A system of psychology

Preface

I SHOULD not be willing to add to the large number of psychology texts already in existence did I not believe that this book, in spite of its faults of omission and commission, possesses certain good points not found in the other English texts of recent date.

My greatest effort has been to present as consistent and systematic a sketch as possible of the general field of normal human psychology, elaborating the details only when they are essential to the general survey. In a field which is in great and increasing danger of becoming unsystematized to the point of chaos, even to the trained specialist, this method of introduction is absolutely essential.

I have tried to show that the data of psychology cannot at present be definitely described except in terms of theories which are more or less ^^philosophical,^^ and that the attempt to divorce the data from the theories would result in the uncritical acceptance of fragments of theories. It is important that the student should grasp this truth in the beginning,

Vlll PREFACE

and not be taught a pseudo-final system of facts which later must crumble cataclysmically when he takes a new point of view.

I have not attempted to write a book so simple that the student might read and understand it without effort: rather, I have endeavored to write that which should demand and reward hard study. The book is not designed to be made the sole basis of a course in elementary psychology. It ought to be accompanied by lectures prepared by a competent teacher, having special reference to the difficulties and lacunae of the text, and to its differences from the psychological theories held by the teacher. Certainly, the book cannot be used as a text from which both students and teacher may draw their information. As a main or supplementary text for semiadvanced students, it should find its greatest usefulness.

The only originality I can claim is in the way in which I have worked up materials borrowed from many places. I have not given credit for my borrowings, because in many cases the sources are too obvious to be mentioned, and in other cases what has been borrowed has been so distorted in the process that the individual to whom I am indebted might resent the ascription if credit were given.

PREFACE IX

The chief influences which have shaped my psychological constructions have come from the writings of James and from my contact, as a pupil, first with Howison, later with Stratton, and finally with Miinsterberg.

Contents

CHAPTER PAGE

I. Introduction:

1. The Meaning of Psychology .... 1

Chapter I

INTRODUCTION I. The Meaning of Psychology

It is much easier to tell the beginner what psychology is not than it is to tell him what psychology is. Just as it would be impossible to give an inteUigible definition of mathematics to a person unfamiliar with the elementary principles of numberrelations, so it is impossible to make clear to the average student the nature of psychology when he is just beginning to study it. In order that one may have a definite idea of what psychology is, he must know some psychology; and a person who has not studied the subject under competent guidance is not apt to know any psychology in the strict sense. It is true, on the one hand, that there is a great deal of information which is popularly called psychological; and, on the other hand, that every person knows much that is really psychology, although the persons in question do not realize that it is such. These two species of misunderstanding contribute to the difficulty of the task when one commences to study the subject scientifically. It is clear, therefore, that what we say now in a general way concerning psychology should be brief, and that the meaning thereof will probably be clear to the student only as he reverts to it after completing the volume.

We may commence advantageously by warning the student against some of the more common misconceptions of psychology. In the first place, while on the one hand psychology is not the " study of the soul,'' on the other hand it is not "soulless'' in the sense of doing away with a soul. It is a commonplace that \jrvxo\oy{a is not to be taken in its literal significance as the name of our field of labor, and that a considerable portion of the psychological discussion gets along without any mention of any sort of "soul." But in a comprehensive analysis it is not possible to avoid reference to something which may properly be called a "soul," although it is by no means the "psyche" of the Greeks and of the current popular conception, and although it is impossible really to study it.

INTRODUCTION 6

In the second place, psychology deals very little with the so-called "occult"; with telepathy, clairvoyance, and the other charlatanisms which are often so successfully employed in separating the fool from his money. Yet if we do not affirm, neither do we deny, that there may be, at the core of some of these concretions of humbuggery, certain elements of psychological interest and importance. The investigation of such matters belongs, however, not properly to psychology, but to ^'psychic research." ^

In the third place, the term "psychological" in current popular usage designates a certain delicacy or niceness of discrimination or adjustment. Thus the "psychological moment" implies an instant of time so appropriate for a certain act that a moment before would be too early, and a moment after too late. Any very precise analysis or description, of the characteristics and activities of human beings; or even a simulation of precision, is called "psychological"; and hence we find mention of "psychological" novels, and so forth. Now while psychology modestly acknowledges the pretension to

^The terms "psychic'^ and "psychical" must be distinguished carefully from "psychological." It is to be regretted that either of the first two terms is ever applied to the data which we study in the name of psychology.

exactness of analysis, she must deny any exclusive claim thereto, and cannot even pose as the only science which analyzes human activity and experience. In this popular sense of the term, physiology, logic, and ethics are, if anything, more " psychological'' than is psychology.

