from succumbing to nostalgia or remorse. Then we use words like "liking" to express the operation of the mechanisms that hold us to our choice.
  • Liking's job is shutting off alternatives. It narrows down our choices and provides artificial clarity.
• Gerrymandering - What is the significance in complicated systems of those pleasant feelings of accomplishment and disagreeable sensations of defeat? They must be involved with how our higher-level agencies make summaries. No single sense of good or bad can reflect much of what went on inside all your agencies; too much information must be concealed, but there are many reasons for oversimplifying.
• Learning from Failure - Some parts of our minds learn from success, but other portions learn mainly when we make mistakes, by remembering the circumstances in which various methods failed to work. We can learn what not to do and what not to think, which permeates our minds with taboos and prohibitions of which we're entirely unaware.
  • It is no accident that there are no exceptions to the rules in mathematical worlds. There we start with the rules and imagine only objects that obey them. But perfect logic rarely works in the real worlds of people, thoughts, and things. We can't so willfully make up the rules for objects that already exist, so our only course is to begin with imperfect guesses - collections of rough and ready rules - and then to proceed to find our where they're wrong.
• Enjoying Discomfort - Nothing would get done if we succumbed to satisfaction. When doing maths, climbing freezing mountain peaks, or playing pipe organs with our feet: some parts of the mind find it horrible, while other parts enjoy forcing those first parts to work for them. We seem to have no names for processes like these, though they must be among our most important ways to grow.

10. Papert's Principle

• Piaget's Experiments - Each normal child eventually acquires an adult view of quantity - apparently without adult help!
• Reasoning About Amounts - We do not learn one single, underlying "concept of quantity". Instead, each person must construct a multilevel agency, the Society-of-More, that finds different ways to deal with quantities.
  • Younger children may possess the ideas they need, but don't know how to apply them! They lack adequate knowledge about their knowledge or have not acquired the checks and balances required to select or override their hordes of agents with different perceptions and priorities.
  • It is not enough to be able to use many kinds of reasoning; one also must know which to use in different circumstances! Learning is more than the accumulation of skills. Whatever we learn, there is always more to learn - about how to use what we already learned.
• Priorities - Young children may place their agents in some order of priority. Most people seem most sensitive to vertical extents. This may be built into our brains or learned, but more height often goes along with other sorts of largeness. No other agent seems so good as Tall for making everyday comparisons.
• Papert's Principle - Some of the most crucial steps in mental growth are based not simply on acquiring new skills, but on acquiring new administrative ways to use what one already knows.
  • The processes which assemble agents into groups must somehow exploit relationships among the skills of those agents. Because Tall and Thin are more similar in character to one another than to Confined, it makes sense to group them more closely together in the administrative hierarchy.
• The Society of More - Each higher-level agent embodies a form of higher-order knowledge that helps us organize ourselves by telling us when and how to use the things we know. Without a many layered management, we couldn't use the knowledge in our low-level agencies; they'd all keep gettin in one another's way.
• About Piaget's Experiments - Stage magicians find that making things disappear does not entertain the youngest children; presumably that are too used to encountering the unexplainable. What happens when More cannot decide what to do? That depends upon the states of other agencies - including those involved in dealing with frustration, restlessness, and boredom.
• The Concept of Concept - How do children accumulate and classify their many methods for comparing things? No child has the time to generate and test all possible combinations to find which ones are sensible. Instead, always try to combine related agents first.
• Education and Development - We can't force children to learn too quickly. There is constantly a tension between organising a hierarchy of concepts and managing the mass of exceptions and only the mature mind can combine the two.
• Learning a Hierarchy - The nerve cells in an animal's brain can't always move aside to make more room for extra ones. So these new layers might indeed have to be located elsewhere, attached by bundles of connection wires. No aspect of the brain's anatomy is more striking than its huge masses of connection bundles.

