HotFreeBooks.com
The Mind and Its Education
by George Herbert Betts
1  2  3  4  5  6     Next Part
Home - Random Browse

THE MIND AND ITS EDUCATION

by

GEORGE HERBERT BETTS, Ph.D.

Professor of Psychology in Cornell College

Revised and Enlarged Edition



New York D. Appleton And Company Copyright, 1906, 1916, by D. Appleton and Company Printed in the United States of America



PREFACE TO THE REVISED EDITION

Authors, no doubt, are always gratified when their works find favorable acceptance. The writer of this text has been doubly gratified, however, at the cordial reception and widespread use accorded to the present volume. This feeling does not arise from any narrow personal pride or selfish interest, but rather from the fact that the warm approval of the educational public has proved an important point; namely, that the fundamental truths of psychology, when put simply and concretely, can be made of interest and value to students of all ages from high school juniors up, and to the general public as well. More encouraging still, it has been demonstrated that the teachings of psychology can become immediately helpful, not only in study or teaching, but also in business or profession, in the control and guidance of the personal life, and in the problems met in the routine of the day's work or its play.

In effecting the present revision, the salient features of the original edition have been kept. The truths presented are the most fundamental and important in the field of psychology. Disputed theories and unsettled opinions are excluded. The subject matter is made concrete and practical by the use of many illustrations and through application to real problems. The style has been kept easy and familiar to facilitate the reading. In short, there has been, while seeking to improve the volume, a conscious purpose to omit none of the characteristics which secured acceptance for the former edition.

On the other hand, certain changes and additions have been made which, it is believed, will add to the strength of the work. First of all, the later psychological studies and investigations have been drawn upon to insure that the matter shall at all points be abreast of the times in scientific accuracy. Because of the wide use of the text in the training of teachers, a more specific educational application to schoolroom problems has been made in various chapters. Exercises for the guidance of observation work and personal introspection are freely used. The chapter on Sensation and Perception has been separated into two chapters, and each subject given more extensive treatment. A new chapter has been added on Association. The various chapters have been subdivided into numbered sections, and cut-in paragraph topics have been used to facilitate the study and teaching of the text. Minor changes and additions occur throughout the volume, thus adding some forty pages to the number in the original edition.

Many of the modifications made in the revision are due to valuable suggestions and kindly criticisms received from many teachers of the text in various types of schools. To all who have thus helped so generously by freely giving the author the fruits of their judgment and experience he gladly renders grateful thanks.

CORNELL COLLEGE,

IOWA.



CONTENTS

CHAPTER I

THE MIND, OR CONSCIOUSNESS PAGE

1. How the mind is to be known: Personal character of consciousness—Introspection the only means of discovering nature of consciousness—How we introspect—Studying mental states of others through expression—Learning to interpret expression. 2. The nature of consciousness: Inner nature of the mind not revealed by introspection —Consciousness as a process or stream—Consciousness likened to a field—The "piling up" of consciousness is attention. 3. Content of the mental stream: Why we need minds—Content of consciousness determined by function—Three fundamental phases of consciousness. 4. Where consciousness resides: Consciousness works through the nervous system. 5. Problems in observation and introspection . . . . . . . . . . 1

CHAPTER II

ATTENTION

1. Nature of attention: The nature of attention—Normal consciousness always in a state of attention. 2. The effects of attention: Attention makes its object clear and definite—Attention measures mental efficiency. 3. How we attend: Attention a relating activity—The rhythms of attention. 4. Points of failure in attention: Lack of concentration—Mental wandering. 5. Types of attention: The three types of attention—Interest and nonvoluntary attention—The will and voluntary attention—Not really different kinds of attention—Making different kinds of attention reenforce each other—The habit of attention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

CHAPTER III

THE BRAIN AND NERVOUS SYSTEM

1. The relations of mind and brain: Interaction of mind and brain—The brain as the mind's machine. 2. The mind's dependence on the external world: The mind at birth—The work of the senses. 3. Structural elements of the nervous system: The neurone—Neurone fibers—Neuroglia—Complexity of the brain—"Gray" and "white" matter. 4. Gross structure of the nervous system: Divisions of the nervous system—The central system—The cerebellum—The cerebrum—The cortex—The spinal cord. 5. Localization of function in the nervous system: Division of labor—Division of labor in the cortex. 6. Forms of sensory stimuli: The end-organs and their response to stimuli—Dependence of the mind on the senses . . . . . . . . . . . . . 30

CHAPTER IV

MENTAL DEVELOPMENT AND MOTOR TRAINING

1. Factors determining the efficiency of the nervous system: Development and nutrition—Undeveloped cells—Development of nerve fibers. 2. Development of nervous system through use: Importance of stimulus and response—Effect of sensory stimuli—Necessity for motor activity—Development of the association centers—The factors involved in a simple action. 3. Education and the training of the nervous system: Education to supply opportunities for stimulus and response—Order of development in the nervous system. 4. Importance of health and vigor of the nervous system: The influence of fatigue—The effects of worry—The factors in good nutrition. 5. Problems for introspection and observation . . . . . . . . . . . . . . . . . . . . . 50

CHAPTER V

HABIT

1. The nature of habit: The physical basis of habit—All living tissue plastic—Habit a modification of brain tissue—We must form habits. 2. The place of habit in the economy of our lives: Habit increases skill and efficiency—Habit saves effort and fatigue—Habit economizes moral effort—The habit of attention—Habit enables us to meet the disagreeable—Habit the foundation of personality—Habit saves worry and rebellion. 3. The tyranny of habit: Even good habits need to be modified—The tendency of "ruts." 4. Habit-forming a part of education: Youth the time for habit-forming—The habit of achievement. 5. Rules for habit-forming: James's three maxims for habit-forming—The preponderance of good habits over bad . . . . . . . . . . . . . . . . . . . . . . . . 66

CHAPTER VI

SENSATION

1. How we come to know the external world: Knowledge through the senses—The unity of sensory experience—The sensory processes to be explained—The qualities of objects exist in the mind—The three sets of factors. 2. The nature of sensation: Sensation gives us our world of qualities—The attributes of sensation. 3. Sensory qualities and their end-organs: Sight—Hearing—Taste—Smell—Various sensations from the skin—The kinaesthetic senses—The organic senses. 4. Problems in observation and retrospection . . . . . . . . . . . . . . . . . . . . . 84

CHAPTER VII

PERCEPTION

1. The function of perception: Need of knowing the material world—The problem which confronts the child. 2. The nature of perception: How a percept is formed—The percept involves all relations of the object—The content of the percept—The accuracy of percepts depends on experience—Not definitions, but first-hand contact. 3. The perception of space: The perceiving of distance—The perceiving of direction. 4. The perception of time: Nature of the time sense—No perception of empty time. 5. The training of perception: Perception needs to be trained—School training in perception. 6. Problems in observation and introspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

CHAPTER VIII

MENTAL IMAGES AND IDEAS

1. The part played by past experience: Present thinking depends on past experience—The present interpreted by the past—The future also depends on the past—Rank determined by ability to utilize past experience. 2. How past experience is conserved: Past experience conserved in both mental and physical terms—The image and the idea—All our past experience potentially at our command. 3. Individual differences in imagery: Images to be viewed by introspection—The varied imagery suggested by one's dining table—Power of imagery varies in different people—Imagery types. 4. The function of images: Images supply material for imagination and memory—Imagery in the thought processes—The use of imagery in literature—Points where images are of greatest service. 5. The cultivation of imagery: Images depend on sensory stimuli—The influence of frequent recall—The reconstruction of our images. 6. Problems in introspection and observation . . . . . . . . . . . . . . 111

CHAPTER IX

IMAGINATION

1. The place of imagination in mental economy: Practical nature of imagination—Imagination in the interpretation of history, literature, and art—Imagination and science—Everyday uses of imagination—The building of ideals and plans—Imagination and conduct—Imagination and thinking. 2. The material used by imagination: Images the stuff of imagination—The two factors in imagination—Imagination limited by stock of images—Limited also by our constructive ability—The need of a purpose. 3. Types of imagination: Reproductive imagination—Creative imagination. 4. Training the imagination: Gathering of material for imagination—We must not fail to build—We should carry our ideals into action. 5. Problems for observation and introspection . . . . . . . . 127

