UNIVERSITY OF CALIFORNIA AT LOS ANGELES PSYCHOLOGY OF THE OTHER-ONE AN INTRODUCTORY TEXT-BOOK OF PSYCHOLOGY BY MAX F. MEYER Professor of Psychology in the University of Missouri SECOND EDITION, REVISED (Solumbta, fttuottri THE MISSOURI BOOK COMPANY PUBLISHERS 1922 Copyright, 1921, 1922, The Missouri Book Co. Published February, 1921 Second Edition, August, 1922 ! . ••• • . .1 ^ PREFACE '(J The present book is the result of the necessity, existing in some colleges and universities, of giving elementary instruction in mod- ern psychology to college students who are only members of the freshman class, to students who have never studied psychology before, to students who may never study it later, to students who have little knowledge of physics and chemistry and perhaps 1^ still less of biology, to students who take an elementary course ^^ in psychology in order to take afterwards a course in educational psychology, and to students who want elementary psychology for O a better understanding of the problems of the social sciences. For these classes of college students this book is written as a text \ to be elaborated by the instructor as he wishes, by the aid of lectures, additional reading assignments, or laboratory work. \ MAX F. MEYER ( -. The University of Missouri PREFACE TO THE SECOND EDITION This is essentially a reprint of the first edition. The theories offered to the student in order to give him an understanding of the fundamentals of human life have in no way been altered. But several unclear statements have been rewritten. And in a few places references have been added to the author's "Manual of Psychology Demonstrations". The booklet just mentioned ought to be used by the student as an aid in the study of this text-book if laboratory facilities can be provided. The changes which have been made in the text occur on the following pages: 3, 5, 6, 9, 46-49. 93, 94. 98. 116. 117, 126, 146-150, 198, 210-213. 220. 267, 339, 363, 367, 429. 436-439. M. F. M. July 1922 L85JU^) CONTENTS Chapter Page 1. The Other-One becomes an object of interest to us ... . 3 2. The Other-One manifests machine-like reactions .... 28 3. The Other-One's reactions are either concerted or local 50 4. Concerted action presents a problem to the architect of the nervous system 67 6- The Other-One appears now attentive, now absent- minded, now inattentive ^1 6. The Other-One varies his mode of reaction gradually or suddenly: He learns and wills 118 7. How the Other-One's developed nervous functions show up anatomically 151 8. The Other-One's most interesting reflexes and instinc- tive actions 176 9. Space perception on the skin: A species of condensa- tion of the nervous functioning 216 10. Nature enables the Other-One to perceive space at a distance 229 11- Nature divides the spectrum for the Other-One's space perception at a distance 262 12. Nature makes a second division of the spectrum .... 279 18. The Other-One is equipped with a sense organ particu- larly suited to signals 293 14. The Other-One's talking machinery 313 15. Rhythm: Motions grouped and thus repeated 334 16. How the Other-One talks and writes to himself .... 354 17. If the Other-One is born blind, or deaf, — what then? 370 CONTENTS Chapter Page 18. The Other-One walks in his sleep. Disturbances of per- sonality. Abnormalities 881 19. The psychologry of the Other-One and the sciences other than psychologry 399 20. The mysteries of the soul 409 Questions and Problems 423 Index 436 PSYCHOLOGY OF THE OTHER-ONE CHAPTER I The Other-One becomes an Object of Interest to Us. Robinson Crusoe has just acquired his man Friday. He is naturally anxious to know what use he can make of his new acquisition. So he goes to the Public Library (this is a sort of Munchhausen tale) and selects the present book as the one most likely to give him the desired information about "The Other-One." In times past one used to turn to psychology books when he wanted to learn something about his Self — his Soul. There are even recently printed psycholog}' books which bear the title "The Science of Selves." This very title is an anachronism. The idea of a Self characterizes in every branch of science what one might call its "prehistoric" period. Man tried in vain to explain the heavenly bodies, the weather, the land, the water, the animals and the plants by regarding them as Selves: Jupiter, Apollo, Neptune, and so forth. Modern science owes its triumphs to the fact that it has learned to restrict itself to descriiDing merely that which one can measure. The psychology of the Other-One follows the same road. Why should Robinson Crusoe, wanting information, use the antiquated, the sterile method? Measuring means always comparing and counting — com- paring a thing by means of our sense organs with another thing which we regard as our standard unit, and counting the number of units. Without the application of our sense organs there is no measuring. But the sense organs are not applicable to a soul, to consciousness. (3) 4 PSYCHOLOGY OF THE OTHEE-ONE. There is a special fact which has greatly retarded the advancement of the psychology of the Other-One, — the fact that the psychology of the Self appears so much easier, so much more promising. Robinson Crusoe, when asked, tells us eagerly that he knows perfectly that he has a Self, a Soul. He adds that he knows this Soul, this mind, this Consciousness (we capitalize in order to show our proper respect) much better and also with even greater certainty ("Cogito, ergo sum," said Descartes two centuries ago) than any of the things of the world. The latter he does not know so directly, but merely indirectly, thru mediation of his sense organs. But for exactly this reason it seems useless to try to teach him anything about what he knows so well, his Self. On the other hand, he admits that he knows his man Friday only by applying his sense organs to Friday ; that zvithout apply- ing his sense organs he ivould not knoiv that his man Friday existed. Therefore Crusoe's desire to know as much more as possible about his man Friday cannot be satisfied by the psychology of Selves. He needs the psychology of the Other-One. He needs the psychology which applies sense organs to the object of study, compares what the sense organs perceive, counts and — leaves the question whether Friday has a Self, a Soul, a Mind, a Consciousness to the single being whom it might concern, to Friday. It is customary that in such a critical case the Devil is also present. (He always tries, as is well known, to em- barrass people if he has a chance.) He is present on the Island clothed as a missionary. He approaches Crusoe with this impertinent question : "Are you going to deny, by selecting this book on the psychology of the Other-One, that your man Friday has a soul, precious and immortal?" NO DEITTAL, BUT "NO STTTDT, OF SELVES 5 Crusoe replies : "If I were a missionary and interested chiefly in the saving of a soul, the question, whether he has one or not, would be of the greatest importance to me. But I merely desire to know what use I can make of him benefiting me and also benefiting him so far as I can know thru my sense organs what may be good for both of us. This I may be able to learn from the psychology of the Other-One. Your question is irrelevant. The Devil changes his clothes and reappears as a philos- opher. "Crusoe," he says, "don't you admit that one can draw conclusions relative to things he has never seen?" — "Him- self," shouts Crusoe, as the Devil has barely finished his sentence. "You left out the word himself at the end of your question. What others have seen, may take the place of what I have not seen myself, because it is inconvenient to look at many things myself. But this does not change the fact that my interest in Friday is restricted to what my or other sense organs reveal. Without any sense organs existing in this world, nobody would conclude that this man Friday existed and add his existence to the stock of scientific knowledge." — "It is true, then, what has been rumored," continues the Devil, "that you take no interest in your man's spiritual welfare, that you are irreligious, and that you have driven the missionary from this Island?" — "What a defamation !" replies Crusoe indignantly. "What is true is merely that I refuse to mix up my scientific interest with my endeavors in religion, poetry and art." Before entering into a detailed study of the Other-One, Crusoe thinks i- advisable to trace in bold outlines the various roads over which he has to travel in reading his book. Let us, he says, compare the Other-One with animals, plants, manufactured engines. Watching him only a few weeks or even only days, we convince ourselves that his b PSYCHOLOGY OF THE OTHER-ONE chief distinction consists in being, not manufactured of virtually changeless materials, as an engine is, but a product of growth, and that he continues to grow in many respects. With plants the Other-One has growth in common. But the differences are immense. First let us note his much greater motility. We can use the term activity instead of motility and then speak of his greater activity. Concern- ing his activity, however, there is a distinction which is not merely one of more or less. The activity of a plant is, so to speak, stereotyped. A certain plant closes its petals whenever it is placed in the shade. The Other-One's action — like the actions of virtually all animals — may for some time appear to us to be stereotyped, too. But sud- denly we observe that an unexpected and novel action occurs. For example, Crusoe gives Friday a piece of meat and finds that he puts this in his mouth and swallows it, gives him a piece of bread and finds that he puts it in his mouth and swallows it. He gives him a piece of chocolate and finds that he puts this in his mouths and swallows it, too. He gives him a piece of chewing tobacco and finds that Friday puts it in his mouth and spits it out. But Crusoe remembers that, when he gave his uncle a piece of chewing tobacco, this Other-One kept it in his mouth for a long time. Generally speaking, the Other-One seems to be capricious, willful. Comparing the Other-One with animals, Crusoe dis- covers that Friday often, especially before performing some important action, talks to himself ; and that sometimes he also makes curious signs in the sand, and that this talking and writing seems to have a great influence on what the particular kind of action is which follows. For example, he finds him doing this before he chooses a particular kind of material and a particular spot on the Island for the con- ENGINES, PLANTS, ANIMALS. 7 struction of a shelter. The Other-One's actions, far from being directly in response to the surrounding things, are often — indeed usually — mediated by a self-created, that is, invented, set of symbols. Some call these symbols "thought;" some call them more objectively "language." Comparing the Other-One with animals, we can say then that he is thoughtful. Recapitulating: The Other-One is more a product of growth than this can be said of an engine or its parts, and has growth in common with plants. The Other-One differs from plants thru his willfulness, his variability of action, which he has in common with animals. The Other-One differs from animals by his thoughtfulness, the mediation of many or most of his actions by symbols, which makes him the lord of the Earth. For the reasons which follow one may speak of a hier- archy of these three functions: thoughtfulness, the highest; willfulness, lower ; growth, the lowest. And one is then justified in calling the Other-One the highest creature in the universe, an animal a creature less high, a plant a lower creature, an engine still lower. Thoughtfulness is not possible without willfulness, for the invention of arbitrary symbols naturally is a function of willfulness, is a kind of variation of a being's reaction to its surroundings. A stereotyped reaction could not be called an invention. And willfulness does not seem possible to any considerable extent without growth, for the vari- ability of action is — altho not absolutely, since an engine. too, may surprise us ; at least in a growing thing, in a prod- uct of growth — dependent on growth. Nobody who has the slighest experience with human and animal willfulness denies that it is the result of a kind of growth, both in the race and in the individual. Robinson Crusoe, in order to 8 PSYCHOLOGY OF THE OTHEE-ONE. know all he can about his man Friday, will ask us two questions. I. What part of his body is it on whose growth first his willfulness, later his thoughtfulness, depends? II. What are the peculiarities of the growth of that part of his body? A popular answer to the first question would be — the brain. A better answer would be — the neural, or nervous, tissue. The brain is simply a conspicuous lump of nervous tissue, but not all of it. In its totality we customarily call the nervous tissue "the nervous system." The answer to the second question cannot be given briefly. We shall have to proceed for it thru many chapters of this book. On reading the last paragraph it occurs to Robinson Cru- soe to ask himself if he did not make a mistake in selecting this book. Are there not many other kinds of books which give information, and perhaps better information, on the nature, the life, of the Other-One? Physiology, anatomy, sociology, economics and other sciences which we meet in any university catalog are also concerned with the Other- One's life. Does this book on psychology, when it applies itself to the study of the Other-One's life, encroach upon these other sciences? — No! There is undoubtedly some, but no more, overlapping between psychology and these other sciences than there is between many other two sciences picked out of the catalog. What sufficiently divides the problems of the psychologist from those of the physiologist or anatomist is the greater social or individual significance of their problems. A stomach ache or a deformed bone are undoubtedly problems of the Other-One's life; but they concern chiefly him, who has them. If you pass this man or woman on the street, it makes little difference to you whether he suffers from the ache or not, whether she limps or not. These scientific DEFINITION OF PSYCHOLOGY 9 problems of the Other-One's life, as problems of mainly individual concern, are problems of the physiologist, who studies digestion, of the anatomist, who studies the structure of the bones. On the other hand, a man whose "life" at this moment consists in striking with his fist another man's face, is a problem which concerns you immensely, even if you are a mere bystander, but still more if you are the one whose face is afflicted. The peculiar muscular contractions in the fighter's arm and body in general, being of social rather than of individual significance — the lone Robinson Crusoe on his island in the past could not fight — are a problem of the psychologist. Having thus drawn a line between the problems of the physiologist and those of the psychologist which is quite sharp enough for all practical purposes of departmental organization in our scientific institutions of teaching and research, we find it no more dif^cult to draw a line between psychology and those other sciences of the Other-One's life whose problems are also characterized by their social sig- nificance. Psychology is not concerned with special social institutions-^the other, the special social sciences, are exact- ly thus concerned. Marriage, for example, is a social in- stitution quite differently specialized in different parts of the world. The sociologist studies the different forms of this relation of the sexes as it appears among Americans, Turks, Chinamen, Hottentots and so forth. The psycholo- gist is interested in marriage only to the extent to which its features are common to the Americans, the Hottentots and all the other human beings on earth. The psychologist is interested only in the fundamental laws of the Other-One's life, not in the special forms which these laws take when applied to particular historical, geographical or ethnological conditions. Like marriage, punishment of crime is a social 10 PSYCHOLOGY OF THE OTHER-ONE. institution and as such an ''mportant object of interest to the sociologist. The psychologist studies this problem of pun- ishment of human beings by other human beings only in its fundamental aspects, in those aspects which are the same in every human being no matter in what country and in what historical period that being lives. The psychologist will hardly offer advice to the xA^merican nation today as to how it should reform its penal institutions. That is the sociologist's business. Another immensely important group of social institutions are the schools. The special problems, however, of the age at which a child should be sent to school, what subject should be taught first, what later, are problems which the psychologist gladly and without any feeling of jealousy leaves to educational science. Let the educator de- cide how children should be guided to grow into citizenship, the psychologist finds problems enough, of a more funda- mental nature, concerning the general possibility of chang- ing the raw material, so to speak, of the Other-One as pro- duced by hereditv into a creature properly adapted to any environment for which Nature neglected to make — could not make — satisfactory provision by heredity. What the psychologist studies is the general possibility of adaptation to any form of environment, no matter what it might be, leaving out of consideration all those historically conditioned needs which are the very crux of the problems of the educational scientist. Political science, to give one more ex- ample, is interested in government. This is another social institution of specialized kind. The psychologist gladly leaves the study of government to political science. Robinson Crusoe thus convinces himself that psychology is the study of human life in a material sense, that is, the study of the life of the Other-One, — but of his life in so far as it is of social significance rather than as it is of sig- LOCOMOTION. 11 nificance for himself, and only in so far as life, in its social aspects, is the life common to all his brothers on earth. Thus is excluded from the province of this study the Other- One's life as it shapes itself under special social institutions. If we call psychology a Natural Science, it is the study merely of the nature of "the Other-One in relation to us." And if we call psychology- a Social Science, it is the funda- mental social science. The social sciences in the common use of this term must then be regarded more properly as the "special" or "applied" social sciences. Looking now at the Other-One, at animals, and at plants (all three the product of growth) from the psychologist's point of view as we have just come to understand it, we can not help being struck by the fact that plants are distinctly unsocial, animalr distinctly social beings. We hardly think of "The Lonesome Pine" of the Kentucky mountain trail as being an abnormally living specimen of its kind, but we cannot think of the lonesome Robinson Crusoe on his island as living a normal life. Animals mix because they move. Locomotion is their most characteristic form of behavior. Exceptions to this rule, of plants being stationary and ani- mals locomotive, strike us so forcibly by reason of their being distinctly exceptions. And even such cases are excep- tions usually only during a part of their lives, such as the oyster which indeed moves about during the early part of its life and settles down to a hermit's life only when older. The relative necessity of locomotion for animals, the lack of this necessity for plants is clearly connected with the fact that only the plants can stretch out their roots and limbs, the organs thru which they obtain food, more and more the longer they live. So far as their limbs are concerned, this means no more than an enlargement of the receptive sur- face exposed to the air and the light. But the growth of the 12 PSYCHOLOGY OF THE OTHEE-ONE. roots means mora than an enlargement of the receptive sur- face. The motion of the soil liquid thru the capillaries of the soil is immensely restricted in comparsion with the motion of the air. There would be an approach to exhaus- tion of the nutritive elements of the soil needed by the roots if the roots did not penetrate into ever new portions of the soil, where the possibility of exhaustion is yet far removed. The animal, however, not having roots, must move bodily to another place when it has consumed all the food obtain- able at its present locality. So we can say that Nature must have endowed, and has endowed, animals with the means of locomotion. The animal moves on when for some time no food has been taken into the digestive cavity, there being no more food available. Let us not say that the animal moves because it is hungry. We are trying to get information about the Other-One and about everything material (animals, plants, engines and what not) to which he might be compared and thereby be- come clearer to us. Now, we do not say that a plant ex- tends its roots because it is hungry. There is no need for saying this with reference to an animal either. And no need even with respect to the Other-One. Nothing is gained thereby, unless anyone thinks that something is gained, for example, in an analogous case by speaking of the sea as the hungry Neptune. Nothing becomes clearer. The animal moves because for some time no food has been taken into the digestive cavity. This is clear enough. Nature's pur- pose in the motion is to remove the animal from the place where there is no food to other places where there may be food. This purpose can be served most efficiently if the loco- motion is motion in a straight line, for motion in curves, in serpentines, in zig-zag lines would not bring the animal so LOCOMOTIOX. 1 o quickly, with so little expenditure of energy of the living body, from the first place to a second place removed from the first possibly a considerable distance. The act of loco- motion, therefore, a form of behavior called forth by the stimulus of lack of food, is locomotion in a straight line. We must not regard it as astonishing that the stimulus should be something negative, the lack of something. When I turn to my neighbor, hand him the newspaper and ask him to read the head lines, I expect him, too, to respond to some- thing negative. And I find that he can do it, can respond to the black letters. What we call black is physically the absence of light. Responding to lack of food is therefore no exceptional case. The details of physiological mechanics bringing about motion in a straight line when this stimulus acts on the animal, do not concern the psychologist especi- ally. They may be studied in a suitable zoological text- book. All that we have to emphasize here is the fact that Nature has made animals so that lack of food, acting as a stimulus, brings about as a response to that stimulus .. locomotion in a straight line. This locomotion in (gen- erally) a straight line is the most fundamental kind of animal behavior, universally applicable from the lowest species to the highest of the animal kingdom, to Man. We want to remember it as the most fundamental form of be- havior. Gradually we shall add to it an ever increasing list of further forms of behavior serving the ever growing needs of the organism in its evolution. Having introduced in the last paragraph the concept of a "stimulus," we must have a clear conception of what is meant thereby. There are many different kinds of things of a physical or chemical nature which may act on the body in such a manner that a chemical change results in the body ; and anything that is capable of doing this may be called a 14 PSYCHOLOGY OF THE OTHER-ONE. stimulus. A candle which illuminates, a violin which sounds, a brick which presses on the skin, influences of all kinds capable of mechanically or chemically tearing, dis- solving the living tissue, such as cutting knives, tearing saw blades, burning acids, also volatile substances like cam- phor, cheese, perfume, substances soluble in our mouth like sugar, salt, alum, temperatures of a substance (gaseous, liquid or solid) in contact with the body which are higher than the temperatures of the body tissues, temperatures which are lower than the temperatures of the body tissues, even electrical currents and the increase or decrease of an electrical current, these and many other substances or con- ditions of substances may be called stimuli when they have a chance to bring about in the body of an animal or a plant a chemical change. It is evident that the meaning of the word stimulus is far extended over its original meaning which is that of a pointed stick used by the ancient Romans (and still used by the inhabitants of certain countries) .o drive their draft animals, their oxen. We have also introduced the concept of a "response." The response is the effect of a stimulus, but not its direct effect. The direct effect of the stimulus is the chemical change, a change of the usual chemical constitution of the tissue affected into another and less usual one. This change we shall always in this book call the "excitation." The excitation in turn calls forth what we shall name the "response." There are two chief kinds of responses. In contractile tissue, in muscles, contraction may occur ; and in secretory tissue, in glands, secretion. The latter is of con- siderably less interest to the psychologist than the former, because of its limited social significance. Of still less in- terest, for the same reason, are such rarer forms of animal responsiveness as the electric strokes of animals like the STIMULUS AND EXCITATION. 15 electric eel or the ray. Let us remember, then, that nearly always for us the effect of a stimulus is an excitation and the effect of this in turn is contraction. Whenever we choose to speak only of stimulus and response, we omit the intermediate link, the excitation. We may, of course, leave it unmentioned where it is unnecessary to mention it, but we must not forget that without the excitation the stimulus, directly, does not produce any response. In the usage of language we often substitute, for brevity's sake, a simple noun for a whole sentence. In order to refer by a simple noun to the fact "that living tissues are capable of undergoing a rapid and pronounced chemical change when acted upon by a stimulus," we shall in this book use the abstract term "sensitivity." The corresponding ad- jective is sensitive. In higher animals we find differentiated sensitive tissue. The meaning of "differentiated" is easily understood. In the very lowest animals every part of the body has the same properties as every other. Every part is equally sensitive, for example. In the higher animals, however, certain parts of the body are so much more sensitive than others that we give them the special name of sensitive tissue. Let us illustrate the distinction. Sunlight falling upon our hand produces there very little effect, and even this only very slowly. It takes days or weeks before we can notice that the skin darkens. The skin is very slightly sensitive to light. The same light falling upon the retina of the eye for only a hundredth of a second produces there a profound chemical change. W^hen a part of the body has assumed one among the properties which all living tissues possess, for example sensitivity, to such a degree that we almost forget that it has those other properties too, altho but weakly, we say that it has become differentiated. 16 PSYCHOLOGY OF THE OTHER-ONE. That we call the body material "tissue" is due to the purely fortuitous fact that, when living bodies were first examined under the microscope, they seemed somewhat to resemble "woven material," the meaning of the French word tissue. The changing of undifferentiated tissue into sensitive tissue is naturally only one of several forms of differentia- tion. Among those properties of the undifferentiated tissue which especially interest us we find, in addition to sensi- tivity, contractility and conductivity. All tissues are contractile, but only when they are so differentiated that they possess a high degree of contractility are they called contractile. All tissues are capable of conducting an excitation from a point anywhere within the tissue thruout the whole tissue ; but only when there is a high degree of conductivity (or, using a physical term that means the same, a "low" degree of "resistance" to the flow of the excitation) is the name "conductive" applied. One must not think of conductivity, in this chemical sense, as something mysterious. We may well think of it as something comparable to the conduction of a drop of syrup, of sugar, thruout the contents of a tumbler of water or of tea. We have all seen the sugar, in such a case, spread thru the water like a cloud. What would you ask for if sent to a butcher shop in order to bring home samples of sensitive, of contractile and of conductive tissue? — You might ask for an eye ball or a piece of the skin of the tongue in order to have sensitive tissue. Not the whole eye ball is differentiated sensitive tissue, of course. But the inner lining of the back wall, the retina, is tissue extremely sensitive to light. The taste buds on the tongue, further, are very sensitive to certain chemical substances, like sugar, salt, quinine, when these are placed SENSITIVITY, CONDUCTIVITY, CONTRACTILITY. 