# Précis of epistemology/How the spirit works

Psychology is the science (or the knowledge) of the spirit (or the mind or the soul). Ethics is a part of psychology, because it is the science of the good of the spirit. Epistemology is a part of ethics and psychology, because it is the science of science (or the knowledge about knowledge) and because science is a good of the spirit.

## Principles of psychology

We know matter from sensory consciousness. We know the spirit from self-consciousness.
Even when we know other spirits, we use self-consciousness, because we put yourself in their shoes and then we become conscious of what we could be.
Sensory consciousness and self-consciousness are inseparable. When we perceive our environment, we are always conscious that we are perceiving it.
For there to be perception, more than detection is needed. Detectors are generally unaware of what they are detecting. For there to be perception, self-consciousness is needed in addition to detection.
We are conscious of our environment in order to be able to act voluntarily on it in an appropriate way.
We are conscious of ourselves in order to be able to act voluntarily on ourselves in an appropriate way.
Acting on oneself and acting on one's environment are often inseparable. We act on ourselves when we are preparing to act on our environment.
A self (or a spirit or a mind) is a totality of perceptions, emotions, imagination, decisions ...
"In what is seen, there will be only what is seen; in what is heard, there will be only what is heard; in what is perceived, there will be only what is perceived; in what will appear to consciousness, there will be only what will appear to consciousness." (The Buddha, Ud 1.10)
To act on oneself is to act on one's perception, one's imagination, one's emotions, one's decisions ...
To be self-conscious is to be conscious of one's perception, one's imagination, one's emotions, one's decisions ...
Information is conscious when it is available for decision making or for monitoring their execution.
An action is voluntary when it is a decision or when it is ordered by a decision.
A decision is an action on oneself. One transforms oneself by passing from the undecided state to the decided state. Decisions are the basic voluntary actions, which order all other voluntary actions. When we act voluntarily we always start by acting on ourselves, because we must first determine our will.
All the decisions already taken determine a program of actions, of transformation of oneself and one's environment. One writes the program by making decisions. Each new decision supplements and modifies the existing program. A spirit is a programmable system who writes one's own program. We act on ourselves by programming ourselves by the imagination and the word. Just as a spirit programs oneself by making decisions, so all spirits collectively program themselves by making collective decisions. We must understand here the concept of program in its richest sense: a life program, work, wisdom, research programs, political, educational, artistic programs ...
One is autonomous when one obeys a law that one has chosen oneself. Decision makes us autonomous, because we can decide the laws to which we obey. Autonomy and therefore freedom of the spirit are made possible by programming oneself.
A spirit programs oneself to think well and live well by giving oneself good principles.

## The connection between detectors and effectors

To be intelligent, we must always adapt to reality, outer and inner.
Cognition is the production and use of internal representations that prepare or lead to action.
To use representations, one must be able to act, one must be an agent, that is to say an animated body: a living being or a robot. An agent is always a system that interacts with its environment through detectors and effectors (Turing 1936, Russell & Norvig 2010).
The detectors (the sensory organs) are connected by a nervous system (the brain, the spinal cord ...) to the effectors (the muscles, the excretory glands ...) in order to produce an intelligent behavior (Churchland & Sejnowski 1992, Gazzaniga & Ivry 2001). We do not know why the electrical activity of a brain can give life to a spirit, but we do know a necessary condition: a brain must connect detectors and effectors, because a spirit perceives the environment in order to be able to act on it.
Sensory perception is the production of internal representations from the signals provided by the sensory detectors. It prepares for action by enabling the agent to adapt to its present environment. More generally, all forms of perception and imagination are ways of producing internal representations that prepare or lead to action.
To understand sensory perception, we must understand how it enables one to act on one's environment in an appropriate way. To understand self-consciousness, we must understand how it enables one to act on oneself in an appropriate way.
The purpose of the eyes is to see (Aristotle, On the soul), but not only. The purpose of the eyes is also to act.

## Brain modules and routine activities

A brain module is a network of neurons specialized in certain tasks of information processing. It has entrance ways, where it receives signals, and exit ways, where it emits signals. It can be very localized (a small nucleus of neurons, a cortical micro-column ...) or quite extensive (a vast network distributed over several brain regions). It has its own skills and a partially autonomous mode of operation.
Cerebral activity as a whole is the result of the coordinated activity of all modules. They exchange signals and thus produce all the internal representations which prepare for action and all the signals which trigger and control it.
A brain module can be in a higher or lower position in the hierarchy of modules. The most subordinate modules are the most peripheral, those which directly control the muscles and the rest of the body, or those which receive information directly from the sensory organs. Subordinate modules are controlled by other higher level modules or provide information to higher level modules. A module generally has a fairly limited competence. It only has access to a small portion of the information available in the brain, and the repertoire of tasks it can perform is also limited. But the modules of the highest level, that is to say those which command the other modules at the highest level, or those which receive information at the highest level, are in principle capable of mobilizing all the resources of the body and its brain. .
The higher a module is in the signal reception hierarchy or in that of their transmission, the more central it is. It is at the center because it synthesizes the information provided by the inner resources, or because it commands and coordinates the inner resources.
The spontaneous activity of the modules is sufficient to explain the routine behaviors that result from instincts or learning. The necessary resources are recruited automatically and perform their tasks as they are used to.