CHAPTER X

ASSOCIATION

1. The nature of association: The neural basis of association—Association the basis of memory—Factors determining direction of recall—Association in thinking—Association and action. 2. The types of association: Fundamental law of association—Association by contiguity—At the mercy of our associations—Association by similarity and contrast—Partial, or selective, association—The remedy. 3. Training in association: The pleasure-pain motive in association—Interest as a basis for association—Association and methods of learning. 4. Problems in observation and introspection . . 144

CHAPTER XI

MEMORY

1. The nature of memory: What is retained—The physical basis of memory—How we remember—Dependence of memory on brain quality. 2. The four factors involved in memory: Registration—Retention—Recall—Recognition. 3. The stuff of memory: Images as the material of memory—Images vary as to type—Other memory material. 4. Laws underlying memory: The law of association—The law of repetition—The law of recency—The law of vividness. 5. Rules for using the memory: Wholes versus parts—Rate of forgetting—Divided practice—Forcing the memory to act—Not a memory, but memories. 6. What constitutes a good memory: A good memory selects its material—A good memory requires good thinking—Memory must be specialized. 7. Memory devices: The effects of cramming—Remembering isolated facts—Mnemonic devices. 8. Problems in observation and introspection . . . . . . . . 160

CHAPTER XII

THINKING

1. Different types of thinking: Chance, or idle thinking—Uncritical belief—Assimilative thinking—Deliberative thinking. 2. The function of thinking: Meaning depends on relations—The function of thinking is to discover relations—Near and remote relations—Child and adult thinking. 3. The mechanism of thinking: Sensations and percepts as elements in thinking. 4. The concept: The concepts serve to group and classify—Growth of a concept—Definition of concept—Language and the concept—The necessity for growing concepts. 5. Judgment: Nature of judgment—Judgment used in percepts and concepts—Judgment leads to general truths—The validity of judgments. 6. Reasoning: Nature of reasoning—How judgments function in reasoning—Deduction and the syllogism—Induction—The necessity for broad induction—The interrelation of induction and deduction. 7. Problems in observation and introspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

CHAPTER XIII

INSTINCT

1. The nature of instinct: The babe's dependence on instinct—Definition of instinct—Unmodified instinct is blind. 2. Law of the appearance and disappearance of instincts: Instincts appear in succession as required—Many instincts are transitory—Seemingly useless instincts—Instincts to be utilized when they appear—Instincts as starting points—The more important human instincts. 3. The instinct of imitation: Nature of imitation—Individuality in imitation—Conscious and unconscious imitation—Influence of environment—The influence of personality. 4. The instinct of play: The necessity for play—Play in development and education—Work and play are complements. 5. Other useful instincts: Curiosity—Manipulation—The collecting instinct—The dramatic instinct—The impulse to form gangs and clubs. 6. Fear: Fear heredity—Fear of the dark—Fear of being left alone. 7. Other undesirable instincts: Selfishness—Pugnacity, or the fighting impulse. 8. Problems in observation and introspection . . . . . . . . . . . . . 201

CHAPTER XIV

FEELING AND ITS FUNCTIONS

1. The nature of feeling: The different feeling qualities—Feeling always present in mental content—The seeming neutral feeling zone. 2. Mood and disposition: How mood is produced—Mood colors all our thinking—Mood influences our judgments and decisions—Mood influences effort—Disposition a resultant of moods—Temperament. 3. Permanent feeling attitudes, or sentiments: How sentiments develop—The effect of experience—The influence of sentiment—Sentiments as motives. 4. Problems in observation and introspection . . . . . . . . . . . . . . 226

CHAPTER XV

THE EMOTIONS

1. The producing and expressing of emotion: Physiological explanation of emotion—Origin of characteristic emotional reactions—The duration of an emotion—Emotions accompanying crises in experience. 2. The control of emotions: Dependence on expression—Relief through expression—Relief does not follow if image is held before the mind—Growing tendency toward emotional control—The emotions and enjoyment—How emotions develop—The emotional factor in our environment—Literature and the cultivation of the emotions—Harm in emotional overexcitement. 4. Emotions as motives: How our emotions compel us—Emotional habits. 5. Problems in observation and introspection . . . . . . . . . . . . . . 239

CHAPTER XVI

INTEREST

1. The nature of interest: Interest a selective agent—Interest supplies a subjective scale of values—Interest dynamic—Habit antagonistic to interest. 2. Direct and indirect interest: Interest in the end versus interest in the activity—Indirect interest as a motive—Indirect interest alone insufficient. 3. Transitoriness of certain interests: Interests must be utilized when they appear—The value of a strong interest. 4. Selection among our interests: The mistake of following too many interests—Interests may be too narrow—Specialization should not come too early—A proper balance to be sought. 5. Interest fundamental in education: Interest not antagonistic to effort—Interest and character. 6. Order of development of our interests: The interests of early childhood—The interests of later childhood—The interests of adolescence. 7. Problems in observation and introspection . . . . . . 254

CHAPTER XVII

THE WILL

1. The nature of the will: The content of the will—The function of the will—How the will exerts its compulsion. 2. The extent of voluntary control over our acts: Simple reflex acts—Instinctive acts—Automatic, or spontaneous acts—The cycle from volitional to automatic—Volitional action—Volition acts in the making of decisions—Types of decision—The reasonable type—Accidental type: External motives—Accidental type: Subjective motives—Decision under effort. 3. Strong and weak wills: Not a will, but wills—Objective tests a false measure of will power. 4. Volitional types: The impulsive type—The obstructed will—The normal will. 5. Training the will: Will to be trained in common round of duties—School work and will-training. 6. Freedom of the will, or the extent of its control: Limitations of the will—These limitations and conditions of freedom. 7. Problems in observation and introspection. . 271

CHAPTER XVIII

SELF-EXPRESSION AND DEVELOPMENT

1. Interrelation of impression and expression: The many sources of impressions—All impressions lead toward expression—Limitations of expression. 2. The place of expression in development: Intellectual value of expression—Moral value of expression—Religious value of expression—Social value of expression. 3. Educational use of expression: Easier to provide for the impression side of education—The school to take up the handicrafts—Expression and character—Two lines of development. 4. Problems in introspection and observation . . . . . 294

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307



THE MIND AND ITS EDUCATION

CHAPTER I

THE MIND, OR CONSCIOUSNESS

We are to study the mind and its education; but how? It is easy to understand how we may investigate the great world of material things about us; for we can see it, touch it, weigh it, or measure it. But how are we to discover the nature of the mind, or come to know the processes by which consciousness works? For mind is intangible; we cannot see it, feel it, taste it, or handle it. Mind belongs not to the realm of matter which is known to the senses, but to the realm of spirit, which the senses can never grasp. And yet the mind can be known and studied as truly and as scientifically as can the world of matter. Let us first of all see how this can be done.

1. HOW MIND IS TO BE KNOWN

THE PERSONAL CHARACTER OF CONSCIOUSNESS.—Mind can be observed and known. But each one can know directly only his own mind, and not another's. You and I may look into each other's face and there guess the meaning that lies back of the smile or frown or flash of the eye, and so read something of the mind's activity. But neither directly meets the other's mind. I may learn to recognize your features, know your voice, respond to the clasp of your hand; but the mind, the consciousness, which does your thinking and feels your joys and sorrows, I can never know completely. Indeed I can never know your mind at all except through your bodily acts and expressions. Nor is there any way in which you can reveal your mind, your spiritual self, to me except through these means.

It follows therefore that only you can ever know you and only I can ever know I in any first-hand and immediate way. Between your consciousness and mine there exists a wide gap that cannot be bridged. Each of us lives apart. We are like ships that pass and hail each other in passing but do not touch. We may work together, live together, come to love or hate each other, and yet our inmost selves forever stand alone. They must live their own lives, think their own thoughts, and arrive at their own destiny.