11. The Shape of Space

• Seeing Red - We are not "simple" machines. When we see something, it activates many, many agents.
• The Shape of Space - We never actually make any direct contact with the outside world. Instead, we work with models of the world that we build inside our brains.
  • Einstein spoke of vast societies of nearnesses.
  • There is little that one could say about any "single touch" - or about what any single sense-detecting agent does. However, there is much more to be said about the relations between two or more skin touches, because the closer together two skin spots are, the more frequently they'll both be touched at the same time.
• Nearnesses - In general, each pair of nearby places on the skin is wired to nearby places in the brain.
  • Other things being equal, the apparent similarity of two stimuli will depend on the extent to which they lead to similar activities in other agencies.
  • Given enough information, a suitably designed agency could assemble a sort of map to represent which spots are close together on the skin.
  • For a child, learning about the spatial world beyond the skin is a journey that stretches over many years.
• Innate Geography - To design a machine to deduce the geography of a space, one could begin with a layer of "correlation agents", one for each tiny patch of skin, each engineered to detect which other skin spots are most often aroused at nearly the same times; those will then be mapped as the nearest ones. A second layer of similar agents could then begin to make maps of larger regions, and several such layers would eventually asemble a sequence of maps on various scales, for representing several levels of detail.
  • If brains do something of this sort, it might explain why we all agreed on what the outer world of space is like.
• Sensing Similarities - Our thoughts are largely shaped by which things seem most similar. Which colors seem the most alike? Which forms and shapes, which smells and tastes, which timbres, pitches, pains and aches, which feelings and sensations seem most similar? Such judgements have a huge effect at every stage of mental growth - since what we learn depends on how we classify.
  • Just as there is nothing to say about a single point, there's nothing to be said about an isolated sensory signal. When our Redness, Touch, or Toothache agents send their signals to our brains, each by itself can only say, "I'm here." The rest of what such signals "mean" to us depends on how they're linked to all our other agencies.
  • The qualities of signals sent to brains depend only on relationships - the same as with the shapeless points of space.
  • Beyond the raw distinctiveness of every separate stimulus, all other aspects of its character or quality - be it of touch, taste, sound, or light - depend entirely on its relationships with the other agents of your mind.
• The Centered Self - We really do not understand how the child learns to understand space. Perhaps we start by small experiments to produce crude maps of the skin. Next we might correlate these with the motions of our eyes and limbs, then develop some agents to represent a few places outside the skin, assemble an agency that represents a network of relationships, trajectories, and directions between those places and slowly expand that network to include new places and relationships.
  • Freud and Piaget observed that children seem to recapitulate the history of astronomy: first they see the world centered around themselves, before slowly learning that they are moving, like any object within a stationary universe.
• Predestined Learning - Every child eventually learns to reach for food. Each child lives through a different history of "reaching-act" experiences but, according to our theory of "nearness models of space", they will all end up with generally similar results because that outcome is constrained by the nearness relations of real-world space.
  • We acquire our conceptions of space by using agencies that learn in accord with processes determined by inheritance. We learn from experience, but the outcomes of our learning are virtually predestined by the spatial geometry of our body parts.
• Half-Brains - Our brains have many pairs of agencies, arranged like mirror-images, with huge bundles of nerves running between them. Each brain has many parts, not only two.
  • A theory - In early life we start with mostly similar agencies on either side. Later, as we grow more complex, a combination of genetic and circumstantial effects lead one of each pair to take control of both to avoid being paralyzed by conflicts. Eventually the adult managers for many skills would tend to develop on the side of the brain most concerned with language because those agencies connect to an unusually large number of other agencies. The less dominant side of the brain will continue to develop, but with fewer administrative functions - and end up with more of our lower-level skills, but with less involvement in plans and higher-level goals that engage many agencies at once. Then if, by accident, that brain half is abandoned to itself, it will seem more childish and less mature because it lags so far behind in administrative growth.
• Dumbbell Theories - Dividing things in two is a good way to start, but one should always try to find at least a third alternative. If one cannot, one should suspect that there may not be two ideas at all, but only one, together with some form of opposite.