17 upon them in solution. Differentiation, after having sep- arated sensitive from other tissues, proceeds and separates tissue sensitive to light from that sensitive to chemical solutions, to sound, to warmth, to cold, and so forth. When asking the butcher for a sample of contractile tissue you would simply ask for meat. Our muscles are our dif- ferentiated contractile tissue. When asking for conductive tissue, you would ask for brains. All the nervous tissue of an animal is differentiated conductive tissue ; but the only nervous tissue which the butcher has handy for you, is the bulky mass of nervous tissue contained in the cranial cavity. Elsewhere in the body it appears only in small pieces not easily handled for commercial purposes. We have previously warned against using such phrases as hungry in the explanation of an animal's behavior. We have before-hand decided to reject all terms that have a sub- jective meaning, that refer to consciousness. We are study- ing the Other-One in preference to Our-Selves. For the same reason we avoid here, in speaking of sense organs (that is, sensitive organs), the use of the term sensations. It is far better to use the term excitations, v/hich has no subjective meaning. Speaking later in detail of the functions of the several senses, again it will not be advisable to speak of such sensations as green, red, and so on. It is much clearer to use the unambiguous and purely objective term and speak of the specific excitation green, and so on. In animals made up of differentiated tissues the excitation obviously cannot serve its purpose, of causing contraction in contractile tissue, without first being conducted from the sensitive tissue, where it originated in consequence of stimu- lation, to the contractile tissue that is to act, by contracting, as a motor of the body. It is only to be expected, then, that the elements or neurons (the "cells" in the strictest terminol- 18 PSYCHOLOGY OF THE OTHER-ONE. ogy of biology, not in the loose sense in which biology still speaks of a "nerve cell") making up the conducting organ, the nervous system, should appear in the shape of long and thin threads, microscopical, but of proportions comparable to those of telephone wires. The reason why they should have this shape are exactly the same, too evident to require enumeration, which give this shape to the conductors of a telephone or telegraph system. These conducting threads, strings, fibers, or whatever we call them, of the living body, under the microscope reveal to the eye several additional features. We shall discuss them here, not so much because the psychologist must under any and all circumstances know them, but rather because the present beginner in psychology ought to be warned against believing that the knowledge of these additional details of the structure of neurons constitutes for him an important part of psychological knowledge. Of great importance for the psychologist is a clear under- standing of the principles ("specifications," so to speak) underlying the architectural plan in accordance with whic'.i the nervous system must have been built up by the Creator out of the building material. The neurons are this building material. These functional principles conditioning the archi- tectural design will be discussed and often referred to in the following chapters of the book because of their great psychological significance. As a matter of fact, at the present time, the details of the building material itself, the mere structural details of individual neurons given in this introductory chapter, do not contribute anything essential to our (present) understand- ing of psychological problems, altho it is possible that new discoveries in the future may allow them to play such a role. The smallest structural elements of which both animal and NEUEONS. 19 vegetable organisms consist have for about a century been called "cells." This means literally boxes — we have a box under our house which we call a cellar. The name appears less strange to us on knowing that those structural elements which were first discovered by means of the microscope happened to look like little boxes. These were plant cells. It was, of course, soon found that not all vegetable elements of structure are box-like. Some, for example the long and thin flax fibers used for the manufacture of linen, do nor resemble a box. But the name cell had already been adopted by the biologists as a general name for elements of structure and was now applied also to those elements to which it was not applicable in its literal meaning. It was equally applied to the elements of structvire in the vegetable and animal kingdom, and the whole growing, living, world was — and is — said by the biologists to consist of cells. Accordingly the strings, which serve as conductors for excitations in the bodies of higher animals, ought to be called cells, too — per- haps nerve cells for the sake of distinguishing them from other kinds of cells. Such, however, is not the case. The term nerve cell has come to mean, vmfortunately, something different. We shall at once see what and why. In its most undeveloped form an individual unit of ner- vous tissue is a small, almost spherical body (compare fig- ure, at a). As this body grows it becomes pointed in one or more places and sends out a string-like prolongation, which continues to increase in length (figure, at b, c and d), ^o that it may become easily a hundred thousand times as long as it is thick, reaching a total length of several feet, whereas its thickness is always microscopical. The original little ball from which the string grew out, continues then to exist as a relatively thick swelling of the string. We must remem- ber, however, that it only looks thus, that it did not originate 20 PSYCHOLOGY OF THE OTHEE-ONE. as a swelling of the string. Being relatively bulky, it is not difficult to understand that this thickened part of the string should have attracted the interest of investigators be- fore the exceedingly fine string. When it was first the a GROWTH OF A NEURON. object of biological research, its belonging, as a part, to the long and fine fiber was quite overlooked. It was studied as an individual thing, and the name cell, generally applied to the elements of biological structure, was applied, instead of to the whole fiber with its swelling, to the swelling alone, which was called a nerve cell. So the inconsistent use of the word cell in its application to nervous tissue, referred to above, came about and is still almost universal. Since about 1890 a new, unambiguous terminology has come into u:e, which we adopt. We call the whole structure, the fiber with its swelling, a neuron, the fiber without its swelling simply fiber or string, and the swelling alone a ganglion cell. Ganglion cell and nerve cell mean the same. The use of the word ganglion cell is explained thus : In nervous tissues gray looking masses are frequent which, on microscopical examination, reveal themselves as ac- cumulations of swellings carrying with them, naturally, the contiguous pieces of their fibers. It is as if we had a large number of '"Opes each having a knot somewhere and had NEURONS. 21 taken all these knots in one of our hands. Such a mass of nervous tissue has long been called a ganglion. Now, it is a peculiar biological fact that these swellings of neurons are not found simply here and there in isolation, but that they are always found in groups, sometimes not very large, sometimes very bulky — these very ganglions. Since the swellings of the neurons are found only in ganglions, they have been given the name of ganglion cells in addition to the name of nerve cells. Many are the forms in which the neurons present them- selves. Our next figure shows an assortment of them. The ^-^^ b c d e TYPES OF NEURONS. swelling may be at one of the ends as in the case of a and c of the figure, or away from either end as in the case of b, d, and e. The long fiber may split into two fibers as in c, or even into more. The swelling may happen to occur just at the point of division of the string. In this case the neuron looks like d. The string may in its course turn sideways, form a kind of loop, and continue from the turning point in the original direction. If now the swelling happens to be at the place of the loop, the neuron must look like c. In all these varieties of form we find the same structure, a 22 PSYCHOLOGY OF THE OTHER-ONE. string with a swelling. Some years ago, when the interest of the histologists was still in the main restricted to the ganglion cell, various kinds of such cells used to be dis- tinguished according to the number of long fibers which they appeared to send out, and called unipolar (a), bipolar (b) and multipolar (d) cells. Since the ganglion cell ha.^ ceased to be regarded as an element of structure in the earlier sense, these distinctions and names have practically lost their significance. The neuron is essentially a string capable of conducting an excitation from one end to the other. All its structural and functional properties are neces- sarily subservient to this end, to conduction. Certain features of the neurons, which have not yet been shown in our figures, should still be mentioned. We said COLLATERALS. that the long fibers sometimes split into two fibers. Another breaking up of a fiber may occur in a manner similar to the way in which a river takes up large tributaries, forming approximately right angles. Such tributaries of a neuron are called collaterals. Still another feature of the neurons is to be mentioned. Each ending of a nervous string looks somewhat like the frayed-out end of a thread. The end breaks up into a large number of relativelv ort branches, the so-called terminal arborization (in the figure of a ganglion cell at a). In ca .e the swelling of the neuron happens to be located at one of NEURONS. 23 the ends of a neuron, these small branches must naturally come out of the swelling itself. This end brush directly pro- ceeding from the swelling is said to consist of dendrites, which is a Greek name meaning about the same as the Latin GANGLION C-ELL. name terminal arborization, that is, tree-like branchings. In the figure of a ganglion cell a neuron is represented whose main fiber is relatively short, almost shorter than the den- drites. This shortness, however, is not the rule, but rather the exception. The main fiber, often also called axis cylinder, usually greatly exceeds the dendrites in length. There is frequently a difference in coloring between the parts of a neuron. The ganglion cell looks dark, the fibers lighter. This has given rise to the distinction of white and gray matter in the brain — gray matter taking its name from the presence of numerous dark ganglion cells among the fibers. In the brain there seems to be a peculiar advan- tage — not yet perfectly understood — in having the gr^" matter spread out over the surface, the cortex, in as thin a layer as possible. To this end the surface is much increased by the formation of large folds, separated by deep fissures, as seen in the figure of the frontal section of the right cere- bral hemisphere. The surface of the brain is estimated to be equal to a square with a side eighteen inches long With- 24 PSYCHOLOGY OF THE OTHER-ONE. out the fissures the surface would be only about one-third of this. The mixture of ganglion cells and fibers makii.g up the gray matter is illustrated by the three figures show- FRONTAL SECTION OF THE RIGHT CEREBRAL, HEMISPHERE. ing in microscopical enlargement sections of the cerebral cortex, stained either so that only the ganglion cells are visible or so that only the fibers are visible. Actually both are present in the same piece of gray matter. The popular idea that the gray matter is of greater importance than the white matter, is of course a superstition. The ganglion cells have a delicate interior structure, and even the fibers are not simple, but possess an interior struc- ture, so that they may be said to consist of fibrils. About the functional significance of these inner divisions of a neuron too little is at present definitely known. The question as to the function of the ganglion cell and the function of the fibrous parts of the neuron is answered NEUEONS. 25 at present in a manner very different from that which .vas customary fifty years ago. It was then often asserted that SECTIONS or THE CEREBRAL CORTEX. Ganglion cells stained. Fibers alone stained. the ganghon cells were the residences of ideas, each little box the seat of one idea, so that the total mental capacity 26 PSYCHOLOGY OF THE OTHEE-ONE. of a person might be determined by counting the number of his ganghon cells. Men of science nowadays recognize tha: an idea, something subjective, spiritual, mental, cannot Le said to be seated anywhere. The ganglion cells do not have any more direct and more important relation to the Other- One's life than that of the conducting strings. On the con- trary, we shall in the following chapters see that we can fairly well understand the Other-One's life without making any reference to his ganglion cells. Their physiological significance is probably, in the main, only of the following two-fold kind. The ganglion cell is the point of vegetation in the neuron, so to speak, from which all growth proceeds ; and it is the storehouse from which the neuron in any emergency can quickly draw the means of subsistence. Let us elaborate this statement. We have seen that the whole string of a neuron grows from a little sphere. This sphere continues to exist even after the neuron with all its ramifications has obtained its full development, and is then the ganglion cell of the neuron. If growth is necessary later, say, because a branch of the neuron has been cut oflf or otherwise destroyed, new growth proceeds from that point of the string which is farthest from, but still connected with, the ganglion cell. — On the other hand, if a conducting string is continually used for hours, changes in the appearance of its ganglion cell occur which probably indicate changes of a chemical nature, called by the physiologists signs of fatigue. It seems that the string, in order to serve continuously for a long time as conductor of an excitation, needs to be resupplied with certain chemi- cals, and that these chemicals are kept in store for the string within the ganglion cell, which, because of its size, is less quickly exhausted than the string. Whether the NEURONS. 27 ganglion cell has any significance in addition to those func- tions which have just been mentioned, seems doubtful. Let us recall, now, what we said to be the most funda- mental of the many diverse forms of animal behavior. Every animal, we said, is by Nature so made that lack of food, acting as a stimulus, brings about as a response locomotion in a straight line. We have to add to this behavior a second form, which is of equally fundamental importance. An animal, in its forward march, is likely to meet an obstacle, for instance, a piece of rock, or a tree, or whatever may be heavy enough so that the weight of the animal would not suffice to push it aside. Unless the animal had a locomotor ability beyond that of moving in a straight line, such an obstacle would forever stop it, would cause its early death by starvation. Nature therefore has given every animal a second form of behavior, that of avoiding the obstacle by changing its own position, its direction, in front of an obstacle, so that, when further proceeding in a straight line, it would leave the opposing object at the side of its path. It is decidedly worth while to study in detail a very simple mechanism capable of changing the direction of an animal in front of an ob- stacle, because we learn thus how exceedingly simple such a mechanism may be, and how unwarranted would be assumptions of mysterious properties of animals, of 'Vital forces" and the like, assumptions toward which we are all too inclined because of the poetical rather than scientific way of thinking of the mass of human society of which we are a part. CHAPTER II The Other-One manifests Machine-like Reactions. Let us imagine a lump of living tissue having the shape of a snail. Let us for simplicity's sake call it a snail. Let us examine and answer the question if this animal could "live," in the sense in which the Other-One lives, however remote the resemblance of their lives may be. The animal we are imagining is still a little simpler than a real snail. Our snail has no house (not all snails have a house), no tentacles, no nervous system, no differentiated tissue whatsoever so far as it concerns us. It is simply a lump of undifferentiated tissue of the shape of a snail. But it has a mechanism driving it forward in a straight line in response to the stimulus of lack of food. The details of this mechanism, however, do not interest us at all. When placed on a pane of glass and observed only with respect to its silhouette, the picture of this imaginary snail is as simple as the outline given in our figure. What hap- pens now, if the snail is gently touched, say, at the front end in the place marked in the figure ? Owing to its sensi- tivity, the tissue touched undergoes a chemical change. We say that it becomes excited. Being contractile, the tissue reacts to its state of excitation by contracting. All the tissue of the right side of the head becomes immediately concentrated, condensed, into the space shaded in the figure. The head assumes an unsymmetrical form like the one shown in the figure. The excitation, first caused only in the neighborhood of the point touched, spreads now in consequence of the con- (28) SNAIL TURNING 29 ductivity of the tissues. It spreads slowly thruout the whole body. Even after having reached the most remote part, the excitation continues in motion, continues to distribute itself. It becomes weaker in the part where it originated, stronger in the remote parts, until its strength has become the same everywhere, until the chemical constitution of the body, different in different places just after the stimulus was applied, again is uniform all thru the body. Wherever the excitation reaches in its movement thru the body, contraction of the tissues occurs. On the other hand, in the region where the excitation originated and where it now weakens, that is, in the shaded space of the figure, the original contraction weakens. We must understand that we are imagining our snail to be sponge-like. We suppose that coritraction in a part of this sponge, since the material is made to occupy less volume when contracted, makes that part denser in a physical sense. This implies a greater weight per volume unit. The tissues become now gradually denser, heavier, in the remoter parts and simultaneously less dense from moment to moment in the region where the stimulation occurred, in the shaded space. This change of the density of the tissues, however, ac- companying the gradual spreading of the excitation, is itself gradual, not sudden, and thus does not produce any further deformation of the body surface, of the animal's shape, like that which followed the sudden application of the stimulus. After a second or two, we find the body with a weak uniform excitation, with a weak uniform contraction, and still with the deformation of the surface at the place where the stimulus was applied. Now, the chemical state which we have called excitation, means the presence, in the tissues, of chemical substances 30 PSYCHOLOGY OF THE OTHEK-ONE. which are not ordinarily there. They must not remain there. A case of illness is an analogy. If we are sick, have SNAir, TURNING. a fever, this also means the presence in our body of chemical conditions, chemical substances, which are not normally there. If they remain, our life gradually weakens and finally ceases. When we recover, this means that these abnormal substances are being removed from the body, that the normal chemical constitution is being restored by those forces which are always active in living matter, whose study makes up the branch of science called physiological chemis- try. In our snail now, too, the normal chemical constitution of the body gradually returns. As it returns, the state of contraction gradually disappears. The body slowly ex- pands again. It expands like a wrinkled football which we blow up. It expands most where it was indented, where the surface offers least resistance. But it also expands everywhere else. The assumption is entirely justified that our snail, too, in expanding loses its wrinkles, so to speak. SNAIL TURNING. 31 The deformation disappears. But at the same time, since the tissues are now everywhere sHghtly and uniformly con- densed, the effect of the expansion shows everywhere on the surface of the body. The expansion shows also on that side of the head which was not stimulated. This brings with it a change of the situation of the axis of the body. Think of the axis (ab) in our figure as if it were a knife edge on which the body could be balanced at the start. There was then as much weight of the body on one side of the solid line as on the other. At a later moment, some time after the deformation, when the excitation and the disturb- ed tissue density have already become uniform thruout the deformed body, the animal could no longer be balanced on this knife edge. It would become necessary to shift the knife edge into a new position (say, xy), the dotted Hne. in order to keep the deformed body now balanced on it. The weight axis, now, of the deformed, but uniformly dense, body is the dotted line. But the very gradual expansion, which accompanies the disappearance of the excitation from the entire body, — this redistribution of normal density and weight — occurs in a body which is already uniformly dense. The weight dis- tribution on tht two sides of the knife edge (xy) is there- fore not appreciably disturbed relative to this knife edge. The second position of the knife edge on the ground there- fore becomes (approximately) the axis of the body restored to its normality perfect in shape and otherwise, as it was before the stimulation. Only one change remains as the consequence of the stim- ulation. What remains is a change of the situation of the animal. The part of the animal which was touched is now somewhat removed, sidewise, from the point in space where the contact occurred. The axis of the animal is farther re- 32 PSYCHOLOGY OF THE OTHER-ONE. moved from the point of the stimulus than it was when the stimulus was applied. The front end of the axis points in a somewhat different direction. The animal faces a dif- ferent direction. It is the same as if the mere contact had been an externally applied forceful push. The fact just mentioned may reveal an importance quite out of proportion to its simplicity. Apply it to the problem of getting an understanding of the role played in animal life by the nervous system. There was no nervous system in our "snail." We, unfortunately and customarily, look upon our "brain," — better, our nervous system, — with a peculiar awe. We think of its function as being the very essence of life. We have to learn to think of it in a very different, far more modest manner, if we desire to possess a sane, well proportioned view of animal life. The snail whose life we are discussing, needs no nervous system in order to live. Suppose the snail is creeping on the SNAIL AVOIDING AN OBSTACLE. ground in the direction of the arrow I in our figure. We agreed to take the mechanics of locomotion in the forward SNAIL TURNING. 33 direction for granted. We may then at once devote our- selves to the more special problem. The snail, creeping for- ward, approaches the stone which accidentally lies in its way. and the right side of its head comes into contact with the stone. We know now, from our previous discussion, what must happen. The part which has been excited by the touch of the stone, contracts. A little later, expansion of the body occurs, but the expansion not only of the part near the stone but of all the body with practical uniformity. The result is a change of position. The axis of the snail now assumes a position more nearly that of the arrow II. The internal mechanism which caused the original for- ward movement, again becomes effective. The snail, moving forward, perhaps again comes into contact with the stone. The same happens as before. The axis turns a little farther toward the left. Again the forward movement begins and now, perhaps, is continued without touching the stone ; the actual path being approximately that indicated by the broken solid line composed of parts of I and II. It may be advisable to call attention to the fact that such an animal does not do what a human being might indeed do : avoid the obstacle by "going around it." Such a simple organism merely changes its direction and immediately proceeds in a new direction. What we have described is by no means an extraordinary event in the animal's life, an unusual kind of behavior. It is practically the complete story of the snail. The snail, in order to live, must eat. Lack of food, continued for some time, results in chemical changes in the body. In con- sequence of structural and functional properties of the body which we cannot study here, these chemical changes bring about a forward movement. A rock (or any other obstacle) lies in the way. If the rock could permanently stop the for- 34 PSYCHOLOGY OF THE OTHER-OXE. ward movement, the snail would starve to death. But, in one or several stages, a change of the situation is brought about by a change of the direction of the animal's axis. Now the snail creeps on. Other obstacles which may be encountered are taken in the same way. On its forward march the snail, by accident, sometime passes over edible substances, which stimulate the mouth organs and, conse- quently, are consumed. Later, lack of food brings about locomotion again, and the same things happen in the same cycle. One may feel inclined to exclaim : An animal's life cannot be so simple, so automatic as that, — dependent on the mere accident that food substances should be in its fortuitous path ! But why not ? It is true, many a snail will fail to come across any food substances and die of starvation. Such is life ! But enough will have better luck and live to propagate the species, for food adapted to the needs jf snails is common on earth. Not onlv food is obtained in this — if one wishes to call it by that name, "mechanical" — way ; protection against in- jury is thus made possible too. If the snail, instead of ap- proaching a rock, had come near a directly injurious sub- stance, it might have changed its route even before touching that substance ; for the tissues of its body are excited, not only by touch, but also by many other influences, for ex- ample by a change of temperature, or by the efTect of a volatile chemical substance. A piece of camphor instead of a rock would have turned the snail some distance before touch would have been possible. Another important method of protecting itself is that of completely retiring within its shell, if the animal has one. This again reqviires no additional mechanism. We silently presupposed above, that the touch of which we spoke was SNAIL TURNING. 35 a very gentle touch. It will, of course, always be gentle .f it results from the snail's — this slowly moving animal's — own motion. If the touch is relatively strong, as when a child touches a snail with a straw, the excitation resulting and spreading with great force all thru the tissues must cause, not only the tissues at the point of contact, but in quick succession also the neighboring tissues, possibly all of the body, to contract vigorously. If the whole body con- tracts strongly, it must, since a part of it is attached to the interior of the shell, necessarily disappear in the shell. A somewhat sophisticated student, nevertheless, was dis- satisfied with this description of the animal's life. What will happen, he asked, if the stone against which the animal moves, happens to touch it in the very center, neither to the right nor to the left? Does this situation not require a mysterious vital force, a will, or whatever you prefer to call it, capable of turning it away from the obstacle? Similar problems were quite the fashion in the claco rooms of the philosophers of the middle ages. If you place a donkey between two bundles of hay, they argued, equally large and equally sweet smelling, he is unable to move in either direction and must starve to death, unless he has a mysterious power, such as a will. Any farmer, however, no matter whether he believes in a free will or in determination by natural causation, knows better. He knows that it is im- possible to make two bundles of hay exactly alike. Only a miracle could bring that about. And if they were alike, the slightest motion of the air would cause the one nostril of the animal to get more of the aroma of the hay than the other, and the animal would turn. So it is here. The animal is affected by many forces other than those which we are studying here. For example, it moves on rough ground. The fore end of its body is not shaped 36 PSYCHOLOGY OF THE OTHER-ONE. exactly like the rear end. Being moved back over the rough ground in consequence of a touch at the very center of the front, and crawling forward again, the animal could only by a miracle touch the stone a second time with its very center. But if the touch occurs only slightly to the right or to the left, the next touch will occur still more to one side, as we have seen ; and the animal will soon move on, leaving the obstacle sidewise. A thoughtful and generous student of our book here in- terrupts us : "We have convinced ourselves," he says, "that our imaginary snail, consisting of undifferentiated tissue, does not need a nervous system in order that it may live. Nevertheless, — why should the Creator be so stingy? Does he not give us many things which are not absolutely neces- sary? He might have offered the snails which populate the gardens and forests a nervous system as a mere luxury !" The conducting strings, the neurons, we have learned, are the elements of which a nervous system is made up. Sup- Cent f a I AN IMPOSSIBLE NERVOUS SYSTEM. pose now, the Creator had appointed us to act as his deputy, to construct a nervous system and to offer it to our nerve- less snail. Having a vague idea that a nervous system in an animal is something like the telephone system of a town, we would probably unite a considerable number of conducting strings in a central point, like our figure called "An impos- NERVOUS SYSTEM. 