Finally, psychology is not the study of the functions of the nervous system. In fact, all the essential points of psychology can be expounded, as they have been developed, without reference to the nervous system, or by reference to a conception thereof which is ridiculously inaccurate. Nevertheless, it is true that psychological principles and facts are more easily described and investigated when referred to the structure and probable activity of the brain and nerves, as understood by the person to whom described or by whom investigated, and we believe that the more closely the physiological conceptions approach agreement with the actual facts of structure and function, the more facile the progress of psychology.

As for a positive definition we may give the following, which will be made clear by the further discussion: psychology is the study of experience; of the reference of experience to its content; of any direct reference which it may have to a subject of

INTRODUCTION O

experience; and of the content of experience in so far as it is directly related to experience.

2. Terminology

The terms used in this book may at first be a series of stumbling-blocks. Not only will the meaning in which many of them are used be found to differ decidedly from the meaning attached to them in every-day language, but in many cases the terms are not used in the senses in which thev are used in other books which will be read by the student. This confusion is unavoidable. The terms have been used in so many different sciences (to say nothing of their unscientific uses), that they have acquired a variety of meanings, and we are obliged to select the significations which seem most appropriate. Some words, such as "mind,^' "intelligence," and "soul," have had, and still have, so many different meanings that they have come at last to mean practically nothing, and we hesitate to use them at all where accuracv is essential. In the choice of the signification to be given to a term we should be guided not only by predominance of present usage amongst psychologists, but also by the historical setting of words, and by popular usage; and having attached a given signification to a term we ought to endeavor to adhere to it throughout.

The term ^* experienced^ is currently used in two ways. In the first place, it means to know, apprehend, or perceive something; as when I say I experience a sound, a color, a pain, or an emotion. In the second place, it means that which is apprehended or directly known, that is, the sound which is heard, the emotion which is felt, etc., are called experiences, or kinds of experience. There has been a great deal of shifting back and forth from the one of these meanings to the other, which has introduced deplorable confusion; and, manifestly, if we wish to avoid such trouble we must adopt and cling to one meaning. We shall, therefore, use the term in the first sense given above; to designate the being aware of something, and not that of which one is aware (except in so far as one may possibly be aware of being aware, which need not concern us here and now). This first meaning is, after all, the fundamental one, and we could hardly avoid using the term in this way even if we used it also in the other.

The noun "experienced^ is equivalent to the word " consciousness,'' and we shall so use it, and shall use the verb ^^tobe conscious of as equivalent to "to

INTRODUCTION 7

experience/' *' Consciousness '^ meant originally "the knowing that one knows/' "the experiencing that one experiences/' to which we above referred parenthetically; but it has completely lost in modern psychological usage that former restriction of meaning. It is, however, used frequently in the sense which we have given as the second meaning of experience, namely: that which is apprehended or known directly. Some authors with due notice use the term in both senses, and others, we regret to say, make similar usage without notification. Outside of psychology the historical meaning is still in vogue to some extent, and the resulting misunderstanding may be readily conceived.

"Knowledge" is a wider term than "experience" or " consciousness," and our use of the former term in defining the other two must be understood with this qualification. It is only direct knowledge as distinguished from indirect, that can be identified as experience. The significance of this distinction will become clearer later.

For that which we experience, or of which we are conscious, we have the convenient and unambiguous term "content of consciousness'^ or "content of experience." Frequently, however, we speak of the "objects" of consciousness or experience, or of

^* psychological objects/' Thus, the sound which I hear is a psychological object, as distinguished from the air vibrations which cause it, which latter are physical objects, and, as we shall see, are not heard or experienced, although we may know of them.

Other terms will be defined and explained in the sections in which their comprehension can be made most easy.

3. Extrinsic Helps

The proper preparation for the study of psychology cannot be prescribed in a way that will cover the needs of diverse individuals. One student will make excellent progress while lacking certain advantages without which another sticks fast. The elements of physics and of anatomy ought to be understood, and the cell-physiology which is given in the thorough courses in elementary biology or physiology is of value. The student will get all he needs of these subjects from good lecture and demonstration courses in them, and, if after his elementary course in psychology he decides to follow it farther in some particular direction, he will then discover in which of the sciences he needs laboratory training. Perhaps the greatest need for the be-

INTRODUCTION 9

ginner is an adequate training in literature, which may be acquired by well-directed reading; for psychology is least of all the subject in which anything can be communicated or comprehended in a special jargon or terminology, but requires all the assistance that can be given by command of the resources of the language of the masters in letters and of the speech of the plainer men. After literary training we should rank in importance a knowledge of physics as a close second.