## Decision: a centralized administration without a central administrator

Decisions can mobilize, coordinate and control inner resources at the highest level.
In order for our decisions to mobilize our internal resources, they must be remembered. Certain modules must be specialized in the recording of our decisions and the distribution of the resulting orders. The stored decision is used to send orders to all the modules concerned by the execution of this decision. The executive modules are those responsible for recording and enforcing our decisions. They are at the top of the hierarchy of control over other modules. They are in a central position.
Executive modules are not innovators. They simply record decisions made elsewhere and automatically distribute the orders that apply them. They are not homunculi, or little geniuses in the head, but only neuronal circuits capable of recording the decisions received on their input channels, and then giving the orders that apply them to their output channels. It is just information processing, not spirits in the machine.
Information is conscious when it is available for decision making or to control their execution. The resources of perception, imagination, emotion, and the memory of past decisions can all be used to make decisions. Decision making is the result of a discussion between our internal resources. The available resources are mobilized to assess the decisions to be taken. As soon as the decision is taken, the executive modules concerned are informed to have it applied. The evaluation which precedes the decision is in a central position because it is a form of perception at the highest level and because it commands the executive modules of the highest level.
The executive modules control actions on the environment and actions on oneself. With decisions one can control perception, imagination, emotion and decision.
The evaluation which precedes a decision is a kind of collective deliberation, in which our internal resources are invited to participate. Once the decision is made, these same internal resources must respect it. The internal organization which allows the will to exist resembles a centralized administration without a central administrator. A common law is decided by all and is binding on all. Our voluntary projects are proposed, developed and evaluated by all of our internal resources, and once adopted, they impose themselves on these same internal resources, which must obey the orders given to them. But there is no chief, no central administrator. Executive modules only record decisions made by the community. They too therefore only obey the common order.
he model of a centralized administration without a central administrator explains why the ego is like a strange loop (Hofstadter 2007), by showing how the ego perceives oneself to act on oneself.
When their behavior is routine, agents do not need to look for solutions for long. They find them spontaneously because their brain modules know how to produce them, by instinct or habit. The agents are content to solve the problems they already know how to solve. But faced with a new situation, the usual reactions are not always adapted. The agent may have the domestic resources to react appropriately, but it does not know how to mobilize them, because it would have to invent a new mode of coordination between his brain modules. None of them have the means to recruit others, even though it would be sufficient for them to work together to achieve the desired ends. The agent would need an inner composer-conductor, able to find truly new solutions (Shallice & Cooper 2011). The model of a centralized administration without a central administrator shows, without postulating the existence of a spirit in the machine, how the brain can function as if it were equipped with such a composer-conductor. All parts of the brain are invited to participate in the composition, as in a collective creation workshop. The executive modules are the conductors.
In the Baars model, consciousness is compared to a blackboard on which conscious information is written. All parts of the brain can write on the board and in return they are always informed of what is written on it (Baars 1988, Changeux 2002, Dehaene 2014). As long as a performance does not gain attention, it remains attached to its place of production and cannot have an effect on the whole system. Its effect is necessarily limited. But if we are aware of it, it can be used to influence the rest of the brain. The model of a centralized administration without a central administrator is a modification of the Baars model: information must be conscious in order to be received by the executive modules which control the whole brain, but it is not necessarily distributed to all parts of the brain. A decision has an effect only on the modules which must apply it or have it applied. If all the modules of the brain were to receive all the conscious information all the time, they would be overwhelmed by a flood of information that they usually could not do anything about.
The model of a centralized administration without a central administrator explains how the brain enables us to have an autonomous will and to voluntarily control perception, imagination and thought. This is a theory that explains the functioning of our brains when we are conscious, but this is not enough to explain the appearance of consciousness from brain activity (Chalmers 1996). Attention selects representations to make decisions and control their execution, but selection alone does not explain why representations so selected become particularly conscious. A robot can also select representations to make decisions without implying any consciousness.
Consciousness arises from brain life, but we do not know how to explain it. Nerve impulses are produced by electric currents in neurons and through their membranes. These are very ordinary ion currents. There is nothing to suggest that they must be messengers of the spirit.

