Studies in psychology

Preface

These studies in psychology are intended primarily for use in the author's own classes. As the title implies they are in no sense complete. Every teacher of psychology has doubtless felt the need of having some of the essential truths of psychology presented in a teachable form. It is the hope of supplying this need in the writer's own classes that prompts to the present little volume.

A second thought is to give students a general idea of the organization of psychology, and a comprehension of its organizing principle to the end that an intensive study of any particular aspect of the subject may be seen in its proper relation to the science as a whole.

An attempt has been made to analyze knowing into its stages of development in order to reveal the function of analysis and synthesis in the organization of the various truths which make up the subject of psychology.

G. W. N.

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Contents

Chapter Page

I. Nature, Subject-Matter and Method of Psychology 11

II. Units of Investigation . ^ 24

CHAPTER I. Nature, Subject-Matter and Method of Psychology

The Meaning of Science. — Every one who has lived very long among people has some knowledge of plant life, of animal life and of the mind. This knowledge he has picked up here and there by experience; by his own experience and by hearsay from others. An examination of this knowledge shows that it exists in bits, scraps and fragments; that it consists of truth mixed with error; that is, it is not very accurate; and that it is not very extensive, and so not complete. Such knowledge, unsystematic, mixed with error, and incomplete is called common, or ordinary, knowledge. Knowledge which is systematic and accurate may be developed from common knowledge by experiment, observation and thinking; that is, scientific knowledge may be developed from common knowledge by experiment, observation and thinking. Such knowledge is science, and the following is the formal definition of it:

Science is systematic and accurate knowledge which results from common knowledge. It appears that science is a product of the mind. It results from the mind's activity. It is a mental thing and has no existence outside of the mind.

It is a mistake to think, for instance, that botany as a science has existed as long as plant life has existed. Botany has existed only since humanity has learned the truths of plant life, has made them into a system, accurate and more or less complete. Plant life is thus many, many years older than botany.

Science is not only the product of one mind but, as we know it, it is the product of many minds, a sort of accumulated product of the mind of humanity.

The Presupposition of Science. — Science is based upon the presupposition that the human mind acts uniformly; that is, that under the same conditions, one person's mind acts in general as other persons' minds act; also, that one person's mind acts at one time in general as it acts at other times under the same conditions. If such were not the case we would seem to live in a world of chaos in which no order of any kind could be found.

Illustration. — ^When ten persons look at snow it appears white to each one; also, if one person looks at snow ten different times, it looks white to him each time. That is to say, the mind acts uniformly to this stimulus, and only this enables us to establish the truth that snow is white. If to one it appeared white ; to a second, green ; to a third one red, and so on, or to one at one time, white ; a second time, green, a third time red, and so on, the truth that snow is white could never be established. And this would be because the mind did not act uniformly.

Mental Phenomena. — If one will turn his mind inward and notice what his own mind does, about the first thing which he will discover is that his mind changes. Now he finds his mind thinking, for instance about grammar, and at another time he finds his mind thinking about history; now, about religion, at another time, about politics ; now about music, at another time, about poetry. At one time he finds his mind happy ; at another time he finds his mind sad. The only way one can think of his mind's heing in these different conditions at different times is that his mind changes. One knows his mind changes, if he can know anything and there is nothing which one can know better than that his mind changes. Indeed, if one studies carefully enough, he will discover that there is nothing else which one can know quite so well as that his mind changes. These changes of the mind psychologists call mental phenomeria. A change is a phenomenon, and a mental change is a mental phenomenon. Other terms frequently used interchangeably with phenomenon are activity and experience. "We thus reach the following statement:

A mental phenomenon is a mental change, or activity, of any kind.

The term, phenomenon, has a first and a second meaning. The first meaning is the meaning explained above. The second meaning is the popular meaning. The popular meaning is that a phenomenon is something marvelous, startling and unusual.

Physical Phenomena. — Any physical thing is a thing which occupies space, such as wood, a book, a horse, or one's body. Or a more fundamental way of thinking of it is, a physical thing is anything which makes possible sensations of resistance; as, a stone, water, ice, iron, etc. If one observes physical things he soon discovers that they change. He can know that physical things change as well as he can know anjrthing except that his mind changes. That his mind changes he knows best of all things. It is the one thing which can not be disproved to him.

That which enables one to know that physical things change is that they are known to be in different positions and conditions at different times, and the only explanation for this is that they change.

The human body occupies space, so is a physical thing. It is observed in different conditions and positions at different times, so is known to change. These changes of the body are physical changes, or physical phenomena.

