Regis Petit's Website

Human and medical sciences

• E1. The life laws
• E2. Hypnosis, between science and mystery
• E3. Smells and flavors
• E4. Genetics
• E5. Human Nervous System and Learning
• E6. Color blindness
• E7. Tattooing

E1. The life laws

A small number of truth seekers, notably Svâmi Prajnânpad, have simply described the laws of life as follows (from the book [Petit Régis, Une approche scientifique du silence]).

1. Definitions
2. Law of difference
3. Law of change
4. Law of causality
5. Law of the psyche
6. The life purpose
7. Silence and fullness
8. To love
9. To desire
10. To act
11. To live in society
12. To give
13. To help others
14. To die
15. Sources

E1.1. Definitions

* Svâmi Prajnânpad, the truth, emotion / feeling, to think / to see

Svâmi Prajnânpad (alias Svâmiji, 1891-1974) was a Bengali Brahmin who had received dual training, classical Vedantic and modern scientific trainings.
A master of wisdom and lucidity, his rigorous approach is a dive into the heart of the unconscious which reveals the difficulties hindering the silence of mental. No God, no ritual, no paradise.
André Comte-Sponville said about him : "This master is content to see, to be one with what he indifferently calls truth or reality, which is neutral, neither good nor bad, neither pleasant nor painful, and promised only change or death." [PDS 2]
According to the specific vocabulary of his teaching [EHM 1] :

• to see consists of recognizing reality as it is without distorting it ;
• to think (functioning also designated by the mental) consists in projecting onto reality what it should be according to our preferences and pleasing ourselves in this imagination ;
• the emotion corresponds to an affective state of reality refusal which accompanies the thought and causes a suffering of separation ;
• the feeling arises when we accept reality and feel oneness with it.

* Inner peace, truth, science

• Outer peace is impossible without inner peace. [GKG 2]
• The truth is the middle ground between fascination and disillusionment with the world. It is found not by seeking it but by creating peace within oneself. [Anonymous]
• What is the truth ? Which is. But this definition is not complete. This is only the first half. The second half is that there is nothing other than what is. [PDS 4]
• To know if you have actually seen or if you have only thought through your mental, there is only one criterion : Do you experience any emotion ? If so, it means that the mental has started to function. When you see, there is no emotion. [PDS 4]
• Svâmiji gave the example of the doctor who "thinks" nothing of the patient when the latter enters his office. He examines it, auscultates it, "sees" the state in which it finds itself. He has no a priori, he does not think but "sees" that is to say examines, observes, reflects, discriminates on facts. [RFD 1]
• You cannot own the truth. We can only be the truth. One must die to the life of the mind in order to be reborn to the life of truth. [PDS 4]
• Yesterday is in your memory. Tomorrow is in your dream. Today is the only reality. [Anonymous]
• Svâmiji said : "What is science ? Only the search for truth." [PSP 1]
• Svâmiji once told me that adhyatma yoga is based on four pillars : vedanta vijnana, manonasha, chitta shuddhi and vasanakshaya. Vasanakshaya means erosion of desire, chitta shuddhi purification of (unconscious) memory, manonasha destruction of mind and vedanta vijnana science of vedanta (or knowledge of the life laws). [DSA 8]

* Ego, attachment, mental, identification

• The ego is a protective shell to keep out anything foreign, new, unknown. It is a structure kind of world apprehension, devoid of flexibility and adaptability to change. [RFD 1]
• Svâmiji said : "Man's very first perception in his life, what he sees as soon as he opens his eyes, is considered by his mental as stable from the beginning. Every object exists for him. Constantly associating, he clings to it. He believes that all these things exist and will continue to exist. He does not want to accept that anything can be lost." [RFD 3]
• The ego expresses itself on different levels : its prime contractor is the mind (manas), the central organ of refusal, whose intellectual aspect is thought (citta), the affective aspect is emotion (bhâvana), the action aspect is desire (icchâ or kâma). [RFD 1]
• The mental develops from physical sensations. The principle is as follows : the form is there, the object is there; and a contact occurs with that. Touch causes sensation. From sensation comes perception. From perception comes design. And where conception comes, both pleasure and pain arise. And so we identify with them. [PSP1]
• Your mental fixations, they belong to you. They prevent you from seeing, accepting and realizing what is. Welcome them with kindness, taking care not to pursue them, not to maintain them. [Anonymous]

* Thought, emotion, desire

• Gurdjieff said that the ordinary man lives mainly in three worlds which are motor (sensations), emotional (emotions) and intellectual (thoughts). But the sage has two other worlds at his disposal : the higher emotionnal world (feeling of unity) where emotions are neutral and without opposites (pleasant/unpleasant), and the higher intellectual world (seeing things as they are) where thoughts are neutral and without opposites (for/against). [OPD 2]
• Svâmiji said : "The mental has two functions : it produces thoughts, it takes one thing for another, and it produces emotions which keep these mental images alive." [RFD 1]
• Emotion is nothing but the product or result of seeing things other than they are. [PDS 9]
• There is a thought behind every emotion. Without thought there can be no emotion. [PDS 5]
• Emotions teach you. They lead you to the truth. From the error, which you take for the truth now, you go towards the truth. [PDS 4]
• Can we have a stable emotion ? Certainly yes. It is no longer an emotion but a feeling. An emotion can never be stable. [PDS 4]
• Svâmiji said : "Desires arise from the double belief that one can obtain something from another and that one can keep it permanently. Both beliefs are false." [DSD 9]
• Desiring something else and rejecting what is are one and the same thing, and the root of all suffering. [DEA 1]

* To be

• To be is to contemplate existence in attentive tranquillity, here and now, everywhere and always. [Anonymous]
• "To be", in the traditional sense of the word, is to be free to have, free from the desire to have, free from the fear of not having. [DSA 7]
• "The behavior of a liberated man ?" He is at ease, in all circumstances. He is at home everywhere. [PDS 4]
• The path of truth has three stages. When you feel "I am alone...", you are in emotion and therefore in ordinary life. When you feel "I am loneliness", you are on the path of knowledge and duality (me and loneliness). When you feel "neither me nor loneliness", you have come to the end of the road and of non-duality : "I am nothing and nobody, I am everyone and everything". [Anonymous]

* Spirituality

• The ways of spirituality seem full of contradictions. Arnaud Desjardins answered : "So ? Everything is true but at different levels. When Swâmi Prajnânpad says 'No one lives in the world, everyone lives in his world', this is the starting shore (the usual human condition). When he says 'Not what should be, but what is', this is the crossing over (the full recognition of duality). When he says 'Swamiji does not act, an action happens', this is the end shore (the perfect non-duality)." [DSA 21]
• Spirituality is an attitude of mind. To depend only on oneself, that is spirituality. [SNR 1]
• Spiritual experience does not absolutely abolish conditioning, but by opening us up to a dimension that transcends it, it makes us internally free from it. [DAF 2]
• Spirituality is nothing but the scent of a full life. [PDS 9]
• Frédérick Leboyer said : "The spiritual life is all the miracles that begin to happen as soon as you put the interests of others before your own". [DAL 4]

E1.2. Law of difference : Every thing is different and unique

• Each person is unique, different and perfect in themselves. [SNR 1]
• Although there are an infinite number of things in the universe, it is remarkable that no two things are the same. They are different from each other. Solids differ from liquids, and both differ from gases. Grass and shrub are different from plants, vines and trees. Animals are different from birds and birds from fish. The same is true for the billions of human beings who live on this earth. Basically what you need to know, is that everything is different. "I am here", "you are there". Both are different. Since everything is different, no one can expect the other to act in a particular way. Since he is different, he can only behave differently. So we must try to understand others rather than attribute to them the qualifier of good or bad. This is how you can overcome differences and perceive the uniqueness of everything. [SNR 1]
• Svâmiji said : "Men are equal as human beings, as carriers of the same infinite potentiality but different in their expressions. No distinction can therefore be made among human beings according to the color of their skin, their sex or their beliefs etc." [RFD 1]
• The other is other. If I want to continue to live in society, I have to adapt to what the other is, to what he expects of me. Adapting does not mean being passive, but changing what can be changed, taking into account the situation and the conditions of the moment. Effective action implies knowledge and information. [RFD 1]
• Svâmiji said : "Two things are different, two people are different... Nobody sees you, everyone sees you as he wants to see you". Therefore : "no one can judge me." [RFD 1]
• Everything is different. There are no two similar bodies, no two similar spirits. To think then that another person will act according to your wishes is contrary to the order of things. [PDS 2]

E1.3. Law of change : Everything that comes goes away

• Everything that can come will go away. The truth will not come. The truth is here and now. [PDS 1]
• Ordinary experience shows that whatever comes always goes. Day breaks, stays for a while and disappears, giving way to night. The night too stays for a while and goes away, giving way to another day. Likewise sadness comes and, after a while, it fades away. Likewise joy, jealousy, anger, etc. Likewise childhood, youth, maturity, old age come and go. Also, we must not rejoice in our fortune or be sorry for our bad luck. These are temporary states, which will disappear. We will remain peaceful, calm and serene no matter what, because what happens must change. [SNR 1]
• Death is an aspect of life, and we modern Westerners have forgotten that. We contrast death and life instead of contrasting death and birth, and remembering that life is the ceaseless play of death and birth. [DSA 10]
• By changing, one thing does not become something else. The first ceases to exist and the second springs into existence. It is we who, by linking the two forms, come to think that the thing has changed. [SNR 1]