## The perception and imagination of the present

Perception and imagination are often thought in opposition. What is perceived is present, what is imagined is not. If for example I am in a familiar place, I can imagine the layout of the place even in the dark. I know that various objects are present and where they are but I do not perceive them directly.
A simplistic and partially false modeling of perception assumes that it is unidirectional. The information is first produced by the sensory detectors and then synthesized in successive steps to the high-level representations, which determine the main perceived objects and the main concepts attributed to them. It is assumed that complex representations emerge from elementary perceptions, as in a pointillist painting. Such a dynamic of production of representations is called upward or bottom-up, because sensory signals are considered as low-level representations, while concepts attributed to complex objects are high-level. This modeling ignores the anticipation effects. It makes it possible to explain the internal representations of objects actually detected, but not the representations of objects or qualities whose presence is only assumed.
In the strict sense, perception is only sensory. Perceived representations are awakened or at least confirmed by information that comes from the senses. But the representation of the present goes beyond strictly sensory perception. We could not even take a step if we limit ourselves to the data directly perceived by the senses, because we have to anticipate that the ground will resist before feeling it directly.
In a general way our representations of the present come from both sensory and memorized informations. For example, when we grasp a familiar object, the gesture is prepared to fit the weight of the object. If we do not anticipate the weight, the gesture is not adapted. This shows that we have an internal representation of the weight before we hold the object in the hand. The weight is therefore represented before the muscular tension sensors provide this information. We can say that the weight was imagined, but we can also say that it was perceived indirectly from the visual image, thanks to a memorized knowledge on the ordinary weight of such an object.
What is perceived is not only determined by the senses but also by expectations and desires, by previous perceptions, memories, prejudices, culture and knowledge. The waiting effects can be so strong that sometimes we think we have seen what we could not see, because it did not exist. Our perceptions therefore have inner sources, they are not only elaborated from the senses. The dynamic of representations is not only upward, but also downward, top-down. The sensing systems that receive the sensory information also receive higher level information. We must model a kind of permanent dialogue between the various stages of perception. Information can travel in all directions, from bottom to top, from top to bottom, and horizontally (Hofstadter & FARG 1995). Any representation can have an influence on the output of others, whatever their level of complexity.
As the representation of a present situation is always part of a system of presuppositions, the present is always as much imagined as really perceived. Sensory perception can even be considered as a form of imagination, stimulated and guided by the senses. It is an imagination of the present in accordance with the data of the senses.
A detection system is above all a warning system. The detection signal warns of the presence of the being detected. The warning function is more fundamental than the detection function, because the system can signal the presence of a being which has not been detected. It is enough that this presence is supposed, or inferred from the detection of other beings.
An inference consists in passing from a condition to a consequence. The consequence is a representation produced, inferred, from the representations which determine the condition. If these representations are verbal, an inference is a step in a reasoning, but representations are not necessarily verbal. Perception proceeds by silent inference as soon as it connects consequences and conditions.
Inferences can be chained because consequences can themselves be conditions that have consequences, and so on. A chain of silent inferences resemble very much a reasoning. The sequence of representations of the conditions and their consequences is similar to that of their verbal descriptions chained in a reasoning.
Silent inferences make that there is no clear boundary between sensory perception and the imagination of the present. When a representation has been produced by inference, as a consequence of a condition already perceived, we can say that it is imagined, but we can also say that it is perceived indirectly from the perception of the condition.
A schema, or a conceptual framework, is a system of preconceptions, that is to say, what is held true before having verified it. A schema determines the beings we expect to perceive with the concepts that we think we should attribute to them and the inferences that we believe we can apply to them.
Sensations are the sources of the bottom-up processes of perception, schemas are the sources of downward processes. They are part of the normal functioning of perception. They are necessary to adapt quickly to the environment, because to act we often do not have time to check everything.
Knowing the right schemas makes all the difference between the expert and the neophyte. An expert often needs only a glance to correctly analyze a situation and draw the necessary conclusions, because she already knows the schemas that make it possible to understand it and she only has to check their adaptation. A neophyte is overwhelmed by the flow of new information, does not know what to look at, does not distinguish the essential from the negligible and rarely asks the right questions, because she does not know the schemas that would allow her to organize her perception of the situation.
In the strict sense, perception is only the imagination of the present when it is awakened or confirmed by the senses. But we can also define perception in a more general sense and speak of the perception of the past (the remembrance, and more generally any form of imagination of the past), of the future (anticipation), of the imaginary (to dream of beings that do not exist) and even of abstract beings (abstract, mathematical knowledge for example). Thus understood perception and imagination are synonymous. Furthermore, self-consciousness is a perception of oneself as a conscious being.