INTROSPECTION THE ONLY MEANS OF DISCOVERING NATURE OF CONSCIOUSNESS.—What, then, is mind? What is the thing that we call consciousness? No mere definition can ever make it clearer than it is at this moment to each of us. The only way to know what mind is, is to look in upon our own consciousness and observe what is transpiring there. In the language of the psychologist, we must introspect. For one can never come to understand the nature of mind and its laws of working by listening to lectures or reading text books alone. There is no psychology in the text, but only in your living, flowing stream of thought and mine. True, the lecture and the book may tell us what to look for when we introspect, and how to understand what we find. But the statements and descriptions about our minds must be verified by our own observation and experience before they become vital truth to us.

HOW WE INTROSPECT.—Introspection is something of an art; it has to be learned. Some master it easily, some with more difficulty, and some, it is to be feared, never become skilled in its use. In order to introspect one must catch himself unawares, so to speak, in the very act of thinking, remembering, deciding, loving, hating, and all the rest. These fleeting phases of consciousness are ever on the wing; they never pause in their restless flight and we must catch them as they go. This is not so easy as it appears; for the moment we turn to look in upon the mind, that moment consciousness changes. The thing we meant to examine is gone, and something else has taken its place. All that is left us then is to view the mental object while it is still fresh in the memory, or to catch it again when it returns.

STUDYING MENTAL STATES OF OTHERS THROUGH EXPRESSION.—Although I can meet only my own mind face to face, I am, nevertheless, under the necessity of judging your mental states and knowing what is taking place in your consciousness. For in order to work successfully with you, in order to teach you, understand you, control you or obey you, be your friend or enemy, or associate with you in any other way, I must know you. But the real you that I must know is hidden behind the physical mask that we call the body. I must, therefore, be able to understand your states of consciousness as they are reflected in your bodily expressions. Your face, form, gesture, speech, the tone of voice, laughter and tears, the poise of attention, the droop of grief, the tenseness of anger and start of fear,—all these tell the story of the mental state that lies behind the senses. These various expressions are the pictures on the screen by which your mind reveals itself to others; they are the language by which the inner self speaks to the world without.

LEARNING TO INTERPRET EXPRESSION.—If I would understand the workings of your mind I must therefore learn to read the language of physical expression. I must study human nature and learn to observe others. I must apply the information found in the texts to an interpretation of those about me. This study of others may be uncritical, as in the mere intelligent observation of those I meet; or it may be scientific, as when I conduct carefully planned psychological experiments. But in either case it consists in judging the inner states of consciousness by their physical manifestations.

The three methods by which mind may be studied are, then: (1) text-book description and explanation; (2) introspection of my own conscious processes; and (3) observation of others, either uncritical or scientific.

2. THE NATURE OF CONSCIOUSNESS

INNER NATURE OF THE MIND NOT REVEALED BY INTROSPECTION.—We are not to be too greatly discouraged if, even by introspection, we cannot discover exactly what the mind is. No one knows what electricity is, though nearly everyone uses it in one form or another. We study the dynamo, the motor, and the conductors through which electricity manifests itself. We observe its effects in light, heat, and mechanical power, and so learn the laws which govern its operations. But we are almost as far from understanding its true nature as were the ancients who knew nothing of its uses. The dynamo does not create the electricity, but only furnishes the conditions which make it possible for electricity to manifest itself in doing the world's work. Likewise the brain or nervous system does not create the mind, but it furnishes the machine through which the mind works. We may study the nervous system and learn something of the conditions and limitations under which the mind operates, but this is not studying the mind itself. As in the case of electricity, what we know about the mind we must learn through the activities in which it manifests itself—these we can know, for they are in the experience of all. It is, then, only by studying these processes of consciousness that we come to know the laws which govern the mind and its development. What it is that thinks and feels and wills in us is too hard a problem for us here—indeed, has been too hard a problem for the philosophers through the ages. But the thinking and feeling and willing we can watch as they occur, and hence come to know.

CONSCIOUSNESS AS A PROCESS OR STREAM.—In looking in upon the mind we must expect to discover, then, not a thing, but a process. The thing forever eludes us, but the process is always present. Consciousness is like a stream, which, so far as we are concerned with it in a psychological discussion, has its rise at the cradle and its end at the grave. It begins with the babe's first faint gropings after light in his new world as he enters it, and ends with the man's last blind gropings after light in his old world as he leaves it. The stream is very narrow at first, only as wide as the few sensations which come to the babe when it sees the light or hears the sound; it grows wider as the mind develops, and is at last measured by the grand sum total of life's experience.

This mental stream is irresistible. No power outside of us can stop it while life lasts. We cannot stop it ourselves. When we try to stop thinking, the stream but changes its direction and flows on. While we wake and while we sleep, while we are unconscious under an anaesthetic, even, some sort of mental process continues. Sometimes the stream flows slowly, and our thoughts lag—we "feel slow"; again the stream flows faster, and we are lively and our thoughts come with a rush; or a fever seizes us and delirium comes on; then the stream runs wildly onward, defying our control, and a mad jargon of thoughts takes the place of our usual orderly array. In different persons, also, the mental stream moves at different rates, some minds being naturally slow-moving and some naturally quick in their operations.

Consciousness resembles a stream also in other particulars. A stream is an unbroken whole from its source to its mouth, and an observer stationed at one point cannot see all of it at once. He sees but the one little section which happens to be passing his station point at the time. The current may look much the same from moment to moment, but the component particles which constitute the stream are constantly changing. So it is with our thought. Its stream is continuous from birth till death, but we cannot see any considerable portion of it at one time. When we turn about quickly and look in upon our minds, we see but the little present moment. That of a few seconds ago is gone and will never return. The thought which occupied us a moment since can no more be recalled, just as it was, than can the particles composing a stream be re-collected and made to pass a given point in its course in precisely the same order and relation to one another as before. This means, then, that we can never have precisely the same mental state twice; that the thought of the moment cannot have the same associates that it had the first time; that the thought of this moment will never be ours again; that all we can know of our minds at any one time is the part of the process present in consciousness at that moment.



THE WAVE IN THE STREAM OF CONSCIOUSNESS.—The surface of our mental stream is not level, but is broken by a wave which stands above the rest; which is but another way of saying that some one thing is always more prominent in our thought than the rest. Only when we are in a sleepy reverie, or not thinking about much of anything, does the stream approximate a level. At all other times some one object occupies the highest point in our thought, to the more or less complete exclusion of other things which we might think about. A thousand and one objects are possible to our thought at any moment, but all except one thing occupy a secondary place, or are not present to our consciousness at all. They exist on the margin, or else are clear off the edge of consciousness, while the one thing occupies the center. We may be reading a fascinating book late at night in a cold room. The charm of the writer, the beauty of the heroine, or the bravery of the hero so occupies the mind that the weary eyes and chattering teeth are unnoticed. Consciousness has piled up in a high wave on the points of interest in the book, and the bodily sensations are for the moment on a much lower level. But let the book grow dull for a moment, and the make-up of the stream changes in a flash. Hero, heroine, or literary style no longer occupies the wave. They forfeit their place, the wave is taken by the bodily sensations, and we are conscious of the smarting eyes and shivering body, while these in turn give way to the next object which occupies the wave. Figs. 1-3 illustrate these changes.



CONSCIOUSNESS LIKENED TO A FIELD.—The consciousness of any moment has been less happily likened to a field, in the center of which there is an elevation higher than the surrounding level. This center is where consciousness is piled up on the object which is for the moment foremost in our thought. The other objects of our consciousness are on the margin of the field for the time being, but any of them may the next moment claim the center and drive the former object to the margin, or it may drop entirely out of consciousness. This moment a noble resolve may occupy the center of the field, while a troublesome tooth begets sensations of discomfort which linger dimly on the outskirts of our consciousness; but a shooting pain from the tooth or a random thought crossing the mind, and lo! the tooth holds sway, and the resolve dimly fades to the margin of our consciousness and is gone.

THE "PILING UP" OF CONSCIOUSNESS IS ATTENTION.—This figure is not so true as the one which likens our mind to a stream with its ever onward current answering to the flow of our thought; but whichever figure we employ, the truth remains the same. Our mental energy is always piled up higher at one point than at others. Either because our interest leads us, or because the will dictates, the mind is withdrawn from the thousand and one things we might think about, and directed to this one thing, which for the time occupies chief place. In other words, we attend; for this piling up of consciousness is nothing, after all, but attention.