E1.4. Law of causality : For every effect there is a cause

• The protruding nail attracts the hammer. [Japanese proverb]
• Everything that comes to you or has come to you, be it a person, an incident, a situation, has come to you because it was drawn to you. In other words, whether you like it or not, you are the one who attracted it. [PDS 4]
• Svâmiji said : "The cause is never outside. The cause is inside. All emotional reactions have their roots in you and you are the only responsible for these reactions. The external world does not there is nothing to do with it. In truth, there is no external cause, everything is in the way of absorption. In daily life, any cause triggers and awakens the true internal cause. The world exists in its intrinsic, fundamental unity. It is as it is. It is neutral and only expresses itself. Only the mental seeks to make it conform to its fantasy." [RFD 1]
• Any inner emotional reaction occurs not based on external causes but based on an internal scenario that picks up the external exciting cause. [PDS 1]
• There is no accident, no miracle, no fate, only a cause and effect relationship. What may not be clear is the web of cause and effect interconnections that produce this or that particular event. In this case, even if the totality of the causes is not known, the effect is present. It is a fact. And it must be accepted as fact, until the tangle of cause and effect can be unraveled. [RFD 1]

E1.5. Law of the psyche : The mental creates a "second", the truth is "one without a second"

• In all conditions and circumstances the truth is always one without a second. The mental creates a second. [PDS 6]
• What is the truth ? Which is. But this definition is not complete. This is only the first half. The second half is that there is nothing other than what is. [PDS 4]
• Nothing is wrong. What exists at a moment is the truth of the moment. [DSD 3]
• If you want to be happy, you have to be comfortable with what happened and what is happening, that is, with what is true. In other words, we have to accept everything. There is "only one" and "not a second". But the mental does not want to accept the one reality and it creates a second in its imagination. He then compares his creation with reality and battles with it. And here is the suffering. There is a conflict between what exists and what has been created by the mental. We create a "second" and we suffer. [SNR 1]
• Svâmiji said : "The truth is there within us. There is nothing to seek outside, nothing to add, to superimpose. You simply have to remove what covers it and prevents you from being in contact with it." [DSD 1]
• Can you say "No, it didn't happen" ? No, you can't say "no". So say "yes". There is nothing in between. What is between yes and no is an illusion. [PDS 1]
• Svâmiji said : "Just accept. Accept that the other is different. Accept everything. Do you feel nervous? Accept this nervousness too, but controlling it if you are not alone, to avoid hurting others. To control does not mean to repress." [DSD 7]
• Svâmiji said : "The reaction, the emotion are in you. The more you refuse, the more what you deny takes on weight, the more the refused thing exists, increased by your judgment on it. With the judgment which is a reaction of refusal, you add a second element to what presents itself, you double its existence : its existence, plus your reaction. On the contrary, if you really see your reaction as a reaction, there will be no further reaction." [DSD 7]
• Arnaud Desjardins said : "To accept does not mean not to act, it is to accept without emotion the raw fact - what is." [LRV 1]
• When an emotion arises, let it express itself as much as possible, be with the emotion or rather, be the emotion, and it will quickly wear out. So, see why the emotion appeared. She came simply because you didn't see the facts as they are. So try to see what the real situation was and how your mental interpreted it ! [PDS 1]
• Svâmiji said : "Bars do not make a prison... It is the refusal of the bars that makes the prison !" [RFD 1]
• Not to hope but to know ; not to believe but to see. This is the path to happiness. [CSA 1]

E1.6. The life purpose

• Existence loves you. It gives you life, not because you deserve it, but because it overflows with love. [Anonymous]
• Man is not an accomplished being. Nature develops him up to a certain point then abandons him to himself, free to become aware of his destiny and to decide whether or not he wants to pursue an interior transformation through his efforts. [OPD 1]
• The ordinary man hastily draws his conclusions about life without research, effort or personal achievement. On the other hand, the overeducated man erects around him a thick wall of words which hides the true face of life. [Anonymous]
• The truth is so simple and people have become too learned. [PDS 9]
• This world is not our home. We are a passing traveler... We entered this world empty-handed and alone, and we will leave it empty-handed and alone. [GKG 1]
• ...So, why try to "have" constantly and without limit ? Nothing will be kept when we die. Isn't it wise to seek rather to "be"? [Anonymous]
• "To be", in the traditional sense of the word, is to be free to have, free from the desire to have. [DSA 7]
• Svâmiji said : "To be free is to be free from mom and dad." [DSA 10]
• We are free from the "other" when we understand what it is. For what ? Free from what ? Free from my own mental creation. [PSP1]
• What we see through thought is the world. What we see without thought is the divine. [Anonymous]
• Renunciation is an untruth. Only detachment is the truth... A ripe fruit does not leave the branch - it detaches and falls. [PDS 10]
• "The behavior of a liberated man ? ". He is comfortable in all circumstances. He is at home everywhere. [PDS 4]
• Svâmiji defined the purpose of human life as follows : "To be able to say and feel : I gave everything I wanted to give, I received everything I wanted to receive, I did everything I wanted to do". [RFD 1]
• Human is the path that leads to truth, to the divine. [Anonymous]
• Svâmiji proposed several stages : "Me only, me and the others, the others and me, the others only." [DAL 3]
• Rigorous observation of the facts on the physical and psychic planes leads to the overcoming of forms and to inner silence. [Anonymous]

E1.7. Silence and fullness

• Large buildings remain stable because part of them (their foundations) is underground. If we want to elevate ourselves, we must become humble. [ARI 1]
• The most unique experience in life is that of inner silence. [Anonymous]
• A religious spirit is silent. He doesn't ask for anything. [NIL 1]
• To use words is to communicate. To use silences is to commune. [Anonymous]
• The supernormal is the normal, but the normal in its perfection. Nothing other than the normal in its plenitude or in its perfection. [PDS 4]
• Svâmiji said : "Perfection has no degrees. There are degrees only in imperfection." [RFD 2]
• Don't look for perfection. If you see your imperfections yourself, you are perfection, without being able to boast, flatter or be proud of them. Just be what lives in you, quite simply. [Anonymous]
• Whatever we discover in ourselves, it is not a question of whether it is good or bad but whether it is or not. [PDS 6]
• When you are absolutely silent, when you are silence, then you disappear as a person and become the whole. The water drop disappears and becomes the ocean. [Anonymous]
• Svâmiji said : "When the river is lost in the ocean, when its waters no longer have any form or name, then it becomes truly great." [LRF 1]
• The truth is nothing other than the realization that "I am nothing, I am nobody ! I am therefore everyone, I am everything". [PDS 7]
• When life is lived fully in each moment for the space of an instant, it is a continuous wonder where time is a unique and unprecedented painting which is born and dies at each instant to be replaced by another painting just as fresh and new. [Anonymous]

E1.8. To love

• Human has the right to be happy and the duty to make himself happy. Starting with loving yourself so fully that the love overflows and reaches others. [Anonymous]
• To love is to understand and feel that the other is different. [PDS 4]
• To love is not to think together but to grow together. [PDS 4]
• Love can only exist between equals. If one feels superior or inferior, it is pity, sympathy, admiration, etc. but it is not love. [PDS 4]
• Judging is not for man. What is for man is to see, to understand and to feel. And inevitably love. [PDS 9]
• Man should not try to be good because it is a lie... It is up to man to be deep and true, not good. Indeed, being good is a relative notion. It's only good covering up the bad. [PDS 9]
• There is no culprit. There are only clumsy people. Clumsy in words, clumsy in actions, clumsy in love. [Anonymous]
• When you seek the society of men, remember that your aim is to find that which is beautiful and good in them. Then you will see the good in everything. [MAM 1]

E1.9. To desire

• No one can act according to my desire, everyone acts according to his desire. [PDS 1]
• All psychological problems can be reduced to a single impossible desire : that of being other than what one is. [EHM 1]
• Desiring something else and rejecting what is are one and the same thing, and the root of all suffering. [DEA 1]
• You are not looking for what is, you are looking for what you desire. [Anonymous]
• To find what you want, all you have to do is see what continually comes without you looking for it. This is what you really want. [PDS 4]
• Svâmiji said : "Not without desire but free from desire." [DAF 1]
• When you kill desire, you acquire powers. But unlike the Bhagavad Gîtâ, the Upanisads teach : "When one is free from desires, one finds peace." [RFD 1]
• Svâmiji said : "To be free is to be free from the "I want" and the "I don't want". Here again being free from desire does not mean having no physical sensations. Thus "to be hungry" is a physical sensation, a sensation appeased by the absorption of food. Desire, mental activity, intervenes when one prefers this or that particular food." [RFD 2]
• All desire is infinite. It is normal to dream of always having more, but the outside world is a limited world. How can a limited world fulfill, satisfy an unlimited desire ? [CSO 1]
• To free oneself from desire, it must be satisfied while knowing that no desire can be satisfied. [PDS 4]
• The question arises : "Why are you not satisfied?" For what ? Because a desire can never be satisfied. For what ? Because the desire belongs to you while its satisfaction depends on the outside. But the outside is not you. Let your desire appear as a need. The desire then will disappear immediately. [PSP1]
• (The desire) Instead of trying to suppress it or to bully it, Swâmi Prajnânpad advised to experience it consciously while remaining attentive to the result obtained (with a size restriction, that of not harming others). Until, from disappointments to complete or partial successes, it can fade by itself and fall like a ripe fruit. [DSD 9]