12. Learning Meaning

• A Block-Arch Scenario - A child evolves a concept of arch through experimentation.
• Learning Meaning - The child is led to learn for itself in order to account for strange events. There are various forms of learning:
  • Uniframing - combining several descriptions into one, eg by observing that all the arches have certain common parts.
  • Accumulating - Collecting incompatible descriptions, eg by forming the phrase "block or wedge".
  • Reformulating - Modifying a description's character, eg by describing the separate blocks rather than the overall shape.
  • Trans-framing - Bridging between structures and functions or actions, eg by relating the concept of arch to the act of changing hands.
• Uniframes - There are good reasons not to notice too much, for every seemingly essential fact can generate a universe of useless, accidental, and even misleading facts.
  • Most differences are redundant. Most of the rest are accidents.
  • On what basis can we decide which features are essential and which are merely accidents? Such questions don't make sense apart from how we want to use their answers. There is no single secret, magic trick to learning: we simply have to learn a large society of different ways to learn!
• Structure and Function - Our most powerful ways of thinking are those that let us bring together things we've learned in different contexts. And to do this we need to build arches between the contexts in our minds.
• The Functions of Structures - We need both structural descriptions for recognizing chairs when we see them and functional descriptions in order to know what we can do with them. We can capture more of what we mean by interweaving both ideas.
• Accumulation - The simplest way to learn, when we can't find a uniframe, is to accumulate descriptions of experiences.
  • A simpler theory of when we start new uniframes would be that in the brain, there is an architectural constraint on how many K-lines are directly accessible to various types of agents. For example, the agents in a certain agency might be able to accumulate no more than about seven branches for each classification in a certain hierarchy. When there are more, the agency would be forced either to merge some examples into uniframes or to turn for help from somewhere else.
• Accumulation Strategies - Whenever an accumulation becomes too large and clumsy, we try to replace some groups of its members with a uniframe. But even when we succeed in finding a suitably compact uniframe, we can expect it, too, to accumulate exceptions eventually, since first descriptions rarely work for all our later purposes.
  • Our various motives and concerns are likely to require incompatible ways to classify things. You can't predict a dog's bite from its bark. Each classification must embody different kinds of knowledge, and we can rarely use more than a few of them at once. When we have a goal that is simple and clear, we may be able to select one particular kind of description that makes the problem easy to solve. But when goals of several types conflict, it is harder to know just what to do.
• Problems of Disunity - Many good ideas are really two ideas in one - which form a bridge between two realms of thought or different points of view.
  • Whenever we build a bridge between structure and function, one end of that bridge may represent a goal or use, while the other end describes what we might use to gain those ends. But it is rare for those structures to correspond neatly to those functions. The problem is that we usually find many different ways to achieve any goal.
  • Our different worlds of ends and means don't usually match up very well. So when we find a useful, compact uniframe in one such world, it often corresponds to an accumulation in our other worlds.
• The Exception Principle - It rarely pays to tamper with a rule that nearly always works. It's better just to complement it with an accumulation of specific exceptions.
  • Children are disturbed to hear that whales are not fish because they are usually more concerned with uses and appearances than with origins and mechanisms. They want to know what do animals do, where do they live, are they easy to catch, are they dangerous, are they useful, what do they eat, how do they taste?
  • The power of ordinary words like "fish" comes from how we make them span so many meaning-worlds at once. But, to do this, we have to be able to tolerate many exceptions. We almost never find rules that have no exceptions - except in artificial worlds that we ourselves create by making up their rules and regulations to begin with.
• How Towers Work - An idea will seem self-evident - once you've forgotten learning it. Many obvious things are done for us by huge, silent systems in our mind, built over long forgotten years of childhood, and which leave no traces in our consciousness.
  • To understand the world of space and time, each child must make many discovered. But the division into Lifting and Sliding has a special importance. We don't have to learn all the ways to move in the world because we can learn to deal with each dimension separately. Lifting isolates the vertical dimension and sliding isolates the horizontal, and that is enough to move around in a 3D world.
• How Causes Work - There can't be any "causes" in a world in which everything that happens depends more or less equally upon everything else that happens.
  • To know the cause of a phenomenon is to know, at least in principle, how to change or control some aspects of some entities without affecting all the rest. The most useful kinds of causes our minds can discern are predictable relationships between the actions we can take and the changes we can sense.
• Meaning and Definition - It is no great surprise to find that "game" has a more psychological character than does "brick", which we can define in physical terms without referring to our goals. But most ideas lie in between, eg "chair", which we cannot describe without referring both to a physical structure and to a psychological function.
• Bridge-Definitions - Our best ideas are often those that bridge between two different worlds. We can often capture an idea by squeezing in from several sides at once, to get exactly what we need by using two or more different kinds of descriptions at the same time.
  • Purposeful definitions are usually too loose - They include many things we do not intend.
  • Structural definitions are usually too tight - They reject many things we want to include.
  • Combining them helps us connect things we can recognize (or make, find, do, or think) to problems we want to solve.
  • To learn to use a new or unfamiliar word, you start by taking it to be a sign that there exists, inside some other person's mind, a structure you could use. But no matter how carefully it is explained, you must still rebuild that thought yourself, from materials already in your own mind. A good definition helps, but you still must mold and shape each new idea to suit your own existing skills - hoping to make it work for you the way it seems to work for those from whom you learn.
  • What people call "meanings" do not usually correspond to particular and definite structures, but to connections among and across fragments of the great interlocking networks of connections and constraints among our agencies. Because these networks are constantly growing and changing, meanings are rarely sharp, and we cannot always expect to be able to "define" them in terms of compact sequences of words. Verbal explanations serve only as partial hints; we also have to learn from watching, working, playing - and thinking.