A truth of a good deal of importance in psychology about mental phenomena is that all mental phenomena are accompanied by physical phenomena. Sometimes the physical phenomena seem to precede the mental phenomena, and sometimes the mental seem to precede the physical, and sometimes they seem to be simultaneous. But, in any case, so far as is known, there is never a mental phenomenon but there is in some way connected with it a physical phenomenon. They are said to be parallel, or they are said to correspond ; that is they are corresponding mental and physical phenomena.

No one whose opinion would carry any influence among scientists would claim to know ultimately what the mind is, nor can any one study the mind directly. But no one knows ultimately what electricity is; no one knows what light is ultimately, nor what gravitation is. We do know, though, how they act or change; that is, we know their phenomena and such knowledge is very valuable to us. We need not be discouraged that we cannot know or study the mind directly, for we can study and know its phenomena and that is as much as we can study and know of anything.

The science which deals with the phenomena of the mind and the parallel, or corresponding phenomena of some part or parts of the body is psychology.

Every science deals predominantly with general truths or laws; that is, truths which are true of many cases. Psychology deals essentially with the laws of mental and physical phenomena, truths which are true of many minds. This when put in the form of a definition is as follows:

Psychology is the science which treats of the laws of mental phenomena together with their corresponding physical phenomena.

Psychology is sometimes defined as the science of the mind. While this definition is in a general way true, it is not very helpful. It does not show specifically what the subject is, and rather implies that the mind may be studied directly, which is not the case. The two objections to the definition are (1) it is too general, and (2) it is misleading.

The word, psychology, is derived from the two Greek words, psyche, meaning mind, or soul, and logos, meaning thought or knowledge. Thus literally psychology is knowledge of soul or mind.

The terms, mind, soul and spirit are used interchangeably by psychologists. Popularly there may be some distinctions in the meanings of these terms and theologians may sometimes make distinctions in their meaning, but such distinctions are not observed in psychology.

Subject-Matter of Psychology. — In the mastery of any branch of science various points of truth must be studied and learned. These truths are usually called facts. Also in mastering any science the connections, or relations, among the facts in the science must be studied and learned. That is to say, in the mastery of any science or branch of science the facts and their relations must be learned. These facts and relations constitute the subject-matter of any science or subject. And thus the following statements of subject-matter are reached:

A suhject-matter of any subject is the facts and relations to he learned in that subject.

A subject-matter is the material of study in any subject.

In the subject-matter of psychology there are in general two points to be found, as follows:

1. Mental phenomena.

2. Corresponding physical phenomena.

In physiology, physical phenomena are studied as well as in psychology. But physiology is not psychology. Not so many physical phenomena are studied in psychology as in physiology. For instance, circulation, respiration, and digestion are studied carefully in physiology, but they are hardly studied at all in psychology.

And again the physical phenomena are studied in psychology in different connections from what they are studied in, in physiology. In psychology the physical phenomena are studied in connection with mental phenomena, in so far as they affect and in turn are affected by the mental phenomena. In physiology physical phenomena are studied in relation to organic structure in the economy of the life of the individual and species.

In short in psychology we study physical phenomena in order to understand psychology; in physiology, in order to understand physiology.

The Methods of Psychology. — The question in this connection is. In what manner may the mind study psychology? That is to say, how may the mind learn, classify and explain the facts of psychology?

There are in general the four following methods of studying psychology worthy of consideration:

1. The Introspective method.

2. The Experimental method.

3. The Comparative method.

4. The Objective method.

The Introspective Method. — The introspective method is the most fundamental method of psychology and is the process of studying psychology by means of introspection. The term, introspection, comes from intro, meaning within and spicere, meaning to look. The ion in the word signifies the act of. Introspection thus is literally the act of looking within.

We learn the physical phenomena around us in the world through our senses ; through sight, hearing, touch, taste, etc. We thus learn that objects move, lightning, thunder, the fragrance of the rose and the aroma of the fruit. But we can not learn the phenomena of the mind in this way. These must be learned by having the mind to look into itself. We can turn our minds in upon themselves and have them learn their own phenomena. We can study our wishes, our hopes, our motives, our thoughts and our feelings. The process of thus looking within with the mind's eye is introspection. And thus the following formal statement for it is reached :

Introspection is the process by which the mind directly learns its own phenomena.

Introspection is also called internal perception.

Difficulties of Introspection. — There are two difficulties for the beginner in psychology in studying by the introspective method.