E1.10. To act

• Thoroughness in the preparation, concentration in the execution, freedom in the face of the result, such can be stated the secret of the action. [DSD 10]
• Venkateshvar wrote : "The effect of action is to reduce separation, that is the distance which separates the subject from the object he desires." [RFD 6]
• There are two types of actor in words : the one who speaks to speak and the one who speaks to give. The first affirms his opinions, the second overflows with compassion. [Anonymous]
• Those who are established in certainty no longer need to convince others at all costs of the correctness of their convictions. [DSA 17]
• Svâmiji said : "He who feels hurt cannot help being aggressive. The victim reacts like an assassin. So the victim and the assassin are two opposite sides, two aspects of the same experience." [RFD 1]
• You complain : "He insulted me". The other simply said a few words. But I felt insulted. I felt hurt. This action, this effect, the anger, or any other emotion, where does it occur ? It was he who spoke. This is where the words were spoken. But the reaction took place here. How ? The words were spoken there, and the reaction took place here ?... How absurd ! Isn't it comical ? If the reaction is here, the cause must also be here. Every emotional reaction has its root in me and it is I who am responsible for all these emotional reactions, and not the outside. [PSP1]
• Svâmiji said : "No one acts for the sake of evil, but everyone acts for the sake of good as he understands it." [DSA 15]
• Right action comes from a silent mental. Activity comes from a restless mental. [Anonymous]
• Svâmiji said : "No one can do anything for anyone. You are the creator of your own world. Only you can do anything for yourself." [RFD 3]
• Be free from emotion, then act. You will get the result and not a result. Knowledge must come intellectually, pass through the feelings and from there manifest in action. [PDS 5]
• It is no longer you who act, but the divine energy which acts through you. [DSA 10]
• No one, saint or sage, has ever acted for himself alone. Everything the sage does for another, he does for himself. But instead of his "self" being limited to his small person, he has become vast like the whole of humanity. Nothing and no one is foreign to him. [DSA 17]

E1.11. To live in society

• Paul Hogan said in the film "Crocodile Dundee" : "Arguing over who owns these rocks is like two fleas arguing over who owns the dog they live on." Thus, the earth does not belong to men. Men belong to the earth. [Anonymous]
• Human conflicts often arise from the illusion of ownership. Water belongs to no one and to everyone. The same holds for the Earth, which will still be here in a million years while humanity has vanished. Thus, an "original" population is merely a temporary tenant, bound to welcome others peacefully. Quarreling over who owns a land is like watching two fleas fighting over the dog they're living on. [Anonymous]
  
• The other is other. If I want to continue to live in society, I have to adapt to what the other is, to what he expects of me. Adapting does not mean being passive, but changing what can be changed, taking into account the situation and the conditions of the moment. Effective action implies knowledge and information. [RFD 1]
• What makes a good manager is his ability to take advantage of the best of each employee. Like a sage, he knows how to appreciate the bright side of everyone without ever condemning the dark side. [Anonymous]
• How should a child be trained ? Svâmiji said : "be strong but not harsh, firm but not severe." [DSA 19]
• Gurdjieff said : "On the outside play your part. On the inside never identify yourself with anyone." [BTC 1]
• Svâmiji said : "Inwardly, be actively passive", i.e. watchful passivity, "and outwardly, be passively active" i.e. be active not from your egocentric demands and your desire to succeed at all costs but from a state that in a completely different language would be called "submission to the divine will". [DSA 17]
• Deliberate neutrality does not mean indifference but discernment. [Anonymous]
• Svâmiji said : "All the social rules to which you conform are valid when you act in society. But for yourself ? They have no value. So everything that happens in you is neutral. It is neither a sin, nor a virtue. Generally speaking you can see that morality is immoral. Only the truth is moral." [RFD 2]
• Svâmiji said : "The animal is subject to nature. Man fights against nature. The wise man achieves unity with nature by accompanying it in its movement." [RFD 1]

E1.12. To give

• Before giving, check if the other is in a position to receive. It is the ability to receive that justifies giving. If you try to give anyway, you devalue what you give. [PDS 1]
• To give yourself you have to own yourself, otherwise who gives what ? [DSA 23]
• Love is like water poured into a glass. If you feel like you are filling up then you are receiving love, you are loved. If you feel like you are emptying yourself then you are losing something, you are suffering, and you can only give your suffering. If you feel like you are filling up to the point of overflowing then you are giving love, you really love. [Anonymous]
• The true gift is an overflow. You are so fulfilled by your inner plenitude that it only overflows. [Anonymous]
• Svâmiji said : "Giving is possible only when, in the mind of the one who gives, there remains no feeling "that he gives" " [RFD 5]

E1.13. To help others

• Advice should not be wasted on people whose need has not arisen. You must first make sure that the other is ready to receive and follow the advice. The teacher must wait until the question is asked, that is, until a doubt has arisen in the student's mind. Doubt, doubt, doubt must appear first. This is the criterion of the need for assistance. [PDS 4]
• Either learn carefully what you don't know, or teach clearly what you know. [Anonymous]
• You cannot lead anyone beyond the point you have reached yourself. [MRD 1]
• Experience is a lantern that illuminates only the wearer [Céline]. To transmit it, you will have to carry the other to the altitude from where he will see clearly himself. [Anonymous]

E1.14. To die

• Death is an aspect of life, and we modern Westerners have forgotten that. We contrast death and life instead of contrasting death and birth, and remembering that life is the ceaseless play of death and birth. [DSA 10]
• By changing, one thing does not become something else. The first ceases to exist and the second springs into existence. [SNR 1]
• ...So it is with the human brain. Some neurons die and are replaced by other neurons. No transformation. No rebirth. Simply dead of a cell which gives way to another cell ready to live. [Anonymous]
• Life is a large circle. When you draw it with a compass, there is a starting point (birth) and an ending point (death). When the circle is complete, these two points merge. Thus, death is not an absolute end, but the conclusion of a journey that returns to the beginning. Nothing dies, everything is accomplished. [Anonymous]
• No one is born, no one dies. There is birth and death, and no one to take part in this phenomenon. [PDS 4]
• This world is not our home. We are a passing traveler... We entered this world empty-handed and alone, and we will leave it empty-handed and alone. [GKG 1]
• When life is lived fully, moment by moment, as a series of unique experiences, then death will be lived in joy as a new experience to be lived. [Anonymous]