13. Seeing and Believing

• Reformulation - Reformulating a problem in new terms can unblock a problem, but how do people find new styles of description that make their problems seem easier?
• Boundaries - We're always changing boundaries! Where does an elbow start or end? When does a youth become an adult? Where does an ocean change into a sea? Why must our minds keep drawing lines to structure our reality? Because otherwise, we'd never see anything at all! We rarely see anything twice as exactly the same. Each time we're almost certain to be looking from a somewhat different view, perhaps from nearer or farther, higher or lower, in a different color or shade of light, or against a different background.
• Seeing and Believing - Children draw unrealistic human shapes (without a body) because they don't have anything like a picture in mind, but only some network of relationships that various features must satisfy.
• Children's Drawing-Frames - Why do older children draw the body separately? They understand the relationships a bit better.
• Learning a Script - How does practice speed things up?
  • Frank Lloyd Wright: "An expert is one who does not have to think. He knows."
  • Experts seem to exercise their special skills with scarcely any thought at all - as though they were simply reading preassembled scripts. Perhaps when we practice to improve our skills, we're mainly building simpler scripts that don't engage so many agencies. This lets us do old things with much less "thought" and gives us more time to think of other things. The less the child has to think of where to put each arm and leg, the more time remains to represent what that picture-person is actually doing.
• The Frontier Effect - The tendency to place new features at locations that have easily described relationships to other, already represented features.
  • Copying is much more complicated than we think. You have to draw each line to a scale and direction consistent with all the others. So it is actually easier for a child to first construct a mental description of the relations involved in the scene, and then to design a drawing-scheme to represent those relationships.
  • It can require more skill to produce what we regard as a simple copy or imitation than to produce what we consider to be an "abstract" representation.
• Duplications - Different kinds of goals require different styles of description.