3. CONTENT OF THE MENTAL STREAM

We have seen that our mental life may be likened to a stream flowing now faster, now slower, ever shifting, never ceasing. We have yet to inquire what constitutes the material of the stream, or what is the stuff that makes up the current of our thought—what is the content of consciousness? The question cannot be fully answered at this point, but a general notion can be gained which will be of service.

WHY WE NEED MINDS.—Let us first of all ask what mind is for, why do animals, including men, have minds? The biologist would say, in order that they may adapt themselves to their environment. Each individual from mollusc to man needs the amount and type of mind that serves to fit its possessor into its particular world of activity. Too little mind leaves the animal helpless in the struggle for existence. On the other hand a mind far above its possessor's station would prove useless if not a handicap; a mollusc could not use the mind of a man.

CONTENT OF CONSCIOUSNESS DETERMINED BY FUNCTION.—How much mind does man need? What range and type of consciousness will best serve to adjust us to our world of opportunity and responsibility? First of all we must know our world, hence, our mind must be capable of gathering knowledge. Second, we must be able to feel its values and respond to the great motives for action arising from the emotions. Third, we must have the power to exert self-compulsion, which is to say that we possess a will to control our acts. These three sets of processes, knowing, feeling, and willing, we shall, therefore, expect to find making up the content of our mental stream.

Let us proceed at once to test our conclusion by introspection. If we are sitting at our study table puzzling over a difficult problem in geometry, reasoning forms the wave in the stream of consciousness—the center of the field. It is the chief thing in our thinking. The fringe of our consciousness is made up of various sensations of the light from the lamp, the contact of our clothing, the sounds going on in the next room, some bit of memory seeking recognition, a "tramp" thought which comes along, and a dozen other experiences not strong enough to occupy the center of the field.

But instead of the study table and the problem, give us a bright fireside, an easy-chair, and nothing to do. If we are aged, memories—images from out the past—will probably come thronging in and occupy the field to such extent that the fire burns low and the room grows cold, but still the forms from the past hold sway. If we are young, visions of the future may crowd everything else to the margin of the field, while the "castles in Spain" occupy the center.

Our memories may also be accompanied by emotions—sorrow, love, anger, hate, envy, joy. And, indeed, these emotions may so completely occupy the field that the images themselves are for the time driven to the margin, and the mind is occupied with its sorrow, its love, or its joy.

Once more, instead of the problem or the memories or the "castles in Spain," give us the necessity of making some decision, great or small, where contending motives are pulling us now in this direction, now in that, so that the question finally has to be settled by a supreme effort summed up in the words, I will. This is the struggle of the will which each one knows for himself; for who has not had a raging battle of motives occupy the center of the field while all else, even the sense of time, place and existence, gave way in the face of this conflict! This struggle continues until the decision is made, when suddenly all the stress and strain drop out and other objects may again have place in consciousness.

THE THREE FUNDAMENTAL PHASES OF CONSCIOUSNESS.—Thus we see that if we could cut the stream of consciousness across as we might cut a stream of water from bank to bank with a huge knife, and then look at the cut-off section, we should find very different constituents in the stream at different times. We should at one time find the mind manifesting itself in perceiving, remembering, imagining, discriminating, comparing, judging, reasoning, or the acts by which we gain our knowledge; at another in fearing, loving, hating, sorrowing, enjoying, or the acts of feeling; at still another in choosing, or the act of the will. These processes would make up the stream, or, in other words, these are the acts which the mind performs in doing its work. We should never find a time when the stream consists of but one of the processes, or when all these modes of mental activity are not represented. They will be found in varying proportions, now more of knowing, now of feeling, and now of willing, but some of each is always present in our consciousness. The nature of these different elements in our mental stream, their relation to each other, and the manner in which they all work together in amazing perplexity yet in perfect harmony to produce the wonderful mind, will constitute the subject-matter we shall consider together in the pages which follow.

4. WHERE CONSCIOUSNESS RESIDES

I—the conscious self—dwell somewhere in this body, but where? When my finger tips touch the object I wish to examine, I seem to be in them. When the brain grows weary from overstudy, I seem to be in it. When the heart throbs, the breath comes quick, and the muscles grow tense from noble resolve or strong emotion, I seem to be in them all. When, filled with the buoyant life of vigorous youth, every fiber and nerve is a-tingle with health and enthusiasm, I live in every part of my marvelous body. Small wonder that the ancients located the soul at one time in the heart, at another in the pineal gland of the brain, and at another made it coextensive with the body!

CONSCIOUSNESS WORKS THROUGH THE NERVOUS SYSTEM.—Later science has taught that the mind resides in and works through the nervous system, which has its central office in the brain. And the reason why I seem to be in every part of my body is because the nervous system extends to every part, carrying messages of sight or sound or touch to the brain, and bearing in return orders for movements, which set the feet a-dancing or the fingers a-tingling. But more of this later.

This partnership between mind and body is very close. Just how it happens that spirit may inhabit matter we may not know. But certain it is that they interact on each other. What will hinder the growth of one will handicap the other, and what favors the development of either will help both. The methods of their cooeperation and the laws that govern their relationship will develop as our study goes on.

5. PROBLEMS IN OBSERVATION AND INTROSPECTION

One should always keep in mind that psychology is essentially a laboratory science, and not a text-book subject. The laboratory material is to be found in ourselves and in those about us. While the text should be thoroughly mastered, its statements should always be verified by reference to one's own experience, and observation of others. Especially should prospective teachers constantly correlate the lessons of the book with the observation of children at work in the school. The problems suggested for observation and introspection will, if mastered, do much to render practical and helpful the truths of psychology.

1. Think of your home as you last left it. Can you see vividly just how it looked, the color of the paint on the outside, with the familiar form of the roof and all; can you recall the perfume in some old drawer, the taste of a favorite dish, the sound of a familiar voice in farewell?

2. What illustrations have you observed where the mental content of the moment seemed chiefly thinking (knowledge process); chiefly emotion (feeling process); chiefly choosing, or self-compulsion (willing process)?

3. When you say that you remember a circumstance that occurred yesterday, how do you remember it? That is, do you see in your mind things just as they were, and hear again sounds which occurred, or feel again movements which you performed? Do you experience once more the emotions you then felt?

4. What forms of expression most commonly reveal thought; what reveal emotions? (i.e., can you tell what a child is thinking about by the expression on his face? Can you tell whether he is angry, frightened, sorry, by his face? Is speech as necessary in expressing feeling as in expressing thought?)

5. Try occasionally during the next twenty-four hours to turn quickly about mentally and see whether you can observe your thinking, feeling, or willing in the very act of taking place.

6. What becomes of our mind or consciousness while we are asleep? How are we able to wake up at a certain hour previously determined? Can a person have absolutely nothing in his mind?

7. Have you noticed any children especially adept in expression? Have you noticed any very backward? If so, in what form of expression in each case?

8. Have you observed any instances of expression which you were at a loss to interpret (remember that "expression" includes every form of physical action, voice, speech, face, form, hand, etc.)?



CHAPTER II

ATTENTION

How do you rank in mental ability, and how effective are your mind's grasp and power? The answer that must be given to these questions will depend not more on your native endowment than on your skill in using attention.

1. NATURE OF ATTENTION

It is by attention that we gather and mass our mental energy upon the critical and important points in our thinking. In the last chapter we saw that consciousness is not distributed evenly over the whole field, but "piled up," now on this object of thought, now on that, in obedience to interest or necessity. The concentration of the mind's energy on one object of thought is attention.

THE NATURE OF ATTENTION.—Everyone knows what it is to attend. The story so fascinating that we cannot leave it, the critical points in a game, the interesting sermon or lecture, the sparkling conversation—all these compel our attention. So completely is our mind's energy centered on them and withdrawn from other things that we are scarcely aware of what is going on about us.