E1.15. Sources relating to life laws

[ARI 1] Association pour le Rayonnement Culturel Indien, Citation de Mata Amritanandamayi, La Lettre N 3 de l'ARCI, 2ème trimestre 1987
[BTC 1] Bouchet Christian, Gurdjieff - qui suis-je, Pardès 2001
[CSA 1] Comte-Sponville André, De l'autre côté du désespoir - Introduction à la pensée de Svâmi Prajnânpad, Accarias-L'Originel 1997
[CSO 1] Cambessédès Olivier, Le quotidien avec un maître Svami Prajnanpad, Accarias L'Originel 1995
[DAF 1] Desjardins Arnaud et Farcet Gilles, Confidences impersonnelles, Critérion 1991
[DAF 2] Desjardins Arnaud et Farcet Gilles, Regards sages sur un monde fou, La Table Ronde 1997
[DAL 3] Desjardins Arnaud et Loiseleur-Desjardins Véronique, La voie et ses pièges, La Table Ronde 1992
[DAL 4] Desjardins Arnaud et Loiseleur-Desjardins Véronique, L'ami spirituel, La Table Ronde 1996
[DEA 1] Delaye Alain, Sagesses concordantes - Quatre maîtres pour notre temps : Etty Hillesum, Vilama Thakar, Svâmi Prajnânpad, Krishnamurti, Volume I, Accarias-L'Originel 2003, 2011
[DSA 7] Desjardins Arnaud, A la recherche du Soi 1 - Adhyatma yoga, La Table Ronde 1977
[DSA 8] Desjardins Arnaud, A la recherche du Soi 2 - Le vedanta et l'inconscient, La Table Ronde 1978
[DSA 9] Desjardins Arnaud, A la recherche du Soi 3 - Au-delà du moi, La Table Ronde 1979
[DSA 10] Desjardins Arnaud, A la recherche du Soi 4 - Tu es cela, La Table Ronde 1980
[DSA 15] Desjardins Arnaud, La voie du coeur, La Table Ronde 1987
[DSA 17] Desjardins Arnaud, Zen et Vedanta - Commentaire du Sin sin ming, La Table Ronde 1995
[DSA 19] Desjardins Arnaud, Retour à l'essentiel, La Table Ronde 2002
[DSA 21] Desjardins Arnaud, Bienvenue sur la voie, La Table Ronde 2005
[DSA 23] Desjardins Arnaud, Lettres à une jeune disciple, La Table Ronde 2006
[DSD 1] Desjardins Denise, De naissance en naissance, La Table Ronde 1977
[DSD 3] Desjardins Denise, Mère sainte et courtisane, La Table Ronde 1983
[DSD 7] Desjardins Denise, La route et le chemin - Carnet de voyage et d'ascèse, La Table Ronde 1995
[DSD 9] Desjardins Denise, Conteurs, Saints et Sages - Des Pères du désert à Swâmi Prajnânpad, La Table Ronde 1998
[DSD 10] Desjardins Denise, Petit traité de l'action, La Table Ronde 1999
[EHM 1] Edelmann Eric, Humbert Olivier et Dr Massin Christophe, Swâmi Prajnânpad et les lyings, La Table Ronde 2000
[FTG 1] Farcet Gilles, Arnaud Desjardins ou l'aventure de la sagesse, La Table Ronde 1987
[FTG 3] Farcet Gilles, La transmission selon Arnaud Desjardins, Le Relié 2009
[GKG 1] Guéshé Kelsang Gyatso, Vivre une vie pleine de sens - Mourir dans la joie, Tharpa France 2017
[GKG 2] Guéshé Kelsang Gyatso, Transformez votre vie. Un voyage plein de félicité, Tharpa France 2009
[LRF 1] Leboyer Frédérick, Portrait d'un homme remarquable - Svami Prajnanpad, Critérion 1991
[LRV 1] Loiseleur-Desjardins Véronique, Anthologie de la non dualité, La Table Ronde 1981
[MAM 1] Mâ Ananda Moyî, L'enseignement de Mâ Ananda Moyî, traduit par Josette Herbert, Albin Michel 1974
[MRD 1] Marol et Roumanoff Daniel, Sois sage, La Table Ronde 1994
[NIL 1] Nduwumwami Louis, Krishnamurti et l'éducation, Du Rocher 1991
[OPD 1] Ouspensky Petr Demianovitch, L'homme et son évolution possible, Denoël 1961 puis Accarias L'Originel 1999
[OPD 2] Ouspensky Petr Demianovitch, Fragments d'un enseignement inconnu, Stock 1974
[PDS 1] Prajnanpad Svami, L'art de voir, Lettres à ses disciples - Tome 1, Traduction de Colette et Daniel Roumanoff, Accarias-L'Originel 1988
[PDS 2] Prajnanpad Svami, Les yeux ouverts, Lettres à ses disciples - Tome 2, Traduction de Colette et Daniel Roumanoff, Accarias-L'Originel 1989
[PDS 3] Prajnanpad Svami, La vérité du bonheur, Lettres à ses disciples - Tome 3, Traduction de Colette et Daniel Roumanoff, Accarias L'Originel 1990
[PDS 4] Prajnanpad Svami, A B C d'une sagesse, Paroles choisies par Daniel Roumanoff, La Table Ronde 1998 puis Albin Michel 2009
[PDS 5] Prajnanpad Svami, L'éternel présent - Questions et réponses - Entretiens avec Pierre Wack, Traduction de Daniel Roumanoff, Accarias-L'Originel 2002
[PDS 6] Prajnanpad Svami, Les formules de Swâmi Prajnânpad commentées par Arnaud Desjardins, Formules et commentaires rassemblés par Véronique Desjardins, La Table Ronde 2003
[PDS 7] Prajnanpad Svami, Le but de la vie - Un été plein de sagesse, Entretiens avec Roland de QuatreBarbes été 1966, traduits par Daniel Roumanoff, Accarias-L'Originel 2005
[PDS 8] Prajnanpad Svami, Svâmi Prajnânpad pris au mot - Les Aphorismes, Recueillis et traduits par Frédérick Leboyer, Accarias-L'Originel 2006
[PDS 9] Prajnanpad Svami, Ceci Ici A présent - Seule et unique réalité, Entretiens avec Frédérick Leboyer (première série, janvier et février 1963), Traduction de Colette et Daniel Roumanoff, Accarias-L'Originel 2006
[PDS 10] Prajnanpad Svami, La connaissance de soi - Citations commentées des Upanishad et histoires (tome 1), Mises en forme par Daniel Roumanoff, Accarias-L'Originel 2008
[PSP 1] Prakash Sumangal et Prajnanpad Svami, L'expérience de l'unité, Traduction de Colette et Daniel Roumanoff, Accarias-L'Originel 1986 puis 2013
[RFD 1] Roumanoff Daniel, Svâmi Prajnânpad - Tome 1 Un maître contemporain - Manque et plénitude, La Table Ronde 1989, puis regroupé avec le Tome 3 chez Albin Michel 2009 sous le titre "Tome 1 Les lois de la vie"
[RFD 2] Roumanoff Daniel, Svâmi Prajnânpad - Tome 2 Le quotidien illuminé, La Table Ronde 1990, puis Albin Michel 2009
[RFD 3] Roumanoff Daniel, Svâmi Prajnânpad - Tome 3 Une synthèse Orient Occident, La Table Ronde 1991, puis regroupé avec le Tome 1 chez Albin Michel 2009 sous le titre "Tome 1 Les lois de la vie"
[RFD 4] Roumanoff Daniel, Candide au pays des Gourous - Journal d'un explorateur de l'Inde spirituelle, Dervy 1990
[RFD 5] Roumanoff Daniel, Svâmi Prajnânpad - Biographie, La Table Ronde 1993
[RFD 6] Roumanoff Daniel, Psychanalyse et sagesse orientale - Une lecture indienne de l'inconscient, Accarias L'Originel 1996
[SNR 1] Srinivasan Ramanuja, Entretiens avec Svami Prajnanpad, Traduction de Colette Roumanoff, Accarias-L'Originel 1984

E2. Hypnosis, between science and mystery

This chapter explores the different facets of hypnosis, including its side effects and potential dangers, the world of show hypnosis, self-hypnosis techniques, as well as the legal and ethical aspects that govern its use.

1. Definition
2. Side effects
3. Dangers
4. Show hypnosis
5. Self-hypnosis
6. Legal framework
7. Ethics of hypnosis
8. Sources

E2.1. Definition :

Hypnosis is an ancient technique dating back more than 6000 years in the Orient and to the end of the 18th century for modern hypnosis. It produces a modified state of consciousness located between wakefulness and sleep.
More precisely, it allows to induce by speech a particular state of consciousness characterized by indifference to the outside and a greatly increased capacity to receive suggestions (in particular the voice of the hypnotist) [ANM][INS][ MAB].
At the psychological level, hypnosis induces a state of deep relaxation based on freely given suggestion [AFI].
At the neurological level, hypnosis involves a change in brain activity, including a decrease in activity in regions associated with processing sensory information and an increase in activity in regions associated with attention and suggestion [MAB].
Hypnosis is used in different medical sectors [MIN] :
- anesthesia (hypnosedation), to reduce the stress of the operation, or even allow certain operations without resorting to general anesthesia, which is replaced by a sedative medication and quality local anesthesia ;
- pain management (hypnoanalgesia), particularly in obstetrics to reduce labor pain ;
- psychotherapeutics (hypnotherapy), to help people achieve a state of deep relaxation allowing them to work on their problems (fear, stress, blockage, etc.) without causing unwanted side effects.

E2.2. Side effects :

Side effects of hypnosis are as follows :
- Temporary and mild effects : headaches, fears, sadness, disorientation, etc. [CFH1][MAB]
- Rare but serious effects : hallucinations, altered memories, personality change, depression, suicidal impulses, etc. [CFH1]
These side effects are not always the consequence of hypnosis as such. They may arise due to the pre-existing vulnerability of the subject, the practitioner's inexperience in dealing with psychotherapeutic problems, the use of inappropriate suggestions, the inability to erase non-therapeutic suggestions or to fully redirect the patient through adequate debriefing [CFH1].
These reactions occur more often in certain contexts such as show hypnosis, or when the training and experience of the practitioner are insufficient [CFH1].

E2.3. Dangers :

The dangers of hypnosis are as follows :
- Incompetent or clumsy hypnotist : he can in particular plunge a person back into a past trauma without knowing how to manage the situation [ATK].
- Absence of prior diagnosis : a practitioner who does not know how to use the hypnosis tool without prior clinical, psychological or somatic knowledge, will not be able to distinguish between the psychological expression of a serious pathology and a disorder that may be sensitive to a hypnotic approach. Thus, anxiety can be a sign of a pulmonary embolism, a myocardial infarction and many other severe disorders. It is therefore appropriate for the practitioner who is going to use hypnosis to be able to have explored all the possible causes of the disorder, or failing that, to have verified with the patient's treating physician that the pathology has been explored and diagnosed or that the psychosomatic origin has been demonstrated [CFH1].
- Non-compliance with medical contraindications : hypnosis should not be practiced on people with heart disease, epilepsy or serious psychopathology (delusions, psychosis, paranoia, etc.) [CFH1][MAB].
- False memories : the unconscious can produce coherent but false responses, often in an attempt to relieve suffering. Hypnosis accentuates this phenomenon [CFH3][BEN]. Any practitioner must refuse any patient request aimed at rediscovering forgotten memories [CFH3] or verifying the reality of a memory (for example, women who believe they were abused as children) [BEN].
- Poor management of emotional reactions after hypnosis, which can lead to persistent discomfort [CFH1][UNI][ATK].

E2.4. Show hypnosis :

Show (or street or fair) hypnosis is a hypnosis technique close to therapeutic hypnosis, practiced for commercial or occult purposes which has nothing to do with the patient's interest [ATK].
Unlike therapeutic hypnosis, the show hypnotist does not establish rapport with the subject, adopt an authoritative and directive approach, do not debrief individually and do not interrupt the hypnotic trance if necessary [CFH2].
The individual on stage volunteered to play the game and showed particular skills in the trance state during the pre-test carried out by the hypnotist. Added to this is the group effect which reduces the unconscious resistance of the individual [UNI]. The show then consists of attracting the audience by producing spectacular reactions (for example, seeing a subject think he is a chicken on a wall) [GRO].
Many people hypnotized on stage say that, although they are aware of being ridiculed, they paid to go on stage, people watch them and they have an astonishing experience [SAR].
Show hypnosis presents dangers that therapeutic hypnosis does not have: dangers in particular for people with with heart disease, epilepsy, serious pathology or psychologically fragile [CFH1][MAB]. Added to this is the non-management of possible emotional reactions upon exiting hypnosis [CFH1][UNI][ATK].