1. It is hard for those who have been used to studying objects learned through the senses to turn their minds to intangible, spiritual things and study them.

2. If one turns his mind upon a mental phenomenon, a thought or a feeling, to study it, it soon disappears and he has only the memory of it to study.

The things in our minds which we know through introspection are objects just as truly as the things we touch, see, hear, etc. But so accustomed do we become to thinking of only the things which we can know through our senses as objects that it is difficult at first for us to see that mental phenomena are objects, also. So since it is difficult to think of mental phenomena at all, it is of course much more difficult to observe, learn, classify and explain them accurately.

It is one thing to have the idea of a tree or the feeling of sorrow, but an entirely different thing to study it. Soon after the mind is turned in to study its ideas or feelings they disappear and only the memory of them remains to be examined. They, therefore, get away almost before one gets a good look at them.

But though the introspective method does have its two difficulties, it is entirely necessary to the study of psychology. Without introspection no one could ever be made to understand mental phenomena. No one can understand anger or pain unless he himself has been angry or in pain and he can know his own anger or pain only through introspection.

Psychology therefore must be studied by the introspective method.

The Experimental Method. — We can experiment with plants directly in the study of botany ; with animals directly in the study of zoology; with chemicals in the study of chemistry or with matter directly in the study of physics, but not with mental phenomena directly in the study of psychology. Yet there is such a thing as the experimental method of studying psychology. We can experiment with the mind indirectly by experimenting with the body, the connection between them being so close, that producing certain bodily conditions induces certain mental conditions; also, producing certain mental conditions induces certain bodily conditions. These connections of the mind with the body, that is, the mind^s connections with the nervous system, eyes, ears, muscles, etc. can be experimented with, and thus mental phenomena changed and studied.

"While experiment is only a means of increasing the accuracy of observation and introspection, it has through its wide application made possible important advances in nearly every field of psychology. To its great benefit psychology has become an experimental science. ' '

The study of the mind in connection with the body and the outside world by the experimental method gives rise to Physiological Psychology and Psychophysics.

The study of mental phenomena wholly by the introspective method gives rise to Introspective Psychology; that is, psychology so far as it can be learned through introspection.

The Comparative Method. — Psychology deals with any kind of mental phenomena, but it predominantly deals with the normal adult human mind. Help however comes to the student of psychology from comparing the phenomena of the normal adult human mind with phenomena of other minds. The phenomena of the normal adult mind may be compared with the phenomena of the minds of the following:

1. Lower animals.

2. Children in various stages of development.

3. Persons with defective or disordered minds. The study of psychology through such comparing is by the comparative method, and gives rise to Comparative Psychology, which is divided into (1) Animal Psychology; (2) Child Psychology, and (3) Abnormal Psychology.

"Those phases of psychology which touch particularly upon the phenomena of development, whether racial or individual, are spoken of as genetic psychology. ' *

The Objective Method. — The mind by its activities produces results in the outside world. These are called objective results. The student can study these objective results of the mind and learn much about it in a way similar to his learning much about electricity by studying the results it produces. These objective results are fixed, certain and definite signs to us of the way the mind works. Some of these results are said to be :

1. Language and science.

2. Institutions of civilization.

3. Artistic creations.

4. Philosophy and religion.

Studying mental phenomena by means of these objective manifestations is by the objective method.

Necessity of Introspection. — It matters not by what method we study mental phenomena we are able to understand them only by referring them to our own mental experiences and this we can do only by introspection. The student of psychology can make no progress whatever in its study without introspection. No one who had never experienced a sensation could be made to understand what a sensation is. The man who had always been blind thought scarlet must resemble the sound of a trumpet.

The introspective method of psychology is thus the most fundamental method, and introspective psychology is the most fundamental kind of psychology.

The Nature of the Mind. — The persistent question always asked the student of psychology either by himself or by some one else and never very satisfactorily answered is What is the mind? It is popular to say that this question can not be answered, discuss why it can not be answered and let it go at that. However, this question is no more unanswerable than the questions. What is electricity ? or What is matter ? And there is no help in the popular evasion from trying to answer it.

The writer has studied every reason which he has had opportunity to study in support of the contention that the mind can not be defined, and not one seems good. To the author it seems that a definition for the mind may be formed which will not violate any law of logical definition ; at any rate, not more than the generally accepted definition of a triangle or of a noun violates the laws of logical definition.