We are also familiar with another kind of attention. For we all have read the dull story, watched the slow game, listened to the lecture or sermon that drags, and taken part in conversation that was a bore. We gave these things our attention, but only with effort. Our mind's energy seemed to center on anything rather than the matter in hand. A thousand objects from outside enticed us away, and it required the frequent "mental jerk" to bring us to the subject in hand. And when brought back to our thought problem we felt the constant "tug" of mind to be free again.

NORMAL CONSCIOUSNESS ALWAYS IN A STATE OF ATTENTION.—But this very effort of the mind to free itself from one object of thought that it may busy itself with another is because attention is solicited by this other. Some object in our field of consciousness is always exerting an appeal for attention; and to attend to one thing is always to attend away from a multitude of other things upon which the thought might rest. We may therefore say that attention is constantly selecting in our stream of thought those aspects that are to receive emphasis and consideration. From moment to moment it determines the points at which our mental energy shall be centered.

2. THE EFFECTS OF ATTENTION

ATTENTION MAKES ITS OBJECT CLEAR AND DEFINITE.—Whatever attention centers upon stands out sharp and clear in consciousness. Whether it be a bit of memory, an "air-castle," a sensation from an aching tooth, the reasoning on an algebraic formula, a choice which we are making, the setting of an emotion—whatever be the object to which we are attending, that object is illumined and made to stand out from its fellows as the one prominent thing in the mind's eye while the attention rests on it. It is like the one building which the searchlight picks out among a city full of buildings and lights up, while the remainder are left in the semilight or in darkness.

ATTENTION MEASURES MENTAL EFFICIENCY.—In a state of attention the mind may be likened to the rays of the sun which have been passed through a burning glass. You may let all the rays which can pass through your window pane fall hour after hour upon the paper lying on your desk, and no marked effects follow. But let the same amount of sunlight be passed through a lens and converged to a point the size of your pencil point, and the paper will at once burst into flame. What the diffused rays could not do in hours or in ages is now accomplished in seconds. Likewise the mind, allowed to scatter over many objects, can accomplish but little. We may sit and dream away an hour or a day over a page or a problem without securing results. But let us call in our wits from their wool-gathering and "buckle down to it" with all our might, withdrawing our thoughts from everything else but this one thing, and concentrating our mind on it. More can now be accomplished in minutes than before in hours. Nay, things which could not be accomplished at all before now become possible.

Again, the mind may be compared to a steam engine which is constructed to run at a certain pressure of steam, say one hundred and fifty pounds to the square inch of boiler surface. Once I ran such an engine; and well I remember a morning during my early apprenticeship when the foreman called for power to run some of the lighter machinery, while my steam gauge registered but seventy-five pounds. "Surely," I thought, "if one hundred and fifty pounds will run all this machinery, seventy-five pounds should run half of it," so I opened the valve. But the powerful engine could do but little more than turn its own wheels, and refused to do the required work. Not until the pressure had risen above one hundred pounds could the engine perform half the work which it could at one hundred and fifty pounds. And so with our mind. If it is meant to do its best work under a certain degree of concentration, it cannot in a given time do half the work with half the attention. Further, there will be much which it cannot do at all unless working under full pressure. We shall not be overstating the case if we say that as attention increases in arithmetical ratio, mental efficiency increases in geometrical ratio. It is in large measure a difference in the power of attention which makes one man a master in thought and achievement and another his humble follower. One often hears it said that "genius is but the power of sustained attention," and this statement possesses a large element of truth.

3. HOW WE ATTEND

Someone has said that if our attention is properly trained we should be able "to look at the point of a cambric needle for half an hour without winking." But this is a false idea of attention. The ability to look at the point of a cambric needle for half an hour might indicate a very laudable power of concentration; but the process, instead of enlightening us concerning the point of the needle, would result in our passing into a hypnotic state. Voluntary attention to any one object can be sustained for but a brief time—a few seconds at best. It is essential that the object change, that we turn it over and over incessantly, and consider its various aspects and relations. Sustained voluntary attention is thus a repetition of successive efforts to bring back the object to the mind. Then the subject grows and develops—it is living, not dead.

ATTENTION A RELATING ACTIVITY.—When we are attending strongly to one object of thought it does not mean that consciousness sits staring vacantly at this one object, but rather that it uses it as a central core of thought, and thinks into relation with this object the things which belong with it. In working out some mathematical solution the central core is the principle upon which the solution is based, and concentration in this case consists in thinking the various conditions of the problem in relation to this underlying principle. In the accompanying diagram (Fig. 4) let A be the central core of some object of thought, say a patch of cloud in a picture, and let a, b, c, d, etc., be the related facts, or the shape, size, color, etc., of the cloud. The arrows indicate the passing of our thought from cloud to related fact, or from related fact to cloud, and from related fact to related fact. As long as these related facts lead back to the cloud each time, that long we are attending to the cloud and thinking about it. It is when our thought fails to go back that we "wander" in our attention. Then we leave a, b, c, d, etc., which are related to the cloud, and, flying off to x, y, and z, finally bring up heaven knows where.



THE RHYTHMS OF ATTENTION.—Attention works in rhythms. This is to say that it never maintains a constant level of concentration for any considerable length of time, but regularly ebbs and flows. The explanation of this rhythmic action would take us too far afield at this point. When we remember, however, that our entire organism works within a great system of rhythms—hunger, thirst, sleep, fatigue, and many others—it is easy to see that the same law may apply to attention. The rhythms of attention vary greatly, the fluctuations often being only a few seconds apart for certain simple sensations, and probably a much greater distance apart for the more complex process of thinking. The seeming variation in the sound of a distant waterfall, now loud and now faint, is caused by the rhythm of attention and easily allows us to measure the rhythm for this particular sensation.

4. POINTS OF FAILURE IN ATTENTION

LACK OF CONCENTRATION.—There are two chief types of inattention whose danger threatens every person. First, we may be thinking about the right things, but not thinking hard enough. We lack mental pressure. Outside thoughts which have no relation to the subject in hand may not trouble us much, but we do not attack our problem with vim. The current in our stream of consciousness is moving too slowly. We do not gather up all our mental forces and mass them on the subject before us in a way that means victory. Our thoughts may be sufficiently focused, but they fail to "set fire." It is like focusing the sun's rays while an eclipse is on. They lack energy. They will not kindle the paper after they have passed through the lens. This kind of attention means mental dawdling. It means inefficiency. For the individual it means defeat in life's battles; for the nation it means mediocrity and stagnation.

A college professor said to his faithful but poorly prepared class, "Judging from your worn and tired appearance, young people, you are putting in twice too many hours on study." At this commendation the class brightened up visibly. "But," he continued, "judging from your preparation, you do not study quite half hard enough."

Happy is the student who, starting in on his lesson rested and fresh, can study with such concentration that an hour of steady application will leave him mentally exhausted and limp. That is one hour of triumph for him, no matter what else he may have accomplished or failed to accomplish during the time. He can afford an occasional pause for rest, for difficulties will melt rapidly away before him. He possesses one key to successful achievement.

MENTAL WANDERING.—Second, we may have good mental power and be able to think hard and efficiently on any one point, but lack the power to think in a straight line. Every stray thought that comes along is a "will-o'-the-wisp" to lead us away from the subject in hand and into lines of thought not relating to it. Who has not started in to think on some problem, and, after a few moments, been surprised to find himself miles away from the topic upon which he started! Or who has not read down a page and, turning to the next, found that he did not know a word on the preceding page, his thoughts having wandered away, his eyes only going through the process of reading! Instead of sticking to the a, b, c, d, etc., of our topic and relating them all up to A, thereby reaching a solution of the problem, we often jump at once to x, y, z, and find ourselves far afield with all possibility of a solution gone. We may have brilliant thoughts about x, y, z, but they are not related to anything in particular, and so they pass from us and are gone—lost in oblivion because they are not attached to something permanent.

Such a thinker is at the mercy of circumstances, following blindly the leadings of trains of thought which are his master instead of his servant, and which lead him anywhere or nowhere without let or hindrance from him. His consciousness moves rapidly enough and with enough force, but it is like a ship without a helm. Starting for the intellectual port A by way of a, b, c, d, he is mentally shipwrecked at last on the rocks x, y, z, and never reaches harbor. Fortunate is he who can shut out intruding thoughts and think in a straight line. Even with mediocre ability he may accomplish more by his thinking than the brilliant thinker who is constantly having his mental train wrecked by stray thoughts which slip in on his right of way.