E2.5. Self-hypnosis :

Self-hypnosis is hypnosis practiced alone, without the help of a practitioner. Like meditation, self-hypnosis is a physical and mental relaxation technique. But unlike meditation :
- The purpose is therapeutic (resolution of a problem) and not spiritual (search for inner peace).
- Relaxation involves an active suggestion or visualization (and not a simple caring attention to the experience of the moment) aimed at achieving a specific objective, such as stress management or improving self-confidence.
- Awareness of the external world disappears in favor of an internal look, while in meditation consciousness is both internal (thoughts, emotions, sensations) and external (perceptions of the environment). The person being hypnotized feels like they are dissociated, with one part of them observing what the other part of themselves is doing, while the meditator is aware of everything that is happening in and around them [PIC].

E2.6. Legal framework :

In France, there is no legal framework to regulate the practice of hypnosis. There is only teaching of hypnosis at the university, associative and private level, as well as various ethical codes of hypnosis.
Two types of hypnosis practices can be distinguished [SEN] :
- Therapeutic hypnosis is practiced by health professionals in the medical field (doctors, psychiatrists, psychotherapists and clinical psychologists) and paramedical field (dentists, midwives, nurses, physiotherapists, occupational therapists and psychomotor therapists).
- Hypnosis known as "better being" is practiced by other professionals under various names : hypnotherapist, hypnopractitioner, hypnologist, hypnosis psychopractitioner, brief therapy practitioner, etc. They must not use certain reserved words such as : "psychotherapist", "patient", "consultation", "diagnosis", "prescription", under penalty of "illegal practice of medicine". We therefore do not speak of "patient" but of "client".
In France the exercise of therapeutic hypnosis in a context other than medical is similar to the illegal exercise of medicine (No. 09-81.778 of the Criminal Chamber of March 9, 2010, and article L.4161-1 of the public health code) [SEN][CFH4].

E2.7. Ethics of hypnosis :

The Confederation Francophone Hypnosis and Brief Therapies (CFHTB) published in 2003 an ethical code of hypnosis based on medical ethics, the principles of which are as follows [CFH4] :
    1. The best interests and well-being of the patient are the highest priority.
    2. Hypnosis is considered a complement to other forms of clinical or supportive scientific practices.
    3. The hypno-practitioner will limit his scientific or supporting clinical use of hypnosis to the areas of competence recognized by the regulations of his profession or the uses relating to it.
    4. The hypno-practitioner undertakes not to use hypnosis or brief therapy as a form of distraction or spectacle.
    5. In all cases, the transition to the practice of hypnosis will remain conditional on obtaining a complete qualification in the professional field considered.
    6. The communication of information relating to hypnosis to the various media is accepted to the extent that it is based on precise scientific knowledge.

E2.8. Sources relating to hypnosis :

[AFI] AFIS, L'hypnose : charlatanisme ou avancée médicale ?.
[ANM] Académie nationale de médecine, Thérapies complémentaires - acupuncture, hypnose, ostéopathie, tai-chi - leur place parmi les ressources de soins, rapport de la séance du 5 mars 2013.
[ATK] Jean-Marc Atkins, Quels sont les dangers de l'hypnose (ericksonienne) ?
[BEN] Jean-Marc Benhaiem, L'hypnose ne permet pas de retrouver la mémoire de faits réels..., Huffpost
[CFH1] CFHTB, Confédération Francophone Hypnose et Thérapies Brèves, Risques et dangers de l'hypnose
[CFH2] CFHTB, Confédération Francophone Hypnose et Thérapies Brèves, Risques et dangers de l'hypnose : hypnose de spectacle
[CFH3] CFHTB, Confédération Francophone Hypnose et Thérapies Brèves, Risques et dangers de l'hypnose : les faux-souvenirs
[CFH4] CFHTB, Confédération Francophone Hypnose et Thérapies Brèves, Livre blanc de l'hypnose clinique et thérapeutique
[FTB] I2FTB, Quel cadre légal quand on fait de l'hypnose ou PNL ?
[GRO] Laurent Gross, EMDR, Hypnose ericksonienne, médicale et thérapeutique à Paris
[IFH] IFH, Institut Français d'Hypnose, Lexique en hypnose thérapeutique
[INS] Inserm, Evaluation de l'efficacité de la pratique de l'hypnose - 2015
[MAB] Emmanuel Mabin, e-academy.fr, Mieux comprendre l'hypnose
[MIN] Ministère de la Santé et de la Prévention
[PIC] Caroline Pico, Similitudes et différences entre hypnose et méditation
[SAR] Corinne Sarazin, Les dangers de l'hypnose eriksonienne ou autre
[SEN] Sénat, Réponse du Ministère des solidarités et de la santé publiée le 14/02/2019
[UNI] Unitheque, Quels sont les métiers de l'hypnose ?

E3. Smells and flavors

Smell and taste are the two senses that aroused the least interest from scientific researchers until the 1960s.
Today, we know that the sensory perception of smells and flavors is a subtle mix between universal principles, personal perception and culture.

1. Smells
2. Flavors

E3.1. Smells

Smells are molecules detected chemically by olfactory receptors located in the nasal cavity.
They can take two distinct routes : a direct route, called orthonasal, located in the nose (concept of "smell") or an indirect route, called retro-nasal, located in the back of the throat (concept of "aroma" released by food in the mouth).
There is to date no universal consensus on the categorization of smells. Only perfumery and oenology have produced specific classifications.
The table below allows you to simply categorize smells according to their effects (unpleasant/pleasant) and their origins (mineral, plant, animal, human).

• Unpleasant
  • Industrial chemistry : sulfuric acid, ammonia, rubber, bleach, gasoline, domestic gas, paint, phosphorus, plastic, sulfur, varnish...
  • Animal and human waste : urine, droppings, manure, fart, perspiration
  • Plant and animal decomposition : fermentation, rot, carrion
  • Stinky plant : spotted arum, foul goosefoot, ginkgo biloba female, common serpentgrass...
  • Exterior : cigarette, smoke, exhaust gases, ozone (electrification), urban pollution , pigsty, tobacco
  • Home : wastewater, sewage, septic tank, humidity, animal litter, mold, trash
  • Cooking : garlic, frying, onion, tripe, vinegar
• Mineral
  • Soil : chalk, tar, earth
  • Exterior : swimming pool chlorine, geosmin (smell of freshly plowed or wet earth), marine iodine
• Plant
  • Wood : bark, leaf, resin
  • Grass : hay, freshly cut grass, humus, straw
  • Plant without flowers : mushroom, fern, moss, truffle
  • Flower : jasmine, lavender, orange, rose, lime, verbena, violet...
  • Fruit : almond, coffee, lemon, strawberry, raspberry, hazelnut, peach, pear...
• Animal
  • Body : leather, musk
  • Production : beeswax, milk, honey, egg
• Human
  • Body : skin
  • Industrial chemistry : perfume, soap, shampoo...
  • Home : candle, air freshener, laundry detergent...
  • Cooking : alcohol, herbs, caramel, spices, cheese, cake, oil, hot bread, freshly popped popcorn, fish, wine...

Sources relating to smells :

Claude Boisson, "La dénomination des odeurs : variations et régularités linguistiques", Intellectica, 1997/1, 24, pp. 29-49.
Sophie David, Danièle Dubois, Catherine Rouby, Benoist Schaal, "L'expression des odeurs en français : analyse lexicale et représentation cognitive", Intellectica, 1997/1, 24, pp. 51-83.
Dico du Vin, Odeurs du vin, nouvelle classification, Dico-du-Vin 2023.
Danièle Dubois, "Des catégories d'odorants à la sémantique des odeurs", Terrain, 47 | 2006, 89-106.
Camille Gaubert, 03.05.2022, "Notre perception des odeurs n'est que très peu liée à notre culture", Cerveau et Psy.
André Holley, "Le physiologiste et la catégorisation des odeurs", Intellectica, 1997/1, 24, pp. 21-27.
L'Atelier du Vin, Guide des arômes du vin et de leur perception en oenologie.
Hervé-Pierre Lambert, "L'imaginaire, les neurosciences et l'olfactif : confirmations et extrapolations", IRIS, 33 | 2012, 37-51.
C. Sulmont-Rossé, I. Urdapilleta, "De la mise en mots des odeurs", chapitre 28 (pp. 373-382) du livre : Odorat et Goût : de la neurobiologie des sens chimiques aux applications agronomiques, industrielles et médicales, Edition QUAE.
Luc a Poyo Vallina, 24 nov. 2022, "Les 10 principales odeurs perçues par l'odorat humain", Divain, .
Wikipedia, Rétro-olfaction.

E3.2. Flavors

Flavors are molecules detected chemically by taste receptors located on the taste buds of the tongue.
Other sensations in the mouth, also called "flavors" in the broad sense, do not involve the taste buds and are sensory (olfactory, auditory, visual) and somesthetic (thermal, tactile, proprioceptive (position and movement) and nociceptive (pain)).
The table below describes the basic flavors, "flavors" being taken in the broad sense. They can then combine with each other to form more elaborate taste sensations.