We have omitted the customary anatomical pictures and discussions from this book, as the result of deliberation and conviction. Cuts of the brain and nervous system are readily accessible to any student who cares to look at them, and it is better for him to be sent to good anatomies to consult a hundred pictures than to have a dozen or so chosen out and put before him. Each instructor, moreover, has his own choices of preparations, models, charts, slides, and cuts, and of methods of presentation of nervous anatomy and histology. A superficial presentation here (and none other could be given in the limits of this book) would be a positive detriment. The books and cuts suggested are merely first aid to the student working alone.

Piersol's Human Anatomy; Howell's Text-Book of Physiology; Quain^s Anatomy^ vol. I, pt. II, and vol. II, pts. II and III; Schafer's Text-Book of Physiology, vol. II, and McKendrick and Snodgrass's Physiology of the Senses are all valuable aids in understanding the schematic anatomy of the nervous system. Excellent plates of brain, eye, and ear are given in the Sorbotta McMurrich Atlas and Text-Book of Human Anatomy, vol. III. We will give references chiefly to Piersol and Quain, because one of these will doubtless be accessible to the student. No specific references will be given to McKendrick and Snodgrass because the book is small, and appropriate material easy to find therein.

As for the general principles of nervous function, the best brief account is found in Howell, chaps. VI to XI, inclusive. The account of the nervous system given in Piersol, beginning on page 996, is especially valuable. For the needs of students of psychology, however. Part First of Ladd and Woodworth's Elements of Physiological Psychology is without doubt the best available general treatise on the structure and functions of the nervous system.

On the physical problems of light and sound, the articles by Lewis and Hallock, respectively, in

^ The references are to the tenth edition of Quain, and third edition of Howell.

INTRODUCTION 11

Duff's Text-Book of Physics, will be found elementary and useful. Zahm's Sound and Music is an intelligible and interesting treatise on acoustics. Unfortunately, the more commendable treatises, such as Barton's TexUBook on Sound, are too technical for the student who is not a specialist in physics. TyndalFs Lectures on Sound are still useful, and Helmholtz's Sensations of Tone (Ellis's translation) is the starting-point for the student interested in the psychology of audition.

Chapter II

PRELIMINARY ANALYSIS OF CONTENT I. Complexity of Content and Complexity of Experience

The content of your experience at any given moment in your life history is exceedingly complex. As you sit reading this book you have visual impressions of various forms and colors from the book and from surrounding objects; you get various sounds; odors; impressions of touch from the book and from your clothing and chair; feelings in the muscles, joints, eye-sockets, and viscera. All these things are sensed or perceived, and simultaneously something is thought of; e, g., the meaning of this print is presented as a content of thought. Add to these factors the emotional complexes of interest, weariness, hunger, satisfaction, disgust, annoyance, or whatever else is giving "tone" to your content, and you begin to see the truth of the opening sentence in this paragraph.

Although the content of experience is demonstrably composed of a multitude of parts or elements

in complicated organic interrelation, it does not fol*

PRELIMINARY ANALYSIS OF CONTENT 13

low that experience itself is complex. This has been a stumbling-block for modern psychology because of the frequent lack of clear distinction between consciousness and its object. It is often said that the content is not complex, but is simple and unitary; and that the elements into which we apparently resolve it by analysis are really new content brought into existence by our analysis. In stricter language, this really means that while the content which you apprehend is complex, and may be resolved into its elements, the apprehension or experience of the content is not itself a complex made up of the apprehensions of the different elements. To this dogma there is so far no reasonable objection, although it may be found ultimately that even experience is not so unitary as it appears to be; or rather, as it suits our presuppositions to think it is.

2. General Classification of Elements of Content In the examination of content of consciousness it is important to ascertain as definitely as possible how many sorts of elementary content there are. By elementary content, or element of content, we mean that portion of content which is not itself complex; that is, which cannot in turn be analyzed into component parts. Of such elements there appear to be four groups, each including a number of subgroups. Further investigation may show that at least one of these groups must be fundamentally revised, and perhaps eliminated, but we must give them all consideration. These four kinds of content are sensations, relations, feelings, and images. We will indicate briefly in the next paragraphs what these terms cover.