37 sible nervous system." Altho the snail can get along without a nervous system, why should it not get along even better when in possession of our gift ! Imagine the snail has accepted the gift and is approaching the obstacle, the rock which we showed in our figure. The moment when the contact occurs one of the peripheral ends of the nervous strings is excited. The strings are so dif- ferentiated that they have an immensely greater conduc- tivity, that is, lesser resistance, than the undifferentiated tissues. The excitation, therefore, is conducted to the point where all the nervous strings are connected and thence with great intensity of flux along all the nervous strings, thus reaching effectively all the parts of the body. Consequently, all the parts of the body contract practically at the same time with great force. A prompt and relatively strong contrac- tion at the point of stimulation, followed slowly (as pre- viously described) by a weak and uniform contraction of the whole body is no longer possible. The resulting change of position is also impossible. The body in its entirety contracts and, after awhile, ex- pands again, to touch the rock, of course, in exactly the same way that it did the first time. In consequence of the touch, the whole body contracts again. It expands again, contracts again, expands again, contracts again, and so on endlessly, or rather until the animal is either exhausted or starved o: both. Any way of avoiding the obstacle is im- possible. It is clear, then, that the snail would be very much worse off with this kind of a nervous system than without any. Without any nervous system it can live quite well, unless it happens to have exceedingly bad luck. With this nervous system it cannot live any more than a human being could live who, whenever he saw or heard anything, instead of 18511 M> 38 PSYCHOLOGY OF THE OTHER-ONE. normally responding to the situation presented, would in- variably have an epileptic fit, a violent and entirely useless, too widely spread, unadapted, muscular contraction. If our snail is wise, it thanks us for our kind intention but begs us to keep our gift. Of course, all that we have proved is that this particular nervous system is unacceptable. Another kind, differently constructed, might be an accep- table gift. One case in which a nervous system could be serviceable in an animal's body would be that in which the contraction is to occur not at all at the point of stimulation, but at some other point. This result can be brought about by conducting away the excitation from the point of stimulation by string- like tissues which cannot themselves contract, but possess a greater conductivity than ordinary, undifferentiated tissues Carried +o another point, the excitation can there perform its normal action, that of causing the contraction desired at that point. This kind of function is necessary in all the more highly organized animals, in the insects as well as in the verte- brates. As example we may use one of the most familar insects, a moth. Everybody knows the striking be- havior of a moth, its flying towards any source of light. It is the result of the nervous connections between the wing muscles and the eyes. The right eye is connected (if not exclusively, at least better) by nervous strings with the muscles of the left wing, the left eye with the muscles of the right wing. If the moth has the source of light on its right side, the right eye receives more light and consequently a stronger excitation than the left eye. The left wing then beats the air more forcefully than the right wing, and the animal is turned to the right until both eyes are excited by the light with equal intensity; that is, until the moth flies directly towards the light. BEHAVIOR OF A MOTH. 39 An inquisitive student here puts before us a question. "Is this behavior of the moth of any value to it?" We answer that it probably is. It may be that the moth is thus aided in getting to places where food is obtainable. It is true that millions of moths are destroyed thru this instinctive action of flying toward the light. Sources of light de- structive to moths on the surface of the earth are an in- vention of mankind, rather recent, for which Nature can- not be expected to have made provision in giving the moth its biological inheritance. So much is plain, that it could do a moth, whose anatomi- cal structure is (relatively) so highly developed, no good whatsoever if an excitation caused by light in the region of the head would cause a contraction of the tissues there, in the head. In order to be of any value to the animal it is necessary that the chief sensory areas, the eyes, and the chief motor organs, the wing muscles, be connected with each other by differentiated tissues of the conducting kind, by nerves. (The student who has but little biological knowledge must, and might here at this moment, be warned against confusing the terms "connective tissue" and "conductive tissue." The former refers to an entirely different kind of tissue with which this book is not concerned. "Conductive tissue" does not connect by binding things mechanically to- gether, but "connects" only by conduction.) Will it side-track us if we discuss here briefly another fact which is of great significance for the behavior of ani- mals ? We said that the movement of the moth's wings was caused by the excitation whic'- comes from the eye. The question may be asked how a continous excitation like that in the moth's eye can cause a discontinuous rhythmical, movement like that of flapping wings. We have no need to 40 PSYCHOLOGY OF THE OTHER-ONE. explain this here in detail, but it is important to point out, that such a transformation of something continuous into something discontinuous is an exceedingly common occur- rence in nature. It is especially important to note that it occurs in the inorganic world, the dead part of nature, as frequently as in the organic world, in living nature, so that we cannot be accused of having neglected the possible claims for recognition of any so-called vital or mental forces when we simply stated that the wings flapped merely because of light falling steadily on the animal's eye. The inorganic world offers many examples. The wind passing steadily over the surface of the ocean does not cause, by friction, a mere motion of the surface water in the same direction. It causes, as we all know, a motion of the particles of water mostly in a vertical direction, up and down, causing waves, which periodically rise and fall a considerable height. Or, when we blow a whistle steadily, the result is a rhythmical movement of the particles of air enclosed in the whistle, a sound in the physical sense. When water flows very slowly from the kitchen faucet, it does not fall in a continuous and very narrow stream, but in periodical drops. Air blown under water thru a tube, simi- larly rises in periodical bubbles. Nobody thinks that such a transformation in these cases requires any hypothetical vital or mental forces. To assume any such forces in the case of muscular activity is equally unnecessary. What we have said about nervous excitation in the eye causing rhythmical motion of the wings is all that need be said, unless we are specially interested in the details of physiologi- cal science. After this deviation we return to our problem of psy- chology. What kind of a nervous system could be regarded as an acceptable gift by our snail, — or by any other animal? NERVOUS SYSTEM. 41 We saw that one kind of behavior is impossible to the snail or any other animal lacking a nervous system, namely, a contraction at one point of the body in response to an excitation started at a different point, without any contrac- tion occurring at this latter point. If the tip of one of the tentacles of a snail — let us think of a snail with tentacles — is afifected by a certain stimulus, say, the heat of fire, it would undoubtedly be safer for the animal to move back by means of its locomotor organs, however far these are from the point of stimulation, than to respond strongly by a contraction of the stimulated tentacle and only weakly or not at all by action of the locomotor organs. We see at once the close connection between the existence of a nervous system and of highly developed special organs, especially of locomotor organs. Higher animals, having legs, must indeed, because they have these special organs, respond to stimuli occurring at certain excitable points of the body, far from the legs, by pushing themselves forward or back on their legs, and perhaps by no other motor reaction. It would be strange indeed if, in order to put the legs in action, a stimulus had to be applied to the legs. It is not necessary to illustrate this function of a nervous system by animal locomotion exclusively. Think of any other form of reaction. Think of a dog who scratches him- self. Different motor organs (muscles) must move a leg to a different place according to whether the insect bites here or there. The snail, which has scarcely any specialized motor organs, just on this account does not absolutely need a nervous system. So much nervous tissue as a real snail possesses, serves minor purposes which do not much con- cern us here. On the other hand, if an animal has specialized locomotor and other motor organs, fins, wings, or legs, with double 42 PSTCHOLOGT OF THE OTHER-OJTE. sets of mnsdes for forward and backward niotion, its ner- Toas sf^tem mtist be designed in accordance with the f ol- lowLsg plan and cannot be dedgned in am^ other waj with- out defeating its pftirpose. Certain excitable points of the body nrast be connected by conducting strings with certain contractile tissoes located in definite points of the body; other excitable points nrast be connected with certain other contractile tissues of the body If we ^nqsfify our way of exTre?? "r I3iis we may say: Bcch sensory (tibat is, esoitat '.e :hr body must be cmmected by a condmctmg strmg wiz '■: : : :e motor (that is, ccmtractile) poimt of the body. Remoiilber, however, that the facts are not qmte so single £i : -e expressed in these words. Actually, a single 5t- :- 7 oint is scarcdy eve- - : : in isolation, and a 5 : - T : --.irtile point, a tracts wiuie all other fit T^" ■': "nl statements of fund - ^^in^ and r^ectii^ r- - " T^ftoally sm^nfer ;;. ■- statements £.r wisr :':'.-: .;' : be of littl: fiber, never con- -= ?t- However, - ■-? purpose of c'-^ct, are -~ even : t- :3er- .'. : -ght, which zt z ;"-i:r3ients may Tt.tr i: tr :nith. ;-t7-t5: \-:.i niost iho & tut --.V not \ — - ♦ VJ- II-* - - 3?e. Kqpler's discover : ; STTTplificaticm of th . we can well affc : SEXSOET AND MOTOR POI^TTS. 43 as ellipses in spite of the :ac: ' --: ' " ir: not strictly ellipses. We must proceed in Psychology." in the 55.me -.vay. Ar-.i we shall in this book often proceed thus. Only by ;:":> fying the facts (using good judgment therdn) can we ir:-^ them within the limits of our thinking capacitjr. This justifies our speaking of the connection of one sensorv' point with one motor point as if such a simple ner- vous connection actually existed. We may represent such nervous connections graphically, that is, in a perfectly arbitrary design selected only with reference to clearness and other conveniences, whidi be- come apparent at a later time. Each sensory point S in our figure is connected with one definite motor point M by a conductor, represented in the figure, of course, by a line. That this connecting line has the form of a flat arch^ made up of three straight lines, is by no means essential. We shall gradually find that this form has sp^cia". aivartizes which no other form -vi;' ^>,-e u? a- ; '. Abstractions make dull reainr The r.z::: z-.'-.z'^z'' is nothing but a statement, in very abstract terms, of the advantages to be derived by representing a nervous con- nection by an arch consisting of three straight lines. Those who dislike dull reading, will omit the next cara—aph arti pass on to the following. -^ny graphical representation :t such a ;"' taiive tart a? that of a functional connect: :n trtweer. t : :^-t> of a '■■:'—- body is an important means ::' i;?:- - r th^ : ::. fact in quantitative terms. In th'f : .' : r . ; - ; , :y is opened for the development of a ? : : e :: h : : r : - • 5 ; ^ :•. : h : theories, scientific laws, are -r-.rt :::.::f :-:: :r' :: quantitative, that is. math / : . :rn:^ descriptions are made either ;:::.;riicaiiy igeon T r , 44 PSYCHOLOGY OF THE OTHER-ONE. analytically (arithmetically, algebraically). We have just shown a part of the method used in the graphical description. It uses a very definite terminology, so to speak. The "terms" are arches consisting of three straight lines each. We shall later see that this enables us to describe important nervous functions in arithmetical terms. And this quantitative method will enable us to draw conclusions as to the func- tions of the nervous system quite impossible if we had stated s; m; Y > Y ^ ., ^ A NEURON ARCHES: DIAGRAMS OF REFLEX PATHS. M. the facts in purely qualitative terms, as is usual in neuro- logical discussions. However, we cannot anticipate these results here. We merely want to indicate that the graphical representation is to serve a very definite purpose. Now let us speak again in the concrete. Each of those straight lines means a neuron. Each of these arches con- sists of three neurons. We may place the arches in our graph side by side like S^ M^ and S^M^ and S^M^. Or they may be drawn nested like S^ M^ , ^b^^b ^^^ ^a^a' Which form we choose depends purely on which form oflfers the greater convenience and clearness in describing whatever we wish to describe. We must never think of the length of any of these lines, but only of their number. It is the number which represents the total length of the conductor. In the form where the REFLEX FUNCTIONS. 45 arches are nested, we do not think of them as differing in size. On the contrary we think of them as being all exactly the same kind of arches, drawing them of different sizes only in order that we may see thein in separation and with- out confusion. We shall see later that the size of any arch, the length of any of its lines, will play no role in our cal- culations of the intensity and direction of function. Only the number, irrespective of the length, of these lines will enter into our calculations. The function of one of these nervous paths just repre- sented by arches, from S to M, is customarily called a reflex function. The choice of the word "reflex" is due to the historical accident that several hundred years ago this function seemed to the physiologists of that time to be somewhat comparable to the reflection of light from a mirror, — namely, in promptitude. When we look at ourselves in a mirror, we do not have to wait any appreciable time before our image appears. It is reflected back at once. Neither do we have to wait long before a person upon whose toe we stepped begins to pull away his foot. On the other hand, we may have to wait a considerable time before the same person puts his hand in his pocket and draws out some money, after we have asked him to lend us a dollar, or ten, or a hundred. Human actions seem to classify themselves naturally into two groups, those which are slow, hesitating, and those which are quick as the reflection of our image in the looking glass. The latter kind the early physiologists called reflex actions ; and we still call them so, altho we nowadays have instruments which enable us to measure even the shortest time intervening between the stimulus and the response (the reaction time) and know that this length of time is rarely less than a tenth of a second, incomparably longer 46 PSYCHOLOGY OF THE OTHER-ONE tlian the time occupied by the retleclion of the light rays from the mirror. Those other, slower, more hesitating- actions are often technically called by psycholog-ists "delayed reactions." 1 heir delay is not due, as a student might think, to the cur- rent in those functions traveling over a longer path. That delay would not amount to much. The delay in "delayed re- actions" is undoubtedly due to a far more complicated con- dition. Compare pages Z7 to 39 of the author's "jManual of Psychology Demonstrations." One of the simplest methods of measuring the reaction tmie is by the use of the instrument of which the essential parts are sketched in our figure. A metal post, P, bears a lever of which one end has a button for the subject's finger. 1 he other end of the lever is flexible, is a steel spring cap- able of vibrating horizontally at the rate of a hundred times MEASURING THE REACTION TIME. per second. This vibrator, V, has a point which writes on a smoked slide, S. H is a hook by means of which the ex- perimenter pulls the slide. A pin not shown in the figure, fastened to the slide, holds the vibrator bent sideways until ic is withdrawn. At the moment of pulling H, the vibrator begins to make a sound and to write every hundredth of a second one wave on the moving slide. As soon as the sound acts on the ear, the excitation runs to the arm muscle, the button is pressed down, the vibrator rises and ceases to write. And the number of waves written on the smoked REACTION TIME 47 slide is the reaction time, generally between ten and twenty, in hundredths of a second. A reflex function is made possible by the existence in the body of the animal of a reflex path, a chain of neurone connecting a definite sensory point with a definite motor point. The remarks following this paragraph will not interest all readers and may be passed over. We cling to these terms "sensory" and "motor" points, altho others would prefer the terms "receptor" and "effector." As we have previously mentioned, the effects of excitations are con- tractions in the striped (skeletal) and smooth (organic) muscles and secretions in the glands. But the skeletal muscles, being the chief motors of the body, have more social importance than the other muscles and the glands. Secretions, compared with motions, have but little social significance and therefore interest the psychologist much less than the physiologist. In our figures the letters S and M (Sensory and Motor functions. Sense organs and Mus- cles) have for the psychologist a better suggestiveness than the letters R and E would have, — in all languages. For similar reasons we shall later speak of sensory and motor neurons rather than of afferent and efferent neurons. There are two further reasons for avoiding the words afferent and efferent. They are difficult to distinguish in the spoken language, in the class room. And they suggest to the stu- dent the very unfortunate conception of the brain as a reservoir or storage tank of something. We do not know what the number of neurons is which, in the higher animals, make up reflex paths. It is quite arbitrary that in our graph we represent this number by three. There is however, a certain probability that the 48 PSYCHOLOGY OF THE OTHER-ONE actual number is often three and never less than three. In one of our arches, which, since they represent reflex func- tions, might well be called "reflex arches," for example in the reflex arch S, S^- MJ-M , the conductor S SJ> will C c c c ' c c for obvious reasons be called a sensory neuron, M^-M a motor neuron. The neuron S^-MJ- will be called a nerve c c center. No particular meaning attaches to the word "center" in neurological usage. It has like so many other terms a purely accidental historical origin. There was a time when even scientists believed that certain parts of the nervous system, of the brain, had the power to act spontaneously, to direct by their own sweet will the actions of the animal. These parts were then called centers, very much as we speak, without being able to give the word any literal meaning, of the center of a government or of a telephone central. In our reflex arch we mean by center simply that neuron which is neither a sensory nor a motor neuron, — not having either of its ends in a sensory or motor point of the body. We may, however, choose now and then to call the point S^ in an indirect, derivative sense a sensory point. But, to make this clear we must add to "sensory" a further, modifying adjective, for example, the adjective "central." That addition then has the sense of a negation, of a limita- tion. Let us then call the point SJ-, on those occasions where we find it convenient and desirable, a "central sensory point." The addition means that it is not a sensory (sensi- tive) point of the body. This is no uncommon usage of language in science. In physics we call latent heat what is not heat, what has no temperature. CENTRAL AND PERIPHERAL 49 A central sensory point is a point in a nerve center from which one can trace a shorter path to a (real) sensory point than to any motor point of the body. In the same manner MJ- will be called and regarded as a central motor point. From it one can trace a shorter path to a motor point (muscle) than to any sensory point of the body. That is all that is meant. Nothing else. Speaking of sensory and motor nerve centers has been common practice in neurology from its early history. We have here merely defined these terms for our use more exactly than is customary. Having called S^-MJ- a nerve center, we may add that it is a "low" or "lower" nerve center, for we shall later have to learn that there are also "high" or "higher" centers. The "lowest" center is that one which makes the shortest con- nection, the shortest among all those paths which may exist, leading from the definite sensory point to the definite motor point under consideration. In other words, each particular reflex function depends on the existence of a particular low nerve center serving the two "corresponding" peripheral points, sensory and motor. Peripheral, of course, is noth- ing but a common term including both sensory and motor. The literal meaning of "peripheral" is here entirely lost. A student feels puzzled when he is asked the question if he could deprive an animal or a person of one of his re- flexes by cutting it out with a knife. The question is really clear and concrete ; and the answer is simply "Yes." Having a reflex means no more than having a definitely located "chain" of neurons. It may be difficult to determine its exact location. And it may be difficult to cut it out without cutting out other things too. But these are difficulties which exist in every surgical operation — in varying degrees. CHAPTER III The Other-One's Reactions are either Concerted or LocAiv The purpose of a reflex is to insvire that the action take place in a certain locaHty when the stimulation occurs in a different locality. A reflex reaction so far as hitherto considered is a local reaction, — local in the sense of not being a general reaction or a reaction in many localities of the animal's body. But local action is not always the action which benefits the animal under the circumstances of the case. Let us look for examples from the Other-One's daily life. The Other-One climbs a tree. He does that by applying two hands and two feet to the tree and its branches. Climb- ing without all four extremities is almost impossible. The four limbs must co-operate. That does not mean that the muscles of all the limbs must contract at exactly the same moment. But they must contract at about the same time. A contraction of one followed by a contraction of another one a minute later could not be called climbing. As we have pointed out in another connection in a previous chapter, in order to understand, to make plain, to "explain" the facts, we must simplify them as much as possible, — in our imagination if we cannot do it actually. Is it possible, in this manner, to place all actions which are not "local" into one class and call them by one name ? The title of this chapter seems to assert that this is possible. And it suggests as name the term "concerted." (50) CONCERTED ACTION. 51 Even in so simple an action as hitting a table with a fist a large number of muscles are involved. The very fist is the result of the contraction of certain muscles bending the fingers. The downward motion of the fist is the result of the contraction of certain muscles producing various motor effects, chief among them the stretching of the arm in the elbow joint. If these muscles remained contracted, the fist, after having hit, would press the table. Other muscles must immediately bend the arm at the elbow joint if it is to be a mere hitting without continued pressing upon. They must begin to contract even before the stretching muscles begin to relax. Any such actions which occur (must occur in the nature of the case) either at the same moment or at almost the same time or in such quick succession that one is justified in saying they occur at about the same time, might well be called concerted. There is no need of limiting the meaning of the term concertedness. It may very well include actions, occurring at about the same time, which have various ad- ditional temporal or even other relations. This abstract statement will be illustrated by concrete examples of such mutual relations. When one hears the word "concert," he thinks of music. That is not the original meaning of the word. It means really nothing but agreement in action. In European politics during the nineteenth century one used to speak of the concert of the Powers. But with no other kind of agreement in action are we so familiar as with that of a company of musicians playing before us. Their concerted- ness of action can teach us an important distinction relative to causes and effects, which we have to make also in speak- ing of concerted actions in any animal or in the Other-One. 52 PSYCHOLOGY OF THE OTHER-ONE. The questions "Why do musicians play?" and "Why do the musicians play in concert?" refer to very different psychological causes. They play because (if we give a simple and striking answer) their stomachs are empty. The stimulus is lack of food. They want to make a living. The stimulation which causes the concertedness of their action is an entirely different one. This stimulus comes from their leader, their conductor, the director of the orchestra, or whatever you call him. They would not play if you offered to give them the sight of their conductor as a substitute for paying them money. And they would not (could not) play in concert (according to the highest standards) if you offered to put a ten dollar bill into each one's pocket as a substitute for giving them their leader. The stimulus com- ing from the conductor of the orchestra is a sign or sound made by him. If a musician does not make his tone at the right time or with the proportionate pitch or strength, the conductor of the orchestra acts as a stimulus which makes the laggard speed up or the bungler correct himself. The conductor of the orchestra, let us remember, does not func- tion as the cause which makes the musician play, but as the cause which makes him adjust his playing. In all concerted action we must carefully distinguish these two classes of stimuli : the class of stimuli causing each of the local actions; and the class of stimuli causing the concertedness of the several local actions, — whatever this concertedness may consist in. Now let us think of some further examples of concerted action of his limbs in the life of the Other-One. Having climbed high up on a tree he wishes to pass from one of its large branches to one of the very near large branches of a neighboring tree. He passes along hanging. In this activity his two arms co-operate. Deprive him of the use of one CONCERTED ACTION. 53 of his arms, and he cannot pass along the branches support- ed by one hand only. This is another example of concerted action. But it interests us not only as an example of con- certed action. It interests us still more by being a con- certed action which is a part of the concerted action of climbing. Being a part of a complex, it is in a sense a local action. It is confined to the arms, whereas climbing is an action of both, the upper and the lower, pairs of extremities. An action, therefore, is concerted or local only in a relative sense. The same action is local in comparison with another of which it is a component ; and concerted in comparison, of course, with another which is one of its components. Walking is concerted action because it consists of action of the two legs in agreement. Walking is local action be- cause it is action in the locality of the lower extremities only, not a concert of the lower and upper extremities as is climbing. Standing on one foot is local action ; and at the same time concerted, in so far as it involves co-operative action of many muscles. Picking an apple from a tree with one hand is likewise, in a relative sense, to be regarded either as local (one hand) or concerted (hand. arm. shoulder, standing feet. etc.). Treacling the pedal of a machine with the right foot and feeding in with the right hand material for the machine to work on. is clearly concerted action ; and yet it is purely local, right-sided, in so far as the left side of the body is inactive. The workman might have lost his left arm and his left leg. When a student is asked what bodily actions his teacher, perhaps lecturing during a whole hour, performed during that hour, he replies: "He talked. He used his speech organs." And that would be a very exact statement, in 54 PSYCHOLOGY OF THE OTHEE-ONE. some sense; for example, before a jury in a court room. And yet, in another sense, it is very inexact. A local action confined to the speech organs is quite impossible under normal conditions. The lecturer not only talks, but also stands, — or sits, in accordance with his temperament. Stand- ing is an action. If you do not believe it, if you think it means doing nothing, enjoying a rest, ask a recruit in the army. And sitting equally is an action. Is a hen enjoying a rest while sitting on eggs? Certainly not. And the lec- turer, while more restful in the sitting than in the standing position, is less restful than he would be in the lying posi- tion. If all muscles relaxed, no sitting would be possible. Be- sides, the lecturer must keep his head steady. If it fell up- on one of his shoulders or his che^t, lecturing would be impossible We see from this last example that a "local" action signi- fies only that the "main" muscular activity is confined to i certain locality in the body. It does not signify that there are no muscular activities outside of that locality. The latter, however, are of minor importance or seem to be so. A purely local activity in a biological sense is virtually im- possible. But in a social sense, from the point of view of those among whom the Other-One daily lives, an action may be called purely local. It means simply that the only activity which, at a given time, was strong enough to be significant, conspicuous, worth mentioning, was the action at a certain locality of the body. No newspaper reporter, for example, would mention that a politician addressing a certain audience, in addition to talking, kept his neck muscles under tension, washed his eyes by winking the normal number of times per minute, now and then swallowed saliva, and frequently shifted the weight of his body from one to the other foot. From a CONCERTED ACTION. 