F.M. Alexander Technique as the Basis of Learning [Lecture]

F.M. ALEXANDER TECHNIQUE AS THE BASIS OF LEARNING

For those of you who are not familiar with the Alexander Technique, I will begin by giving a short account of how F.M.Alexander made his now famous discovery.

Alexander lived from 1869 to 1955. He was born in Tasmania and as a young man he became deeply interested in the theatre, especially Shakespeare. His particular love was to perform one-man recitations of Shakespeare’s works and he was a successful and popular actor. Such were the demands made on his voice, however, in carrying out his profession that he developed problems with his throat, which resulted in hoarseness to the point where he could not speak.

He consulted his doctor, and after trying various treatments, he realised that the medical profession could not cure him. This meant that his beloved career as an actor was threatened and this realisation prompted him to reason that whatever was wrong with him must be caused by something he was doing to himself.

With the aid of a mirror, Alexander spent years of meticulous study of himself, not only of how he used his vocal mechanisms, but also his whole psycho-physical organism. He saw that any movement of a specific part of his body could not be done in isolation, but was a function of his whole being. He realised also that he was completely dominated by habitual, unreasoned use of himself: after many years of experimenting he gradually freed himself of its tyranny.

How did Alexander do this? From his observations in the mirror, he saw that he was not doing with his body what he felt or thought he was doing; e.g. he noticed that in everything he did he disturbed the integrity of his head-neck-back relationship, by stiffening unduly the muscles of his neck, which resulted in his head being pulled back and down into his shoulders causing his spine to distort harmfully, so that he became shorter in stature. This disturbance of the “primary control” as he called it, that is the balanced relationship of his head, neck and torso, caused severe pressure on his vocal mechanisms and restricted his breathing, thus causing the distressing hoarseness.

His harmful habit of stiffening his neck, pulling his head back and down and shortening and narrowing his back was even more apparent when he attempted to recite from the works of Shakespeare, because of the added stress of dramatic expression, voice projection, etc.

Having made these discoveries, Alexander then thought that the way to cure himself of his voice trouble was simply to stop, by an act of will, the stiffening of his neck muscles, the pulling-back of his head and the shortening and narrowing of his back. In other words, he would stop disturbing his head-neck-back relationship, the primary, unifying mechanism in the body. When he tried to do this, however, he was greatly startled to find that despite his ‘will-to-do’ he could not prevent these unco-ordinated events from occurring and he realised that they were habits which he had developed over the years, habits which had become so ingrained, mentally and physically, that he could not change them directly. In other words, he discovered that if his neck muscles were harmfully stiffened, his head pulled back and down and his back shortened and narrowed he could not simply free his neck, put his head forward and up, and pull himself up in order to make his back longer.

This brought him to the knowledge that it is a common belief among the vast majority of us that if we are asked to perform an act in a new, unfamiliar way, we can simply do it. This belief is a fallacy. To perform an act in a familiar fashion is easy enough, but to do so in an unfamiliar manner involves experiences where we must take steps into the unknown.

What are these unfamiliar steps into the unknown? They involve the adoption of an indirect method of changing harmful, unco-ordinated use of the psycho-physical mechanisms of the self. As Alexander found, he could not directly change his habits and he had to find a way of doing so indirectly. He also had to find a way of knowing, without doubt, that he had done so.

The indirect method that he adopted happened as follows. Alexander realised that if he was ever to change his negative habits he must side-step them by refusing, at the crucial moment when he wanted to move, to do anything until he thought or directed his neck to be free, his head forward and up and his back to lengthen and widen. He would then do something, sit down for example, and maintain as the priority the conscious directions to his head-neck-back relationship all the way through the movement of sitting down. In other words, by stopping at the crucial moment and refusing to react habitually to the stimulus of sitting down (or whatever), he inhibited at source his habitual, unco-ordinated behaviour.

This process of inhibition was his most important discovery. It is not something hanging in the air like some doubtful, vague, metaphysical flight of fancy, but is a physical fact of the nervous system, a fact which has since been confirmed by the investigations of medical science. By 1949 the medical profession had discovered and accepted inhibition as a natural, vital function of the nervous system.  In relation to the functioning of the nervous system, to refrain from performing a movement is just as active as performing one. It is worth noting that Alexander discovered inhibition in the most practical way through experience as far back as the last decade of the 19th century and a growing number of people, who are interested in making radical, constructive, conscious changes in themselves, have been learning how to use it ever since. The word “radical” is used here to emphasise that, in order to change, we should first learn how to inhibit or stop, at source, all our old, harmful habits of misuse of our psycho-physical organisms.