Sensations are such things as color, sound, odor, and warmth. Look at a drop of red ink on a paper before you; the color — the red — abstracted from its position on the paper, from its reference to other objects, from its familiarity, from its likeness or unlikeness to other colors; in short, from everything but the color as presented, is a sensation. So the sweet from sugar on the tongue, abstracted from all the attendant impressions in the mouth, from the fact that it is sugar, from the pleasantness, etc., is a sensation.

It is one of the commonplaces of psychology that a sensation is never presented alone to your experience. Neither is a mere group or complex of sensations ever presented alone to the adult, and probably not to the infant. Always there are other elements, such as difference, familiarity, unpleasantness, etc., joined with it. Nevertheless,

PRELIMINARY ANALYSIS OF CONTENT 15

we can pick out from among the mingled factors of the complex the sensation itself and consider it in detail.

Relations are easily recognized, or at least some of them are. Similarity, difference, sequence, intermediacy, possession, etc., are experienced just as directly as are sensations. Perhaps the instances given are not simple; perhaps they may be analyzable into simpler relations, but they are sufficiently good specimens.

Feelings are most easily identified in emotions or passions. Joy, sympathy, ennui, rage, hunger, pleasure, are contents which involve complexes of bodily sensations, relations, and in addition the feelings which are their most important characteristics. The total complexes named may all with fairness be called emotions, and their analysis presents probably the maximum of difficulty with which psychology has to contend. But it is reasonable to conclude for the present that they cannot be completely accounted for without taking into account elements of feeling. If it should eventually be demonstrated that these feelings are nothing but specific sensations, we will have neither done nor suffered harm by listing them as elements or quasi-elements.

Images are generally considered as being the "copies" or "revivals" of sensations and of complexes of sensations previously experienced. Having been conscious of the sensation of red under the influence of physical light-waves you may later experience an "image" which is in some respects like the sensation, and which will represent it. By the images of sound, color, touch, and of sensations from the muscles, we are enabled to "think" of content which is not present; this is practically the doctrine as Aristotle handed it down, and it is the doctrine of current psychology.

We regret the necessity of departing radically from established opinion, but feel the obligation to warn our readers at once of our conclusion that the belief in the existence of such forms of content is a delusion, flowing partly from certain peculiarities of consciousness and partly from metaphysical prejudices. We shall present the case in detail in the proper place, not slighting the current theory.

3. Terminology In contradistinction to content imagined, we speak of content inhtited or apprehendedy and oppose intuition or apprehension to imagination. Thus, when light-rays fall upon my retina, I intuit a light

PRELIMINARY ANALYSIS OF CONTENT 17

sensation. Sometimes the sensation is said to be present as opposed to a sensation or other content merely imagined. Perception appHes to intuition, and to intuition plus imagination; usually it has the latter reference. This will be clear to the reader after he has studied the chapter on perception. Intuition is popularly used to signify an occult or inexplicable awareness of some fact; it is needless to say that as we use the word it has no shred of that meaning, which is a perversion of the correct signification.

Chapter III

I. Sensation, Physical Stimulus, and Physiological

Process

Sensation — that which is experienced through the senses, or through sense — must be distinguished rigidly from the physical stimulus, on the one hand, and the nervous activity which is caused by this stimulus, on the other hand. The normal stimulus is some activity of what we call "matter,'' usually outside of, but acting on, the body of the individual. Thus, the oscillation of the air particles which act on the inner organs of the ear and produce sound; the vibration of the ether which stimulates the retina of the eye and occasions the experience of light; the chemical activity of substances, which produces odor; these are instances of stimuli. There is little difficulty in distinguishing stimuli from sensations, even for the beginner, for a little reflection convinces us that these physical facts are not experienced, but only inferred. WTien, for instance, I hear a tone, I am not conscious of the back-and-forth

movement of the air particles; and when I see a color I am not experiencing the undulations of the ether. In the latter case the stimulus is so far from being experienced that it has required great labor to discover its real nature (assuming that we do know it now) by inferences from observations, and it took years for those who held the present theory to convince of error those who drew different conclusions from the observations. Even to-day physicists do not profess to have a complete understanding of the actual behavior of the ether and some of them doubt its existence. Yet an ignorant man, who has never heard of ether, and whose views on the transmission of light are amusing, may experience light and color sensations which are as highly developed as those of any one. The smell of a volatile substance depends doubtless on the arrangement of the atoms in the molecules (or on some such physico-chemical factor), but smell itself gives no direct information as to this arrangement. So it is throughout. What you experience through the senses is not a material object, or any part of a material object, although we have learned all we know concerning material objects from a study of the behavior of sensations. We have discovered during the last ten centuries a great deal about the physical activities corresponding to most of our sensations, and the general principles of their behavior; which helps to create in the unreflective the belief that we experience directly the physical activities themselves.