## Imagination and the simulation of perception

The modes of the imagination are numerous:
* Memories: the imagination of the past that we have lived.
* Anticipations: the imagination of the future, considered as possible or certain.
* Fictions
* Putting oneself in other people's shoes: to imagine what another perceives, feels, imagines, decides ...
* Assumptions about the present: the imagination of a supposed present which is not perceived.
To act we must perceive and imagine the present, because we have to adapt to reality, but we must also imagine the absent, the goals that we set for ourselves and that we have not yet achieved, the means to implement and the foreseeable consequences of our decisions.
Perception systems can function as alarms even if the beings whose presence they signal have not been detected. They can report a hypothetical presence. They thus make it possible to completely overcome the senses and simulate the perception of a scene that is not present. The imagination of the past, of the future and of purely imaginary worlds is perception without detection, therefore a simulation of perception. The resources of perception are mobilized to represent an environment that is not present, only imagined.
Simulating perception consists in simulating the activation of our detection systems. One can simulate sensory perception and partially reconstitute sensory images or impressions, but imagination is not necessarily associated with sensory images. To imagine a dangerous being it is not necessary to make a visual image of it, or to imagine its voice, or any other form of simulated sensory perception, it is sufficient to simulate the activation of a danger detector. You can imagine yourself in the vicinity of a dangerous being even if you do not perceive anything of it, except that it is dangerous.
By imagination we can combine representations in new configurations that we never perceived. The parts have been perceived, but their assemblage is invented, it is purely imaginary, it represents a fictitious being, a kind of chimera. By assembling fragments of sensory images, like a patchwork, we can create an image of a being that does not exist. In general, the assembly of concepts makes it possible to create representations of beings which have never existed and which may never exist. Combinatorics multiplies the possibilities endlessly.
With silent inferences, we can predict the chain of consequences of our decisions. We can thus explore by imagination the paths that we could follow. We thus discover at the same time the goals that we could reach and the means to reach them.
The importance of representations of the present and the future for the preparation of action is evident, that of representations of the past is a little less. Remembering prepares us for action indirectly, if only by helping us to perceive the present and the future, by inference from the knowledge of the past. But the imagination of fictions, how can it prepare for action? It seems it is taking us away from it. To act well one must have feet on the ground, one has to adapt to what really exists. What is the use of imagining beings who will never exist?
The work of the novelist is similar to that of the mathematician. She posits conditions, an initial situation and constraints, and then exposes their consequences, which are often inescapable, in the same way that a mathematician proves theorems from axioms and hypotheses. When we imagine fictions, we can fully utilize our abilities to infer. It is not only a question of inventing assemblages of representations, but above all of imagining all that results from it, all that our inner dynamic of production of representations by inference can provide from these inventions. The imagination of fictions reveals the power of inference.
We know another spirit by imagining that he perceives, that he imagines, feels, thinks, wants and acts. We imagine that he perceives by imagining what he perceives. We imagine that he imagines by imagining what he imagines. Sympathy is to feel what he feels. In general, we know him as a spirit by putting ourselves in his place (Goldman 2006, Rizzolatti & Sinigaglia 2006). We can imagine that we want what he wants and that we do what he does. A spirit is a universal simulator because he can simulate all other spirits, at least if they have the same faculties - for a human being it is easier to put oneself in the place of a human being than in the place of a bat.
A spirit knows the spirit both by knowing oneself and by putting oneself in the place of other spirits, of all the spirits one can imagine.
Everything that can be perceived, imagined, felt, thought or decided by some, can be perceived, imagined, felt, thought or decided by all the others. To know oneself as a spirit is at the same time to know what everyone else can do with their spirit. Conversely, everything that others do with their spirit shows us what we can do ourselves. "Nothing human is alien to me." (Terence, Heautontimoroumenos, v. 77)
I know another spirit by putting myself in his place in imagination. Likewise, he knows me by putting himself in my place. When I wonder what he thinks of me, I try to imagine what he imagines when he puts himself in my place, I imagine what he imagines of me. I can also imagine what he imagines when he puts himself in the place of a third.
The same content can be imagined in various ways: a past that we have lived, a projected future, a simple hypothesis, a content imagined by others, and even a content that others believe we imagine. When we remember, we put ourselves in the place of the other that we were. When we look to the future, we put ourselves in the place of who we could be. From this point of view we know ourselves in the same way as we know others, putting ourselves in the place of ourselves in imagination. When I imagine what I could be, I am in a position similar to that of another who imagines what I could be. When I imagine how someone else imagines me, I imagine what I could be if I were like he imagines me.
When a content is represented by perception or imagination, it is always accompanied by a signal which characterizes the mode of representation. Such a signal can be quite complex because it must answer the following questions: is it a content directly perceived or only imagined? Is it about the present, the past or the future? Is this certain or only possible? Is it attributed to someone else or to myself? Is it attributed to another by another or by myself? Is it attributed to myself by another or by myself? ... If such a signal did not exist, we would not be able to tell the difference between fantasy and reality.