14. Reformulation

• Using Reformulations - If we can't solve a problem, we can try to find a way to describe it in different terms. Reformulation is the most powerful way to attempt to escape from what seems to be a hopeless situation.
  • To outsiders it may see that creative people have an endless source of novel ways to deal with things, but they often have merely variations on far fewer themes. For the creatives, they may think, why can't outsiders understand how to think about these simple kinds of problems?
  • The most productive kinds of thought are methods that lead us to formulating useful new kinds of descriptions
  • New ideas often have roots in older ones, adapted for new purposes.
• The Body-Support Concept - The body represents those parts of a structure that serve as the direct instrument for reaching the goals and the support represents all the other features that merely serve that instrument.
  • To understand how something works, it helps to know how it can fail.
• Means and Ends - Even when we simply put something on a table, we're likely to employ several descriptions at the same time - perhaps in different sections of the mind. The quality of our understanding depends upon how well we move between those different realms, discovering systematic cross-realm correspondences.
  • These correspondences are the roots of fruitful metaphors; they enable us to understand things we've never seen before. When something seems entirely new in one of our description-worlds, it may turn out that when translated to some other world it resembles something we already know.
• Seeing Squares - We often self-impose assumptions that make our problems more difficult, and we can escape from this only by reformulating those problems in ways that give us more room.
  • Most of what we think we see comes from inside our brain; we respond not only to visual features, but also to our remembrances of things we've seen before and to our expectations of what we ought to see.
  • Human vision must somehow combine the information that comes from the outer world with the structures in our memories.
• Brainstorming - Your brain is constantly preparing ways to reformulate ideas by building up connections between different kinds of descriptions. Then when you finally change your view to find another way to look at things, you can apply a lifetime of experience as easily as turning on a switch.
  • It may be rash to change yourself too much just to accommodate a single strange experience. To take every exception seriously is to risk the loss of general rules that previous experience has shown to work most frequently.
  • It isn't any accident that the things that we can always do are just the ones we should rarely do.
• The Investment Principle - Our oldest ideas have unfair advantages over those that come later. The earlier we learn a skill, the more methods we can acquire for using it. Each new idea must then compete against the larger mass of skills the old ideas have accumulated.
  • We're almost always immersed in the short run. So the principles of investment and of exception make us reluctant to tamper with our well-established skills and uniframes lest we endanger all that we have built upon those old foundations.
  • Why do so many animals contain their brains inside their heads? Because this arrangement was inherited well over 300m years ago and it would be too costly and complicated to change now. DNA has scarcely changed a single bit in a billion years and even though it does not seem to be particularly efficient or reliable, we are stuck with it.
• Parts and Holes - Why focus so sharply on the concept of a container? Because without that concept, we could scarcely understand the structure of the spatial world. And this is true also of psychological things, as a mental implement for envisioning and understanding other, more complicated structures. The idea of a set of all possible directions is one of the great coherent cross-realm correspondences that can be used in many different realms of thought.
• The Power of Negative Thinking - The optimistic strategy makes sense when one sees several ways to go - and merely has to choose the best. The pessimistic strategy should be reserved for when one sees no way at all, when things seem really desperate.
• The Interaction-Square - Is the simplest way to represent what happens when two causes interact.
  • The spatial agency in our Society of More is not really involved with space at all, but with interactions between agents like Tall and Thin, and an interaction-square provides a convenient way to represent all the possible combinations.
  • Only rarely, it seems, do people deal with more than two causes at a time; instead we either find ways to reformulate such situations or we accumulate disorderly societies of partially filled interaction-squares that cover only the most commonly encountered combinations.