The difference between the sensation and the nervous process, especially that in the brain, is harder to grasp than is the difference between sensation and stimulus. This difficulty is at once exemplified and increased by the fact that many physiologists seem to teach that there is no difference.

The psycho-physiological confusion is rendered well-nigh hopeless by the ambiguity of the term " nervous process/' and though the ambiguity is not dangerous in physiology, it is productive of much trouble when physiology is brought into relation with other studies. The terms " brain/' "nerve/^ etc., may mean the actually experiencible; that is, visible and tangible objects; and " nervous process,'' accordingly, may signify changes which may actually be watched, or which might be observed if sufficiently delicate instruments were available. On the other hand, the terms may signify the matter and material changes which are supposed to be at the basis of these observable things or changes, and which, of course, we infer, but do not experience. If, for example, someone could lay bare your brain and with proper instruments observe the operations of that mechanism, his sensations would be, loosely speaking, brain processes; at least, the brain processes observed would be partly composed of his sensations. But this is not what the physiologists mean; they mean that your sensations, while you observe anything whatsoever, are identical with your brain processes. This meaning does not refer to the brain processes in the first sense mentioned, although often taken in that way, for no thoughtful person would be guilty of supposing that while, for instance, you are watching an indigo blue light, that shade of blue could be discovered by observation of your brain cells. In general, if you could watch the light (or other object), and at the same time watch through some instrument all the changes observable in the brain and nerve cells, you would find practically nothing in common in the two objects.

The brain processes the physiologists mean when they say that a sensation is a brain process are the material facts and transformations which are not observable directly as brain facts, but which we can infer; in short, the things represented by the symbols of chemistry. What you see, when you examine a nerve, are only sensations of light and color;

what you feel are touch sensations; you do not see or feel the matter of the nerve. The sensations you experience and which you may suppose to be the nerve under examination are really transformations in your own material nerves, which cannot be experienced by anybody or anything except your own " mind/* or perhaps can only experience themselves. Thus, the sensation, when followed relentlessly back in the physiological system of events, is apparently found to have disappeared completely, and to have been replaced by something else.

The vulgar way of accounting for this vanishing of . sensations under scientific scrutiny is to suppose that the "mind'* experiences these brain changes and experiences them (wrongly, indeed,) as sensations. This is merely an unintelligent reversion to an older and more respectable theory — that the processes in the brain ^produce the sensations in the " mind," — which theory does not identify the process with the sensation. A more modern way is to say that the brain process experiences itself. Thus, we do away with the concept of "mind," except as a name for a certain activity of brain cells and arrive at a point of view which is apparently quite simple. But this little subterfuge saves us only for a moment, and either method of explanation, if consistently adopted and carried out, lands us either in the conclusions of the Hindu Vedantists, that the world which we seem to experience is not real but only illusion; or in idealism, which holds Mind to be the only reality. If we wish to hold to the theory that there is a real world to experience, we must hold that sensation is not brain state nor brain activity.

The student will probably ask himself — very likely has asked while reading this chapter — " Where is sensation ?^^ The commonplace answer, ^*Itis in the brain,^' seems to commit one to the doctrine of sensation as a brain state; and yet, where else can the sensation be? The sensation is not in the brain unless the whole body is in the brain. Suppose you have before you a red surface and ask yourself, "Where is the red?^' Put your finger on the surface, and the evident answer is, that it is where the finger is; that is, "out there,'^ in space. Of course, there is a possibility that you are deluded in both cases, and that neither the color nor the finger are "there,^^ but are both in the brain; or rather, since the brain itself is in the same class with the finger, the whole outfit is " in the mind." Thus, if you begin by assuming that the sensations are in the "mind," as opposed to a "real world," you will conclude in the end that the whole knowable universe is in the "mind/^ unless you are too busy, too lazy, or too dull, to carry the process you have started to its logical conclusion. If you are satisfied, and call this mental universe " real,'^ you have reached idealism. If you are dissatisfied, and think this does not give you reality enough, you have reached the Hindu view of the world as Maya, or illusion.^

We do not feel either of these conclusions to be satisfactory, and, therefore, are forced to assume that sensations are not in the brain, but are where they are experienced as being, or are so in many cases. In some instances they may be at some other point of space, and, hence, wrongly "located'^; and there may indeed be in all cases a certain amount of error in location; but error is possible here, as elsewhere, only if there is a basis of correctness.