55 social point of view the politician merely talked. He did not, for example, talk and dance. This, however, the re- porter could rightfully have said of some chorus girl of the operetta stage, and he would then have reported a case of concerted action, where two actions, talking (with the speech organs) and dancing (with the feet) would have been equally pronounced and occurring in necessary agree- ment. The pronunciations and the writing actions in the use of a language are both good examples of concerted action. Pronouncing "ferret" is a concert of muscular activities. Pronouncing "fret" is another one. The comparison of the two cases illustrates the importance of the relative force of each constituent action. In other cases of pronunciation the succession of the elements is of main importance. In writing it often happens that the succession of the elements is incorrect. A certain one of two muscle sets, both of which are ready for action, precedes the other one instead of being preceded by the other one. The author once knew a student who usually "lasped" into writing Odgen the i?ame of his teacher which really was Ogden. The cause of it is obvious. In the English language the writing actions of d and g in this succession are a much more common form of concert than g succeeded by d. Think of badge, edge, ridge, lodge, cudgel. These examples will suffice to keep us aware of the fact that it is never useful to think of concertedness in any but a relative sense. A concerted action may, according as it is compared, be local. In that case we shall regard it theo- retically, that is, in artificial and intentional simplification, as a mere reflex action and represent it by a single reflex arch. In so far as we consider its real complexity, it need not consist of strictly simultaneous (but only of about 56 PSYCHOLOGY OF THE OTHEE-ONE. simultaneous) muscular contractions. The agreement of the several components may be of one kind or of another, of many kinds still to be illustrated by further examples. All that the term concertedness implies is a definite manner of co-operation of a definite number of localities of an animal's body leading to a definite real or apparent end. And the co-operation must take place within a period of time so small that one can speak of it as "the present" time. For example, "at the present time Robinson Crusoe is climbing a tree." Or, "at the present time he is walking." The simpler the manner of co-operation of different localities, the easier it is to make it clear and understandable as the result of definite causes, of definite biological func- tions. In low animals the manner of co-operation of several local contractions is likely to be simpler than in high animals. It is therefore advisable to study and understand clearly a case of concerted action in a very low animal. In the jelly- fishes the ordinary locomotion is a good example of concer- ted action. Let us study it in detail. TWO CROSS-SECTIONS OF A JELLY- FISH. A jelly-fish has a bell-shaped body. The figure shows it in cross-section. The so-called vegetative organs and the feet or tentacles have been omitted because they do not in- terest us in this connection. On contraction of the bell, in the manner indicated by the dotted line, the water — the medium in which the jelly-fish lives — is pressed out of the CONCERTED ACTION 57 concave side, and the animal, naturally, moves in the di- rection of the convex side. As a matter of fact, the move- ment of a jelly-fish in the water is rarely seen to be as simple as our statement suggests. The usual position of the animal is with the cavity downwards, tho not neces- sarily with the axis exactly in the vertical position. And its usual locomotion is oblique rather than in the direction of the axis. But, as we have previously justified it in gene- ral, so we here as elsewhere simplify the actual case and regard it as a motion along the axis in the direction of the convex side. It is plain enough that a straight-way locomotion could then result only under certain conditions. For example, it would be impossible if the tissues on one-half of the rim of the bell contracted while those on the other half relaxed, expanded, or even only lagged behind a little in contracting. This lagging behind, however, could easily be brought about by the uncontrolled play of certain conditions, — which we now have to study. To understand these conditions, let us first imagine the analogous case of eight leaky places on a water pipe. Sup- pose the frequency of the dropping at each place to be about the same, say, one drop a second. But even then we could not expect all the eight drops to fall simultaneously : as we say in physics, we could not expect that there be no phase difference among the eight drops. The eight drops would probably fall from the eight leaks in a quite irregular suc- cession. Let us make the application of this analogy. The rhythmical contraction all around the rim of the bell would be caused by the chemical constitution of the jeUy-fish at the time in question, when perhaps no food has been taken for some time and locomotion thus has become necessary. Now, lack of food is a very slowly developing, 58 PSYCHOLOGY OF THE OTHEE-ONE. slowly acting stimulus. The excitation resulting from it has a chance to distribute itself continuously all over the body, — to distribute itself more quickly than it develops. It is therefore quite impossible that it differ appreciably in various parts of the body at the same time. The excitation being the same in all the divisions of the rim of the bell, no division would on account of stimulus and excitation have a frequency of periodic contraction differing from that of any other division. Of course it is here presupposed that, the greater the excitation, the greater the frequency of the resulting contraction. In spite of the uniformity of the excitation (the chemical condition) thruout the body, however, there might be a slight difference of the frequency of the bending inwards of the divisions of the rim, if the tissues happen to be un- equally flexible. In consequence of a wound there might remain a scar, and the tissues of this region might therefore, or simply by accidents of growth (what animal could be absolutely perfect in symmetry!) be a little more or a little less tough than elsewhere. A difference of frequency would result. What would be the result of a difference of frequency for the locomotion of the animal? If of two paddle wheels on the two sides of a steamer one would go faster, strike the water nore frequently, what would be the result? The steamer would continuously turn to one side, gradually de- scribe a circle. That would help little to remedy the evil of lack of food, — in the analogous case of a jelly-fish. Now suppose the frequency of contraction, fortuitously, to be the same everywhere. That would by no means in- sure that the contractions occur in all the divisions of the rim of the bell simultaneously. There would be as little probability for that as for the falling, simultaneously, of CONCEETED ACTION 59 those eight drops at eight leaky places of a pipe. And what would be the result for the locomotion of the animal? The same as if several boatsmen rowing a boat in a race would not drop their oars in the water simultaneously, but in irregular succession. The boat would not advance in a straight line but wabble, so to speak, irregularly and jerkily from either side to the other. That would be a considerable waste of effort. Could the simultaneity be insured? In the boat race it is insured by the captain of the team, who, if necessary, counts aloud. His words are not the stimulus which makes the oarsmen work. (We remember the conductor of the orchestra!) His words are the stimulus which makes them correct the imperfections of the concert of their actions. The boat no longer proceeds in an irregular serpentine, but in a straight line. It has a chance to win the race. In the jelly-fish, as soon as one of the divisions of the rim of the bell "spontaneously" (that is, in response to the stimulus "lack of food") begins to contract, this contrac- tion itself assumes the role of a stimulus. From it results a new excitation, — in the very tissues contracting, an ad- dition to the excitation previously existing in them, which has caused their contraction. But what becomes of this new excitation ? All tissues are, as we know already, to some degree sen- sitive, contractile and conductive. The new excitation is therefore conducted to all the other divisions of the bell, even tho there be no differentiated conductive tissue. Those other divisions are almost ready to contract, in response to the stimulus "lack of food." They would contract in any case, one soon, another one just a moment later, and so forth. The additional excitation reaching them "speeds them up," causes them to contract now, all of them virtually 60 PSYCHOLOGY OF THE OTHEE-ONE. at the same moment. One must remember in this connec- tion that the velocity of propagation ("velocity," not rato, not quantity of flow) of any small unit of excitation is quite considerable ; probably not much less than 100 feet per second. And from one side of a jelly-fish to the op- posite is a distance of only a few inches. So all the divis- NERVOUS SYSTEM OF A JELLY-FISH (ACALEPHA). ions would contract virtually at the same moment. In physical terminology, — that is, in the mathematical termino- logy of the physicist, — one would say that the phase dif- ference of the periodic contractions of the various divisions was zero. What now about any possible differences of their periods, — or (since this means really exactly the same) of their frequencies? We have made it clear previjusly that a difference of frequency is much less likely than a difference in phase. The stimulus "lack of food" is a slowly developing stimulus, the excitation is therefore evenly distributed ; and consider- able differences in the toughness of the tissues are probably rare. If any difference in frequency is to be expected, we would expect only a slight one. And frequencies differing slightly would readily be equalized by the same factor which does away with the phase differences. If those divisions of the rim of the bell which lag behind, are forced to con- CONCEETED ACTION. 61 tract at the moment when the first contracts, and thus at the beginning of the next period again all contract at the same moment, and again and again, there can obviously be no frequency difference. In the locomotion of a jelly-fish the concertedness of the actions of the various divisions of the animal consists in the fulfilment of two conditions : in equality of the frequency of the various local contractions and in the phase difference of their periods being zero. And this concertedness — we understand now — is brought about simply by the fact that a contraction of tissue, altho resulting, of course, from a stimulus, can itself be a stimulus. This latter stimulus is analogous to the class of stimuli coming from the leader, in the example of the orchestra. Naturally, there is no special leader in the body of a jelly-fish. Any part may accidentally assume this role. The stimulus "lack of food" is analogous to the stimulus "lack of food" in the other case. We shall later see that in the highest animals, too, con- traction of contractile tissue may be itself a stimulus. In- deed, the muscles, for that reason, must be regarded, not only as motor organs responding to sense organs, but them- selves as sense organs to which other muscles may respond. This interesting fact, altho it suggests itself, cannot be dis- cussed further at this moment, since that would interrupt our present line of thought. But this may still be said in this connection, that one must not think it strange that the muscles should have two different functions. In fact they have still other functions. They are also the "stoves" which heat the body. And they are organs of secretion which, as such, like glands are of much importance. Biologically there is nothing strange in an organ having a multiplicity of even diverse functions. 62 PSYCHOLOGY OF THE OTHER-ONE. Equality of frequency and phase is one example. Serial occurrence is another example of concertedness. We find serial occurrence of actions in the highest as well as in the lower animals. All writing and speaking can furnish exam- ples. Or an experience of the following kind. Think of an insect alighting on your nose. Many are the responses which may occur. But which of them in all probability will be the first? Most probably you twitch or wriggle your nose ; the insect is disturbed and leaves. No further action then follows, — there being no further stimu- lus. But the insect may have such a good hold on your nose that such slight movements will not cause it to leave. A second reaction occurs. Yovi shake your head. But if this does not remove the insect, and if the stimulus, therefore, persists, you make a hand movement. With which hand? If you are what most people are, right-sided (this is a better designation than right-handed), you move the right hand. This will surely brush the insect off, if your hand can reach the nose. But imagine you are a captive among Indians and tied to a tree. The third reaction, that of the muscles controlling your right hand, therefore remains as ineffective as those preceding. Your fourth reaction will then be that of your left hand. It is ineffective like the third. Your fifth reaction is that of the right foot. Why should you not try to take a reed or a similar thing between your toes in order to brush the animal off? People who have no hands may be seen to take even a writing pen or knitting needles between their toes! If the right foot does not suc- ceed, the sixth reaction may be that of your left foot. And after that a general twitching of all the muscles of the body may follow, general convulsions. You would not, with a mere sigh, permit the insect to destroy your nose in the man- ner in which in the classical paintings Prometheus reacts to the vulture gnawing his liver. CONCEETED ACTION. 6 c» The reactions in a case like our example are not likely to occur in an irregular series, but in a definite one. And in a series, not simultaneously and immediately. Similar to serial reactions are circular reactions. The simplest circular reaction, consisting of two members only, is alternation. With alternate or reciprocal actions we are very familiar in engines. The piston of a steam engine, going one way, operates a lever which initiates its going the other way ; this makes it go again the former way, and so forth. The heart of animals consists essentially of two chambers thru which, because of self-closing valves, the blood can pass only in one direction. The contraction of one chamber acts on the other chamber causing it to start contracting. The contraction of the other acts on the one, and so forth. At a first gla-nce all that seems necessary biologically in order to bring this about is the fact already mentioned, that a contraction becomes itself a stimulus, that is, the cause of an excitation. This excitation is conducted to the other muscle. The other muscle then contracts and, as a stimulus, causes in itself a new excitation, which is conducted to the former muscle, and so forth. If we, accepting the responsi- bilities of the Creator, desire to improve the conduction, we do that by introducing differentiated conductive tissue. We take two reflex paths, put the sensory end of one of these "chains" of neurons in one muscle and its motor end in the other muscle. In the latter muscle we place also the sensory end of the other neuron chain ; and the motor end of this we locate in the former muscle. Two reflexes joined in this manner seem to be all that is necessary for this form of concert. If there are three members in the circle of action instead of two, three reflexes are joined end to end. And so forth with higher numbers. 64 PSYCHOLOGY OF THE OTHEK-OXE. In a true series, — not occurring in a "circle" like pump actions, but running along a "line," from one end of the series to the other without repetition of the series, — nothing more seems to be required, either, than a number of reflex paths joined and one initial stimulus from outside the muscle group. Draw some reflex arches side by side as in a pre- vious figure, but join the sensory point of the arch on the right to the motor point of the arch on the left. Continue adding in this manner as many reflex arches as you wish. This looks like a simple solution of the architectural prob- lem confronting the Creator in any case of serial or of circular action. — But it is not. The solution just suggested may solve the problem in many of the simpler cases. But it is far from being a solution general!) possible in biology. Two conflicting con- ditions seem to make life impossible. The problem would be hopeless if a complete denial of the demand of either the one or the other were insisted on. But what are these two conflicting conditions? One is the need, in the life of animals, of concerted action of various kinds. The other condition is the need of local responsiveness in the sense of one action being overwhelm- ingly strong in comparison with the responses occurring at the time in other localities of the body. It would be terrible if a jelly-fish, for example, could move only in a straight line without ever changing its direc- tion, — if a contraction of one division of the rim of the bell would invariably force all the other divisions to contract at the same moment. It would be terrible if the ability of a boy to climb a pole straddling forever precluded the pos- sibility of moving his hands alone, that is, without alternately moving now hands, now feet, again hands, again feet, and so on, — if he were thus condemned to be all his life a kind CONCERTED ACTION". 65 of jumping jack, if he could not eat without exercising at the same time "half bend of the knees." It would be terrible if chewing, swallowing, and pushing things down the esoph- agus, which often occur in this order in a series, could never occur otherwise, — if chewing could never be followed by spitting, and swallowing never by vomiting. And yet these terrible consequences seem to be inevitable if concerted action is always and only the result of perfec- ting the conductivity of the tissues concerned, or, in the higher animals, of joining reflexes together. How can the reflexes, by functioning separately, give the animal local responsiveness, if the very cause of their existence, the separateness and localness of the response, has been denied by joining them in groups or series? On the other hand, — this is the dilemma — how can con- certedness be the result of anything else but of the con- ductivity from acting member to acting member of the inter- posed tissues, or of the junction of several reflexes? The reflexes must be joined. The problem is obviously, not merely a problem of joining or not joining, but rather of joining in the proper or in an improper manner. It is a problem, seemingly, of architectural design within the con- ductive tissue, within the nervous system. In order to force yourself to understand the problem better, imagine yourself to have received from the Creator an appointment of serving as his assistant, to have received the task of constructing for the benefit of a given animal a nervous system which will fulfill its needs. It is the same as in understanding any engine, a sewing machine, a clock. Put its pieces together so that it works, and you have made its function perfectly clear to you. If you cannot actually, materially, construct the machine, you can construct it by making a drawing, putting the 66 PSYCHOLOGY OF THE OTHER-ONE. elements together on paper. Design a nervous system by joining together reflex arches, as if you were the Creator's architectural deputy. That will make you understand the problem and at least some of the possibilities of its solu- tion. This does not mean, however, that you have any right, taking the interest of science at heart, to indulge in any fanciful designs of a nervous system unrelated either to the facts of the animal's behavior or to the neurological knowl- edge of the time. You must, indeed, limit yourself strictly to the results of anatomy, histology, physiology, organic chemistry, etc. But where the knowledge of the facts by contemporaneous science is incomplete, you not only can but must All the gaps by hypotheses. A scientific hypothesis has a double value. First, it satis- fies an intellectual person's practical need of understanding what he experiences. The hypothesis is not ''the known," but it is "an analogy of the known." Human as we are, if we do not satisfy our desire to understand things at least by constructing an hypothesis, we fall easily into the habit of completing deficiencies of knowledge by imagining mys- teries as causes. And secondly, a good hypothesis has the immense value of spurring us on and showing us the way in research, of pointing to a fruitful direction in which to look for facts whose knowledge may in the future be substituted for the analogies of which an hypothesis is constructed. What, then, will be the hypotheses of nervous architec- ture and nervous function by means of which you fulfill the imaginary task given you by the Creator? CHAPTER IV Concerted Action presents a Problem to the Archi- tect OF THE Nervous System, In modern discussions of the function of the nervous system a phrase is often found which we have thus far avoided. One hears much about "the integrative action of the nervous system." This phrase means exactly the same as what is expressed by saying: "Concerted action depends on the architectural and functional properties of the nervous system." It is likely to be misunderstood by an inexperi- enced student as meaning that the nervous system's only function is that of integrating, "making a whole," insuring the concertedness of the animal's actions. But the previous chapters have shown us the very opposite of integration. The separateness, the localness of a response to a stimulus is also a purpose of the existence of the nervous system. And the latter purpose is no less exacting in its demands than that of unifying the animal. What does "concerted action" ask of the architect of its house, so to speak? What is the most general demand made on the nervous system by concerted action? Is this not readily agreed on by all the parties to the contract, that some nervous current, no matter whence it comes, must be able to go to all those points where the contractile tissues are located which are to act in concert? Must not the leader of the orchestra be able to reach all, be visible and audible to all the musicians? (67) 68 PSYCHOLOGY OF THE OTHER-ONE. No one believes that this is sufficient, and that, this de- mand granted, all problems have disappeared. But, thinking of the problem of concertedness in the simplest possible way, this is certainly the most fundamental necessity. Some current must go to all those points. In the case of the jelly-fish — as to coming — we saw that this current came from one of the contracting divisions of the rim, caused by the contraction itself ; and— as to going — that it went everywhere because of the conductivity of all the tissues. The question remains if this current would not be too weak if it had to pass wholly thru undifferentiated tissue. Now, it need be only weak because, as we remember, it has to hasten only, not to cause, the contraction of the several divisions. Nevertheless, it might be too weak. Then the Creator would have to come to the animal's aid as the architect and builder, would have to furnish it with dif- ferentiated conductive tissue. Turning back to our figure of the jelly-fish as seen from above, we notice there ra- diating nerve fibers serving this purpose. If the Creator has appointed you to place these fibers in the animal so that they serve this purpose best, you will probably connect them all in one point. You will make them all radiate from one point. Then good conductivity from any division of the rim to any other division is in- sured. Nevertheless the animal, if It can speak to you, its "bene- factor," and if it is wise, will protest against this gift. Fre- quently external stimuli act upon the body and require, not a straightforward locomotion, but a change of direction as response. For example, the jelly-fish, while swimming, strikes a rock with one side of the bell. The jelly-fish then must change its direction. That division which touched NERVOUS AECHITECTURE. 69 the rock must contract more strongly than any other, especi- ally than the diametrically opposite division, in order to bring about the change of direction. Without conduction, the predominance of the action of the one division touched would be certain. But with perfect conduction to all other divisions it would be equally certain that no such predomi- nance of a local reaction, no local responsiveness to an ex- ternal stimulus, would be possible. We only repeat here. We have already referred to this fact, the impossibility of such a conductive system, in the second chapter, while discussing the life of our imaginary snail. Here is, then, the necessity for a compromise. And this compromise is effected in the jelly-fish by having the eight radial fibers not join in the center, but stop short before reaching each other. Thus undifferentiated tissues, tissues of high resistance, are interposed to weaken the excitation coming from one of the divisions to such an extent that only one division can react strongly to the external stimulus. All others react only weakly. It is interesting to note that compromising, which is the very foundation of all social life of animals, of all social institutions of mankind, is found to be an essential function in the individual life of any one of the very lowest animals which possess a nervous system. The unity of all organized nature, which is the fundamental concept of modern biology, is exemplified by this role played in any life, low or high, by compromises. Two conflicting conditions seem to make life impossible. But the problem would be hopeless only if a complete denial of the demands of either the one or the other were insisted on. On the one hand, concerted action calls for the most perfect conduction from any division of the rim of the bell to all the others. On the other hand, 70 PSYCHOLOGY OF THE OTHER-ONE. local responsiveness calls for the interposition of high re- sistances between the diametrically opposite divisions of the rim. The compromise must then consist in this, that all the divisions are connected by conductors, but in such a way that conduction from one point of the rim to opposite points is by the properties of the conducting medium itself more resisted than conduction to neighboring points. Nature has, as we saw, solved the problem by stopping the differentiated radiating conductors as far short of the center as the condition of local responsiveness requires, leaving in the center enough undifferentiated tissue inter- posed to meet this requirement. Another way of fulfilling the condition of varying resistance is by resorting to the length of the differentiated conductors without interposing any undifferentiated tissue. There can be no doubt that the length of a nervous conductor determines its resistance as the length of telegraph and telephone wires determines their resistances. The longer the conducting string, the greater its resistance. Nature has solved the problem in this way in another kind of jelly-fish, called hydromedusa. Here all the points NERVOUS SYSTEM OF A JELLY-FISH (HYDRO- MEDUSA). of the rim are connected by differentiated conductors form- ing a ring, as shown in our figure illustrating the nervous system of this species. If any division of the rim contracts, NEEVOUS ARCHITECTURE. 71 the excitation is by this ring conducted to all other divisions. But the excitation reaching opposite parts of the rim is much weaker than that Vvhich reaches neighboring ones, in accordance with the varying length of the conductor. This difference in the intensity of the conducted excitation does no harm in the case of ordinary, straightforward locomotion. The rhythmical contraction is in this activity the result of the chemical constitution of the body which, perhaps, has been the result of lacking food for some time. This chemi- cal state differs but slightly in the various parts of the body. The different parts of the rim, therefore, would contract and expand in almost the same periodicity anyway. A very slight excitation conducted from elsewhere is then sufficient to hurry up any part which without this excitation would lag behind. Thus there is concerted action. But when a stimulus acts from without on any point of the rim, only those parts are caused to respond strongly which are in that neighborhood. The other parts of the rim, receiving the effect of the stimulus as a weaker and weaker excitation the longer the piece of the rim over which the excitation has to travel, are considerably affected only if yet rather near the point of stimulation. The divisions opposite this point remain practically unaffected by the stim- ulus. There is local responsiveness. The problem of combining undisturbed local responsive- ness with universal connection of all the parts of an animal's body by conductors of low resistance can therefore be solved architecturally in more than one way. Our figures of the two species of jelly-fishes represent two solutions of the problem, both actually found in nature. But the second solution seems the more perfect one, because the universal communication thru conductors is in this case more perfect , while local responsiveness is as satisfactorily retained as in 72 PSYCHOLOGY OF THE OTHEE-ONE. the other case. This more perfect solution of the problem resorts to the differences of the resistances of the conduc- ting paths as dependent on their varying length. We shall have to keep this in mind. The example of the jelly-fish has taught us that there must be a gradation of resistances. Imagine a sensory point called A and a motor point called B. If it is desirable for an animal's well-being that an excitation occurring at A be followed most readily by a contraction at the point B, the points A and B must be connected by a conductor of small resistance. Let us call those sensory and motor points which are thus connected corresponding points when- ever we need a brief term by which we may refer to them. If, as in the case of a jelly-fish or a snail, these cor- responding points are virtually identical, only different names for the same place perhaps, the conduction is a self- evident fact even without any special conductors. If, as in the case of the moth, A is an eye and B the muscle of a wing, at a distance from each other, the conduction be- tween the corresponding points must be mediated by a nervous string, or a chain of nervous strings, of the shortest length possible under the anatomical conditions. But all — or at least some — of the other, non-corresponding, contrac- tile points of the body must also be in some way connected with the sensitive region A. Otherwise no concerted action might be possible. The moth, for example, would hardly be able to alight on a twig or leaf which happens to impress itself on the animal's eye and towards which the moth must act, not only with its wings, but also with its legs, in order to alight. These further connections with the point A, however, in order to leave the connection A-B in its proper functional condition, must have a higher resistance, — as we have seen, must be longer than A-B. NERVOUS ARCHITECTURE. 