• Taste level : Flavors detected by the taste buds of the tongue :
  • sweet or sweet (examples : sucrose, sugar)
  • sour (examples : citric acid, lemon juice)
  • salty (examples : sodium chloride, table salt)
  • bitter (examples : broccoli, caffeine, quinine present in particular in tonic-type drinks)
  • tasty or delicious or "umami" in Japanese (monosodium glutamate (MSG) which is the dominant flavor of breast milk and also a food additive (code E621) present in particular in some yeasts, soybeans and Asian broths)
• Olfactory level : "Flavors" detected retro-nasally in the form of aromas released by foods in the mouth.
• Auditory level : "Flavors" detected by hearing :
  • crispy, crunchy, brittle (examples : biscuit, chips)
• Visual level : "Flavors" detected by sight :
  • appetizing (examples : food on the plate, wine in the glass)
• Somesthetic level : "Flavors" detected by the trigeminal nerve of the face that innervates the mucous membranes of the mouth, nose and eyes :
  • spicy (examples : ginger, mustard, chilli, pepper) detected at the nociceptive level
  • sparkling (example : carbon dioxide present in "soda" type drinks) detected at the tactile level
  • fresh, cold (example : fresh mint) detected at the thermal level
  • lukewarm, warm (example : soup) detected at the thermal level
  • iced, hot detected at the nociceptive level
  • astringent (examples : lingonberry, banana or persimmon too green, fresh walnut, tannin, tea) detected at the tactile level by the tightening of taste buds
  • texture of rough, grainy, fibrous, pasty, viscous, smooth, juicy... type detected at the tactile level by the surface of the oral tissues
• Somesthetic level : "Flavors" detected by the trigeminal nerve of the face that innervates the joints, ligaments, tendons and muscles of the lower jaw :
  • texture of soft, hard, elastic, brittle... type detected at the proprioceptive level during masticatory movements
• Somesthetic level : "Flavors" detected by the trigeminal nerve of the face that innervates the tendons and muscles of the tongue :
  • shape of cube, sphere, edge... type detected at the proprioceptive and tactile level during lingual movements
• Other "flavors" whose origin is not clearly identified to date :
  • bland or tasteless (example : pure water)
  • metallic (examples : iron, zinc)
  • fatty or oily or "oleogustus" (example : cooking oil)
  • starchy or alcaline (starch present in pasta and other starchy foods)
  • calcium
  • licorice

Sources relating to flavors :

Le Thi Maï Allafort, Connaissez-vous les mots du goût ? Lorsque les textures font le plaisir !, Marie Claire.
Christine Belloir, Récepteurs gustatifs humains : étude des relations structure-fonction, Thèse 2019, Université de Bourgogne.
Diane Boivineau, Evaluation gnoso-praxique linguale des enfants avec trouble structurel du langage oral, Mémoire 2013/2014, Université Paris VI.
Loïc Briand, "La chimie du goût", CultureSciences-Chimie.
Juliette Defossez, Vers un langage du goût : approche expérimentale d'une communication multimodale à destination des mangeurs, Thèse 2014, Université de Bourgogne.
Audrey Dufour, 24/01/2017, "Comment reconnaît-on les saveurs ?", La Croix.
Goûts et Papilles, C'est quoi le goût ? Odeur, saveur, flaveur....
FasterCapital, Au-delà du goût : comment la texture influence notre perception des aliments.
Claire Gresser, Contribution à l'étude de la composante trigéminale dans la posture cervico-faciale, Thèse 2005, Université de Lorraine.
Tanya Lewis, 5 octobre 2021, "Ce que les piments peuvent nous apprendre sur la douleur", Pour la Science.
Christophe Otte, Olivier Otte, Régulation des dysfonctions maxillo-faciales de l'enfant, Clinique OPS.
Dale Purves, George J. Augustine, David Fitzpatrick, Lawrence C. Katz, Anthony-Samuel LaMantia, James O. McNamara, Neurosciences - Les sens chimiques, DeBoeck
Rapport du groupe PNNS - Qualité gustative des aliments et environnement des repas : restauration scolaire, hospitalière et aide alimentaire, décembre 2010.
Si on me coupait la langue, pourrais-je toujours savourer mes repas ?, La sensation trigéminale.
Wikipedia, Goût.
Wikipedia, Thermorécepteur.

E4. Genetics

1. Introduction
2. Cell description
3. Epigenetics
4. RNA
5. Sources

E4.1. Introduction :

Genetics is the science that studies the organization, functioning, regulation and modification of genes, both in their transmission from one generation to another and in their expression within the same individual.
It includes six major scientific fields [PER][CHA] :

1. Genome organization and cell manufacturing
Each cell in the human body contains a complete copy of the organism's genetic material (the genome), carried by DNA (Deoxyribonucleic Acid).
This genome contains all the instructions necessary to produce all of the body's proteins. However, in practice, each cell expresses only a portion of the genes, depending on its specialization. For example, a muscle cell will produce mainly contractile proteins, and few or no proteins specific to neurons or immune cells.
Proteins play an essential role in the body. On the one hand, they perform structural functions by maintaining and repairing tissues. On the other hand, they act as regulators of vital functions, notably participating in genetic regulation (histones and transcription factors), hormonal regulation (hormones), digestive regulation (enzymes), oxygen transport in the blood (hemoglobin), and immune defense (antibodies).
Each cell thus produces two main types of proteins :
- Effector (or target) proteins, such as structural proteins, transport proteins, hormones, enzymes, that perform the body's cellular and physiological functions.
- Regulatory proteins, such as histones and transcription factors, that control gene expression.
Once produced, proteins are transported to their sites of action (cells, organs, tissues). Some, like hormones, travel through the blood to reach distant organs.

2. Genetic Regulation
Genetic regulation is the control of gene expression, particularly through modulation of DNA accessibility, without modifying the DNA sequence.
The main players in this mechanism are :
- Non-coding DNA sequences (not translated into proteins), which consist mainly of Non-coding genes and Intergenic sequences.
- Regulatory proteins, which are of two main types : Histones ensuring the compaction of the DNA around them and therefore the modulation of its accessibility, and Transcription factors which bind to non-coding DNA sequences to activate or repress gene expression.
- Epigenetic modifications, which are reversible additions of chemical groups to DNA molecules and also to histone tails, altering DNA accessibility and therefore the body's response to internal and external stimuli.
- Long non-coding RNAs, which act as indirect regulators, for example, guiding proteins to specific regions of DNA.

3. Genetic Variation
Genetic variation is the production of genetic differences. The main mechanisms are as follows :
- Mutation : Lasting modification of the DNA sequence at the gene, chromosome, or entire genome level.
- Recombination (crossing-over) : Exchange of DNA segments between homologous chromosomes during meiosis, creating new genetic combinations.
- Polymorphism : Coexistence of several normal genetic forms in a population, as demonstrated by the ABO blood group system in humans, which produces a diversity of groups (A, B, AB, O, etc.).
- Transposition : Change in the position of a DNA segment within the genome.
- Genetic drift : Random change in the frequencies of different forms of a gene in a small population, often due to chance events (catastrophes, isolation) that reduce the number of individuals.
- Migration (or gene flow) : movement of individuals from one population to another, resulting in the arrival or departure of certain gene forms in the host population.
- Random mating : reproduction where partners are chosen at random, promoting genetic mixing within the population.

4. Genetic Repair
Genetic repair is the correction of errors or damage in DNA. The main mechanisms, classified by increasing severity of the damage, are as follows :
- Direct repair : For a slightly damaged base
- Base excision repair (BER) : For an absent or severely damaged base
- Copy error repair (MMR) : For an erroneous sequence following DNA replication
- Nucleotide excision repair (NER) : For a damaged sequence
- Single-strand break repair (SSB repair) : For a broken strand, with the intact second strand serving as a template
- Double-strand break repair (DSB repair) : For a broken double strand

5. Genetic Transmission
Genetic transmission is the transmission of hereditary information at the individual level (between cells of the same organism) or transgenerationally (from one generation to the next). The main mechanisms are as follows :
- Replication : Faithful copying of DNA before each cell division.
- Mitosis : Cell division of somatic (body) cells producing two identical daughter cells with the same number of chromosomes as the parent cell.
- Meiosis : Cell division of germ (reproductive) cells producing two gametes (egg and sperm), each containing half the number of chromosomes. This division does not fragment the genetic information but intelligently redistributes it between the gametes through shuffling and control mechanisms, allowing fertilization to reconstitute a complete and unique genetic heritage.
- Fertilization : Fusion of two gametes (egg and sperm) to form an egg cell (zygote) with a full chromosome number.
- Mendelian inheritance : Transmission of hereditary traits via genes located on nuclear chromosomes (therefore inherited from both parents), according to Mendel's laws.
- Non-Mendelian inheritance : Transmission of hereditary traits that do not follow Mendel's laws, either due to the location of genes outside the nuclear chromosomes (such as mitochondrial DNA inherited only from the mother, or chloroplast DNA), or due to specific mechanisms affecting nuclear genes (such as parental imprinting, incomplete dominance, dynamic mutation, sex-linkage).
- Epigenetic transmission : Transmission, at the individual or transgenerational level, of regulatory marks of gene expression, without modification of the DNA sequence.