## Memory and invention

Our memory is much more than a device for recording and restoring information. It determines everything we imagine, not only the past that we reconstruct when we remember, but also the future, the fictitious, the hypothetical ... It even determines what we perceive, because our perceptions depend on schemas that we have memorized.
Memory works like an oracle with limited skills. We can ask it any question, submit any problem to it, or solicit it in various ways (what if ...?), and it answers, within its means, sometimes simply by acknowledging its ignorance. But it is much more than a system for recording already known answers. It can find new answers, or new solutions, because it can synthesize the information it has acquired.
In relation to its memory, a spirit is at the same time a spectator and an actor. He watches what his memory gives him to imagine, he listens to what it gives him to think, he receives its teachings, and he can never know more than what it wants to teach him. But he is also an actor, because he decides what beliefs he approves, and because memory delivers its teachings taking into account everything he has approved beforehand. Beliefs are like a program used by memory to give its answers. A spirit is like the programmer of his memory.
Memory is like capital. It is not there only to be preserved but especially to bear fruit, to perceive well, to imagine well, to think well, to know well and to live well.

## Programming by the imagination

A program is defined by goals to be achieved, rules to be respected and beliefs about the initial conditions.
A rule can sometimes be considered as a goal: to respect the rule. It is a goal that we always reach, as long as we respect the rule, and that we never finish reaching, as long as we must continue to respect the rule.
A rule is not necessarily stated in words. It suffices to memorize the connection between the perception, or the imagination, of the conditions and the imagination of the consequence.
Imagination without speech is enough to determine goals, beliefs and rules. We just have to imagine what is wanted, what is believed and how the rules are applied. Silent knowledge is knowledge that needs no words, knowledge that we learn only with perception and imagination.
Several types of rules:
* If A is then B must be done
These are conditional orders. They are fundamental for adaptation to reality, because they relate actions to their conditions.
* If A must be done then B must be done
These are rules that make it possible to connect means and ends, or ends between them.
* If A is then B is or will be
These are inferences that increase knowledge about the reality to which we must adapt, by linking causes and effects.
The rules of the first two types are rules of production of goals. Those of the third are rules of production of beliefs. We can also give ourselves rules of production of rules.

## Emotions

The concept of emotion is difficult to define and its use is often very imprecise. Should we distinguish moods and emotions, moods because they are durable, emotions because they are brief? Is tranquility an emotion or independence from emotions? Is jealousy an emotion or a more complex state that mixes emotions and will?
We can define emotions from some basic emotions (sadness, fear, anger, disgust, shame, joy, appeasement, pride, surprise ...) and include all the variations and combinations, or from some general characters:
* An emotion is triggered by the detection of specific conditions, fear by the detection of danger, sadness by the detection of misfortune, anger by the detection of the unacceptable ...
* This detection is followed very quickly by reflex reactions and physiological changes that enable the body to adapt to the novelty of its situation.
* Emotions determine motives, ie desires or aversions. They tell us the goals that deserve to be pursued, and what we must flee or avoid (Damasio 1994). They are therefore very important to the will, because they enable us to evaluate our projects, and for learning, because they point out what deserves to be memorized.
Because it is triggered by specific conditions and because it causes specific reactions, a particular emotion, such as fear, can be characterized by the activity of a brain module, or a system of modules that coordinate their activities. Input channels carry the signals that awaken, modify or suppress the emotion. Output channels carry the signals that provoke typical emotional reactions (LeDoux 1996).
An emotion is a combination of perception and action. I perceive what moves me when it moves me by attributing to it the property of moving me. The expression of an emotion is an action.
We evaluate what we perceive and imagine by relating it to the emotions we feel, and we make our decisions based on these evaluations. An emotion, especially if it is strong, can exert a sort of empire over all bodily activity, interior and exterior, because it dominates all decision-making.

## Self-consciousness

If I see that the sky is blue, I am not only informed about the state of the sky, I am also informed about myself, namely that I see the sky, I know myself as a being who perceives the sky.
Self-consciousness, or introspection, is the knowledge of oneself as a spirit, that is, as a being who perceives, imagines, feels, decides...
Does introspection require sensory organs? Is there a sensory interface between the perceived self and the perceiving self? When I know that I see the sky, is it an introspective eye that shows me that I see the sky?
A sensory organ is always an interface between an inside, the nervous system, and an outside, the environment beyond the skin or the interior milieu under it. The external signals are received by the sensory interface and translated into internal signals, usable by the nervous system.
Introspection does not require a sensory organ because there are no external signals to translate into internal ones, no separation between a perceiving self and a perceived self. Everything happens inside. All information about the agent, as it perceives, imagines, feels, thinks or wants, is already present inside the agent. To develop its faculties of introspection it has only to exploit these internal sources of information. A sensory organ of introspection is not necessary because the information sought is already present inside.
The self is what perceives, what feels, what imagines, what thinks, what desires, what wants and what acts. There is no self separate from perception, imagination, emotion, decision... no central administrator in the brain, only a centralized administration.
Two perceptions of the same agent are not the same as two perceptions of two different agents. The perceptions, imagination, emotions, decisions ... of the same agent form an integrated whole because the administration is centralized, not because there is a central administrator.
The signals which characterize the modes of the imagination reveal the activity of the agent as a being who imagines, therefore as a spirit, as a conscious being. A represented content is accompanied by a signal that characterizes the way it is present to consciousness. These signals are to self-consciousness what signals of sensory origin are to sensory awareness. They can be detected by inner detectors which attribute concepts to the agent himself, as a conscious being.
To give a good program of actions on a reality, it is necessary to know both this reality and the agent or agents who apply the program. Self-consciousness is necessary to act voluntarily on one's environment because one must know one's capacities, needs and obligations. Self-consciousness is doubly necessary to act voluntarily on oneself, because one must know this reality that one is and on which one acts, and because one must know one's capacities of action on oneself, one's needs and obligations.