73 The shortest possible connections between corresponding points are exactly what we have called in a previous chapter reflex arches. We must now find a way of representing graphically those nervous conductors which lead from each sensory point to those motor points which are not corre- sponding. These conductors which are not reflex paths must be, as we have found, longer than the conductors directly con- necting corresponding points. It is clear, then, that no good purpose could be served by representing the connections between non-corresponding points as they are represented in our figure showing two nested reflex arches. The figure is intended to demonstrate merely how neurological func- tions ougth not to be — but how they nevertheless some- times are — described. Si Mi St Sa Ma Mb A WRONG DESIGN OF CON- NECTIONS. Let US agree that any straight line, no matter what its length, shall represent one neuron of standard length and of a unit of resistance. Such lines as S^M^, which has a crook between its straight ends, are also regarded simply as straight lines, because the crook signifies nothing but insulation from the line crossed on the paper. All this is customary in such drawings. We then measure the re- sistance of a path in the drawing by counting the number of lines of which the path is composed. This number gives 74 PSYCHOLOGY OF THE OTHER-ONE. the resistance of the path in units. The conductivity is in- versely proportional to the resistance and can be measured by the reciprocal value of the resistance. For example, if a certain resistance is 4, the conductivity is | ; and if the resistance is f , the conductivity is ^. Now imagine the connections between non-corresponding points made by nature as in our drawing. Count the units of resistance. The conductor S^^S^M^Mg connecting the non-corresponding points Sj, and M^ has not a greater resistance than the conductor S^S^M^M^, since both are made up of three standard lengths, altho our requirement is that it shall have a greater resistance, a lesser conduc- tivity. We must look for a different design in order to represent the actual conditions of conductive connection properly in a graph. Neurology, that is, the anatomy and physiology of the nervous system as it actually exists and functions in animals and in man, teaches us an important fact which we ought to represent in any diagram of nervous connections. It has been found that the same two points (one sensory and one motor) are almost always connected in several ways, by shorter and also by longer conductors. For example, if pain is caused in a dog's foot and the foot is withdrawn, the nervous excitation may travel from the foot to the spinal cord and thence to the muscles moving the foot. Or, it may travel from the spinal cord farther on to the dog's brain, thence back to the spinal cord and now only to the muscles. In an early stage of neurology a merely two-fold con- nection, including or not including the "brain" (a somewhat indefinite something), was supposed to exist. One then spoke of two neural "levels" to which the lower and the higher "nerve centers" (another rather undefined some- thing) belonged. The number of these so-called levels of NERVOUS ARCHITECTURE. 75 connection was later increased to three, and three classes of lower and higher centers were spoken of. From three the number grew to four. And so forth. Today there can be no doubt that the number of different levels of connec- tion is very great. It may be among the hundreds or thousands. The total number of neurons available for the architecture of the nervous system is so great (five thousand millions or more) that in a human being certainly even a thousand levels of lower and higher centers are far from impossible. It seems best to keep out of this field of spec- ulation. However, there is no reason for thinking of the number of different levels of connection as being very small. He who thinks only of a two-fold connection of greater and lesser length between corresponding points, and re- Sc Si Sa A WRONG DESIGN OF A NERVE CENTER. members our requirement that the connections of non- corresponding points shall be longer than the (direct) con- nections of corresponding points, will readily suggest to us as a suitable design for the architecture of the nervous system our figure showing three nested reflex arches and additional neurons radiating from the center C. 76 PSYCHOLOGY OF THE OTHEK-ONE. In this figure we can travel from, say S^, to the corre- sponding point Mg over a longer route by C (four standard lengths), or over a second and shorter route (three standard lengths) avoiding C. And we can travel from S to a non- corresponding point, say M,,, only over a longer route SgS^CM^Mf, of four standard lengths. The same rule holds good for other combinations of sensory and motor points. Before continuing the discussion of the question whether this is a suitable architectural design for a nervous system, we may use this opportunity of making clear why we have drawn each conductor, each neuron, in the shape of an A>- CHECK VALVES AT A MEETING POINT OF NEURONS. arrow-like rod. We can easily agree and remember that the point of any arrow shall mean that no excitation can enter here from any other neuron, whereas the split end shall mean that an excitation can enter here, but cannot pass out. In our figure with the lettering A-B-C-D three neurons meet in one point, D. An excitation here may pass from AD into either DB or DC, but no excitation can pass from either CD or BD into DA. It is as if a multiple check valve located at D allowed the flow of a fluid in one direction, but prevented the flow in the opposite direction. The facts known to neurology not only permit, but seem to force us to assume that the meeting point of two or more neurons functions like a check valve. NEEVOUS ARCHITECTURE. / t Experiments have proved, it is true, that an excitation may travel in a neuron in either direction. But normally no excitation originates within a neuron. And with res- pect to the propagation from neuron to neuron, neurologi- cal experiment and observation seem to agree with the view expressed in our drawings. Everybody knows that our feet are connected with our eyes as well as with our ears ; of course, also with other sense organs. If a strange and ferocious looking animal sud- denly appears to any ordinary person's eye while he is sit- ting, he jumps up and starts running — on his feet. If he is sitting in the theater, and suddenly the fearful cry "fire" strikes his ear, he also jumps up and starts running — on his feet. That is, the muscles moving his feet are connected with his eye as well as with his ear. But his eye and ear are connected with many other mus- cles too. PClse, for example, he would not turn his head in response to a friend's call or eat what is placed before him on the dinner table. Neurologists have discovered in the brain the so-called motor region of the feet. If this region of the brain is artificially stimulated, the muscles belonging to the feet con- tract and move the feet. Suppose the excitation caused in the brain by this artificial stimulus could proceed, not only in the direction of the motor organs most closely connected, but also in the direction of sense organs ; then a good deal of it would go to the eye and the ear. The eye and the ear, receiving the artificially produced excitation from the brain, would send it on to many muscles of the body. It should then have been observed that in re- sponse to the artificial stimulation mentioned not only the feet, but many parts of the body moved. If such were the case, the neurologists would never have discovered the motor region of the feet. 78 PSYCHOLOGY OF THE OTHER-ONE. We are justified, then, in our assumption of a one-way propagation of an excitation from neuron to neuron, always "away from the nearest sensory points and toward motor points." The anatomical connection between neurons is of such a wonderfully elaborate kind, that it seems quite probable that the meeting points have some peculiar functions. This is quite likely to be one of them, — to serve in the manner of check valves. The neurons do not run into each other like wires soldered together, but the end branches of one surround in a curious way the end of the other neuron. This has been called synapse. The word "synapse," of Greek origin, has exactly the same meaning as the Latin word "contact." The contact between neurons is of a peculiar kind, so much so that some have said it ought not to be called contact at all, — and have called it synapse. We shall speak of it again at a later ttme. We must now return to the question whether the design of our figure showing three nested reflex arches is suitable for the architecture of the nervous system. It would be, if we could restrict ourselves to thinking of only a two-fold connection between corresponding points, to thinking of only two levels, two classes of (lower and higher) nerve centers. But such a restriction is impossible. A concrete case will easily show why. We recall the kind of concerted action which, in the pre- ceding chapter, we called "serial" action. Remember the example of the irritating insect sitting on your nose. Nature has enabled you to respond by a series of movements, be- ginning with easy ones, continuing with those which are in- creasingly cumbersome. If at any moment the stimulus is removed, the series of movements is discontinued. What will you do, if you have accepted the position of assistant NEEVOUS ARCHITECTURE. 79 to the Creator and you have been given the task of design- ing a nervous system which will make possible such serial activity ? First you will ask yourself if the condition of a succes- sive occurrence of these actions can possibly be reduced to a condition of a mere gradation in the conductivity of vari- ous nervous paths. You will recall that it is well known that many muscles of the animal body are so made that the contraction does not begin at the very moment when we have reason to believe the excitation begins to act on the muscle, but only after the excitation has had an oppor- tunity to accumulate the effect on the chemical condition of the muscle up to a certain degree. It is like balancing a plank on a fence post which is flat on top, placing an empty bucket on one-half of the plank not too far sideways to disturb the balance, and slowly pouring water in the bucket until the bucket spills the water. When will it spill the water? The first few drops pouring into the bucket will have no visible effect on the plank. But after a while the bucket will become heavy enough to dis- turb the balance. The plank will tip and all the water will be spilled at once. "All or none." The greater the rate at which we pour the water in the bucket, the sooner the bucket spills. If the stream running in is very weak, the bucket will spill its contents only after a very long time. Interrupting our thought here a moment, we may mention that an excitation on entering a muscle is often given the name of "innervation." This word has it origin in the thought of a "nervous" excitation passing "into" a muscle. We can use the words "excitation" and "innervation" in- discriminately, for passing into a muscle (or gland) is the purpose of ever) excitation which has its origin in sensitive tissue. It is not customary, however, to use the word "in- 80 PSYCHOLOGY OF THE OTHER-ONE. nervation" except when the excitation is discussed as enter- ing into a muscle. The innervation, then, can be said to accumulate in a muscle until its accumulation has reached that degree which the muscle requires before it contracts. Then we can indeed reduce the condition of a successive occurrence of movements to a condition of a mere gradation in the conductivity of various nervous paths. The sensory point on the nose must be connected by a nervous path of low resistance (that is, by a very short path) with the muscles of the nose, by a path of more resistance with the neck muscles shaking the head, by paths of further increasing resistances with the right arm, the left arm, the right foot, and so forth. Where the resistance is greatest (the conductivity lowest), the flow of the excitation is smallest. Where the resistance is small, the nervous current is strong in proportion. In accordance with the strength of the current, the various muscles receive a sufficient amount of innervation after a varying length of "latency." This means that during a varying length of time the presence of the excitation, ac- cumulating in the varying muscles, remains "concealed." It remains concealed until "the bucket spills." The strongest current goes to the nose. The muscle of the nose "spills" first, so to speak. That is, the first re- action is a twitching of the nose. The neck muscles con- tract second. Those of the rigth arm, the left arm, and so on, contract in the succession corresponding to the increas- ingly great resistances of the nervous paths. If, however, the stimulating insect is at any moment brushed off, from that moment the current of excitation ceases, no further accumulation of innervation takes place in any muscle, and no further contraction and movement are observed. NEEVOTJS AECHITECTUEE. 81 The three nested reflex arches with their connections by- additional neurons at C, obviously do not make possible any array of nervous paths in accordance with the condition that every path from the same sensory point to another and another motor point shall have a different resistance. In the design a single path — we have seen — has the resistance of three units; and all others (in the design only two others — but any number equal to the number of arches drawn, minus one) have the same, invarying, resistance of four units. If the stimulus acts on the sensory point S^, the motor point M^ reacts first (under the assumption made). But the motor points M^, and M^. would not react succes- sively to the prolonged stimulation, but simultaneously. We must therefore look for another architectural design, if we want to fulfill the task which we imagine ourselves to have accepted from the Creator. A very simple consideration convinces us that it is a mistake to try to represent a nerve center by a point. In the design of a reflex arch the horizontal line repre- sents a nerve center. The lines falling down from it repre- sent sensory and motor neurons. The "synapses" belong- ing to the horizontal line may be regarded as belonging to what we wish to call the nerve center. This nerve center is, of course, a "low" nerve center. Its two "synapses" may be temporarily considered as if they were a sensory and a motor point. In this sense we have in a previous chapter called them central sensory and motor points. Nothing prevents us from placing over a pair of central sensory and motor points an arch exactly like a reflex arch placed over a pair of peripheral (true) sensory and motor points. Nothing prevents us from placing over this second arch (the second story of the architecture, so to speak) a third; over the third a fourth; over the fourth a fifth; and 82 PSYCHOLOGY OF THE OTHER-ONE. SO forth, as long as there is any necessity, functionally, for going to higher and higher levels of connection. But if over a pair of central sensory and motor points a higher story is placed which consists only of neurons falling from a single central point, C, no further arch can be placed over this single central point. We have then reached the highest nerve center, beyond which no higher center is even thinkable. Everything we know about the anatomy and histology of the nervous sytem and about the behavior of animals con- tradicts such a conception of the architectural plan of the nervous system. If we wish to play out a trump, we can say that such a conception of a nervous system with a fixed ordinal number (second, third, or higher, but fixed) attached to the highest possible nerve center is a flat denial of the theory of evolution. The evolution of the nervous system consists, in higher animals and Man, in the evolution of higher and higher centers, making more and more indirect connection, more and more varied combination, of the existing reflexes possible. There can be no limitation of this evolution. The higher centers must be arches just as the lower centers are arches. And the connection between any juxta- posited arches must be made by a center which is higher than either center of these two arches. The main feature of a center, in a drawing, is a horizontal line and never a single point. The principle of design for the connection of two (or more) arches by means of a superposed arch can be stated thus : In order to draw the superposed arch, always draw first its horizontal line in a convenient position, and mark the end points of this line S and M. Then drop from the S point as many "shunted" sensory neurons (legs, so to speak) NERVOUS ARCHITECTURE. 83 as you have S-points in the story just below, in order to reach these S-points. And from the M-point of the hor- izontal line drop an equal number of motor neurons (legs) to the M-points just below this level. The accompanying figure shows the method of design clearly by drawing the arches the blacker, the higher the centers. 5a 4 ^h.s2L..'." Phrenology like psycholog}' literally means science of the soul. It goes without saying that those eighteenth century phrenologists (especially their master, Gall, a physician) had nothing in common in ideals or purposes with the char- latans who have been going under the same name during the nineteenth century,— and even to the present day. Our ancestors from the northern parts of Europe thou- sands of years ago located the soul, not like the Greeks in the diaphragm, but in another muscle which is quite active during many emotions. So they developed the habit of speaking of different people as having a big, soft, hard, broken, warm, cold, etc. heart. And like the Greeks they did not mean thereby a muscle, but referred to the Other- One's soul. During the last centuries, with the rise of the science of anatomy, even popular language has come to recognize that the Other-One's behavior depends on his nervous system more than on any other part of his body. Popular language, however, does not speak of the "nervous system," mentions but rarely the Other-One's nerves, and speaks usually of his "brain." Why is that so? The brain is so much more conspicuous than any other part or parts of the nervous system that it is the only part for which there exists a truly popular name, the very name "brain." One can buy brains in the butcher shop. Other parts of the nervous system are not offered for sale there as such, because they cannot easily be removed from the carcass and handled separately. The question which readily suggests itself and which this chapter will attempt to answer, is : Why have the highly developed nervous functions, with which we have become acquainted in the previous chapters, led to making a part of the nervous system so conspicuous over all others? The BEAIN 153 functions with which we have become acquainted are re- flexes, instinctive actions, and habits. The fewer instinctive actions and habits a species of ani- mals can show, the lower it is placed in the stage of evolu- tion. The more instinctive actions an animal has, and es- pecially the more habits instead of mere reflexes, the higher we call it. In general higher animals — everybody knows — also have a larger, lower animals a smaller brain. Reflexes, instinctive actions, and habits depend — we have learned — on definite structural, architectural, peculiarities of the nervous system. It seems interesting and promising, therefore, to raise the question why these structural peculi- arities should result in the remarkable anatomical con- spicuousness of one bulky mass of nervous tissue, that is, in a "brain" making its appearance, — and a brain ever in- creasing in size. Why does not, in the process of evolu- tion from lower to higher animals, merely the total quan- tity of scattered conductive tissue increase, but remain scattered thruout the body? Local responses, we have seen, require nothing further than reflex paths, which, being entirely independent of each other, may be located anywhere in the body provided the ends of each path are in the proper sensory and motor points. Paths serving simple reflexes may be scattered and need not become conspicuous save to the investigator armed with a microscope. But the necessity of a number of muscular actions oc- curring in concert introduces at once a new element into the anatomical aspect of the case. An animal as low as a worm already shows this new feature clearly. In our figure of the bulk of the nervous system of an earthworm, showing its anatomical form in the head, the middle segments, and the tail, we see lengthwise a series of black nodes. Each of these nodes serves one of the segments of which the 154 PSYCHOLOGY OF THE OTHER-ONE worm consists. We know these segments well from mere observation of this familiar animal with the naked eye. For the locomotion of the worm it is essential that each of the segments be capable of contracting separately from all the others. Since the worm's body is long and narrow, we expect that successive pieces, from the front to the rear, should function in relative independence. To make this still clearer, let us remember how the worm moves forward. The abdominal side of the body possesses tiny bristles point- ing backwards, so that no part of the body easily slides backwards on the ground. If, then, a fraction of the body, at the front end, lengthens in the manner which everybody knows from observation, the front end must be pushed for- ward. Suppose now the first half of this front end, the head, so to speak, remains inactive on the ground, but the second half actively shortens, and during the same time an equally THB NERVOUS SYSTIOM IN THE HEAD. MIDDLE SEXJMENTS AND TAIL OF A WORM. long third piece directly behind actively lengthens. The effect must be that the elements of the second piece are, more or less, pushed forward. GANGLIONS OF A WORM 155 If now the third piece, which has just extended itself lengthwise, contracts lengthwise, and the directly following fourth piece lengthens at the same time, while all the rest of the body remains inactive on the ground, the elements of the third piece are pushed forward, more or less. When in the same way the fourth and every succeeding piece has been moved forward, we can say that the worm as a whole has made a step forward. It is immediately clear that the nervous system of this animal must be so constructed that the successive pieces can function in relative inde- pendence. They must be nervously furnished in such a manner that they can function like so many separate organs, that each as a whole possesses what we have called local responsiveness. Each segment must have, in a sense, its own nervous system. Therefore there are visible to the eye as many "nervous systems" or "ganglions" as there are segments. The "swelling" (this is what "ganglion" literally means), the conspicuous node, results from the fact that the re- flex arches of the segments (in each of which there are UAJ^ GROUP FORMATION IN THE NERVOUS SYSTEM. naturally many muscle fibers) must be anatomically pulled together in order to be given a common superposed arch or "center." And thus they form a relatively bulky and 156 PSYCHOLOGY OF THE OTHER-ONE conspicuous mass, the node, the gangHon. In our figure "group formation," which is of course a mere sketch il- lustrating principles, such a node may be thought to be the mass of nervous tissue included in the dotted ellipse within which the point S^ab is located. Observation with the microscope reveals that each of these ganglions, even at "a" in the figure of the worm, con- sists of two relatively separate parts, we may say of a right ganglion and a left ganglion. Toward the head this double- ness becomes very conspicuous, and the nervous cord in the region marked "b" in the figure assumes a ladder-like appearance. In the head region, marked "c", the two halves of the cord separate so widely because they have to pass around the mouth opening, for the cord in the invertebrate animals is located on the ventral side of the animal ; and the mouth opening is located on the same side since animals naturally feed from the ground. In front of the mouth the two halves of the cord join again and carry the two head ganglions (or the one double ganglion of the head, if we prefer to say so) of which we shall have to speak a little farther on under the name of the brain. The fact that each segment of the worm has a right and a left ganglion, is easily understood. The right half and the left half of each segment sometimes function in relative independence. This is the case whenever in the region of this segment the worm is not straight, but curved, — when the path of the worm on or in the ground is curved in this place. In each half of the segment the muscle fibers have then their concertedness of action. Each half may contract without the other contracting too. But usually both halves act in concert, and for this purpose the "rung of the ladder" vmites the two ganglions. There is not an equally pronounced separation between the upper and the lower half of each segmental ganglion. HEAD GANGLIONS 157 Why not? — Animals, generally speaking, live on the sur- face of the earth (only exceptionally above or below its surface) and move forward or to the right or the left on the surface. They do not, in general, move up into the air and down into the ground, notwithstanding exceptions, of which the very earthworm may be said to be one. Even the earthworm, in its wanderings, obviously turns much more frequently to the right and to the left than down- wards or upwards. So the "local response" of the upper, or lower, half of the segment without the other half is not an action for which special provision is as important as for the local response of each of the lateral halves. The front ganglion and the next, directly behind the mouth opening, are larger than any others. Using the customary designation "brain" for the most conspicuous mass of nervous tissue in the animal body, one could call these two ganglions together, at "c", or the frontal gan- glion alone the worm's brain. But the very fact that one hesitates before deciding to call either both together or the frontal one alone the brain, demonstrates how misleading this very appellation really is. Apart from the greater size there is nothing distinguishing found in the worm's brain. The function is of the same kind as that of any other gan- glion. The muscle fibers are especially numerous in an animal's head. They act there in especially numerous combinations, in many varied forms of concert. Not only are movements of the head of great importance for locomotion — the rest of the body follows where the head goes — , but there are in the head also the mouth organs which move while taking in the food. And because of the importance of the muscle actions occurring in the head, it is only natural that there are placed there also very numerous sensory points, whose stimulation calls forth those varied muscular reactions. 