15. Consciousness and Memory

• Momentary Mental State - Consciousness does not concern the present, but the past: it has to do with how we think about the records of our recent thoughts.
  • Most agencies are there to learn to recognize events inside the brain. Only a small minority of our agents are connected directly to sensors in the outer world, like those that send signals from the eye or skin. And the agents that are engage in using and changing our most recent memories lie at the roots of consciousness.
  • We become less conscious of some things when we become more conscious of others because some resource is approaching some limitation - we have only a limited capacity to keep good records of our recent thoughts.
  • This kind of self-inspected probe is prone to change just what it's looking a. Would any process not become confused that alters what it's looking at?
• Self-Examination - There is a common myth that what we view as consciousness is measurelessly deep and powerful - yet actually, we scarcely know a thing about what happens in the great computers of our brains.
• Memory - I suspect that we never really remember very much about a particular experience. Instead, our various agencies selectively decide, unconsciously, to transfer only certain states into their long-term memories - perhaps because they have been classified as useful, dangerous, unusual, or significant in other respects. It would be of little use for us simply to maintain vast stores of unclassified memories if, every time we needed one, we had to search through all of them.
  • Instead, each of us must develop fruitful and effective ways to organize our memories - but how that's done is inaccessible to consciousness.
  • Short-term memories last only for seconds or minutes.
  • Long-term memories can persist for days or years or all one's life.
• Memories of Memories - It's hard to distinguish memories from memories of memories. There's little evidence that any of our adult memories really go way back to infancy; what seem like early memories may be nothing more than reconstructions of our older thoughts
  • Memories from our first five years seem oddly isolated and probably involve incidents so significant that they probably occupied the child's mind repeatedly over a period of years. They are often described as seen though other, older eyes
  • The "amnesia of infancy" is probably an inevitable result of growing out of infancy. To remember is not merely to retrieve but also to recreate how your earlier mind reacted (by becoming an infant again). As you grow you have to sacrifice your earlier memories because they're written in an ancient script that your later selves can no longer read.
  • From every moment to the next, your mental state is shaped not only by signals from the outer world, but by agents activated by the memories these evoke. Only a part of your impression comes from agents activated directly by your vision; most of what your higher-level agencies experience comes from the memories those vision-agents activate.
  • It is only when a recognition involves substantial time and effort that we speak of "remembering".
  • Memories are processes that make some of our agents act in much the same ways they did at various times in the past.
• The Immanence Illusion - Whenever you can answer a question without a noticeable delay, it seems as though that answer were already active in your mind.
  • Memories can't really bring things back from the past - they only reproduce some fragments of our former states of mind. Why do they feel so real? Because real-time experience is just as indirect! The closest we can come to apprehending the world, in any case, is through the descriptions our agents make.
  • Perceptions can evoke our memories so quickly that we can't distinguish what we've seen from what we've been led to recollect.
  • The experience of seeing things has a relatively rigid character, in contrast to the experience of imagining things. Every change that the rest of your mind tries to impose upon your vision-agencies is resisted and usually reversed. Perhaps this is what we identify with vividness or objectivity.
  • Sometimes our sense of objectivity can get reversed - as when an attitude or memory becomes more stable and persistent than what it represents, particularly our attitudes toward things we love or loathe are often much less changeable than those things themselves - particularly in the case of other people's personalities. Here, our private memories can be more rigid than reality.
• Many Kinds of Memory - A brain has no single, common memory system. Instead, each part of the brain has several types of memory-agencies that work in somewhat different ways, to suit particular purposes.
  • Most likely, some types of memory mechanisms retain the records of sensations only for seconds. We use others to adopt habits, goals, and styles that we hold only for days or weeks. And we make personal attachments that endure through many months or years. Yet suddenly from time to time, we'll modify some memories that seemed, till then, quite permanent.
• Memory Rearrangements - Because each memory-unit must wait until the previous step is finished, the timing of each script step may have to depend on various condition sensors. But these processes also need ways to interrupt themselves while they call on other agencies or memories for help, just like we may have to do when dealing with things in the outside world.
• Anatomy of Memory - We'll assume that every substantial agency has several "micro-memory units," each of which is a sort of temporary K-line that can quickly store or restore the states of the micro-memories themselves. When any of these temporary memory-units are reused, the information that we stored in them is erased - unless it has somehow been transferred into more permanent or long-term memory-systems. It seems that in human brains, the processes that transfer information into long-term memory are very slow and so most temporary memories are permanently lost.
• Interruption and Recovery - Why do we get confused when we're interrupted? Because then we have to keep our place in several processes at once. Yet, psychologically, we're unaware that ordinary thinking is so complicated - the processes are too many levels away from those we use to work the short-term memories involved with language and consciousness.
• Losing Track - Why do visual processes so rarely encounter difficulties of interruption? they can support more simultaneously operating processed that our language-systems can, so there are fewer interruptions, and they can choose for themselves the sequence in which they attend to details, whereas language-agencies are controlled by the person who is speaking.
  • It takes many years to learn to use those memory-systems well.
• The Recursion Principle - When a problem splits into smaller parts, then unless one can apply the mind's full power to each subjob, one's intellect will get dispersed and leave less cleverness for each new task.
  • The best way to solve a hard problem is to break it into several simpler ones, and break those into even simpler ones, but then we face the problem of mental fragmentation.
  • We can also work on the various parts of a problem in serial order, one after another, using the same agency over and over again, but this takes more time.
  • Our short-term memories must work too fast to have any time for consciousness.