## Voluntary self-control

Voluntary control is always self-control, because a decision is an action on oneself. But using one's decisions to control one's perception, imagination, emotions and decisions is more self-control than voluntary control of one's environment.
Sensory perception is not only a passive process, awakened by the sensory organs, it is also an active process, which depends on our decisions. We voluntarily control perception by setting goals, rules and beliefs. We can give ourselves a program of observations to explore our environment, or to know ourselves.
Concept detection can be an almost instantaneous process, if the detection signal is produced as soon as information about the detected being is provided, or progressive, if the detection system takes the time to accumulate information before giving its result.
As a conscious belief is evaluated before being approved, the whole evaluation process is part of the perception of the assigned concept. The evaluation capacities which precede the decision are concept detection capacities. As all concept assignments can be subject to conscious approval, the decision system works like a universal detector, capable of detecting any concept, as soon as it has learned to do so. We can invent all the concepts we want by giving ourselves the means to detect them.
As long as they are not refuted, one can freely choose one's beliefs. They are prejudices, presuppositions, hypotheses or convictions. Even when they are refuted, we can sometimes keep them, doubting the refutation.
The interpretation of perceived reality is part of perception. By choosing our assumptions, our interpretation schemas, we voluntarily control our ways of perceiving, we can discover or invent new ways of perceiving.
One voluntarily controls one's imagination in the same way that one controls one's perception, because the imagination is a simulation of perception, or is part of perception. We are much more free in the control of the imagination than in that of sensory perception, because we do not have to take into account the data of the senses.
One voluntarily controls one's imagination with goals, rules and beliefs. We program the imagination by the imagination. Spirits use their imagination to program their imagination. We can pose problems with our imagination, and solve them by programming our imagination.
Decision-making processes depend on our previous decisions. We can make decisions about how we decide. For example, taking a resolution is deciding once and for all, all the times we have to decide again. We can also decide to adopt rules that guide decision-making. For example, never endorse a belief until it is well proven.
We cannot voluntarily and directly control the triggering of emotions, but we can voluntarily control their expression. We can also indirectly control their triggering by acting voluntarily on our environment, our perception or our imagination. Emotions do not only depend on reality, they mainly depend on its interpretation. By voluntarily controlling our interpretations, we can control the triggering of emotions.

## Meaning through imagination

Why do words make sense? What makes sound sequences useful for communicating? What gives words and statements their meaning?
When one understands a description, one imagines what is described. Words and verbal expressions arouse the imagination as soon as we understand their meaning. One imagines what is described when one simulates its perception, when one activates, in simulation mode, the detection systems which would be awakened if we perceived what is described. When concepts detected by our perception systems are associated with verbal expressions which name them, we can both describe what we perceive, by naming perceived concepts, and imagine what is described by simulating the detection of named concepts (Saussure 1916).
In the case of a simple description, the speaker understands what she says if she perceives or imagines what she describes, and the listener understands what is said as soon as she perceives or imagines what is described. Knowing how to describe what we perceive or imagine and knowing how to perceive or imagine what is described are the foundations of language understanding. All uses of speech rely on descriptions.
A verbal expression has a meaning when it names a concept or an individual. The named concept, that is to say, the property or the relation, is the meaning of an expression that names a concept. The named individual is the reference of an expression that names an individual.
A concept is empirical when it is an observable property or relation.
We know a concept when we know how to assign it, when we know the assignment criteria. For empirical concepts, one must be able to observe their presence.
The same verbal expression can have several meanings. The same name can be used to name several concepts or several individuals. It can be interpreted in several ways.
Silent knowledge is the knowledge that precedes speech and results from perception and imagination. It can be translated into words as soon as the detection systems that it uses are named by verbal expressions. Descriptions are then a translation into words of what is described. The laws which relate the description of conditions to the description of consequences are a translation of silent inferences. A reasoning which combine these laws is a translation of a sequence of silent inferences. In this way, silent knowledge can be translated into words, and thus communicated.
The understanding of speech can be conceived in a purely passive mode, as if the words were the notes of a score and the understanding, the music performed by an inner mechanical piano. But imagination is not only awakened by words in this passive way. The understanding of speech is also and especially active. We understand because we want to understand, and what we understand, that is, what we imagine, depends on our expectations and interpretations.
Interpretation of observations is itself a part of observation. An observation can be the conclusion of reasoning based on other observations and principles. Theories are part of the instruments or devices of observation.
Concepts of silent knowledge do not need a theory to be observed. They are purely empirical.
Silent knowledge is fundamental to the development of reason, because talking knowledge begins as a translation of silent knowledge. It can then fly on its own because it can speak about speech. We need the purely empirical concepts of silent knowledge to make sense of our empirical theories.
To understand a discourse, one must identify the concepts named by words and expressions. We have to find or invent the ways of perceiving the named concepts. When a child learns to speak, at the same time he or she learns new words or expressions and ways of perceiving the named concepts. When a speech invents new expressions, it invites us at the same time to invent new ways of perceiving.
Speech gives us the means to invent and communicate ways of perceiving. All the concepts invented by one can be communicated to the others.