A word of caution. The term ‘inhibition’ as used in the Alexander Technique should not be confused with ‘suppression’. Suppression, in the conventional sense, is negative and dangerous to the welfare of the individual. Alexandrian inhibition is a vital, dynamic process, which is exactly the opposite of suppression. It is truly the gateway to positive change.

So, what did Alexander discover? He found that his reactions to the stimuli of everyday living were unsatisfactory because they were always too quick, too stressful and were carried out with too much strenuous effort. These habitual reactions caused him to develop harmful muscle-tension patterns throughout the body, which caused him subsequently to lose his voice. More importantly, however, he realised that throughout his life he had thought himself into these muscle-tension patterns and it was his wonderful power of thinking that enabled him to release them and thus free himself from his throat trouble. His throat trouble disappeared in the process of re-educating his whole psycho-physical-emotional organism. He had set out to cure a specific symptom and discovered something much more important i.e. that the human being is a psycho-physical-emotional unity which must be considered as a whole. Specific symptoms will vanish during the re-educative process of improving the general use of the self.

Before considering the educative benefits of the Alexander Technique for children, let us first look at a fundamental requirement for all of us no matter what we wish to learn. This fundamental is good health.

Alexander’s initial motivation, when he tried to find out what it was that he was doing to himself, was to get rid of his throat trouble: in other words, to make himself healthy again by “curing” a specific symptom. During this attempt to “cure” himself, he found, as stated earlier, that his reactions to the stimuli of living were unsatisfactory because he, like most of us, was an inveterate ‘end-gainer’.

What is ‘end-gaining’? It is the desire to arrive at the finish of what one wishes to do without considering the co-ordinated means of gaining that end. ‘End-gaining’ results in inappropriate and, therefore, unsatisfactory psycho-physical-emotional reactions to stimuli. One example of an unsatisfactory mental reaction is ‘mind-wandering’ which manifests as not managing to keep your mind on the thing you are doing at that very moment, or on the abstract subject you are trying to study. Most children as well as adults suffer from this inability to pay sustained attention.

An example of an unsatisfactory emotional reaction would be sticking to one’s belief, or opinion, when in your heart you know the other person is right. For example, the professor who would not look through Galileo’s telescope because he knew that, in one glance, all his so-called ‘scientific knowledge’ of a lifetime would be swept away. Strictly speaking, thoughts cannot be separated from emotions. The basic ‘I’ thought, the ego, is a ‘thought-emotion’. A person cannot have a purely mental, or a purely emotional reaction.

And then an example of an unsatisfactory physical reaction would be to sit down in a way which results in the integrity of the head-neck-back relationship being harmfully interfered with by stiffening and shortening the neck muscles, which in their turn affect every other muscle in the body. But again, physical reactions cannot be separated from mental reactions. One must start with the thought “I wish to sit down” and the physical act occurs. The phrase “I wish to sit down” also has an emotional content. If one ‘wishes’ or ‘wants’ or ‘has the desire to’ then that is an emotion. And, as we discovered earlier, mental acts cannot be separated from emotion, then the conclusion is that the human creature is a psycho-physical-emotional unity.

In relation to health, the understanding that the human being is a psycho-physical-emotional unity is of deep significance. Our three basic functions of thinking, feeling and willing manifest through psycho-physical-emotional reaction and action. So, for the purpose of illustration only, let us separate these three aspects of ourselves and consider them one at a time. We will begin with a habitual, mental reaction such as worry. We tend to worry about the same things all the time. Even if there is no cause to worry we usually find something to worry about. This is a mental habit based on fear, an emotion. But this mental habit results in a physical reaction, namely, too much muscle tension, which leads to habitual muscle shortening.

Let us now consider a habitual emotional reaction such as ‘depression’, another symptom of our reaction to the stress of modern life. When a person is depressed he or she is unhappy and this negative state leads to too much muscle tension, which leads to habitual muscle shortening.