16. Emotion

• Emotion - The use of fantasies, emotional or not, is indispensable for every complicated problem-solving process. We always have to deal with nonexistent scenes, because only when a mind can change the ways things appear to be can it really start to think of how to change the way things are.
  • Too much commitment leads to doing only one single thing; too little concern produces aimless wandering.
• Cross-Exclusion - Each member of a group of agents is wired to send "inhibitory" signals to all the other agents of that group. This makes them competitors (OR operator). When any agent of such a group is aroused, its signals tend to inhibit the others.
• Avalanche Effects - The most active agent can quickly "lock out " all the others. So we need additional control mechanisms, which are common across all biological systems
  • Conservation - Force all activities to depend upon some substance or other kind of quantity of which only a certain amount is available
  • Negative Feedback - Supply a "summary" device that estimates the total activity in the agency and then broadcasts to that agency an "inhibitory" signal whose strength is in proportion to that total. This can damp down incipient avalanches.
  • Censors and Suppressors - While conservatism and feedback schemes tend to be indiscriminate, these are more sensitive and versatile in learning to recognize - and then to avoid - specific patterns of activity that have led to trouble in the past
  • All human communities seem to work out policies for how their members ought to think, in forms that are thought of as common sense or as law, religion, or philosophy.
• Motivation -
• Exploitation - Each part of the mind exploits the rest, not knowing how the other parts work but ony what they seem to do.
  • One needs a process that sometimes works before one can proceed to improve it.
• Stimulus vs Simulus - One agency can exploit another by providing a stimulus to activate it. Perhaps the simplest way would be to force the highest-level agents into whichever states would result from seeing a certain scene. A simulus could activate some suitable K-lines to simulate the higher-level effects of a true stimulus.
• Infant Emotions - In contrast to the complex mixtures of expressions that adults show, young children seem usually to be in one or another well-defined state of activity - contentment, hunger, sleepiness, play, affection, etc. Older children show less sudden mood changes, and their expressions suggest that more different things are happening at once. Our minds may thus originate as sets of relatively simple, separate need machines.
  • To help their offspring grow, most animals evolve two matching schemes. Babies have intense, focused irresistible cries to arouse parents, who contain baby-watching systems with high priority. These systems could be wired to the remnants of our own infantile needs, so that we react to the cries with urgency and sympathy.
• Adult Emotions - Our earliest emotions are built-in processes in which proto-specialists control what happens in our brains. Soon we learn to overrule those schemes, as our surroundings teach us what we ought to feel. Parents, teachers, friends, and finally our self-ideals impose upon us new rules for ho to use the remnants of those early states: they teach us how and when to feel and show each kind of emotion sign.
  • By the time we're adults, these systems have become too complicated to understand - we've passed through so many stages of development and our minds have been rebuilt too many times to remember or understand much of how it felt to be an infant.
  • What are emotions anyway, and what are all the other things we label moods, feelings, passions, needs, or sensibilities? We find it hard to agree on the meanings of words like these, presumably because few of them actually correspond to clearly distinct mental processes. Instead, when we learn such words, we each attach to them variously different and personal accumulations of conceptions in our minds.
  • Commonsense psychology has not even reached a consensus on which emotions exist.