6. Natural Selection
Natural selection is an evolutionary mechanism that sorts individuals according to their ability to survive and reproduce.
Given the hereditary variations between individuals, natural selection favors certain traits within this diversity : individuals carrying genetic characteristics that are advantageous for their survival and reproduction in a given environment produce more offspring.
This concept of natural selection evolved historically in four stages (illustrated by the giraffe) :
- Lamarck (inheritance of acquired traits, 1809) : The giraffe lengthens its neck to reach high leaves and passes this acquired trait on to its offspring.
- Darwin (natural selection, 1859) : In giraffes, those born with longer necks through random individual variation survive better and reproduce more, thus producing more offspring.
- Neo-Darwinism (modern genetics, Collective, 1930-1940) : In giraffes, those born with longer necks due to random genetic mutations (not environmentally driven) survive better and reproduce more, thus producing more offspring.
- Epigenetics (regulation of gene expression, Waddington, 1942) : In giraffes, in addition to random genetic mutations, difficulty reaching high leaves could alter the expression of genes involved in neck growth, without changing the DNA sequence. These epigenetic modifications could be temporarily passed on to their offspring.

In summary :
Cellular functioning, through its major functions (organization, production, regulation, variation, repair, transmission), subtly illustrates the dynamic balance between assimilation and accommodation, as described by Jean Piaget.
Like the intelligence of living organisms which constantly adjusts its patterns to integrate or transform experience, the cell assimilates most events according to its genetic and epigenetic programs. But it also knows how to accommodate, that is, adjust or remodel its mechanisms, in the face of novelty or disruption.
This adaptive balance, the driving force of cellular plasticity, provides, on a larger scale, the innovations that are influenced by natural selection.

E4.2. Cell description :

A hierarchical description of the eukaryotic cell (with nucleus) is given as follows [PER][CHA] :
Note : The number shown is relative to the adult human being.

Eukaryotic cell = Plasma membrane + Cytoplasm + Nucleus. Number = 37 trillion
|
| Plasma membrane = Envelope separating the interior and exterior of the cell.
|
| Cytoplasm = Cytosol + Organelles
| |
| | Cytosol = Aqueous medium containing ions, nutrients, and enzymes.
| |
| | Organelles = Free ribosomes + Endoplasmic reticulum + Mitochondria + Golgi apparatus + Lysosomes + Cytoskeleton
| | | Free ribosomes = synthesize proteins from messenger RNA. Number = 10 million
| | | Endoplasmic reticulum (ER) = Synthesizes lipids (smooth ER) and other proteins (rough ER, with attached Ribosomes).
| | | Mitochondria = Produce cellular energy (ATP) through cellular respiration. Contain their own DNA (mitochondrial genome). Number = 100 to 10,000 (according to cell type).
| | | Golgi apparatus = Sorts, packages and transports molecules (mainly proteins and lipids) to their final destination (internal or external to the cell).
| | | Lysosomes = Digest cellular waste. Number = 300 to 500
| | | Cytoskeleton = Maintains cell shape and participates in cell movement.
|
| Nucleus = Nuclear membrane + Nucleoplate + Chromatin + Nucleoli
| |
| | Nuclear membrane = Double envelope separating the interior and exterior of the nucleus.
| |
| | Nucleoplate = Gelatinous medium containing enzymes and ions.
| |
| | Chromatin = Nuclear genome + Regulatory proteins + Associated RNAs + Epigenetic modifications
| | |
| | | Nuclear genome = Set of Chromosomes. Number = 23 pairs of chromosomes.
| | | | Chromosome = Compacted DNA molecule (double helix consisting of two antiparallel strands of nucleotides) = Coding genes + Non-coding genes + Intergenic sequences
| | | | | Coding gene = DNA sequence containing the information necessary for protein synthesis. Number = 20,000 coding genes per nuclear genome.
| | | | | Non-coding gene = DNA sequence containing the information necessary primarily for functional RNA synthesis.
| | | | | Intergenic sequences = Non-coding DNA sequences located between two adjacent genes (coding or non-coding). They notably constitute the anchoring platforms for Regulatory proteins and also include a diversity of repeated sequences. Proportion = 90 % of the nuclear genome.
| | | | | Nucleotide = Phosphate group + Deoxyribose sugar + Nitrogenous base. Number = several million per chromosome
| | | | | | Nitrogenous base = Adenine (A), Thymine (T), Cytosine (C), or Guanine (G). Number = 3 billion pairs of nitrogenous bases per nuclear genome.
| | |
| | | Regulatory proteins = Histones + Transcription factors
| | | | Histones = Proteins that compact DNA around themselves and thus modulate its accessibility.
| | | | Transcription factors = Proteins that bind to non-coding DNA sequences to activate or repress gene expression.
| | |
| | | Associated RNAs = Main mediators of gene expression
| | | | Messenger RNA (mRNA) = Copies a coding Gene (the blueprint for protein production) and transports it to the Ribosomes.
| | | | Transfer RNA (tRNA) = Transports amino acids to the Ribosomes and positions them according to the provided blueprint.
| | | | Ribosomal RNA (rRNA) = Forms the backbone of the Ribosomes and assembles amino acids into protein chains according to the provided blueprint.
| | | | microRNA = blocks specific messenger RNA, preventing their translation and thus reducing the production of effector proteins.
| | | | Long non-coding RNA (IncRNA) = Indirect regulator, for example, guiding proteins to specific regions of DNA.
| | |
| | | Epigenetic modifications = Reversible additions of chemical groups to DNA molecules and histones, thus altering DNA accessibility.
| |
| | Nucleoli = Synthesize ribosomal RNAs. Number = 1 to 5

E4.3. Epigenetics :

Epigenetics constitutes a biological underpinning common to all acquisition-based learning (memory stabilization, brain plasticity, metabolic adaptations). It allows cells to encode lived experience through changes in gene expression without altering the DNA sequence, unlike genetic mutations.
This fundamental mechanism dynamically regulates gene expression according to the physiological or environmental context, thus allowing the organism to adapt effectively to internal and external stimuli, including :
- Climate variations (temperature, humidity)
- Dietary changes (deficiency, excess, nutritional quality)
- Habitat changes (urbanization, pollution, migration)
- Physiological stress (illness, intense exercise)
- Traumatic stress (emotional shock, violence)
This regulation is achieved through reversible chemical modifications, such as :
- DNA methylation, by adding methyl groups to the DNA.
- Modification of regulatory proteins (mainly histones) around which DNA is wrapped.
These modifications dynamically control access to genes and their expression levels, allowing their activation or repression without altering the underlying genetic content.

Two levels of plasticity are distinguished :

Individual plasticity : When stimuli are moderate or transient, the changes remain confined to somatic (body) cells and are not transmitted to subsequent generations.
For example :
- The Arctic fox changes its coat (white in winter and brown in summer). Fox cubs are born with a coat adapted to their season of birth, but their ability to change color then depends on environmental stimuli (study by Zimova M., Mills L.S., Nowak J.J., 2016).
- In humans, skin tanning in response to the sun is a temporary adaptation specific to each individual (study by Slominski A., 2004).

Transgenerational plasticity : When stimuli are intense or prolonged, the changes also affect germ cells (sperm and oocytes). These marks are then transmitted to offspring and influence their phenotypes (behavioral, physiological, and morphological traits) for one to three generations before fading.
For example :
- In water fleas (Daphnia), parental exposure to predator signals induces the development of morphological defenses (helmets or spikes) in the offspring, even if the young have never encountered a predator themselves (study by Tollrian R., 1995).
- Male mice exposed to prolonged cold give birth to offspring better adapted to low temperatures (study by Chan J.C., 2020).
- Male mice conditioned to fear an odor transmit a specific hypersensitivity to that odor to their offspring (study by Dias & Ressler, 2013).
- In humans, malnutrition before pregnancy in the mother or father can have a lasting effect on the child's health, even if the child subsequently grows up in a normal food environment (study by Gete DG., Waller M., Mishra GD., 2020).

In the case of cognitive learning, epigenetics is closely linked to brain plasticity (neural networks) at two complementary coding levels [MER] :
- A structural level : Learning modifies the strength and organization of synaptic connections between neurons, ensuring the storage and consolidation of acquired information (memory).
- A biological level : Learning induces epigenetic modifications in the genome of neuronal cells, which regulate the expression of genes involved in synaptic plasticity and stabilization of neuronal networks.
Warning : Despite the profound impact of intensive cognitive activity (such as musical practice) on brain plasticity and neuronal epigenetics, these changes remain strictly individual. To date, no hereditary mechanism, genetic or epigenetic, has been demonstrated to transmit these adaptations to offspring.

E4.4. RNA :

RNA (RiboNucleic Acid) is the dynamic relay between DNA and all cellular activities, ensuring the transmission, translation and regulation of genetic information within the cell.
All RNAs are synthesized by direct copying of DNA sequences (transcription) through the action of RNA polymerase, a special protein initially present in the cell and then produced by messenger RNA, like all other proteins.
Warning : No RNA is a protein. RNA polymerase, despite its name, is not an RNA but a protein (enzyme) that makes RNA.

A specific type of RNA, messenger RNA (mRNA), is a partial and targeted copy of genetic information, then transmitted to ribosomes (in the cell cytoplasm). Ribosomes then "read" this messenger RNA (coding RNA) as a blueprint for making (synthesizing) proteins.

Other types of RNA, known as non-coding RNA, do not contribute to protein production. They are functional and perform key regulatory functions, such as :
- Blocking specific messenger RNAs to prevent their translation (e.g., microRNAs), thereby reducing the production of effector proteins.
- Controlling access to DNA via epigenetic modifications (e.g., long non-coding RNAs), thereby modulating gene expression without altering the DNA sequence.