## Meaning through principles

As soon as the concepts named by expressions are identified with empirical concepts, therefore with ways of perceiving or detecting, the truth of attributions can be decided by observation. The assignments of concepts are true as soon as the observations which they translate are true (Locke 1690).
Observation is not the only criterion of truth, because theories impose the truth of their principles (Leibniz 1705, Kant 1787). Theories, or theoretical frameworks are the talking equivalent of silent conceptual frameworks. A theory is determined with a system of names, intended to name concepts, and a system of principles, axioms and definitions, which make it possible to reason with the named concepts.
As soon as empirical concepts are not purely empirical, their observation depends on a theoretical interpretation, we need a theory to know how to assign them, we must therefore know principles in order to know them. To understand speech we need to know principles, because they are used to determine the meanings of expressions.
A theory receives an empirical interpretation when the named concepts are identified with observable properties or relations that together form an empirical conceptual framework. The same theory can be interpreted by several different empirical conceptual frameworks, but it places constraints on acceptable empirical meanings. The interpretation must not contradict the principles of the theory. For example, the truth of the principle of transitivity, 'if x is greater than y and y is greater than z then x is greater than z' is accepted by definition of the relation 'is greater than'. This relation can be interpreted in many empirical ways, but the principle of transitivity can never be contradicted by our perceptions. If it leads to an erroneous anticipation, it will be said that the observed relation has been misnamed, that it is not an empirical meaning that can be given to the expression 'is greater than'.
The paradox of Condorcet (1785), in political science, illustrates the priority of an a priori principle:
One can assume that electoral results give strength to the various candidates and consider measuring this force. Assume that in an election where each voter must rank three candidates A, B and C in order of preference, the three ABC, BCA and CAB orders have each been chosen by one-third of the electorate. It seems that the force of A is greater than that of B, since two-thirds of the electorate prefers A to B. Similarly B is stronger than C, and C is stronger than A. The principle of transitivity is therefore contradicted by experience. But it is not refuted, it has only been poorly applied, because such an electoral system does not make it possible to measure the strength of the candidates. It will not be said that the theoretical framework (the measure of the magnitude of the forces) is false, but only that it is not adapted to the perceived reality.
In general, an expression can have many empirical meanings, and new ones can always be invented. But when principles are true by definition they impose constraints on interpretation, limits on the empirical meanings we can give to our expressions. The empirical meanings of our expressions cannot be chosen freely without regard to principles. The truth of the principles usually takes priority. If an expression is used in a way which contradicts a principle, it will be said that the interpretation is not correct, or that it is not one of the interpretations permitted by the principles. In this way, we can be sure that our principles are always true, because an interpretation that would make them false is a priori excluded.
The principles of a theory are accepted by definition of their terms. Their truth is supposed to be known as soon as the meaning of expressions is understood (Pascal 1657). Sometimes axioms are said to be disguised definitions, because they serve to give meaning to their terms, and thus to define them.
The logical consequences of axioms and definitions are the theorems of the theory defined by such principles. A theory can be used in a way that resembles perception, like a system of detectors. To know if a statement is true or false, it is enough to prove it by a logical reasoning or to prove its negation. In this way the names of concepts are associated with theoretical detectors that determine whether the concepts are true of the named individuals. Theoretical detectors detect what they must detect by finding logical proofs, based on accepted principles. If they do not find any, their detection has failed. « The eyes of the soul, whereby it sees and observes things, are none other than proofs. » (Spinoza, Ethics, Book V, prop. 23, Scolie) Just as the eyes of the body enable us to see visible beings, so logical proofs from principles enable us to know purely theoretical beings. We detect purely theoretical concepts by reasoning from the principles that define them.
Words and verbal expressions can be interpreted in many ways and thus receive many empirical or purely theoretical meanings. To determine an empirical interpretation, it is enough to associate to the named concepts perceptual systems which enable us to detect them. In order to determine a purely theoretical interpretation, it is enough to associate to the named concepts systems of principles which enable us to reason with them.
According to the interpretation given to it, the same statement can be at the same time a purely theoretical truth and an empirical truth. Such an ambiguity can be very useful, because by developing a purely theoretical knowledge, one at the same time obtains an empirical knowledge. We do not even need to change the wording. Obviously for such magic to occur, the theory and its interpretation must be adapted to the observed reality in order to make it intelligible. The encounter between purely theoretical truth and the empirical truth is the goal of all empirical sciences, because we want to know by reasoning what we know by the senses or by self-consciousness.
Logical principles always make us pass from the true to the true (Aristotle, Prior analytics). When affirmations are true, their logical consequences can not be false. More precisely, whatever interpretation we give to affirmations, if these affirmations are true, according to the supposed interpretation, then the logical consequences are also true, according to the same interpretation. The relation of logical consequence does not depend on the interpretation of what we affirm, it depends only on the meaning of the logical operators.
When we prove a conclusion by logical reasoning, the premises determine sufficient conditions of truth. Whatever interpretation is chosen, if the premises are true, then the conclusion is true. Reasoning serves not only to prove, but also to explain the conditions of truth. To understand a theorem, one must know its proof, because it gives truth conditions which specify how one must interpret it. A proof sheds light on its conclusion not only by showing us its truth but also by giving us the principles which determine the meaning of the expressions used.
When we learn a language, we learn at the same time new expressions, new ways of perceiving, which give empirical meanings to these expressions, and new principles with which we can reason. We develop thus our empirical knowledge and our theoretical knowledge at the same time. The two are inextricably entwined because in general one needs theories to determine empirical meanings.
To know if a statement is true, one must first specify its meaning. The same speech may be sometimes true, sometimes false, it depends on its interpretation. Most of our controversies come whether from misunderstandings, because we give different meanings to the same expression, or lack of precision, because we leave in the vague the truth conditions of what we say. We do not explain the principles which decide theoretical truth or we do not specify the devices of observation which decide empirical truth.
The diversity of interpretations can make communication of knowledge very difficult. The speaker must respect a principle of clarity: to provide clarification so that his speech can be interpreted correctly. The listener must respect a principle of charity: always to interpret a discourse in the way that is most favorable to it, as far as possible. It is always possible to dispel misunderstandings and to reach consensus, because we can all do the same reasoning and perceive the same world.