5. TYPES OF ATTENTION

THE THREE TYPES OF ATTENTION.—Attention may be secured in three ways: (1) It is demanded by some sudden or intense sensory stimulus or insistent idea, or (2) it follows interest, or (3) it is compelled by the will. If it comes in the first way, as from a thunderclap or a flash of light, or from the persistent attempt of some unsought idea to secure entrance into the mind, it is called involuntary attention. This form of attention is of so little importance, comparatively, in our mental life that we shall not discuss it further.

If attention comes in the second way, following interest, it is called nonvoluntary or spontaneous attention; if in the third, compelled by the will, voluntary or active attention. Nonvoluntary attention has its motive in some object external to consciousness, or else follows a more or less uncontrolled current of thought which interests us; voluntary attention is controlled from within—we decide what we shall attend to instead of letting interesting objects of thought determine it for us.

INTEREST AND NONVOLUNTARY ATTENTION.—In nonvoluntary attention the environment largely determines what we shall attend to. All that we have to do with directing this kind of attention is in developing certain lines of interest, and then the interesting things attract attention. The things we see and hear and touch and taste and smell, the things we like, the things we do and hope to do—these are the determining factors in our mental life so long as we are giving nonvoluntary attention. Our attention follows the beckoning of these things as the needle the magnet. It is no effort to attend to them, but rather the effort would be to keep from attending to them. Who does not remember reading a story, perhaps a forbidden one, so interesting that when mother called up the stairs for us to come down to attend to some duty, we replied, "Yes, in a minute," and then went on reading! We simply could not stop at that place. The minute lengthens into ten, and another call startles us. "Yes, I'm coming;" we turn just one more leaf, and are lost again. At last comes a third call in tones so imperative that it cannot be longer ignored, and we lay the book down, but open to the place where we left off, and where we hope soon to begin further to unravel the delightful mystery. Was it an effort to attend to the reading? Ah, no! it took the combined force of our will and of mother's authority to drag the attention away. This is nonvoluntary attention.

Left to itself, then, attention simply obeys natural laws and follows the line of least resistance. By far the larger portion of our attention is of this type. Thought often runs on hour after hour when we are not conscious of effort or struggle to compel us to cease thinking about this thing and begin thinking about that. Indeed, it may be doubted whether this is not the case with some persons for days at a time, instead of hours. The things that present themselves to the mind are the things which occupy it; the character of the thought is determined by the character of our interests. It is this fact which makes it vitally necessary that our interests shall be broad and pure if our thoughts are to be of this type. It is not enough that we have the strength to drive from our minds a wrong or impure thought which seeks entrance. To stand guard as a policeman over our thoughts to see that no unworthy one enters, requires too much time and energy. Our interests must be of such a nature as to lead us away from the field of unworthy thoughts if we are to be free from their tyranny.

THE WILL AND VOLUNTARY ATTENTION.—In voluntary attention there is a conflict either between the will and interest or between the will and the mental inertia or laziness, which has to be overcome before we can think with any degree of concentration. Interest says, "Follow this line, which is easy and attractive, or which requires but little effort—follow the line of least resistance." Will says, "Quit that line of dalliance and ease, and take this harder way which I direct—cease the line of least resistance and take the one of greatest resistance." When day dreams and "castles in Spain" attempt to lure you from your lessons, refuse to follow; shut out these vagabond thoughts and stick to your task. When intellectual inertia deadens your thought and clogs your mental stream, throw it off and court forceful effort. If wrong or impure thoughts seek entrance to your mind, close and lock your mental doors to them. If thoughts of desire try to drive out thoughts of duty, be heroic and insist that thoughts of duty shall have right of way. In short, see that you are the master of your thinking, and do not let it always be directed without your consent by influences outside of yourself.

It is just at this point that the strong will wins victory and the weak will breaks down. Between the ability to control one's thoughts and the inability to control them lies all the difference between right actions and wrong actions; between withstanding temptation and yielding to it; between an inefficient purposeless life and a life of purpose and endeavor; between success and failure. For we act in accordance with those things which our thought rests upon. Suppose two lines of thought represented by A and B, respectively, lie before you; that A leads to a course of action difficult or unpleasant, but necessary to success or duty, and that B leads to a course of action easy or pleasant, but fatal to success or duty. Which course will you follow—the rugged path of duty or the easier one of pleasure? The answer depends almost wholly, if not entirely, on your power of attention. If your will is strong enough to pull your thoughts away from the fatal but attractive B and hold them resolutely on the less attractive A, then A will dictate your course of action, and you will respond to the call for endeavor, self-denial, and duty; but if your thoughts break away from the domination of your will and allow the beckoning of your interests alone, then B will dictate your course of action, and you will follow the leading of ease and pleasure. For our actions are finally and irrevocably dictated by the things we think about.

NOT REALLY DIFFERENT KINDS OF ATTENTION.—It is not to be understood, however, from what has been said, that there are really different kinds of attention. All attention denotes an active or dynamic phase of consciousness. The difference is rather in the way we secure attention; whether it is demanded by sudden stimulus, coaxed from us by interesting objects of thought without effort on our part, or compelled by force of will to desert the more interesting and take the direction which we dictate.

6. IMPROVING THE POWER OF ATTENTION

While attention is no doubt partly a natural gift, yet there is probably no power of the mind more susceptible to training than is attention. And with attention, as with every other power of body and mind, the secret of its development lies in its use. Stated briefly, the only way to train attention is by attending. No amount of theorizing or resolving can take the place of practice in the actual process of attending.

MAKING DIFFERENT KINDS OF ATTENTION REENFORCE EACH OTHER.—A very close relationship and interdependence exists between nonvoluntary and voluntary attention. It would be impossible to hold our attention by sheer force of will on objects which were forever devoid of interest; likewise the blind following of our interests and desires would finally lead to shipwreck in all our lives. Each kind of attention must support and reenforce the other. The lessons, the sermons, the lectures, and the books in which we are most interested, and hence to which we attend nonvoluntarily and with the least effort and fatigue, are the ones out of which, other things being equal, we get the most and remember the best and longest. On the other hand, there are sometimes lessons and lectures and books, and many things besides, which are not intensely interesting, but which should be attended to nevertheless. It is at this point that the will must step in and take command. If it has not the strength to do this, it is in so far a weak will, and steps should be taken to develop it. We are to "keep the faculty of effort alive in us by a little gratuitous exercise every day." We are to be systematically heroic in the little points of everyday life and experience. We are not to shrink from tasks because they are difficult or unpleasant. Then, when the test comes, we shall not find ourselves unnerved and untrained, but shall be able to stand in the evil day.

THE HABIT OF ATTENTION.—Finally, one of the chief things in training the attention is to form the habit of attending. This habit is to be formed only by attending whenever and wherever the proper thing to do is to attend, whether "in work, in play, in making fishing flies, in preparing for an examination, in courting a sweetheart, in reading a book." The lesson, or the sermon, or the lecture, may not be very interesting; but if they are to be attended to at all, our rule should be to attend to them completely and absolutely. Not by fits and starts, now drifting away and now jerking ourselves back, but all the time. And, furthermore, the one who will deliberately do this will often find the dull and uninteresting task become more interesting; but if it never becomes interesting, he is at least forming a habit which will be invaluable to him through life. On the other hand, the one who fails to attend except when his interest is captured, who never exerts effort to compel attention, is forming a habit which will be the bane of his thinking until his stream of thought shall end.

7. PROBLEMS IN OBSERVATION AND INTROSPECTION

1. Which fatigues you more, to give attention of the nonvoluntary type, or the voluntary? Which can you maintain longer? Which is the more pleasant and agreeable to give? Under which can you accomplish more? What bearing have these facts on teaching?

2. Try to follow for one or two minutes the "wave" in your consciousness, and then describe the course taken by your attention.

3. Have you observed one class alert in attention, and another lifeless and inattentive? Can you explain the causes lying back of this difference? Estimate the relative amount of work accomplished under the two conditions.