Lastly, a physical reaction: We will stay with the example of sitting down in a chair. During the journey from standing to sitting, the integrity of the head-neck-back relationship is interfered with, as described earlier and this interference leads to too much muscle tension, which leads to habitual muscle shortening.

What these three illustrations mean is that what we are manifests in the muscles. They indicate our psycho-physical-emotional state. If you watch a baby in particular, you will see how s/he expresses joy by moving every muscle in the body, toes and fingers moving, arms waving around, legs kicking, lips smiling etc. When the baby is unhappy all the muscles tense up as s/he cries.

We can now see that our way of misusing our psycho-physical-emotional selves manifests as muscle-shortening, fixed muscle-tension patterns. The problem, however, is that muscle-shortening is not generally recognised as a symptom of ill-health. But if a muscle cannot function at its optimum, then it becomes inefficient and can, therefore, be shown to be unhealthy, just as the liver, if it did not function optimally, would be considered unhealthy and the doctor would prescribe some remedy to restore it to good health.

Unfortunately, shortened muscles cause many things in the body to become unhealthy. The spine, for example, distorts and this causes the torso to slump, which in turn causes all the vital organs such as the heart, lungs, liver, stomach, intestines, uterus etc. to drop. This results in tremendous pressure being put on them. Many ailments result from this such as heart disease, poor breathing, sluggish circulation, digestive problems etc. All these are usually diagnosed as separate symptoms and attempts are made to cure them on a specific basis. But no medical diagnosis could be complete without considering the person’s use of themselves, which affects their functioning.

In our everyday acts we can learn to improve the use of the self by ‘thinking in activity’, a MENTAL process which brings PHYSICAL change which will make us happier, an EMOTIONAL state. We should not separate these aspects of the self, they function as a whole. Alexander discovered that specific symptoms cannot be treated separately and that misuse of the psycho-physical-emotional organism as a whole causes these specific symptoms. If we wish to improve our health we must first solve the problem of our negative reactions to the stimuli of everyday living. This is why F.M. Alexander called his discovery “a technique for dealing with human reaction”.

The schoolteacher’s task is difficult because the majority of children have developed many harmful psycho-physical patterns of misuse before they even start school at the age of five or six. Why is this? Two major reasons stand out. The first is fear, usually the fear of doing something wrong, something that does not please the parents. Too often children are told, “Do it right, do it quickly, do it quietly and do it my way!” and this causes them anxiety and unhappiness. The second reason is love. Whichever parent the child loves best is the one s/he will copy. S/he will subconsciously adopt the parent’s misuse right down to how the parent breathes. The child’s ability to imitate is tremendous.

The children then start school and the pressure of ‘getting it right’ is perpetuated during their studies. Sometimes they are made to feel anxious when the teacher adopts a method such as the example which follows: – A friend of mine told me recently that her 8 year old daughter came home from school crying because the teacher attempted to check her knowledge of arithmetic by asking her, “What is 7 x 4?” The teacher told the child “I will ask you 7 x 4 and then I will count 1, 2, 3 and you must give me the correct answer immediately after 3”. The child complained to her mother that the pressure of the situation stopped her from thinking clearly and she could make no reply. This of course really irritated the teacher, but more importantly it caused the child psychological and emotional distress. How many of us have suffered such an experience numerous times?

Such pressure and distress increases in the child’s later education because of the system of sitting examinations. Such a method breeds division among people as they approach adulthood because the ‘clever’ children are praised and rewarded for their ‘success’ and the ‘stupid’ ones are made to feel inferior because of their ‘failure’. Who could estimate the untold damage done to all of us through this insensitive and segregatory system? With this type of education children are taught how to conform and become part of the system which we call society. It prepares them for work and does not teach them how to live. This way of ‘education’ is synonymous with indoctrination.

F.M. Alexander was greatly concerned about the plight of the children and called them ‘his most important client’. Other people shared this concern, prominent among them being John Dewey (1859-1952) the American philosopher and educationalist. He was born in Vermont and received his PhD degree from John Hopkins University of Maryland before his appointment in 1894 as professor of philosophy and pedagogy at the University of Chicago. He resigned in 1904 and joined the faculty of Columbia University where he remained until retirement in 1930 and as professor emeritus until 1939.