## Programming by the thought

« Do you accept my description of the process of thinking?
- How do you describe it?
- As a discourse that the mind carries on with itself about any subject it is considering. You must take this explanation as coming from an ignoramus ; but I have a notion that, when the mind is thinking, it is simply talking to itself, asking questions and answering them, and saying Yes or No. When it reaches a decision — which may come slowly or in a sudden rush — when doubt is over and the two voices affirm the same thing, then we call that its judgment. So I should describe thinking as discourse, and judgment as a statement pronounced, not aloud to someone else, but silently to oneself.
- I agree. »
(Plato, Theaetetus, 189e-190a)
Thought is the imagination of speech. To think is to speak to oneself in imagination. One is at the same time speaker and listener.
Speech is the voluntary emission of signals to influence the imagination and the will of those who receive them. Why do we want to influence our own imagination and our own will? We talk to others to communicate to them what they do not know, but why do we talk to ourselves? Can we communicate to ourselves what we do not already know?
To think is to explore with the imagination all that can be done with speech. Speech is used to communicate beliefs, rules and goals. We can thus define programs that we give or impose on others, or that we give to ourselves.
We program ourselves by thought. We apply and complete the program with each new thought.
Just as we can train others and be trained by them with speech, so can we train ourselves with thought, by setting up programs and applying them.
Silent imagination, without thoughts, is enough to teach ourselves what we do not already know, because we can discover by imagination the chain of consequences of our silent inferences. A rule determines all its applications, but we can know the rule before knowing the applications. Each new application of the rule is a discovery.
By programming ourselves with principles, we make ourselves capable of discovering everything they teach, all their applications. By thinking through a well-thought-out program, we learn by thinking what good principles teach.
We build ourselves by word and thought, but we can also say that it is the word that builds us.
In the beginning was the Word, and the Word was with God, and the Word was God.
He was with God in the beginning.
Through him all things were made;
without him nothing was made that has been made. In him was life,
and that life was the light of all mankind.
The light shines in the darkness,
and the darkness has not overcome it.
(John 1, 1-5)
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