158 PSYCHOLOGY OF THE OTHER-OXE The large size of the head ganglions is simply the result oi the multiplicity of forms of concertedness among a multi- plicity of reflex functions of the head segment, — with ">ne exception. This exception consists in the need of having a certaiu concertedness of all the segments of the body established in such a manner that this total concertedness — or integra- tion — depends on stimuli received by the head rather than ovi stimuli received by any other part of the body. The head — that is, the part that moves in front of all the other parts — is more likely than any other part to receive any kind of stimuli for the reason that it moves toward these stimuli. And the head will also receive, in general, the most significant stimuli. To give a simple illustration, having gone into a cul-de-sac, it is the head, obviously, which will receive whatever stimuli may be characteristic of this pe- culiar situation, which demands that for the time being the tail assume the role of the head and take the lead in the locomotion. Since the sense organs of the head are, then, the m.ost important sense organs for this total concertedness of ac- tion, it is quite natural that by the superposed arches serv- ing this total concertedness all the lower centers should be drawn together within the region of the head rather than in any other locality of the body. In our figure "group formation" these superposed arches, the highest centers, are represented in the dotted ellipse within which the points S^, S* and M"* are found. The addition of the nervous tissue of these highest centers of course helps to make the head ganglions relatively still more big and conspicuous. Nevertheless, there is no particular kind of functioning found in this "brain" which cannot be found in the other ganglions too. GAXGLIOXS OF A STAEFISH 15 4 rt'YCHOLOGY OF THE OTHER-ONE greatly strengthen the right-sidedness, for the teacher gen- erally insists that the pupil use the right hand. But when the child learns to skate, and nobody tells him whether to slide a certain curve on one foot or on the other, he easily discovers himself, not only that he is right-sided rather than left-sided, but also that he is right-sided rather than merely right-handed. We shall have to say a little more about this in a later chapter, in discussing rhythm. The change from left-sidedness to right-sidedness during babyhood seems to find its explanation in the following facts and conclusions. As to the time of the development of the right hemisphere of the brain in comparison with the left, we are entitled to a conclusion from analogy. The human brain with its complex functions is not fully de- veloped until years after birth. The brain of larger animals of a longevity comparable to that of man, with its simpler, but no less important functions, is fully developed some months after birth. May not a similar rule govern the development of the left and the right hemispheres? The temporal part of the left hemisphere, with its highly com- plex speech functions, is not fully developed until years after birth — so much we know. By analogy we conclude that the symmetrically corresponding part of the right hemisphere, with its simpler, though no less important functions, develops to maturity at a much earlier period. If this is so, activity of that hand which is governed by the right hemisphere, must become conspicuous at a much earlier period than activity of the other hand. Indeed, the left hand, whose muscles are closely connected with the temporal part of the right hemisphere, is the preferred mem- ber in the activities of the first few months after birth. Thus the fact that a normal human child is at first left-handed appears plain enough. On the other hand, the question why the human adult is one-sided and right-sided is an entirely different one. The RIGHT-SIDEDNESS 205 answer to the first half of this question, why he is one- sided, we can leave entirely to the physiologists. The answer to the second half of the question, why he is right- sided, may be found in his need of securing protection, fur- nished by Nature thru heredity, for his most vital organ, his heart. The heart, previously covered, becomes ex- posed (in consequence of man's erect position) to the enemy fighting with weapons (in consequence of his erect position) rather than with his jaws. Right-sidedness gives some protection to the heart. One might think, further, that a mistake has been made in not mentioning among the Other-One's reflexes or in- stinctive activities the important activity of walking. But we have hardly any right to regard that as instinctive. The reflexes of locomotion seem to be poorer in the species man than in many animals. Even creeping, in babies, seems to be an acquired habit rather than an instinctive ac- tivity. Walking is probably a compound habit, built up out of the habit of balancing on one (either) leg plus the positive localizing reflexes. The complete ability of locomotion in the upright po- sition involves two distinct abilities of muscular action: the ability to rise from a lying to a standing position and the ability to balance on either leg. The ability to rise is only imperfectly developed as long as holding on an object, a chair or the like, is necessary in order to rise. This im- perfect ability usually precedes by several months the child's ability to rise to his feet from the floor without the aid of any supporting object. The ability to balance on (either) one leg is naturally preceded — as a rule — by the ability to balance on both legs, which, on the whole, is more easily acquired. The governing reflex of the whole group in question seems to be that of straightening the legs in response to 206 _ PSYCHOLOGY OF THE OTHER-ONE pressure against the soles. A child about nine months old, or even considerably younger, may absolutely "refuse" to be held on anybody's arms in a sitting, flexible position. The reflex of straightening the legs causes a stiffening of the body. The mother then naturally places the child, no longer easily held in her arms when in this straight position, with his feet on her knees, or a table, or the floor. The child then stands, in a way, but retains this standing position only because he is kept from tumbling by his mother's arms. Soon the child learns to use his own hands, in the control of which he has by this time already acquired con- siderable skill, in order to keep from tumbling. He grasps whatever is in sight and reach and thus learns to keep in a standing position. While the child is standing before an object, holding on with both hands, one of the hands accidentally loses its grasp, the body weight is thrown on the leg of the other side, and consequently that leg is straightened. The body as a whole, perhaps, is thus somewhat raised, and with it that leg which remained slightly bent. But now this leg, hanging and subject to the effect of gravity, straightens somewhat ; and when the body regains its vertical position and the foot of this leg touches the ground, it straightens perfectly, owing to the reflex repeatedly mentioned. The weight of the body is thus thrown again — lightly — upon the other leg. A swinging movement of the body may thus result, from the left to the right, from the right to the left, and so forth. This is balancing sideways. It is clear that this movement needs only a slight modifica- tion to become a regular walking movement. Children who are just beginning to walk, do indeed, usually, walk in this pendulum-like fashion, comparable to the walking of a sailor. One finds here and there in psychological literature the assertion that the walking of a child is the result of an in- LEARNING TO WALK 207 stinct consisting in a tendency of the legs to swing fore and back in directions opposite to each other, and that these in- stinctive movements can be observed in a baby a few months old when held suspended. While such opposite fore and back swinging movements of the legs may sometimes be observed, it seems doubtful if they have much significance for the acquisition of the ability to walk, since one does not walk in suspension, but on a supporting surface. In any case, it is possible to derive the alternate movements of the legs in walking from the reflex of straightening each leg in response to pressure against the sole, without assum- ing any specific "instinct of walking." We described how a child may learn to stand alone, balancing himself sideways. But in order to stand really alone he must also keep from losing his balance in the forward and backward directions. From falling forward he may be kept by the same reflex of straightening men- tioned before. When the body begins to move forward, less weight is placed on the heels and more on the soles. Accordingly the foot straightens, the heel is raised above the ground and the body is kept from moving forward siiice the centre of gravity is now behind the point of sup- port. On the other hand, when the body begins to move back- ward, more and more weight is placed on the heels, the pressure on the soles vanishes, and the muscles which keep the legs straight relax. The knees then bend forward and thus a part of the weight of the body is thrown in front of the previous center of gravity, thus restoring the balance. Just as the swinging of the body to the left and right, so these kinds of movement have great significance for walk- ing. In the walking movements of a grown person the heel of one foot, when the body is already falling forward, rises with the straightening of the foot and raises, with 208 PSYCHOLOGY OP THE OTHEK-ONE the whole body, the other foot perhaps quite sufficiently from the floor. This other foot, now free, by the mere force of gravity swings forward. We have been trying to explain how a child learns to balance his body in the upright position, both sideways and front-back, without having to hold to an object. This bal- ancing is virtually already walking. Before this accom- plishment of standing free, the child usually begins to walk along by pieces of furniture, changing the hold of his hands as he walks on. What reflex is the basis of this locomotion? It seems that, in response to a visual stimulation, not only the hand but the foot, too, stretches toward the thing which impresses the eye. This is simply the positive localizing reflex. The localizing reflex is the essential factor changing standing (balancing) into true walking. Imagine a child standing before a bench, holding on with both hands, and an object, say, a pencil, lying on the end of the bench to the right. The effect of the stimulation of the eye by the pencil is a stretching of the right arm and the right leg to the right. The body then falls to the right until the right foot again touches the ground. The body is now some- what displaced to the right. The feet are farther apart than normally and are therefore, in consequence of special reflexes which we need not discuss, brought together to their normal position, but of course without any essential change of the body sideways. Now the whole stretching of the right hand and the right foot to the right is repeated until the hand grasps the object. Thus comes about walk- ing along pieces of furniture or the walls of the room. In the same way free walking results after the child has learned to balance himself without any support by his hands. While standing, in response to a stimulation of his eyes by an object he moves one leg slightly toward the ob- LEARNING TO WALK 209 ject, shifts his weight so that it rests on this leg and draws the other leg after, secures his balance, then moves again the first leg toward the object, and so on. One might call this form of locomotion walking on one leg only. In a week or two this one-sidedness gives place to the regular form of walking in which both legs take part equally. For many months thereafter, however, a child's walk remains clumsy because the legs are kept so far apart, owing to the anatomical fact that this opening of the legs sideways is the normal position until birth, which but gradually changes into that of the older child and adult, and also to the fact that balancing is easier in this position. Usually a child learns to balance himself standing still without support by his hands, before he learns to move in the upright position. But there are exceptional cases where children, being held in the upright position, are suddenly attracted by an object, perhaps the mother's voice, and start off running successfully five or six steps until they have reached the object. If walking is thus the outgrowth of standing, it is well to "encourage" free standing as much as possible after the baby has learned to stand while holding to things. What does it mean to "encourage" him? Let us reduce the pro- cess to its essential elements. (1) The child, when beginning to tumble, reflexly draws in his legs. (2) He has often tum- bled, when standing and losing the hold of his hands. (3) Subsequently, by habit, he draws in his legs at once (in other words, he sits down) when standing and losing the hold of his hands. But he cannot practice balancing his body if he sits down. Therefore (4) we give his hands the same or similar sensory impressions as if they were sup- porting the body. For example, we let the standing child grasp for support a small stick or pencil which we are holding, and then, 210 ' PSYCHOLOGY OF THE OTHEE-ONB gradually, we cease to hold it. The child then balances and, although nothing supports him, receives almost the same stimuli in his hands and eyes as if he were still sup- ported by the stick in his hands. The process of balancing suffers no sudden interference by a new stimulation (caused by the withdrawal of an object from his hands) and its reaction of sitting down. The "encouragement" which we give the child is therefore a purely negative event in the education of his nervous system : we keep an obstacle out of the way. Summing up, we may say that walking is a habit, a con- certed action acquired, not inherited in this concerted form, and based on the three classes of reflexes (1) stretching (stimulus: strong pressure on the sole), (2) bending (also called grasping, in hand actions, — the stimulus being gentle pressure on the sole), and (3) positive (and in the main visual) localization. In psychological, and even more in sociological, dis- cussions certain "human instincts" are often spoken of, which we do not care to enumerate among the fundamental forms of behavior of animals and of the Other-One for which Xature has made provision by heredity. We ought to give our reason why we do not regard them as special classes. Let us for this purpose give first the complete list of the eight forms of behavior which we have regarded as most interesting from our point of view. 1. Straight locomotion in response to lack of food. 2. Turning the body axis sidewise in response to an obstacle. 3. Positive localization, on the body surface or outward. 4. Negative localization. 5. Grasping (bending, action of the flexor muscles). 6. Adjustment of the sense organs. 7. Signaling. 8. Sleeping. SO-CALI^ED INSTINCTS 211 For example, "hunting" is sometimes mentioned as ;i human instinct. It seems that this form of behavior is a habit based essentially upon (1) and (2). "Tramping" is about the same. If one wants to distinguish between hunt- ing and tramping, one may say that to the former (3) and (5) also contribute strongly, for the hunter likes to follow the game (if he sees any) and to bring some home. Further, "acquisition" or "hoarding" seems to be a habit based on (3) and (5). "Manipulation" or "construction" seems to be about the same habit. A child, let us say, picks uj) one of a number of wooden blocks lying about in his room. He receives the visual stimulation of a similar block, and since the nervous path is still favored by the reduction of the resistance due to the previous stimulation, reacts in the same way, walks towards it and puts on it his hand in which he still has the first block. Since now he cannot pick up the second block, he opens and raises his hand and, there, has before him a structure, one block upon another. Since this double block is a more striking stimulus than any of the single ones, it is quite natural that he returns to it, after having picked up one more of the blocks lying about. Is not all the so-called constructive activity simply a more or less complicated habit of the same kind as this very simple example? This habit of gathering and piling up must develop from the two reflexes of localizing and of grasping, provided the child is surrounded by things which are sufficiently similar so that two or more of them together make a similar, but more intensive sensory im- pression than a single one ; and what child does not live under such surroundings? It is hardly necessary, then, to assume a mysterious particular instinct of constructive- ness. That the habit of taking to pieces, derived from the reflex of grasping, becomes united with this habit of putting 212 PSYCHOLOGY OF THE OTHER-ONE together is plain enough, for taking apart brings about ever new opportunities for putting together. It is unfortunately true that taking to pieces is not inevitably followed by put- ting together. Nevertheless "destructiveness" is no more a human "instinct" than "constructiveness." "Fear," running away, is a habit based on (4), negative localization. The peculiar attitude of a person in bodily pain seems to belong to the same form of behavior. He shrinks away from the objects of pain. He curls up or writhes, bends and twists all his limbs. "Attention" is sometimes called an instinct. What is re- ferred to is obviously habits based chiefly on (6), to some extent also on (3). "Sociality" is sometimes called an instinct. It refers to those habits which are based on (7). The response to the signal brings about social relations. The so-called instinct of "idleness" is based on (8). A person who acts habitually "sleepy" when we expect him to expose his sense organs to all or to certain stimuli, is an idler. In connection with "instincts" it has become the custom among psychologists to speak of "emotions." From the social point of view emotions are most curious phenomena. But if we analyse them psychologically, we find that they are nothing but "wasted" reflexes and habits. If a per- son shows most or virtually all the symptoms of "sleep," that is, reacts with the sleeping reflexes above discussed, but during the day and under conditions where such reac- tion serves no purpose, naive observers, poets, may be ex- cused for speaking of his sorrow and anguish and telling us that his very soul has been stirred up. But to the scientific observer this sorrow and anguish is merely a wasted sleep- ing reflex. The situation calling forth the reflex action is one of disappointment. And the reflex action means re- SO-CALLED EMOTIONS 213 tiring to a state of inore or less prolonged inactivity. We can at once derive the symptoms and comprehend the biological value of his reaction if we recall that in animal life and in the life of primitive man the most ordinary kind of disappointment consists in the want of food. Imagine a winter month : every article which might serve as food covered by snow and impossible to find, for weeks or longer, until the weather changes. An animal which, under these circumstances, would continue to run about for food, would soon fall dead from exhaustion. However adverse the siluation, the body can survive living on the substances stored away in its own tissues, if it only consumes this lim- ited supply economically. For this the first requirement is that all muscular activity be reduced to a minimum. Thus we understand why the nervous system, in a dis- appointing situation, tends to leave the skeletal muscles in a state of relaxation. A person in great sorrow is so far from being master of his skeletal muscles that he drops like Romeo in Friar Laurence's cell, falling upon the ground and "taking the measure of an unmade grave." A disappointed person looks like the face on the left side of our double diagram of facial expressions. The relaxa- tion of the facial muscles causes the angles of the mouth to be pulled down by the weight of the lower jaw. But why should such a face look pale? Recall the animal just spoken of, disappointed in its food supply. If it does not exercise its muscles, little or no heat is produced, for the skeletal muscles are, physiologically, the very furnaces of the body. If little heat is produced, the loss of heat must be safeguarded against. Thus the biological value of the contraction of the muscles in the Vvalls of the blood vessels becomes evident. The contraction of the vessels prevents the blood from circulating much in the periphery of the body where cooling mainly takes place. 214 PSYCHOLOGY OF THE OTHEK-ONE The cooling by the conduction of heat through the tissues covering the body is little to be feared as long as the warm blood is kept in the inner parts of the body and prevented from circulating through the periphery. The actual cool- ing of the skin, exciting the sensory points of the skin, causes the reflex and habitual response of the animal's seek- FACIAL EXPRESSION IN SORROW AND IN JOY OR ANGER. ing shelter, again reducing the loss of heat, of physiological energ>'. Thus contraction of the blood vessels of the skin keeps the animal alive until a change of the external con- ditions enables it to resume its ordinary manner of life. The winter sleep of animals might, in a sense, be called a prolonged emotion of sorrow. But in this case the sleep- ing reflexes are not wasted. In the case of Romeo they are wasted. Many psychologists attempt to place each class of "emotions" parallel with one particular class of "instincts." The sleeping reflexes would then become the basis both of the habit or "instinct" of acting sleepy or lazy and, when wasted, of the "emotion" of sorrow. The reflexes (3) and (5), which result in the habits or so-called instincts of acquisition, hoarding, manipulation, might then well be said to be, when wasted, the bases of the emotions of joy and of anger. That the angry person manipulates things too much and very wastefully, is suf- ficiently known. And the joyful person "localizes," picks out, not this or that thing, but the whole world, in order PLAYING 215 to "grasp," to embrace it, — but ordinarily to no good pur- pose. The strong (primitive) activity of grasping, or try- ing to grasp, with the jaws (having teeth for that end) gives the face the feature shown on the right side of our double diagram of facial expressions. We see this "grin- ning" both in what we call joy and what we call anger. The horse, standing on a railway track, which runs away from an approaching train, is not said to display an emotion. It demonstrates its negative localizing reflexes (4). But if it wastes these reflexes by running away from a news- paper flying in the wind, we speak of it as having an emotion. Sometimes we speak of "play" rather than of emotions, when an animal exercises its reflexes to no directly useful end. We speak of play especially in the case of young an- imals and of children, where wasted reflexes are naturally more frequently seen than in the case of adults. Even when directly wasted, the exercise of the reflexes may be indirectly helpful. It has often been pointed out by psy- chologists — and quite rightly, it seems — that thru play the young acquire useful habits before dire necessity demands their acquisition. When the Other-One's play becomes connected with Art, or when he plays with a work of Art or even with a product of Nature like a beautiful landscape chiefly by ad- justing his sense organs to it, we say that he has an "es- thetic" emotion. He calls those things beautiful which he discovers to be particularly suitable for this play of adjust- ing his sense organs. And by Art he means the production of such things. As a matter of course with advancing age, experience and training the esthetic emotions become in- finitely varied by becoming interwoven with the Other- One's innumerable habits. CHAPTER IX Space Perception on the Skin : A Species of Condensa- tion OF THE Nervous Functioning. We mean by a spatial perception any muscular reaction which can be regarded as based on the positive localizing reflexes in such a manner that for two — or any larger num- ber of— localizing reactions which remain unexecuted an entirely different muscular reaction, serving any end what- soever, is substituted. The equipment which Nature has given the Other-One in order to make localizing movements possible has already been discussed and is very simple. It consists of a large number of nervous conductors, reflex paths, each starting at a particular sensory point and ending in that set of muscle fibers (schematically speaking, that motor point) the con- traction of which will bring a movable part of the body, most commonly the tip of the index finger of the right hand, into the neighborhood of the sensory point in ques- tion. We say advisedly "neighborhood." The Other- One's muscular apparatus works, of course, with a certain inaccuracy. This would show itself clearly if the Other- One would localize, "try to touch," the same sensory point a large number of times, perhaps a hundred times, and leave a mark on it with an inked point of the finger tip after the performance of each localizing movement. Suppose the sensory point to be touched is selected on the upper arm about midway between the shoulder and the elbow. Suppose we consider the distribution of the marks just mentioned only in the direction lengthwise on the arm, and disregard completely whether the marks distribute them- selves crosswise in any manner or not. In the distribu- (216) CUTANEOUS THRESHOLD 217 tion lengthwise we should mark, following the general scientific custom, the two points, one lying toward the shoulder, the other toward the elbow from the sensory point, between which we should find one half of the marks of all the localizing movements, that is, fifty of the hun- dred. Imagine, in order to have something definite to speak of, that the distance between these two points hap- pens to be just an inch as in our figure between the vertical I I I I I I iM I 1 1 1 1 mil s iiiiliiliiHiuiianamiiniiiiiiiiiiiiii nil M I I I I Ml I I I t I I I MAK-KS OF THE LOCALIZING REFLEX. lines. Now imagine, further, that you are assistant to the Creator of the world and that the task has been assigned to you of placing in the skin of the arm, from shoulder to elbow, a sufficient number of sensory points. How close together would you place them? (Now suppose that your standard of efficiency happens to be "half and half" in the sense which will be apparent at once.) You would obviously not waste them by putting them closer together than an inch. Due to the inaccuracy of the execution of the movement, one half of the marks, we supposed, fell farther than half an inch above or below the sensory point. If you place the sensory points one inch apart, half of the marks will fall closer to the sensory point touched than the sensory points untouched, whose localization by a movement is not de- manded by any present need. If you place the sensory points closer together, fewer and fewer than one half can be said to have fallen closer to the sensory point touched than to the sensory points untouched. It would obviously be a waste of biological building ma- terial to possess sensory points which, altho untouched, col- lect in their neighborhood more than one half (or more than 218 PSYCHOLOGY OF THE OTHER-ONE any other definite fraction which represents your standard of biological efficiency in your creation) of the marks which were intended for a different point as a target, this target receiving then in its neighborhood only a certain minority of the marks. We have here one of the reasons why creative Nature should place a rather limited number of sensory points in the skin, why Nature should establish what is technically called a threshold of sensibility, and a rather large thresh- old. Of course, we do not assert that Nature may not, for this or that other reason, distribute the sensory points less closely or more closely together than corresponds to the muscular accuracy. It may, for example, be quite sufficient for an animal's need of protection, if the sensory points are farther apart, because the animal's paw or the human hand, in making a localizing movement, is capable of touching — covering — a broad area. By the way, in this discussion we have intentionally not concerned ourselves with the fact that what we schematically call a sensory point is not a geometrical point, but an area of some size served by numerous branches of the same neuron fiber in question. Taking up the study of these details of the finer anatomy of the skin would be likely to carry our interest from psychology into physiology. An experiment will make the further discussion more concrete. We ask the Other-One to close his eyes. Then we touch him, after a "ready" signal, lightly, but with suf- ficient firmness and long enough, one to two seconds, with two compass points. He answers our question, whether we touched him with one point or with two. We repeat the experiment with a different distance. If we choose to make the distance increase, or decrease, with regularity, we must touch him now and then with only one point in SPATIAL DISCBTMINATION 219 order to test his sincerity. If he answers "two" in such a case, we tell him that we have no use for him as a subject of experimentation. Finally we make an array of our data, with distances regularly changing and the Other-One's answer to each distance added. We then notice at one end of the array only judgments of "one," at the other end only judgments of "two," and in the middle both judgments mixed. The dis- tance standing in the center of this "mixed" region we call the threshold. The experiment is made lengthwise on the arm, and it is also, separately, made crosswise on the arm. The most in- teresting result is that the threshold lengthwise is greater than the threshold crosswise. One reason for this will be pointed out later. Let us now consider the relation between the experiment on discrimination as just described and the localizing reflex. At the first glance it may seem that (1) localizing a point stimulated and (2) calling out either "one" or "two" ac- cording as two nearer or farther points have been stim- ulated, are two forms of human behavior which have nothing in common. But that is not so. They are very closely related functions. The latter form of behavior is a modifi- cation of the former, a habit based on the localizing reflex. It will make it much easier for us to understand this, if we first recall what reaction is most commonly, in the Other-One's life, substituted for any single one of his re- flex actions. The most common substitution is that of "naming." A human adult whose shoulder is irritated, in innumerable instances, for example in the presence of his physician, pronounces the word "shoulder" instead of moving his finger to the shoulder. If his elbow is stim- ulated, he pronounces the word "elbow." This is one of the most common habits in human life, reacting by a word 220 PSYCHOLOGY OF THE OTHER-ONE instead of reacting by a directly useful muscular activity. The naming reaction is indirectly useful, chiefly thru its social consequences, since the word in turn is likely to bring about in another individual, or in many other in- dividuals, that directly useful reaction which the person stimulated did not perform. When the Other-One says "shoulder," his physician will probably put his finger on the Other-One's shoulder. Now imagine, first, that the following happens. The Other-One is touched on his shoulder; but peculiar neuro- muscular complications delay the reaction. His shoulder is touched again ; and now both of these stimuli are re- sponded to by a single reaction, perhaps that of pronouncing the word "same." Same in the sense that the muscular reactions were the same. No one will deny that this is possible, that an animal body, instead of reacting separately to each of two successive stimuli, reacts to both of them in a new way with a single movement, of course not in this case reflexly, but in consequence of habit formation. Secondly, imagine that the Other-One's shoulder is touched first; but special conditions again delay the reaction. His elbow is now touched ; and both these stimuli are then responded to by a single reaction, perhaps that of pronouncing the word "different." Different in the sense that the muscular reac- tions were different, as they naturally must have been. It is clear that the pronunciation of such a word as "same" or "one" in the former case and of such a M^ord as "different" or "two" in the latter case is nothing but a peculiar kind of habit, consisting in a single reaction occur- ring as the effect of two (in our case successive, but not necessarily always successive) stimuli, this single reaction taking the place of the two localizing reflex reactions which originally belonged to, were causally connected with, the two stimuli. SPATIAL DISCRIMINATION 221 What we have just done, has been nothing but a logical analysis and clear statement of what is meant by that form of behavior which we customarily call "discrimination" of two points. Let us now return to the result of our ex- periment concerning the comparative threshold lengthwise and crosswise on the arm. We found that the threshold was considerably larger lengthwise than crosswise. Why has Nature placed the sensory points closer together in the direction crosswise, thus increasing in this direction the number of distinct reflex actions possible and also, then, the number of substituted word reactions "different" or "two"? The reference to a limit of muscular accuracy in localizing the spot obviously is no answer here. We can give an answer to this question which is applicable, not only to the arm, but to the whole body surface. The sensory points are the closer, the greater the curva- ture of the surface region in question, the farther apart, the less the curvature. It goes without saying that the curvature crosswise on the arm is much greater than length- wise. We then have before us the same question in dif- ferent terms. Why does Nature increase the number of sensory points whenever the curvature increases? This question can be answered when we remember that the purpose of the existence of sensory points on the body surface is a localizing reaction, but that the end of the localizing limb is not a sharp point. A finger tip, and more so a flat hand, is capable of covering a considerable area, say, of the arm, in the localizing reaction. But this covered area has a considerable extent only lengthwise, that is, where the curvature is small. Even a great inaccuracy of the localization lengthwise will still result in the stimulated part being covered by the flat hand, as when we swat a mosquito sitting on our arm. Not so crosswise. If the mosquito moves only half an inch or so in the direction 222 PSYCHOLOGY OF THE OTHER-ONE crosswise, the striking hand will not kill it. To kill the mosquito in the changed position, a very different combina- tion of contracting muscles is required, and the excitation must be carried over distinctly different conductors. It is immediately clear, then, that an