With Charles S. Pierce, William James and George H. Mead, Dewey was founder of the philosophic movement known as pragmatism, which is the doctrine that the only test of the truth of human cognitions or philosophical principles is their practical results. This philosophy reflected American culture and insisted that the way to test ideas was to check whether or not, when applied in practice, the results were the ones expected. Crudely stated, this has been taken to mean the test of an idea is whether or not it worked in practice. At Chicago, Dewey started an elementary laboratory school in which he tested his ideas. His educational writings date from this time. ‘THE SCHOOL AND SOCIETY’, 1902, and ‘THE CHILD AND THE CURRICULUM’, 1902, followed by ‘HOW WE THINK’, 1916. Two of Dewey’s later books, ‘HUMAN NATURE AND CONDUCT’, 1922, and ‘EXPERIENCE AND NATURE’, 1925, tell of his experiences with the Alexander Technique.

Dewey’s influence on educational theory has been profound. Between the wars most American professors of education acknowledged his leadership. His influence on primary school practice was, perhaps, greater than at the secondary level. Progressive education had in Dewey one of its most articulate theorists.

Dewey had lessons in, and studied intermittently, the Alexander Technique from 1920 onwards. The greatest benefit he said he got from lessons was the ability to stop and think (inhibition) before acting. Another benefit was the improvement in his breathing and his doctor commented on how – even at the age of eighty-eight – mobile his ribs were.

Alexander wrote four books:

1. MAN’S SUPREME INHERITANCE

2. CONSTRUCTIVE CONSCIOUS CONTROL

3. THE USE OF THE SELF

4. THE UNIVERSAL CONSTANT IN LIVING

John Dewey wrote introductions to three of them and a few quotes from these introductions are given below.

MAN’S SUPREME INHERITANCE:

“In the larger sense of education, this whole book is concerned with education. But Alexander touches on education in the narrower sense. He is aware of the perversions and distortions that spring from that unnatural suppression of childhood which too frequently passes for school training.”

CONSTRUCTIVE CONSCIOUS CONTROL:

“For although there is nothing esoteric in his teaching it is difficult for anyone to grasp its full force without having actual demonstration of the principle in operation.”

“The perversion of our sensory consciousness of ourselves has gone so far that we lack criteria for judging the doctrines and methods that profess to deal with the individual human being.”

“The most striking fact of Alexander’s teaching is the sincerity and reserve with which he has never carried his formulation beyond the point of demonstrated facts.”

“Alexander has demonstrated a new scientific principle with respect to the control of human behaviour, as important as any principle which has ever been discovered in the domain of external nature.”

Note: The “control of human behaviour” in the above quote is constructive conscious control of the individual, by the individual, not by some outside agency like a government or some other body.

“It is a discovery which makes whole all scientific discoveries and renders them available, not for our undoing, but for human use in promoting our constructive growth and happiness.”

“The one factor which is the primary tool in the use of all these other tools, namely ourselves as the basic condition of our employment of all agencies and energies, has not even been studied as the central instrumentality.”

“But the method is not one of remedy; it is one of constructive education. Its proper field of application is with the young, the growing generation”.

THE USE OF THE SELF:

“Education is the only method which humankind possesses for directing its own course. But we have been involved in a vicious circle. Without knowledge of what constitutes a truly normal and healthy psycho-physical life, our professed education is likely to be mis-education. Every serious student of the formation of disposition and character which takes place in the family and school knows – speaking without the slightest exaggeration – how often and how deplorably this possibility is realised. The technique of Alexander gives to the educator a standard of psycho-physical health.  It supplies also the ‘means-whereby’ this standard may be progressively and endlessly achieved, becoming a conscious possession of the one educated. It provides the conditions for the central direction of all special educational processes. It bears the same relation to education that education itself bears to all other human activities. It contains in my judgement the promise and potentiality of the new direction that is needed in all education.”

There can be no doubt that Dewey was deeply influenced by Alexander’s work. Dewey, perhaps America’s greatest philosopher and pedagogue, a co-founder of the practical philosophy of pragmatism was shocked to discover that he did not possess psycho-physical equilibrium. He was the intellectual type who thought that his body was simply useful for carrying his brain around. During early lessons when he attempted to perform the seemingly simple act of sitting down in a conscious, co-ordinated manner – as explained by Alexander – that ran contrary to his habitual behaviour, he found he could not do it and described his failure as “an experience not congenial to one’s vanity, the most humiliating experience of my life, intellectually speaking.”