E4.5. Sources relative to genetics :

[CHA] ChatGPT, le moteur d'Intelligence Artificielle développé par OpenAI.
[MER] Karine Merienne, Anne-Laurence Boutillier, Régulations épigénétiques et plasticité cérébrale : vers de nouvelles thérapies dans les maladies neurodégénératives ?, 2016.
[PER] Perplexity, le moteur d'Intelligence Artificielle développé par Perplexity AI.

E6. Color blindness

Figures 1, 2 and 3 above : Jean Jouannic's test n°7 (cf [OPT]) : The group showing two vertical alignments of similar colors indicates the type of color blindness (green, red, blue).

1. Introduction
2. Genetic cause
3. Accessibily standards
4. Sources

E6.1. Introduction :

Color blindness (or dyschromatopsia) refers to a disorder of color perception, most often of retinal origin.
The retina contains two types of light-sensitive cells. Rods provide grayscale vision, especially in low light. Cones provide color vision, primarily in bright light.
Cones are divided into three categories, each sensitive to a range of wavelengths roughly corresponding to green, red and blue.
In a color-blind person, one or more of these categories are absent or function abnormally, according to the following classifications :
- Green deficiency : deuteranopia (absence) or deuteranomaly (altered function),
- Red deficiency : protanopia (absence) or protanomaly (altered function),
- Blue deficiency : tritanopia (absence) or tritanomaly (altered function),
- Simultaneous deficiency of all three : achromatopsia.
In populations of European descent, about 8 % of men are affected by some form of color blindness, compared to only 0.5 % of women. Red-green confusion accounts for the vast majority of cases.

A little-known subtlety : spatial summation.
The accurate perception of a color does not depend solely on which cones are stimulated, but also on how many cones are activated at the same time. This is the principle of spatial summation.
When a colored surface is large and uniform, the cones send a stable signal. In a person with colour blindness, this signal is different but consistent, enabling the brain to associate it with a colour name, without reproducing the perception of so-called "normal" colour vision.
Thus, a color-blind person can easily distinguish a traffic light, a large colored area on a map, or a painted wall. The surface is large enough for the signal to be reliable.
What may escape them is a thin green line on a red background, a word written with a fine ballpoint pen, or the colored bands on electronic resistors. The stimulated area is too small, and the color blends into the background.

Another little-known aspect is the relationship between color perception and the words used to name colors.
In a color-blind person, the correspondence between the perceived sensation and the name of the color is unstable and differs from that of non-color-blind individuals.
Lacking a reliable and repeated association, the brain reinforces less strongly the link between visual perception and color vocabulary. It then relies more on other, more reliable cues - context, shape, position, brightness, memory - rather than on the color and its name.

E6.2. Genetic cause :

Color blindness is most often of genetic origin. More rarely, it can be acquired during life as a result of certain ocular or neurological diseases, or from medications that affect the retina.
In hereditary cases [PER][CHA], color blindness results from anomalies in the genes that code for the pigments of the cones, most often those sensitive to green and red, and more rarely those sensitive to blue. In the most common forms (red or green deficiency), the genes involved are carried on the X chromosome.
Girls (XX), who inherit one X chromosome from each parent, express color blindness only if both X chromosomes carry the anomaly, which is rare. They can nevertheless carry the anomaly without being color-blind themselves, and pass it on to their children.
Boys (XY), who inherit an X chromosome from their mother and a Y chromosome from their father, are affected if they receive an X carrying the anomaly (a single copy is sufficient). This is why the condition is much more common in men than in women. A color-blind man therefore passes his affected X chromosome to all of his daughters, who become carriers of the anomaly, but to none of his sons, to whom he passes only his Y chromosome.

E6.3. Accessibility standards :

The World Wide Web Consortium Web Content Accessibility Guidelines (WCAG) are the global reference for the accessibility of websites and applications. For color blindness, four major rules apply :
- Use of color (Criterion 1.4.1 - Level A) :
Color must not be used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. For example, a hyperlink should not be identified by blue color alone, but also by underlining. In charts, lines should be distinguished by shapes (dashes, symbols, etc.), not only by color.
- Text contrast (Criterion 1.4.3 - Level AA) :
For normal-sized text, the minimum required contrast ratio is 4.5:1. For large text, the required ratio is 3:1 (18-point text, or 14-point bold).
- Non-text contrast (Criterion 1.4.11 - Level AA) :
Essential graphical objects (such as thin lines and charts) must also meet a minimum contrast ratio of 3:1.
- Enhanced contrast (Criterion 1.4.6 - Level AAA) :
The required ratio increases to 7:1 for normal text and 4.5:1 for large text. In its official implementation guidance, WCAG recommends applying this rule to key graphical elements as well.

In addition to these standards, the Author of this site has produced a matrix of 24 safe contrasts selected from the 16 x 16 possible combinations of foreground and background colors defined in the HTML 4.01 standard. These 24 combinations are particularly well suited for people with green-deficient color vision.

E6.4. Sources relating to color blindness :

[CHA] ChatGPT, le moteur d'Intelligence Artificielle développé par OpenAI.
[OPT] Opticien-lentilles.com, Test n°7 (Jean Jouannic).
[PER] Perplexity, le moteur d'Intelligence Artificielle développé par Perplexity AI.

E7. Tattooing

1. Introduction
2. Medical contraindications
3. Tattoo removal
4. Main points to check before getting a tattoo
5. Sources

E7.1. Introduction [PER][CHA] :

Tattooing is a practice that consists of introducing pigments permanently into the dermis, the deep layer of the skin, using needles. The design becomes visible through the epidermis once healing is complete. This permanent body modification is most often chosen for aesthetic, symbolic, or cultural reasons.
From a biological standpoint, tattooing is an invasive procedure. However, the foreign substances implanted in the skin are generally tolerated by the body, much like a dental implant or a prosthesis.
Health surveillance data indicate that about 95 % of tattoos cause no complications, 5 % lead to manageable complications, and less than 1 % require long, complex treatment, sometimes including surgery.
Warning :
- Socially, a very visible tattoo, such as on the hands, neck, or face, may limit certain professional or social opportunities.
- Psychologically, a tattoo should remain acceptable despite personal changes, such as shifts in taste, relationship breakups, or aging.
- Practically, during the healing phase, a fresh tattoo must be protected from sunlight, prolonged bathing, scratching, and friction.

In France, public information requirements, hygiene rules applicable to professionals, and the monitoring of adverse effects are governed by the Public Health Code.
The decree of March 5, 2024 specifies the official training, certification, and hygiene requirements for practicing tattooing, permanent makeup, and body piercing.
"Tattoo vigilance" the system designed to collect and analyze reports of adverse effects, is overseen by ANSM, the French National Agency for Medicines and Health Products Safety.

E7.2. Medical contraindications :

There are very few absolute contraindications to tattooing. However, several so-called "relative" contraindications require prior medical advice. These include :
- Chronic skin conditions, such as psoriasis, eczema, vitiligo, or lichen planus.
- A particular tendency toward scarring, with a history of keloid scars (raised scars), or very reactive or inflamed skin.
- An allergic tendency, especially in cases of allergy to metals, dyes, or cosmetics.
- Autoimmune diseases or immunodeficiency, such as lupus, rheumatoid arthritis, inflammatory bowel disease, or well-controlled HIV.
- Treatments that affect healing, immunity, or bleeding, such as anticoagulants, antiplatelet drugs, or long-term corticosteroids.
- Controlled chronic conditions such as diabetes or significant venous insufficiency in the area to be tattooed.
- Pregnancy and breastfeeding, as a precaution.

E7.3. Tattoo removal :

Tattoo removal aims to reduce the visibility of a tattoo or make it disappear, most often by laser, by breaking up the pigments in the skin. It never restores the skin or the body to their original state.
Tattoo removal is generally much more expensive than the initial tattoo, time-consuming, requiring many sessions spaced over several months, painful at each session, and the result remains variable.
Black is the easiest color to remove. Color mixtures and very dense inks make the process much more difficult.

E7.4. Main points to check before getting a tattoo :

The choice of tattoo artist is essential. The main points to check before getting a tattoo are as follows :
- For individuals who do not belong to a healthcare profession, practicing tattooing requires obtaining the mandatory certificate of "Training in hygiene and sanitation conditions for tattooing, body piercing, and permanent makeup practices". This training is provided by accredited organisations, in accordance with the French Public Health Code and the decree of 5 March 2024. It leads to certification issued under the supervision of the ARS (Regional Health Agency), valid for 5 years, after which the training must be renewed.
- No commercial pressure or encouragement to make a quick decision.
- Clear information about contraindications, risks, and healing/cicatrisation.
- Use of identified, compliant, and traceable inks.
- Prior questions regarding allergies, medical treatments, or skin conditions.
- Clean, organised studio with visible hygiene standards.
- Wearing single-use disposable gloves, changed between each client and after any contact with a non-sterile object (telephone, door handle, computer keyboard, etc.).
- Use of sterile or single-use equipment for any item in contact with the skin, blood, ink, or working area.
- Opening of needles and main consumables in front of the client.

E7.5. Sources relating to tattooing :

[CHA] ChatGPT, le moteur d'Intelligence Artificielle développé par OpenAI.
[PER] Perplexity, le moteur d'Intelligence Artificielle développé par Perplexity AI.

Copyright © 2005 Régis Petit.               Last page update : May 21, 2026.