animal needs to have its sensory points on the body surface much closer together as the curvature increases. It may be wise to add to the last statement, that this does not imply that the number of sensory points should be ex- pected to be strictly proportional to the curvature as defined in mathematical terms. An assertion of strict proportion- ality would lead to the absurd consequence of the sensory points being an infinite distance apart where the body sur- face has no curvature, is flat, not to speak of the still more absurd consequence of the distance between the sensory points being negative where the surface is concave, as in the palm of the hand. For reasons which are apparent in a discussion of space perception, it is advisable to raise the question as to how many dimensions are involved in the description of the mutual relations of those stimuli which call forth this form of behavior, the localizing reaction on the skin. The an- swer to this question is that the stimuli may all be described as belonging to a two-dimensional space. The objection that the skin, in which the stimulated sensory points are located, obviously fills the three dimensions of common sense space, is not a real objection. Of course, nobody making this objection would mean by it that the skin has thickness and in this respect has three dimensions. The stimuli in question are not applied to a varying depth in the skin. The objection could have a meaning only in the sense that the skin surrounding the Other-One's body is not flat. It could not surround the body if it were flat. But two-dimensionality and flatness CUTANEOUS SPACE PERCEPTION 223 are not the same, mathematically. We can make this clear even in purely biological terms, leaving all abstract mathe- matics aside. Imagine you could skin the Other-One in such a way that all the nervous conductors having endings in the skin would remain intact. Think of the nerve fibers as being stretchable, like rubber threads. Imagine that you had spread out his skin on the flat floor like a fur rug, without in the least interfering with any of the normal nervous connections between the points of his skin and the Other-One's muscles. It then becomes clear at once that the skin is functionally a two-dimensional structure. You could distribute the stimuli over the (now flat) skin lying on the floor in exactly the same two-dimensional relations as before (when the skin surrounded the body) and call forth in the Other-One exactly the same muscular re- sponses. That the skin is curved over the body, obviously does not change its functional two-dimensionality. We therefore say that the space perception on the skin is a perception of only two-dimensional space. But the only example we have hitherto given of this space percep- tion has been the rather simple case of the discrimination of two points. Let us now turn to cases of space percep- tion which are a little more complex, and see whether they too can be reduced to habits based on the localizing reflex. Imagine the following case. The Other-One, in the dark, is trying to find a pen point which he knows is lying among other things on the table in his room. He puts his hands on the table. A number of sensory points forming an oval spot on the skin are stimulated by contact on his right hand. A number of sensory points along one line are stimulated on his left hand. He ought to pick up that thing which is lying under the latter. It is the pen point wanted. What is lying under the right hand is a medal. Of course, instead of using both hands, the Other- 224 PSYCHOLOGY OF THE OTHER-ONE One may put the same hand, first on the one thing, then on the other. We are deahng here with the problem of the perception of spatial form reduced to simple terms. We might give names to the sensory points and call them for the pen point a-c-e-g-i (they are, of course, in reality much more nu- I I 1 I I 1 I 1 I 1 I a b c d e f g T, i k I I 1 SPACE PEECEPTION AS A NERVOUS FUNCTION. merous than five), for the medal b-e-g-1-o. We notice that some, but not all, which are found in the one group, are also found in the other. We may imagine that the reac- tion, say, the bending or the stretching of the arm in all its joints, is anatomically very simple, that it involves the contraction of only a single muscle, the passing out of the nervous current at a single motor point. The nervous func- SPACB PERCEPTION THE REVERSE OF MOTOR CONCERTEDNESS. tion is then exactly the opposite of what we have called on the motor side concerted action, which we have discussed in a previous chapter. Motor concertedness is characterized CUTANEOUS SPACE PERCEPTION 225 by an expansion of nervous function which one might rep- resent by a fan-shaped diagram Hke that on the left side of our figure, at A. In space perception, on the other hand, we let the "soldiers," so to speak, who started out marching in open formation, arrive at their aim, M, in close forma- tion, as at B in the figure. Here they arrive as a single unit of motor function, in the other case. A, as five units of motor function. We have already called this, in contra- distinction to concertedness, condensation of the nervous functioning, or "motor condensation" if we call concerted- ness "sensory condensation." Space perception then is a species of condensation of nervous functioning. Discrimination of two points on the skin is the very simplest example of space perception. An example of a more complex discrimination has just been given. Another example would be that of reacting dif- ferently to three stimuli applied to points forming a straight line and applied to three points marking a triangle. Or distinguishing — of course again by different muscular re- actions, most usually the names pronounced — one kind of triangle from another kind. Or one triangle from another one which is merely larger. It is clear that in thus distinguishing different sizes and different forms, some of the group of sensory points call- ing for the one reaction may be identical with some of the sensory points of the group calling for the other reaction. In our figure "space perception as a nervous function" this is expressed by the fact that the points e and g are found in both the groups a-c-e-g-i and b-e-g-1-o. How such habits of space perception may be formed on the basis of the localizing reflexes, we have illustrated by the example of the discrimination of two points on the skin. But we must not think that all space perception, all such condensation of the nervous functioning, results mere- 226 PSYCHOLOGY OF THE OTHER-ONE ly from habit formation. There is very definite evidence, especially in the reflex reactions to reflex "signaling," that certain kinds of space perception are inherited. But since the plainest examples are found in visual space perception, we shall give them on a later occasion in the next chapter rather than here where we are discussing cutaneous space perception. Space perception is an especially fertile field for the cul- ture and observation of so-called illusions. Any wasted reflex or habit may be called an illusion (just as it may be called an emotion). The crowing of a rooster (a signaling reflex) may be called an illusion of the rooster when there is nobody to hear the sound. Striking a table with a fist when nobody is present to be caused to run away or shrink from the person who does it, may be called an illusion. Swallowing a pill, when it is only a sugar-coated pea, may be called an illusion. In the last mentioned case, the action is applied to something, but is nevertheless wasted because it is misapplied. It is not difficult to see why the probability of an action being misapplied is especially great in nervous functions which are of the nature of a condensation of the totality of the nervous currents. If the currents coming from b, e, g, 1, and o all concentrate toward the motor point Mq in our figure and four of them (one of the five happening to be absent, we speak of the other four) concentrate ordinarily toward some different motor point Mx, it is only to be ex- pected that the mere weakening or total failure of that one of the five currents should once in a while be insuf- ficient to keep the other four from concentrating just the same toward the motor point Mq. The following is a con- crete example. Perhaps the most famous illusion in cutaneous space per- ception is that which goes under the name of "Aristotle's ILLUSIONS 227 illusion," which indicates how long it has been known. Place the Other-One's hand palm upwards on the table and cross his ring finger over the middle finger. The tip of the ring finger then lies next to the index finger and the tip of the middle finger next to the little finger. Of course, before doing any of these things you have already blind- folded him. Now touch gently the tips of the crossed fin- gers with a single object, for example a bean or a round pencil. The Other-One will then probably tell you that he was touched by two things. The explanation is simple enough. When the tip of the ring finger is stimulated on the side which ordinarily lies next to the little finger and also the tip of the middle finger is stimulated on the side which lies ordinarily next to the index finger, the Other-One ordinarily must execute two separate localizing-grasping movements before he has "picked" all the stimulating objects. He has learned to substitute the word "two" if he substitutes a naming reac- tion for these reflex movements of "picking." It is true, the nervous function includes in such a case also the excita- tion of the kinesthetic sense organs in the muscles which hold the fingers parallel. Now, in the experiment in which the subject is blind- folded, this kinesthetic excitation is not the proper one. The proper one is not there (there is something else in its stead). But, as we already said, the absence of one ner- vous current among several in the case of nervous condensa- tion does not always keep the others from concentrating in the same motor point. If they do concentrate in the same motor point (and as a matter of fact and ancient expe- rience, far back to Aristotle, they frequently do), the Other- One tells us "two." Of course, his reaction is not always and by absolute necessity saying "two;" but frequently, perhaps in a majority of the cases, he does say "two." 228 PSYCHOLOGY OF THE OTHER-ONE. It is an illusion because the response is misapplied. The Other-One will quickly admit that the response "two" was misapplied, was "wasted," when we uncover his eyes. We ask him to pick up and give us the two beans. But after having picked up one, he finds no second bean to pick up. CHAPTER X Nature Enables the Other-One to Perceive Space AT A Distance. The eye must be regarded as a group of sensory points of the skin whose sensitivity has been changed so that they can be stimulated, no longer by pressure very easily, but by certain ether waves, by light, even when this light is only very weak. In our chapter on reflexes we referred to the fact that the sensory points of the Other-One's retina have been equipped by Nature with definite reflexes. When the lower region of his retina is stimulated, his arm moves up ; and so forth. We called these reflexes positive localization in the outw^ard direction. From them is derived, by con- densation of the nervous functioning, space perception at a distance, just as space perception on the skin is derived from the localizing reflexes of the skin. Let us mention a concrete example from the Other-One's life. One evening, long after sunset, we find him walking in the wilderness trying to discover a resting place for the night, a human habitation. On his right there is a hill ; on his left another. Over the latter appears a bright spot which is round. Over the former there is a bright spot which is rectangular. He ought to turn to the right where he will approach an illuminated window. Over the hill to the left there is something he could never hope to approach, the moon. Obviously, the case is in all essentials the same as that, discussed in the last chapter, of discriminating by distinct reactions a pen and a medal, both touching the skin. In- (229) 230 PSYCHOLOGY OF THE OTHER-ONE stead of the localizing reflexes serving the skin, we find here those serving the retina. And just as there, so we find here a substituted motor function. For several, a definite group of, localizing reflexes a single habit is sub- stituted, the habit of approaching the illuminated rectangle, and of leaving behind one's back the luminous disk. With the localizing reflexes of the retina we are already ac- quainted. In discussing the localizing reflexes we spoke of the fact that the eye ball functions like a pin hole camera (it actually is a lens camera) and that the establishment of reflex paths here is as simple a problem for the archi- tect of the nervous system as it is in localization on the skin. In the preceding chapter we called attention to the fact that those condensations of the nervous functioning which we call space perceptions are not entirely the result of habit formation, that certain space perceptions are pro- vided by the inheritance of nerve centers higher than those which serve the simple localizing reflexes. We promised to give an example of inherited visual space perception. We can noAv give it. This example has already been men- tioned in a previous chapter, but there for a different pur- pose. We discussed the fact that animals as well as in- fants possess by inheritance reflexes of reacting to signals of form which are given out by other animals (or animal- like things, as we shall see). We illustrated the discus- sion with a simple figure being a sketch of the main fea- tures of a stuffed puppet. These features are a circular or oval border line and within it a triangle (a "snout") below, and two smaller circles ("eyes") above. The fact that young and entirely inexperienced babies react to such a form with the nega- tive localizing reflexes, in ordinary life called "fear," shows INHERITED AND OTHER NERVOUS CONDENSATIONS 231 beyond doubt that they possess this condensation of nerv- ous functioning, "spatial perception." Instead of several (a large possible number of) positive localizing reflex ac- tions, one substitute action occurs, which happens to be in this instance a negative localizing reflex. How the habit formation and the functioning of estab- lished habits in visual space perception are influenced by the geometrical relations between the sensory points on the retina, becomes evident in a study of the geometric-opti- cal illusions. We shall presently give a number of especial- ly striking and typical examples of such illusions. Let us remember that such illusions are "wasted" reactions. And let us keep in mind in the following discussions that until the contrary is especially stated, we shall concern ourselves with the two-dimensional visual space perceptions, that is, those where the location of the sources of the emanating stimuli is completely described by reference to the so- called "field of vision." For the present we leave "depth" out of consideration. The geometric-optical illusions furnish striking illustra- tions of the fact that space perception is a species of con- densation of the nervous function. By various factors we can guide the special direction which the condensation takes in the nervous system. Thus we can vary the reaction in the most astonishing, often seemingly contradictory, illogi- cal, wasteful manner, without essentially changing the form of the object, that is, without essentially changing the partic- ular sensory points stimulated. Let us ask the Other-One which two of the upper three lines, a, b, and c, in our figure are the continuations of the lower two lines, d and e. Maybe the Other-One will re- fuse to answer our question and rather say that none are continuations, that d and e pass thru the vacant spaces be- 232 PSYCHOLOGY OF THE OTHER-OXE tween a, b, and c, as they actually do. But if he answers it as it is put, he will certainly not say b and c. He will say a and b. Why? — Some psychologists have held the vertical lines responsible for this choice. They have said that the illusion is due to the overestimation of the acute angles formed by the lines of the figure. It is perfectly true that there is a tendency to overesti- mate acute angles and underestimate obtuse angles. And the reason for it is clear. Look in one of the corners of your room at the angles you see there. They are three obtuse angles. But you know that in reality they are three right angles. Right angles are exceedingly common in architecture and furniture. They are common enough also in trees, since these generally stand vertical on the ground. A log or trunk of a fallen tree lying at the foot of a living one and forming a right angle is nothing rare. So every- body is very familiar with the fact that angles which are apparently acute are in reality often larger than they seem. These experiences may have some influence on the esti- mated size of acute, and in the opposite manner of obtuse, angles. But that this influence must be small and cannot be the deciding factor in the Other-One's illusion just mentioned, becomes clear when we make him look at the middle of our figure. Which two of the upper lines, f, g, and h. are the continuations of the lower two lines, i and k? The illu- sion is just as strong altho there are no vertical lines nor angles. And let no one introduce "imaginary," merely sug- gested, lines as explaining the illusion. Imagination, when we speak of the Other-One, is only a synonym for his "habits" of handling the things in question, for example, of drawing lines in a thing or design which is given to him without them. Now, that he may have and SIGNIFICANCE OF INTERVAL 233 use habits of drawing lines, we need not deny. And that these habits influence the acquisition or the function of other habits such as answering our question addressed to NERVOUS CONDENSATION DEPENDING ON DISTANCE OF POINTS STIMULATED. him, we need not deny. But, if we can find a more directly acting cause for his manner of answering our question, this direct cause will interest us much more than those in- direct, contributing, causes. We need not introduce any new principle of explanation. We merely remember what we have asserted about space perception in general. Two lines are called by the Other- One a single line under certain conditions, just as two points are called one point under certain conditions. Two points and two lines are the more easily regarded as one, that is, as each other's continuations, the more the nervous currents coming from the points stimulated — other condi- tions being equal — unite to act as one current. We can also express this thus : the more completely the total nerv- ous function is condensed into one motor point. Where the distance between two stimulated points is far less than the threshold, the fulfilment of the condition just mentioned is obvious. It is then due solely to our natural 234 PSYCHOLOGY OF THE OTHER-ONE equipment. Where the distance between two stimulated points is considerably greater than the threshold and never- theless the response demonstrates that there has been con- densation of the nervous functioning, the condensation, on the other hand, is a habit. Such a habit must be formed quite naturally whenever the successful localizing reflex "number 1" makes the success of the localizing reflex "num- ber 2" impossible, — for example, if, after "grasping" one of the lines or sticks (whatever they may actually be), the Other-One finds no second line or stick any more to grasp. This habit, once formed, altho it is a habit of reacting to stimulations farther apart than the threshold, cannot in its functioning be entirely independent of the distance being very large or only moderately (tho always above the threshold) large. Surely, when the distance of the points stimulated is larger, the condensation must be less liable to occur ; and when the distance is less large, the condensa- tion must be more likely to occur. Where instead of points we have lines, the distance just referred to as being greater or less must be the distance between the end points marking the break, the discontinuity. Other conditions (which might also be determinants of the condensation) being equal, we must accept the rule that, the less the distance, the greater the probability of condensation of the nervous functioning. Or, is it not true that in our actual and practical experi- ence, whenever the middle part of what seems a crooked stick is invisible, the stick is the more frequently found to be a single crooked stick, and the less frequently found to be two separate straight pieces, the closer together lie the ends of the two visible straight pieces? This rule applied to our illusion diagram explains the Other-One's — at first surprising — answer quite readily. It is true that the "nervous current i" (one will understand SIGNIFICANCE OF INTERVAL 235 what is meant by this abbreviated phrase) may, on abstract logical grounds, no more easily unite with "the current f " and pass with it into a unitary motor outlet than with the "nervous current g." This is certainly true so far as the mere direction and position of the stimulating lines are concerned. The lines are parallel and a definite distance apart. Why not call them two? — But from the nearest end of the line i to the nearest end of the line g is a much greater distance than to the nearest end of the line f. Thus it goes almost without saying that condensation occurs much more easily with reference to the nearer neigh- bors i and f ; and that the Other-One will more frequently call i and f together "one straight line with an accidental break in the middle" than i and g together. For further demonstration of the much greater impor- tance of closeness than of any other factor contributing toward condensation of the nervous functioning let us look at the right side of the last figure. Which two of the three upper lines, 1, m, and n, are the continuations of the lower lines, o and p? There is no preference here, no illusion. It makes no difference whether we draw vertical lines thru the endpoints or not. Even when we have drawn them and the angles are quite clearly seen, so that the Other-One is in no manner kept from overestimating the acute ones, he does not "waste" his reaction. The distances are here the same between the end point of o and the end points of 1 and m ; the same between the end point of p and the end points of m and n. It is therefore not to be expected that either the pair 1 and m should be preferred to the pair m and n or the latter pair to the former, when the question is raised how the lines o and p are to be continued upwards. That is, there is no cause for any illusion. 236 PSYCHOLOGY OF THE OTHER-ONE If on tl^ie contrary the angles were powerful factors, the Other-One should have an illusion in spite of the equality of the breaks. Since he scarcely has any illusion, it is clear that his habitual overestimation of acute angles is not the chief cause of this illusion here. The cause of the illusion is much more fundamental, much more elementary. As we have seen, it consists in the simple fact that sensory points on the retina (and the same rule holds for the skin) which are closer together are more likely to be function- ally joined by what we have called condensation than sen- sory points which are farther apart. Another important fact must be mentioned here. Psy- chologists have often relied too much on mere logic. If for two reactions (localizing reflexes) a single new reac- tion (saying "one") is "substituted," then the single re- actions are "excluded." So logic rules. But the facts are otherwise. Most striking is this event in the discrimination of two points ; and there is no essential difference between dis- crimination on the skin and on the retina in this respect. The Other-One sometimes says : "I call it one and am a little inclined to call it also two." (Of course, this happens only in the neighborhood of or somewhat below the thresh- old, unless the Other-One is a pure guesser and insincere subject.) It is impossible to interpret away the lack of logic of the statement. However, what has formal logic to do with the case? Near the threshold the condensa- tion is pronounced enough to bring forth the substituted re- action "one" and yet not enough pronounced so that cur- rents of considerable strength will not be able to get still to the reflex motor points of localizing each point separate- ly. Why should this not be so? It is perfectly natural. In the following figure of incomplete circles there is a further illustration of the principle of nervous "condensa- SIGNIFICANCE OF INTERVAL. 237 tion depending on distances." At A the little vertical dash (small arc) on the right does not seem to belong to the circle. It seems to lie too far to the right. With refer- ence to B we ask the Other-One the question: "Which two of the three vertical dashes (small arcs) on the right III ANOTHER EXAMPLE DEMONSTRATING NERVOUS CONDENSATION. belong to the two circles?" — He tells us: "The two left ones." Why does he not tell us "The two right ones?" The circles have intermediate positions relative to the locations of the circular continuations of the dashes. Therefore, logically one of these answers should be as probable as the other. Actually the second answer never occurs. The greater nearness between the end points at the break deter- mines the answer. The nervous currents of the two right dashes do not together with the nervous currents of the circles lead to the single motor response "one ring." The distance of the end points is (relatively) too great. At C the two large arcs are, in a geometrical sense, in- termediate between the three small arcs. No two of the arcs are parts of a single one of the concentric circles, of which there are actually five. But if you ask the Other- One which two of the three arcs on the right he would pre- fer to call the continuations of the two arcs on the left, he will choose the outer ones. He will not, as in the pre- ceding case, choose the inner ones. It is perfectly clear, why. The end points of the two outer arcs on the right 238 PSYCHOLOGY OF THE OTHER-ONE in this case are closer to the end points of the left arcs; the end points of the two inner arcs on the right are farther from the end points of the left arcs. So the former nerv- ous currents enter more readily into a condensed func- tion ; the latter currents tend more to remain an expanded nervous function. There are, however, geometric-optical illusions (that is, we remember, "wasted" space perceptions) in which ap- pears clearly the overestimation of acute (and underesti- mation of obtuse) angles. This tendency to regard angles as more approaching in size a right angle than they actual- ly do, is illustrated very conspicuously as the main factor THE WRONG ESTIMATION OF ANGLES (PEE!SPECTIVE) SEEMS TO CAUSE THE TROUBLE. of the illusion in the figure where two parallel slanting lines are the stimulus to which the Other-One responds by saying that they are curves tending to surround the upper and the lower centers of radiation. On the other hand, the principle of "nervous condensa- tion depending on distances" is again clearly brought out by the three slanting lines, which, because of the nature of AREAS COMPETING WITH POINTS 239 the lines which mark their endings, the Other-One most probably will pronounce as of unequal length. It is a story- like that told of the founder of Rome, who bought as a site for his city just enough land to permit him to spread out a cowhide. But he was careful to cut the hide into a very long and narrow strap before he spread it on the ground. In R the stimulated sensory points which mark the ends of the line spread out forming, so to speak, two triangles. The vertices of the triangles lose their signifi- cance in comparison with the inclosed areas. The nervous currents of these endpoints are quite likely, therefore, to fail to play in the condensation of the nervous function that role of relative importance which they ought to play in comparison with the triangle areas. Since the triangles DIFFERENT FORMS OF NERVOUS CONDENSATION RESULT HERB IN SO.ME "WASTED" IVEACTIONS. are relatively near each other, the response resulting from the condensation is accordingly that of calling the ends of the thing "near" or the whole thing "short." 240 PSYCHOLOGY OF THE OTHER-ONE In S, on the other hand, the nervous currents represent- ing the forks which spread out and inclose the triangle- shaped areas, when they play their undue role and enter strongly into the condensation of the nervous functioning, call forth a "wasted" response of naming the thing "long." In T the end marks do not include such areas, which can either extend the figure or cramp its length especially. So the Other-One is likely to call S longer than T, and R shorter than T. The space perceptions (or illusions) hitherto discussed are essentially two-dimensional space perceptions. That is, no express reference is contained in them to distances from the eye varying with different objects or different objective points from which stimuli emanate. Such reference to the third dimension, depth, or distance from the Other-One may, however, be said to have been implied, tho not ex- pressed, when we spoke of the underestimation of the ob- tuse angles in the corner of a room and its ceiling. The Other-One there underestimates angles which are obtuse only because in reality their lines lie outside of the two dimensions of the field of vision in which they apparently lie. Very numerous are those two-dimensional space percep- tions (themselves substitutes for localizing reflexes, as we saw) for which in turn a "depth" localizing habit function is expressly substituted. The substitution, that is, consists in extending a limb farther or less far into the depth. Such substituted habit functions fully deserve the name of per- ceptions of the third dimension. (But there are other per- ceptions of the third dimension, to be discussed later, which are not substitutes for two-dimensional space perceptions, but for other reactions.) Of the two-dimensional space perceptions thus utilizable the following list contains those TWO DIMENSIONS AND THE THIRD 241 with which everybody is most famiHar. But there are many others. They are a most important subject of study for the artist in black and white and for the painter in colors. TWO-DIMENSIONAL SPACE PERCEPTIONS REPLACED BV LOCALIZING IN THE THIRD DIMENSION. 1. 2. 3. (C). 4. (F). 5. 