Every student who thinks soon learns that the most persistent thing in the world in which he lives is force or energy; that is, that which will do work. Force does all the work done in the world of any kind whatever. Force working in various ways which the mind can in any way know we call various things. Force manifests itself in one way and it is called electricity; in another way and it is called heat ; in another way and it is called gravitation; in another way and it is called a tree; in another way and it is called a mullen stalk ; in another way and it is called a horse; in another way and it is called a star, and in another way and it is called mind. But the form in which the force which we call the mind manifests itself is consciousness. Something is known of consciousness by every one who studies psychology. This knowledge is obtained by comparing consciousness with unconsciousness as manifested in self and in others.

From the above expressed thought the following definition of mind is reached :

The mind is that force which manifests itself in the phenomena of consciousness.

It is not supposed this definition will be fully appreciated by the student who is a beginner in psychology nor by those who are through prejudice antagonistic to thinking of mind as force. But it gives some definiteness to the idea of what mind is, and it is believed that further study of psychology will contribute to the appreciation of the view, and to the realization of the help in the definition.

Read the following:

1. Angell's Psychology, pp. 1 to 7.

2. Pillsbury's Essentials of Psychology, pp. 1 to 10.

3. Dewey's Psychology, pp. 6 to 13.

CHAPTER 11.

The Units of Investigation.

Meaning of Unit of Investigation. — The subject of psychology is a science, and has resulted from the fact that the human mind is dissatisfied with common, or ordinary, knowledge and abhors vagueness. In its effort to develop science from ordinary knowledge it begins by stripping away from the subject of study all irrelevant, accidental and occasional facts, seeking the elemental, simple and persistent. In this process it reaches the most elementary, simplest and persistent form of the subject-matter, and this is the unit of investigation. The following is the formal statement for it :

The unit of investigation in any science is the simplest, most elementary, and most persistent form of its subject-matter. That is to say, it is the simplest, most elementary, and most persistent whole thing with which the science deals.

Each science has its unit of investigation. The chemist knows that his science is primarily concerned with the element: namely, oxygen, hydrogen, carbon, calcium, sodium, chlorine, nitrogen, etc. He studies their number, qualities, atomic weights, combinations and products. The element thus is the unit of investigation in chemistry.

The botanist has found that his unit of investigation is the organic vegetable cell. He studies its structure,, development, combinations and products.

The zoologist has found that his unit of investigationis the organic animal cell. He studies its structure, development, combinations and products.

The science of psychology differs somewhat fromother sciences with regard to its unit of investigation. Other sciences have but one unit, psychology has two. This is because of the distinct divisions in the subject-matter of psychology: first, the mental phenomena, and secondly, the corresponding physical phenomena.

The unit of investigation in the study of mental phenomena is the sensation. The unit of investigation in the study of physical phenomena is the nerve cell.

How the Unit May Be Studied. — The psychologist may study his unit of investigation in psychology in four ways.

His first task is to observe it so that he may know what it is ; that is, that he may know its nature ; that he may identify it so that he may be able to think about it in some definite way.

His second task is to find out how it behaves itself ; how it acts; what its processes are when subjected to a variety of stimuli under various conditions.

His third task is to find out what new products or combinations are brought into being as a result of the activities or processes of the unit of investigation.

The psychologist 's fourth task is to discover, formulate, state and learn the laws and principles governing the activities of both the sensation and nerve cell.

The Nerve Cell. — The nerve cell is a small body of nucleated grayish white matter, nervous matter, including any thread-like extensions reaching from it. Both central body and the thread-like extensions are parts of the nerve cell ; that is, when there are extensions. Some undeveloped cells have no extensions. The extensions .are of the same kind of material as the central body and are continuous with it. It is sometimes thought that just the central body is the nerve cell, and that the extensions from it are not parts of the cell. But this is wrong. It takes both the central body and the extensions to make the nerve cell. Nerve cells consisting thus of the central body and the extensions are called neurones by students of the nervous system.

Forms of Neurones. — ^Neurones are of various forms. The central body may be spherical, cylindrical, pyramidal, or caudate, and all are more or less irregular. All neurones of course have the thread-like extensions. There are mere germ cells which have no extensions from them. They are, so to speak, undeveloped, or baby, cells. They are called neuroblasts.

Material of Nerve Cells. — ^Nerve cells are composed of a granular, viscid substance usually called protoplasm. Protoplasm is a living substance. Vitality is one of its necessary characteristics. There is no such thing as dead protoplasm. Its exact chemical composition is unknown, though it is known to be complex to a high degree. Its main characteristics are vitality, absorption, secretion, and excretion. That is to say, it is living, it takes outside substances into itself, it gives out useful juices, and throws off waste products.