4. What distractions have you observed in the schoolroom tending to break up attention?

5. Have you seen pupils inattentive from lack of (1) change, (2) pure air, (3) enthusiasm on the part of the teacher, (4) fatigue, (5) ill health?

6. Have you noticed a difference in the habit of attention in different pupils? Have you noticed the same thing for whole schools or rooms?

7. Do you know of children too much given to daydreaming? Are you?

8. Have you seen a teacher rap the desk for attention? What type of attention was secured? Does it pay?

9. Have you observed any instance in which pupils' lack of attention should be blamed on the teacher? If so, what was the fault? The remedy?

10. Visit a school room or a recitation, and then write an account of the types and degrees of attention you observed. Try to explain the factors responsible for any failures in attention, and also those responsible for the good attention shown.



CHAPTER III

THE BRAIN AND NERVOUS SYSTEM

A fine brain, or a good mind. These terms are often used interchangeably, as if they stood for the same thing. Yet the brain is material substance—so many cells and fibers, a pulpy protoplasmic mass weighing some three pounds and shut away from the outside world in a casket of bone. The mind is a spiritual thing—the sum of the processes by which we think and feel and will, mastering our world and accomplishing our destiny.

1. THE RELATIONS OF MIND AND BRAIN

INTERACTION OF MIND AND BRAIN.—How, then, come these two widely different facts, mind and brain, to be so related in our speech? Why are the terms so commonly interchanged?—It is because mind and brain are so vitally related in their processes and so inseparably connected in their work. No movement of our thought, no bit of sensation, no memory, no feeling, no act of decision but is accompanied by its own particular activity in the cells of the brain. It is this that the psychologist has in mind when he says, no psychosis without its corresponding neurosis.

So far as our present existence is concerned, then, no mind ever works except through some brain, and a brain without a mind becomes but a mass of dead matter, so much clay. Mind and brain are perfectly adapted to each other. Nor is this mere accident. For through the ages of man's past history each has grown up and developed into its present state of efficiency by working in conjunction with the other. Each has helped form the other and determine its qualities. Not only is this true for the race in its evolution, but for every individual as he passes from infancy to maturity.

THE BRAIN AS THE MIND'S MACHINE.—In the first chapter we saw that the brain does not create the mind, but that the mind works through the brain. No one can believe that the brain secretes mind as the liver secretes bile, or that it grinds it out as a mill does flour. Indeed, just what their exact relation is has not yet been settled. Yet it is easy to see that if the mind must use the brain as a machine and work through it, then the mind must be subject to the limitations of its machine, or, in other words, the mind cannot be better than the brain through which it operates. A brain and nervous system that are poorly developed or insufficiently nourished mean low grade of efficiency in our mental processes, just as a poorly constructed or wrongly adjusted motor means loss of power in applying the electric current to its work. We will, then, look upon the mind and the brain as counterparts of each other, each performing activities which correspond to activities in the other, both inextricably bound together at least so far as this life is concerned, and each getting its significance by its union with the other. This view will lend interest to a brief study of the brain and nervous system.

2. THE MIND'S DEPENDENCE ON THE EXTERNAL WORLD

But can we first see how in a general way the brain and nervous system are primarily related to our thinking? Let us go back to the beginning and consider the babe when it first opens its eyes on the scenes of its new existence. What is in its mind? What does it think about? Nothing. Imagine, if you can, a person born blind and deaf, and without the sense of touch, taste, or smell. Let such a person live on for a year, for five years, for a lifetime. What would he know? What ray of intelligence would enter his mind? What would he think about? All would be dark to his eyes, all silent to his ears, all tasteless to his mouth, all odorless to his nostrils, all touchless to his skin. His mind would be a blank. He would have no mind. He could not get started to think. He could not get started to act. He would belong to a lower scale of life than the tiny animal that floats with the waves and the tide in the ocean without power to direct its own course. He would be but an inert mass of flesh without sense or intelligence.

THE MIND AT BIRTH.—Yet this is the condition of the babe at birth. It is born practically blind and deaf, without definite sense of taste or smell. Born without anything to think about, and no way to get anything to think about until the senses wake up and furnish some material from the outside world. Born with all the mechanism of muscle and nerve ready to perform the countless complex movements of arms and legs and body which characterize every child, he could not successfully start these activities without a message from the senses to set them going. At birth the child probably has only the senses of contact and temperature present with any degree of clearness; taste soon follows; vision of an imperfect sort in a few days; hearing about the same time, and smell a little later. The senses are waking up and beginning their acquaintance with the outside world.



THE WORK OF THE SENSES.—And what a problem the senses have to solve! On the one hand the great universe of sights and sounds, of tastes and smells, of contacts and temperatures, and whatever else may belong to the material world in which we live; and on the other hand the little shapeless mass of gray and white pulpy matter called the brain, incapable of sustaining its own shape, shut away in the darkness of a bony case with no possibility of contact with the outside world, and possessing no means of communicating with it except through the senses. And yet this universe of external things must be brought into communication with the seemingly insignificant but really wonderful brain, else the mind could never be. Here we discover, then, the two great factors which first require our study if we would understand the growth of the mind—the material world without, and the brain within. For it is the action and interaction of these which lie at the bottom of the mind's development. Let us first look a little more closely at the brain and the accompanying nervous system.

3. STRUCTURAL ELEMENTS OF THE NERVOUS SYSTEM

It will help in understanding both the structure and the working of the nervous system to keep in mind that it contains but one fundamental unit of structure. This is the neurone. Just as the house is built up by adding brick upon brick, so brain, cord, nerves and organs of sense are formed by the union of numberless neurones.



THE NEURONE.—What, then, is a neurone? What is its structure, its function, how does it act? A neurone is a protoplasmic cell, with its outgrowing fibers. The cell part of the neurone is of a variety of shapes, triangular, pyramidal, cylindrical, and irregular. The cells vary in size from 1/250 to 1/3500 of an inch in diameter. In general the function of the cell is thought to be to generate the nervous energy responsible for our consciousness—sensation, memory, reasoning, feeling and all the rest, and for our movements. The cell also provides for the nutrition of the fibers.



NEURONE FIBERS.—The neurone fibers are of two kinds, dendrites and axons. The dendrites are comparatively large in diameter, branch freely, like the branches of a tree, and extend but a relatively short distance from the parent cell. Axons are slender, and branch but little, and then approximately at right angles. They reach a much greater distance from the cell body than the dendrites. Neurones vary greatly in length. Some of those found in the spinal cord and brain are not more than 1/12 of an inch long, while others which reach from the extremities to the cord, measure several feet. Both dendrites and axons are of diameter so small as to be invisible except under the microscope.

NEUROGLIA.—Out of this simple structural element, the neurone, the entire nervous system is built. True, the neurones are held in place, and perhaps insulated, by a kind of soft cement called neuroglia. But this seems to possess no strictly nervous function. The number of the microscopic neurones required to make up the mass of the brain, cord and peripheral nervous system is far beyond our mental grasp. It is computed that the brain and cord contain some 3,000 millions of them.

COMPLEXITY OF THE BRAIN.—Something of the complexity of the brain structure can best be understood by an illustration. Professor Stratton estimates that if we were to make a model of the human brain, using for the neurone fibers wires so small as to be barely visible to the eye, in order to find room for all the wires the model would need to be the size of a city block on the base and correspondingly high. Imagine a telephone system of this complexity operating from one switch-board!

"GRAY" AND "WHITE" MATTER.—The "gray matter" of the brain and cord is made up of nerve cells and their dendrites, and the terminations of axons, which enter from the adjoining white matter. A part of the mass of gray matter also consists of the neuroglia which surrounds the nerve cells and fibers, and a network of blood vessels. The "white matter" of the central system consists chiefly of axons with their enveloping or medullary, sheath and neuroglia. The white matter contains no nerve cells or dendrites. The difference in color of the gray and the white matter is caused chiefly by the fact that in the gray masses the medullary sheath, which is white, is lacking, thus revealing the ashen gray of the nerve threads. In the white masses the medullary sheath is present.