In Alexander’s teachings, Dewey found the means of realising the pragmatic approach to life that he himself had advocated. Of this he said, “In the study I found the things which I had ‘known’ – in the sense of theoretical belief – in philosophy and psychology, changed into vital experiences which gave a new meaning to knowledge of them.”

We will now move on and consider what F.M. Alexander had to say about the child and education. Most of what follows is paraphrased from his books.

A child, once it has emerged from its first state of absolute helplessness, and before it is coerced into certain mental and physical habits, is the most plastic and adaptable of living beings. At this stage the child has the complete potential for learning constructive conscious control of the self in every situation s/he is likely to face in life; the complete potential for learning the co-ordinated use of the psycho-physical self as s/he interacts with the environment and with other people. The usual procedure, unfortunately, is to thrust certain habits upon the child without enough consideration of cause and effect and to insist upon these habits until they become subconscious and pass from the region of intellectual guidance.

Too often, we thoughtlessly bind the pliable child to some method of working without considering whether that method is good in itself. We impose a rigid rule of physical and mental outlook on the children. Too often we know that, in ourselves, the rule has not worked very well, but it is the rule which was taught to us and we pass it on by precept. Too often, the adults are unaware that they are holding up their own imperfections for imitation.

If we are to avoid the development of negative, harmful, subconscious habits in the child, we must teach them conscious control. Give the child conscious control and you give him or her poise.  Without poise s/he will soon be cramped and distorted by the environment. Give the child the reasoned control of her psycho-physical being and you fit her for any and every mode of life. She will come to possess wonderful powers of adapting to any and every environment and will be able to shape life to her own needs. Constructive conscious control, as a fundamental of education, can give the child of today as full a command of the use of the self as possible in all forms of human activity. It constitutes the co-ordinated means of adapting to, and freely expressing themselves in, the ever-changing vicissitudes of civilised life.

The children’s reactions to their immediate environment, i.e. the desk, must also be considered. In adopting the habit of misusing themselves by crouching and slumping over the desk when reading and writing, the child and the teacher do not realise that their kinaesthetic sense, that is the sense of what they are actually doing with their bodies at the time, is being demoralised. At a time when natural activity should be encouraged, these kinaesthetic systems concerned with correct and healthy body movements are being grossly distorted. This causes faulty sensory awareness in every act that the child performs, not only in school, but in all the activities of life. In other words, this sensory awareness becomes so untrustworthy that the young person, like the adult, does not actually know the co-ordinated ‘how’ of performing everyday acts. They do not know that in everything they do they are habitually upsetting their psycho-physical-emotional unity. There is not, of course, an ideal desk to sit at and so, obviously, we must educate the children in the co-ordinated use of the self, not redesign the furniture.

Up to now, the educationalists have given the children what they thought the young ones needed, but in future we must give them the co-ordinated ‘means’ by which they themselves may satisfy their needs and command their own advancement.

Alexander attempted to give this very method to the children in the ‘Little School’, as it was known, which he founded in London in 1924, together with Irene Tasker, an Alexander Technique teacher and schoolteacher who had also undertaken the Montessori training. Tasker was in charge of the ‘school’ teaching of the children and Alexander gave them individual lessons in his technique.

With the Alexander Technique as the foundation for learning, the children were shown the value of working with the ‘means’, never with ‘ends’; shown how to apply the principles in every kind of activity; shown how to, in the words of Professor John Dewey, ‘think in activity’. As long as they applied the principles, the children could be left to carry on their reading, writing etc. with the minimum of help from the teacher.

Tasker planned the school work in a way which helped the children meet any special needs they may have had. She also found interesting subjects that they could share. In her book, ‘CONNECTING LINKS’, Irene Tasker describes some of the experiences at the ‘Little School’:

“The little ones contributed specimens of handwriting, older ones wrote stories and plays and poems, many describing the fate of ‘end-gainers’. They all used the typewriter, which I found excellent for the practice of the inhibitory-means-whereby principle. They found that if they refused to strike the keys until they had arranged their fingers on the appropriate keys for at least three letters ahead, they prevented, instead of made, mistakes. Prevention of mistakes, by encouraging the children to wait long enough to have their means clearly and thoroughly prepared before going on to gain their end, proved to be a result of carrying out Alexander’s principle in the schoolroom. Of course all attempts cannot be successful and we know how we learn by mistakes, but as Alexander says, ‘Confidence is born of success, not of failure’, and our processes in education and in the general art of living must be based upon principles which will enable us to make certain of the satisfactory means-whereby an end may be achieved. And thus to command a large percentage of those satisfactory experiences which develop confidence, as against a small percentage of those unsatisfactory experiences which tend to undermine our confidence and make us unhappy.