Nerve Fibers. — Nerve fibers are parts of nerve cells, the extensions, or prolongations, leading off from the central bodies. They are too small to be seen with the naked eye, but vary much in both diameter and length. Some are as large as one twelve hundredth of an inch in diameter, and some are no larger than one one hundred thousandth of an inch in diameter. They vary in size between these two extremes. They have a branching structure and vary in length from a part of an inch to several feet.

There are in general two kinds of nerve fibers : those which carry impulses toward nerve centers and those which carry impulses away from nerve centers. Those of the first kind are called afferent nerve fibers and those of the second kind efferent nerve fibers.

The derivation of these words helps in remembering their meaning. Afferent is from ad meaning tOj and ferre, to carry. Afferent nerve fibers are thus carrying to nerve fibers. Efferent is from ex meaning from, and ferre, to carry. Efferent nerve fibers are thus carrying from nerve fibers.

Sensory and motor are terms which mean nearly the same as afferent and efferent when applied to nerve fibers, but not quite the same. Sensory and motor are not quite as broad terms as afferent and efferent. Nerve fibers which carry impulses to nerve centers which do not result in consciousness are afferent nerve fibers, but not sensory. To be sensory the fibers must carry impulses which result in consciousness.

The fibers carrying impulses from the iris of the eye to the brain are afferent, but not sensory.

Nerve fibers carrying impulses from their nerve centers which do not result in muscular action are efferent, but not motor. Such are the fibers carrying impulses from centers to the liver, resulting in the secretion of the bile.

The function of nerve fibers is to carry impulses to unify the action of the nervous system. By means of the nerve fibers thus the touch corpuscles in the toes are in communication with the nerve centers in the highest part of the brain.

Number of Nerve Cells. — The number of nerve cells in the human body is so great that one can form no adequate idea of them. It is estimated that there are as many as ten thousand millions in the brain and spinal cord. At any rate it is certain that every one has many millions which remain unused and so never develop.

' ' Our picture of the nervous system is of a mass of ten thousand millions or so of these minute organisms enclosed within a bony case, the skull and spinal column."

It is well known that cells increase in number by cell division. Nerve cells increase in number in this way early in the life of the human being, but this increase ceases before birth. There is no increase in the number of nerve cells in the human body after birth. Not one of us has a nerve cell more than he had when he was born. Some of us may have fewer, but none has more.

Connections among Nerve Cells. — Contrary to popular belief, no two nerve cells in the human body have a continuous nervous connection. Each nerve cell is a distinct and separate thing. There is no extension from any nerve cell which is continuous with any extension from any other nerve cell. Each neurone is thus anatomically independent. No connection of continuity exists between the neurones.

How then are nerve cells connected? Very much in the same way as the branches of two trees growing side by side are connected, or in the same way as the roots of an elm tree are connected with the roots of an oak growing adjacent. This connection is a connection of contact. Neurones thus have connections of contact, but not connections of continuity.

Classes of Neurones. — The classes of neurones are (1) sensory; (2) motor, (3) associating. **The sensory are receiving neurones; the motor send impressions out to the muscles, while the associating neurones serve to bring sensory and motor neurones into connection. As the sensory neurones always lead toward the center, they are sometimes called centripetal or afferent, and for a similar reason the motor neurones are the centrifugal or efferent elements." The associating neurones are in a way located between the sensory and motor neurones furnishing pathways for impulses between them.

Axones and Dendrons. — It has previously been seen that developed nerve cells consist partly of extensions, or prolongations, from the central body.

''These are of two kinds, (1) the axone, a fiber having the quality of conductivity and becoming what we have called the axis cylinder of a simple nerve, or nerve fiber; (2) the dendron, which divides into finer branches or rootlets, called dendrites. Their functions are somewhat uncertain, including possibly that of nutrition in the service of the cell body, but probably that of conductivity also.''

^'Axones. — The axones have a branching structure and vary greatly in length, from a fraction of an inch up to two or three feet, according to location and use. They often branch greatly, throwing off side branches called laterals, which branch again in turn. They usually terminate in little tufts resembling the fingers of a hand, or the rootlets of a plant, and known as the arborization of the axone. The arborization of one axone may, in appearance, clasp or encompass the cell body of another neurone, or the arborization of one axone may interlace with the dendrites of another, and thus effect communication with it by a process thought to be similar to that of electrical induction."