4. GROSS STRUCTURE OF THE NERVOUS SYSTEM

DIVISIONS OF THE NERVOUS SYSTEM.—The nervous system may be considered in two divisions: (1) The central system, which consists of the brain and spinal cord, and (2) the peripheral system, which comprises the sensory and motor neurones connecting the periphery and the internal organs with the central system and the specialized end-organs of the senses. The sympathetic system, which is found as a double chain of nerve connections joining the roots of sensory and motor nerves just outside the spinal column, does not seem to be directly related to consciousness and so will not be discussed here. A brief description of the nervous system will help us better to understand how its parts all work together in so wonderful a way to accomplish their great result.

THE CENTRAL SYSTEM.—In the brain we easily distinguish three major divisions—the cerebrum, the cerebellum and the medulla oblongata. The medulla is but the enlarged upper part of the cord where it connects with the brain. It is about an inch and a quarter long, and is composed of both medullated and unmedullated fibers—that is of both "white" and "gray" matter. In the medulla, the unmedullated neurones which comprise the center of the cord are passing to the outside, and the medullated to the inside, thus taking the positions they occupy in the cerebrum. Here also the neurones are crossing, or changing sides, so that those which pass up the right side of the cord finally connect with the left side of the brain, and vice versa.

THE CEREBELLUM.—Lying just back of the medulla and at the rear part of the base of the cerebrum is the cerebellum, or "little brain," approximately as large as the fist, and composed of a complex arrangement of white and gray matter. Fibers from the spinal cord enter this mass, and others emerge and pass on into the cerebrum, while its two halves also are connected with each other by means of cross fibers.



THE CEREBRUM.—The cerebrum occupies all the upper part of the skull from the front to the rear. It is divided symmetrically into two hemispheres, the right and the left. These hemispheres are connected with each other by a small bridge of fibers called the corpus callosum. Each hemisphere is furrowed and ridged with convolutions, an arrangement which allows greater surface for the distribution of the gray cellular matter over it. Besides these irregularities of surface, each hemisphere is marked also by two deep clefts or fissures—the fissure of Rolando, extending from the middle upper part of the hemisphere downward and forward, passing a little in front of the ear and stopping on a level with the upper part of it; and the fissure of Sylvius, beginning at the base of the brain somewhat in front of the ear and extending upward and backward at an acute angle with the base of the hemisphere.



The surface of each hemisphere may be thought of as mapped out into four lobes: The frontal lobe, which includes the front part of the hemisphere and extends back to the fissure of Rolando and down to the fissure of Sylvius; the parietal lobe, which lies back of the fissure of Rolando and above that of Sylvius and extends back to the occipital lobe; the occipital lobe, which includes the extreme rear portion of the hemisphere; and the temporal lobe, which lies below the fissure of Sylvius and extends back to the occipital lobe.

THE CORTEX.—The gray matter of the hemispheres, unlike that of the cord, lies on the surface. This gray exterior portion of the cerebrum is called the cortex, and varies from one-twelfth to one-eighth of an inch in thickness. The cortex is the seat of all consciousness and of the control of voluntary movement.



THE SPINAL CORD.—The spinal cord proceeds from the base of the brain downward about eighteen inches through a canal provided for it in the vertebrae of the spinal column. It is composed of white matter on the outside, and gray matter within. A deep fissure on the anterior side and another on the posterior cleave the cord nearly in twain, resembling the brain in this particular. The gray matter on the interior is in the form of two crescents connected by a narrow bar.

The peripheral nervous system consists of thirty-one pairs of nerves, with their end-organs, branching off from the cord, and twelve pairs that have their roots in the brain. Branches of these forty-three pairs of nerves reach to every part of the periphery of the body and to all the internal organs.



It will help in understanding the peripheral system to remember that a nerve consists of a bundle of neurone fibers each wrapped in its medullary sheath and sheath of Schwann. Around this bundle of neurones, that is around the nerve, is still another wrapping, silvery-white, called the neurilemma. The number of fibers going to make up a nerve varies from about 5,000 to 100,000. Nerves can easily be identified in a piece of lean beef, or even at the edge of a serious gash in one's own flesh!

Bundles of sensory fibers constituting a sensory nerve root enter the spinal cord on the posterior side through holes in the vertebrae. Similar bundles of motor fibers in the form of a motor nerve root emerge from the cord at the same level. Soon after their emergence from the cord, these two nerves are wrapped together in the same sheath and proceed in this way to the periphery of the body, where the sensory nerve usually ends in a specialized end-organ fitted to respond to some certain stimulus from the outside world. The motor nerve ends in minute filaments in the muscular organ which it governs. Both sensory and motor nerves connect with fibers of like kind in the cord and these in turn with the cortex, thus giving every part of the periphery direct connection with the cortex.



The end-organs of the sensory nerves are nerve masses, some of them, as the taste buds of the tongue, relatively simple; and others, as the eye or ear, very complex. They are all alike in one particular; namely, that each is fitted for its own particular work and can do no other. Thus the eye is the end-organ of sight, and is a wonderfully complex arrangement of nerve structure combined with refracting media, and arranged to respond to the rapid ether waves of light. The ear has for its essential part the specialized endings of the auditory nerve, and is fitted to respond to the waves carried to it in the air, giving the sensation of sound. The end-organs of touch, found in greatest perfection in the finger tips, are of several kinds, all very complicated in structure. And so on with each of the senses. Each particular sense has some form of end-organ specially adapted to respond to the kind of stimulus upon which its sensation depends, and each is insensible to the stimuli of the others, much as the receiver of a telephone will respond to the tones of our voice, but not to the touch of our fingers as will the telegraph instrument, and vice versa. Thus the eye is not affected by sounds, nor touch by light. Yet by means of all the senses together we are able to come in contact with the material world in a variety of ways.

5. LOCALIZATION OF FUNCTION IN THE NERVOUS SYSTEM

DIVISION OF LABOR.—Division of labor is the law in the organic world as in the industrial. Animals of the lowest type, such as the amoeba, do not have separate organs for respiration, digestion, assimilation, elimination, etc., the one tissue performing all of these functions. But in the higher forms each organ not only has its own specific work, but even within the same organ each part has its own particular function assigned. Thus we have seen that the two parts of the neurone probably perform different functions, the cells generating energy and the fibers transmitting it.

It will not seem strange, then, that there is also a division of labor in the cellular matter itself in the nervous system. For example, the little masses of ganglia which are distributed at intervals along the nerves are probably for the purpose of reenforcing the nerve current, much as the battery cells in the local telegraph office reenforce the current from the central office. The cellular matter in the spinal cord and lower parts of the brain has a very important work to perform in receiving messages from the senses and responding to them in directing the simpler reflex acts and movements which we learn to execute without our consciousness being called upon, thus leaving the mind free from these petty things to busy itself in higher ways. The cellular matter of the cortex performs the highest functions of all, for through its activity we have consciousness.



The gray matter of the cerebellum, the medulla, and the cord may receive impressions from the senses and respond to them with movements, but their response is in all cases wholly automatic and unconscious. A person whose hemispheres had been injured in such a way as to interfere with the activity of the cortex might still continue to perform most if not all of the habitual movements of his life, but they would be mechanical and not intelligent. He would lack all higher consciousness. It is through the activity of this thin covering of cellular matter of the cerebrum, the cortex, that our minds operate; here are received stimuli from the different senses, and here sensations are experienced. Here all our movements which are consciously directed have their origin. And here all our thinking, feeling, and willing are done.

DIVISION OF LABOR IN THE CORTEX.—Nor does the division of labor in the nervous system end with this assignment of work. The cortex itself probably works essentially as a unit, yet it is through a shifting of tensions from one area to another that it acts, now giving us a sensation, now directing a movement, and now thinking a thought or feeling an emotion. Localization of function is the rule here also. Certain areas of the cortex are devoted chiefly to sensations, others to motor impulses, and others to higher thought activities, yet in such a way that all work together in perfect harmony, each reenforcing the other and making its work significant. Thus the front portion of the cortex seems to be devoted to the higher thought activities; the region on both sides of the fissure of Rolando, to motor activities; and the rear and lower parts to sensory activities; and all are bound together and made to work together by the association fibers of the brain.

1  2  3  4  5  6     Next Part
Home - Random Browse