Our speaking work was also directed towards a common end, the performance the children gave at the end of term to their parents and friends. In the speaking work, I would give them, for instance, two or three lines from Shakespeare to repeat and I would say the words as many times as they needed to become sure of their meaning. Then, and only then, did they attempt to say the words themselves. It may have been slow but it was sure progress and by the time we wanted to act in the performance the children were sure of what they had to say.”

After attending one of these performances Alexander said: “The performance afforded a pleasing and exhilarating experience, for instead of the bustle and excitement usually associated with children’s performances at end of term, there was a calm and deliberate attitude pervading all that was done”. Irene Tasker was sitting in the audience obviously confident the children would not fail to be true to the principles of non-endgaining. Even the youngest pupil carried out his parts with the assurance of the trained and experienced performer. When one little girl forgot her lines she was not in the least disturbed. No shuffling of feet or twitching of mouth and fingers, just placid non-endgaining until she remembered and then on she went as if nothing had happened. It was noticeable that the attitude of calm and confidence was passed on from the young performers to the adults in the audience.

Tasker also said: “I think that the confidence which came to these children, manifesting, as they did, various shortcomings and difficulties, was largely due to their sharing the experience of learning to say ‘No’ (inhibition) before starting a job or an activity. Indeed they had great fun with it. They found it worked to have their ‘means’ clearly thought out before tackling a new piece of work. Professor Dewey, who visited the class for two mornings, sitting quietly in a corner while we carried on as usual, said to me on leaving ‘It is quite evident what you are aiming at here – and I wish I were a pupil in this class!'”

It is surely the aim of every thinking, caring schoolteacher to make the children happy and of this Alexander said: “The characteristic note of true happiness is struck when the healthy child is busily engaged in something which interests him or her. To know ‘how it works’ is the natural desire of every child. Children are always interested in machinery and it is significant that in schools where experiments have been made in re-education of the use of the self on a general basis, the children show more interest in this work than in any other. They are not slow to recognise that they themselves are the most interesting machines and their natural interest in mechanics finds full scope in their own re-education. This interest in the working of their own psycho-physical mechanisms grows steadily and comprehensively. Any process of development of the child (or adult) in using the mechanics of the organism should precede all other experience and this would increase the value of knowledge gained through study of inanimate mechanical contraptions. One can recall the expression of interest, happiness and satisfaction shown by the child when one has enabled her to understand for the first time that her unduly stiffened neck is due to attempts to do with the neck muscles what should be done by some other part of the mechanism. Experience has proved to me that with re-education on a general basis, children find a new interest in all their activities and they are happy to find that they can improve at games by conscious general direction of themselves, instead of the usual specific directions they receive in coaching lessons. When they learn to inhibit, that is say ‘No’ to some stimulus to misdirected activity this prevents over-excitement of the fear reflexes and their happiness increases with their psycho-physical improvement.”

In conclusion, if the teachers could learn that free-expression balanced with self-discipline would allow the children to consciously participate in, and to be in harmony with, the only constant in the universe, namely CHANGE, such conscious participation and harmony would allow them to realise true happiness, which could be defined as psycho-physical-emotional balance. Surely, this should be the aim of all education.

Alexander once more: “I wish to say something to the many people who say ‘I am quite content as I am’. To them I say, firstly, if you are content to be the slave of habits, instead of master of your own mind and body, you can never have realised the wonderful inheritance which is yours by right of the fact that you were born a reasoning, intelligent man or woman. Secondly, and more widely, I ask you, ‘What about the children?’ Are you content to rob them of their inheritance, as perhaps you were robbed of yours by your parents? Are you willing to send them out into the world ill-equipped, dependent on precepts and incipient habits, unable to control their own desires and already on the way to psycho-physical degeneration?”

This lecture was first published in Rock ‘N’ Ruminations by Daniel McGowan. You can download the PDF of this book for free here:  FREE DOWNLOAD