6. Relative size of similar forms (A). High or low position in the field of vision (B), Transposition or cutting of one picture by another Shadow above (D), below (E), or on another object Indistinctness or lack of details. Atmospheric perspective or change in coloring. The smaller of two houses, instead of being called smaller in the field of vision, may be called more distant. A house, instead of being described as standing higher in the field of vision, may be called more distant than another house which appears lower. An oak tree which cuts a house is called nearer than a fir tree which is cut by the house. A round place in the wall, dark above and illuminated below 242 PSYCHOLOGY OF THE OTHER-ONE is called a depression — maybe one made by a cannon ball. If illuminated above and shaded below, it is called a pro- trusion — perhaps the cannon ball itself, fastened with mor- tar in the hole. The shadow of a tree on the ground, when the sun is beyond, gives to this patch of ground the name of "nearer." Indistinctness, lack of details on a person seen, is interpreted as greater distance in comparison with an- other person who shows more details. Mountains which appear bluish gray or lights which appear reddish (altho this feature is not form, but color, it may be mentioned in this connection) are called farther than mountains which appear greenish and lights which appear more whitish. It is no wonder that the substitutions (these substitu- tions which so often are far more valuable to the Other- One than the replaced reactions!), after having become firmly established functions, sometimes proceed in the other direction. The following illustrates this. The moon stimu- lates on the retina an area of virtually the same size no matter whether it is high or low above the horizon. The atmospheric influences, when the moon is low, affect its color, but hardly the area stimulated on the retina. Why, then, does the Other-One call the moon larger, when he sees it low? Now, to the Other-One the Earth is essentially a flat disk covered by a crystalline bowl, the sky. The moon is a luminous spot on this bowl. The depth of this overhead bowl is less than half its diameter. A bright spot at the rim (the far off rim!) of this bowl, which stimulates on the retina an area no smaller than that stimulated by a bright spot at the bottom (the near bottom!) of the bowl, deserves therefore to be called a spot much larger than the latter. Thus the Other-One calls the moon larger when he sees it at the horizon, at the rim of the crystalline bowl. TWO DIMENSIONS AND THE THIRD 243 Being reddish helps a little in this illusion, for a lantern being carried away and disappearing finally in the fog be- comes more reddish the farther it is carried. We can ask the Other-One to convince himself by an ex- periment of the cause for calling that bright spot larger when he sees it at the rim of the shallow crystalline bowl. We make him look steadily for several minutes at a small piece of bright-colored paper on the table before him. When now he looks aside, he tells us that he sees an after-image. But when we make him look aside, we make him look, not only on the table, but also on the distant wall of the room. He then tells us that he sees the after-image on the wall much larger than on the table. This experiment shows again, that not only is a judgment of distance (that is, the action of calling a thing distant) often substituted for a judgment of size, but that also size may be substituted for distance by simply reversing the former substitution. All these substituted actions to which we have referred above under the common title of "space perceptions of the third dimension" are undoubtedly habits, acquired. There is no reason for assuming that mere heredity enables the Other-One to call a thing (not necessarily by speech, but say, by any suggestive action) nearer or farther as soon as he has once acquired the habit of calling it by one or the other name found in the above list of two-dimensional space perceptions. Not all visual space perceptions of the thiid dimension, however, are substitutions for space perceptions in the two dimensions of the field of vision. Some perceptions of the third dimension are substitutions for (or rather additions to) certain reflex movements which we have already more or less discussed when we spoke of the reflexes of adjust- ing our sense organs. The reflex of exposing the fovea 244 PSYCHOLOGY OF THE OTHER-ONE to stimulation and the reflex of accommodating the lens have such additional actions joined to them that they be- come habits of perception of depth. If the lens is first accommodated for a thing at one dis- tance and then for a thing at another distance, the action of calling one of these things nearer and the other farther can easily be added to the adjusting actions. What is added is a perception of depth, in accordance with the usu- al psychological terminology. We understand, of course, from all that has been said already, that the perception does not always consist in the pronunciation of a word, a name. It may as well consist in stretching the arm farther or less far, throwing a stone with more or less force, and so forth. In this case of accommodation it is not necessary, natural- ly, for the Other-One to have two eyes in order to perceive depth. Accommodation occurs also in the one-eyed per- son. The reflex of exposing the fovea places the axes of the eyes so that they form the so-called angle of convergence. Instead of speaking of the "adjusting reflex of the retina," one might therefore speak of the "reflex of forming the angle of convergence." But, of course, the Other-One must have two eyes for this, since one line alone can not form an angle. He adds to the movement of forming this angle an appropriate reaction of the perception of depth. Nature undoubtedly could have equipped the Other-One by heredity with reflexes of "localizing in more or less depth," making these reflexes dependent on and quickly fol- lowing the adjusting reflexes of accommodation of the lens and of forming the angle of convergence. But there is no evidence that Nature did give the Other-One such equip- ment as a pure inheritance. These visual perceptions of depth all seem to be habits. ADJUSTING REFLEXES AND VISUAL DEPTH 245 Still a further substitution of the same class, a further method of depth perception, is left to be discussed. It is among the most important, perhaps in life the preferably used, of the methods of perceiving depth. This is the so- called "stereoscopic vision." It is again a substitution for a two-dimensional space perception. But it differs greatly from all those already discussed (in our list above). In those only one eye was required. High and low position in the field of vision (figure B), for example, does not re- quire the use of two eyes. It is perfectly obvious in a single eye's image. The perception of depth which is called stereoscopic vis- ion is based on the fact that the two pictures of the two eyes are not identical. The existence of two different pic- tures being essential, the use of both eyes is then of course a requisite. The two pictures are not dift'erent in such a way that where there is a horse, for example, in one, there might be a cow in the other. The objects, the visible things, are the same. But in a lateral direction they do not have exactly the same places. (Vertically, the locations of the objects in the one eye's picture do not differ from those in the other.) The objects, or details of the objects, do not have exactly the same lateral distances from each other. And this fact can be utilized, as we shall see, for perceiv- ing the third dimension with marvelous accuracy. In order to understand stereoscopic vision well, it is neces- sary to understand the functional relations in general be- tween the nervous currents coming from one retina and those coming from the other retina. We find there also certain problems concerning two-dimensional space percep- tion which have not yet been discussed. Having two eyes is a luxury so far as their use for local- izing reflexly is concerned, where (disregarding such an- 246 PSYCHOLOGY OF THE OTHER-ONE atomical details as the "blind spot") the second eye can do nothing that the first eye could not do alone. Neverthe- less, the Other-One not only has two, but carries them in such a position that most objects are pictured in both eyes and objects pictured in one eye and not in the other are decidedly a minority of little importance on account of their indistinctness. In general, then, we do not go far astray when we say that what is seen by one eye is also seen by the other. Let us now consider one of the consequences of this ar- rangement. In our figure the two circles at R and L represent cross-sections thru the Other-One's eye-balls (who stands below us, if you wish, and whose eyes are seen from above thru a transparent skull). The median plane, the plane which divides his body into two symmetrical halves and passes thru the tip of his nose, is indicated in the figure by the dotted line lying between R and L. The ob- ject A, for example an electric light or an apple, sends TWO EYES FIXED AND EXPOSED TO VARYING STIMULATIONS. rays to the two "pin holes" and stimulates the retinas. The Other-One has a reflex of adjusting the axis of his eye so that it coincides with the direction of the most significant one of the innumerable surrounding stimuli. We assume that the axes of the eyes have thus adjusted them- selves toward A; and we shall regard them as stationary CO-OPERATION OF THE TWO RETINAS 247 in our following considerations. In order to make them conspicuous, they (AR and AL) have been drawn some distance beyond the back of the eye ball. The object C also sends rays thru the pin holes. This object, from the point of view of the Other-One, whose eyes we see in our figure, lies on the right side of his median plane. It stimulates in each eye a point on the left part of his retina. The reflex response to the excitation caused on either retina by A is a forward movement of the localizing hand along the median plane. The reflex response to the excita- tion caused on either retina by C is a movement of the hand somewhat to the right, tho mainly forward. All this is plain. But what is the result of moving the light C to the position of B? Nothing is changed in the left eye (we remember that we supposed the eyes to remain stationary) and the reflex response is still to the right forward. But the right retina is stimulated by B in such a manner that the reflex movement of the hand is straight forward in the median plane. We already know that of two simultaneous nervous proc- esses one is often swallowed up, so to speak, by the other. But this is not always the case. Assume that this does not happen here, that neither nervous process suffers a deflec- tion. The arm, being pulled by certain muscles somewhat to the right, by other muscles straight forward, will then move according to the law of mechanics along the "re- sultant," not quite straight forward, but deviating slightly to the right. The hand will then probably touch, localize, the object B. Now recall what we said about substituting one reaction, for example, the pronunciation of the word "one" or the word "two," for two localizing movements. Apply this to the movements localizing object A. The right eye calls 248 PSYCHOLOGY OF THE OTHER-ONE forth a muscular activity tending to localize A. The left eye calls forth exactly the same muscular activity localiz- ing A. When for these two identical localizing reactions a single speech reaction is substituted, it naturally is the pronunciation of the word "one." Now make the application to point B. The right eye, we said, calls forth a muscular activity tending straight forward in the median plane. But the left eye calls forth a muscular activity tending somewhat toward the right, since the left part of the retina is stimulated. When for these two different localizing reactions a single speech re- action is substituted, it is the pronunciation of the word "two." Now imagine that B is the only object before the Other- 'One and that, after having heard him say "two" before witnesses, an evil-minded person, say, the attorney of the other side in a legal case where the Other-One is one of the litigating parties, localizes with his own arm — picks the apple, let us say — before the Other-One's eyes the object B. And immediately he asks the Other-One : "How many apples did I pick?" The Other-One answers "one," and the lawyer: "Then please pick the other apple, for you said a moment ago that there were two." There the Other- One stands, shamefaced. There is no other apple in sight. Of course, he cannot call himself a liar, especially here, in court. Think of the consequences ! And besides, he has not been insincere. So he replies like a gentleman : "Ex- cuse me. I was mistaken. I did not want to say it. I shall not say it again. I ought to have said there was one apple. In the future, I promise, I shall say in such a case, truthfully, that there is only one." But now the evil one has him in his grip. While some- one is momentarily obstructing the Other-One's view, he CO-OPERATION OF THE TWO RETINAS 249 hangs up the apples A and C, screening them so (by screens not indicated in the figure, to keep it simple) that A can not stimulate the left eye and C can not stimulate the right eye. "How many are there?" he asks. The Other-One remembers what he has promised. His retinas are stim- ulated exactly as they were in the former case by the apple B. He answers timidly "one." He expects that this answer will work better. But he congratulates himself too soon on his quick adaptability. He hears the lawyer's diabolical laughter while he picks two apples, A and C, gives them to the Other-One and asks him whether he will accuse him of having picked any apple that was invisible to the Other- One. The Other-One can not honestly accuse him of hav- ing done that. There the Other-One stands, confounded, having said "one apple" and holding two apples in his hand, exposed to the charge of being an habitual liar. If we have reported these facts in a dramatic form, we have done that in order to draw some serious conclusions from them in a later part of this book, where we discuss hysteria and other abnormalities. Generally, under per- fectly normal conditions of the organism, this kind of trouble is rather mild. Indeed in ordinary life, outside of the psychological laboratory, with perfectly normal people no such trouble as that reported above as having happened in court is to be feared. Why not? The Other-One does not in ordinary life keep his eyes as still as they were supposed to be during the whole story. In ordinary life, when he says "one" or "two," his judg- ment is the combined result of innumerable successive stimulations of his ever moving eyes. The essential fact which we want to bring out in our discussion at this mo- ment is not the possibility of trouble of a practical kind, but is the following. 250 PSYCHOLOGY OF THE OTHER-ONE Whether the Other-One appHes to the objective situation to which his eyes are momentarily exposed the name "one" or the name "two," does not depend on whether the points stimulated on the two retinas are mathematically corre- sponding or not corresponding. During the second half of the nineteenth century it was fashionable among physi- ologists and psychologists to construct geometrically that peculiarly curved, bowl-shaped surface, for any possible distance before a person's nose, of which every point would stimulate the retinas in mathematically corresponding points. They called this surface the horopter. (One might translate this "locus of sights.") The construction of the horopter was undoubtedly a good mathematical exercise, but its biological significance was not equal to the amount of the labor spent in construct- ing it. The correlation between the mathematically just corresponding or mathematically non-corresponding points on the retinas, on the one hand, and the speech reactions "one" or "two," on the other hand, is not absolute (as the theory and construction of the horopter assumes), but de- pendent on innumerable accidents of life at the moment in question. The correlation between correspondence on the retinas and the speech reaction has no absolute mean- ing, but a meaning only in terms of probability. When the two points are mathematically corresponding, the probability of the Other-One's speech reaction being "one" is very great and the probability of his speech re- action being "two" is exceedingly small. In practice this means that to repeated questions "One or two?" he is heard to answer nearly always "one," very rarely if ever "two." The less the two retinal points correspond mathematic- ally, the greater the probability of his answering "two," while the probability of his answering "one" decreases ac- CO-OPERATTON OF THE TWO RETINAS 251 cordingly. This means, for example, that with a certain deviation from mathematical correspondence the Other-One is found to answer repeated questions now by "one." only a second later perhaps by "two," a little later again by "one," and so forth ; maybe as many times "one" as "two." With still greater mathematical deviation, he answers usu- ally "two" and but rarely "one." However, the mathe- matical deviation may be very great indeed, and yet he may answer "one" as in the case above, where the answer "one" was — honestly — expected to work better in court, altho as a matter of fact it didn't. Any one who does not object to poetical or figurative language, will permit us to compare the relation of the two retinas with the relation of two persons living together, say, husband and wife. The wife, having just bought a new hat, addresses her husband with: "Is not this hat beauti- ful?" The husband replies: "It is truly beautiful." They have but one opinion. They are in their domestic func- tions but one. They co-operate, do not compete. But sup- pose that the husband replies : "That hat looks like a bird's nest." They have different opinions. They are in their domestic functions two. They compete, they are rivals. So your retinas sometimes compete ; you then say "two." Sometimes they co-operate ; you then say "one." In the nerv- ous system this competition between two currents from the two eyes is equivalent to a small degree of "condensation" of the nervous functioning; co-operation is equivalent to much "condensation." The reaction is more likely to be a single reaction in the latter case. One must not think, however, that there is never any retinal rivalry when the two points stimulated on the two retinas are mathematically corresponding. The following experiment will illustrate such cases without exhausting 252 PSYCHOLOGY OF THE OTHER-ONE them. The mathematically corresponding points are here stimulated in qualitatively different ways. The three figures (each being double) must be given to the Other-One with the request to look at one half with the one eye and at the other half with the other eye. And the Other-One's remarks while looking during a few min- utes must be carefully noted. Still better than to give him these little figures is it to give him larger sizes of them and to ask him to look at them thru an ordinary stereoscope. In such a case as that of the soldier and the donkey ap- pearing in the visual field of the right eye, the house and the tree in the visual field of the left eye, there is perhaps completely successful rivalry, a fight to the finish, in the sense that there is no co-operation based on a compromise. But it should then rather be called complete division of DIVISION OF LABOR' BETWEEN THE TWO EYES. labor than rivalry. The one retina says: "Here above is the foliage of a tree." The other retina, not receiving any stimulus to which a localizing movement upwards would be in order, instead of denying its existence, says nothing. The organism acts in accordance with the one order re- CO-OPERATION OF THE TWO RETINAS 253 ceived. With respect to the donkey, the roles, active and passive, of the retinas are exchanged; otherwise it is the same case. Competition here leads to complete submission of one of the competing parties. Such a relation between husband and wife might be the equivalent of perfect do- mestic happiness, but it would not be real co-operation. It is simply division of labor. A similar illustration would be the presentation to one eye of one capital letter of the alphabet and to the other eye of another letter so that the organism would respond : "It is a monogram." A little different is the case of the divided squares, half white, half black, one divided horizontally, the other verti- cally. In two of the four quarter squares there is perfect co-operation. "To the left above there is black," says the husband. "Black as pitch," confirms the wife. "To the right below there is white, snow-white," say husband and wife with the same unanimity. But with respect to the IN PARTS THE RETINAS ARE CO-OPERATING, PARTS THEY ARE WRESTLING. IN OTHER Other two subdivisions there is rivalry. "There is black," says the husband. "There is white," retorts the wife. "No, there is black." the husband again ; and so forth. And the household, the organism, carries out now the one order, 254 PSYCHOLOGY OF THE OTHER-ONE immediately afterwards the reverse, then again the first. That is, the Other-One, whose retinas are exposed, calls out : "It is black. No ; no longer. A white cloud is pass- ing over it. It is white now. But no, a black cloud is passing over it. It is black again." And all this within the brief time of a few seconds. The two retinas are wrestling, so to speak. For a moment one has the upper hand, a little later the other. Sometimes, however, this rivalry leads, sooner or later, to a curious kind of co-operation based on compromise, "All right," says the wife, "if you insist, I shall call it black; but it is a rather luminous black." And the husband, with similar generosity : "All right, if you insist, I shall call it white ; but it is a rather obscure white." And the house- hold, the organism (that is, the Other-One whose retinas are exposed,) calls out: "It seems to be only one, a lumi- nously-blackish-obscurely-whitish thing." Never mind the lack of logic in the combination of the epithets. Real life is not always logical. The Other-One might, of course, say that it is like a piece of black glass seen in the light of the day with the usual reflections of bright things surrounding him. Similar and yet more different again is the retinal ri- valry or co-operation when we use colors. Suppose you fill the Other-One's visual field of the left eye with blue, except that as an aid in the performance of the experi- ment there is a small black dot in the center of the field. The visual field to which the right eye is exposed has the same black dot in the center, but the right half of this field is green and the left half is red. The two retinas in this case co-operate rather readily with respect to the right half of the field. There is here much condensation of the nerv- ous functioning for some reason which we shall mention CO-OPEEATION OF THE TWO EETINAS 255 presently and understand well in a later chapter. The right half is pronounced to be a greenish-blue or a bluish-green. With respect to the left half of the field, however, the NERVOUS CONDENSATION DEPENDING ON SIMILARITY. retinas usually function together in about the same man- ner as they did with respect to white and black in the former case, altho with a little more inclination toward a compromise. "It is blue," says the organism. "No, it is no longer blue. A red cloud has just passed over it ; it is red. But a blue cloud is again passing over it." And so forth the Other-One's remarks. There is but little conden- sation, then, of the nervous functioning. Competition reigns, and deflection now in this, now in that direction. Sometimes, however, that is, during certain moments alternating with those just described, the two retinas co- operate with red and blue too, compromise as they do with green and blue. The Other-One then pronounces the thing a reddish-blue, a violet, or a bluish-red, a purple. There is then an increased condensation of the nervous function- ing. The fact that rivalry is less probable, less frequent, that condensation is more probable, between the green and the blue excitations than between the red and the blue ex- citations, is apparently due to the fact that the excitations green and blue, as we shall see in a later chapter, are in a lesser degree dissimilar than the excitations red and blue. 256 PSYCHOLOGY OF THE OTHER-ONE After these discussions of the functional relations of the nervous currents having their origins in the two retinas, we can quite readily understand that method of depth per- ception which customarily goes under the name of stereo- scopic vision ; and we therefore return to it now. We said in our beginning of its explanation that the reaction was in this case substituted for a perception of the differ- ence of the place, of one thing laterally from another thing, in the one eye's field of vision and in the other eye's field of vision. The Other-One, following our request, holds before his face a finger of his left hand and a pencil in his right hand. He holds, for mere convenience's sake, the pencil about twice as far from his face as the finger. And he holds the finger just a little to the left of the pencil, in order that the one may not obstruct the view of the other. We then ask him to close alternately either eye (but without mov- r\ r\ L R STEREOSCOPIC VISION. ing his head) and to draw a sketch of what he sees with the left eye and what with the right eye. In our figure we see this sketch drawn by him. L shows what he saw with his left, R what he saw with his right eye. L and R are plainly two different two-dimensional perceptions. In order to record the special kind of difference between the two perceptions, we request the Other-One to draw in the field or frame marked I the pencil as it actually ap- pears (at the finger's side) to the right eye; and then to STEREOSCOPIC VISION 257 draw it also dotted in the position in which it would ap- pear (at the finger's side) if this eye's image were, what it is not, an exact copy of the left eye's image. He draws figure I and tells us that obviously the pencil has suffered a displacement. We ask him to state in which lateral di- rection it has been displaced. He replies "To the right." We record the answer. I. "The pencil (being farther) is displaced in the right eye's image to the right." Now we request the Other-One to draw in the field II the pencil as it actually appears to the left eye ; and then to draw it dotted in the position in which it would appear if this eye's image were, what it is not, an exact copy of the right eye's image. He draws figure II and tells us that obviously the pencil has suffered a displacement. We ask him in what direction it has been displaced. He replies "To the left." We record the answer. II. "The pencil (being farther) is displaced in the left eye's image to the left." Now we request the Other-One to draw in the field III the finger as it actually appears to the right eye ; and then to draw it dotted in the position in which it would appear if this eye's image were, what it is not, an exact copy of the left eye's image. He draws figure III and tells us that the finger has suffered a displacement. We ask him in what direction it has been displaced. He replies "To the left." We record his answer. III. "The finger (being nearer) is displaced in the right eye's image to the left." Now we request the Other-One to draw in the field IV the finger as it actually appears to the left eye ; and then to draw it dotted in the position in which it would appear if this eye's image were, what it is not, an exact copy of 258 PSYCHOLOGY OF THE OTHER-ONE the right eye's image. He draws figure IV and tells us that the finger is displaced. We ask him in what direction it is displaced. He replies "To the right." We record his answer. IV. "The finger (being nearer) is displaced in the left eye's image to the right." Now we have in four distinct statements a complete de- scription of all the diflference which can be found to exist in the two perceptions due to the use of two eyes. I and II combined describe the perception of the lateral displace- S » M ■ -N f-\ * f^ n A /^ f 11 III IV THE LATERAL DISPLACEMENT FOR A FARTHER AND FOE) A NEARER OBJECT. ment of the farther one of the two objects. Ill and IV combined describe the perception of the lateral displace- ment of the nearer one of the two objects. Of course, the term "displacement," we must never forget, refers always to the place laterally occupied by one object in comparison to another object. Speaking of a single object the term would be meaningless. Experience, repeated innumerable times from earliest in- fancy, results in the formation of a substitution habit. The Other-One substitutes the reaction of calling a thing "farther" than another, when that thing, in the two dimen- sions of the field of vision, might be called "displaced in the right eye's image to the right and in the left eye's image to the left." And the Other-One also substitutes the reaction of re- garding a thing as "nearer" than another, when that thing STEEEOSCOPIC VISION" 259 might be called "displaced in the right eye's image to the left and in the left eye's image to the right." These two substitute reactions, and nothing further, are the whole nerv- ous function which is entitled in theoretical discussions "stereoscopic vision." We understand from our preceding discussions that this substitution depends on the existence of a considerable and sufficient amount of condensation in the nervous function- ing. How could the thing otherwise be pronounced to be "one, but farther" or "one, but nearer?" It would, when there is little condensation in the nervous functioning, be pronounced "a thing in this place and a second thing in that different place." And a substitution likely to occur would then be the pronunciation "two different things." But one must never deceive himself by arguing that, logically, when for the pronunciation "two" the pronuncia- tion of the judgment of "distance" is substituted, the form- er judgment of doubleness is thereby barred. Logic in this sense does not apply to nervous functions. We have found this before. "Substitution" may easily turn out only an "addition" when we study the reactions to given situations. The condensation of the nervous functioning may be so strong that the two retinas cease to "rival," that they "com- promise" and call the thing "only one, but at a definite relative distance." This condensation may yet be insuffi- ciently strong to imply that virtually no nervous flux goes to the motor points of the two separate reactions "this place" and "that different place." And then the Other-One makes us the illogical, but actual and frequent enough state- ment : "This one pencil seems farther than the finger, and at the same time I am inclined to say that there are two different pencils." 260 PSYCHOLOGY OF THE OTHEK-ONE Of course, this result is the more to be expected — in other words, the condensation is the less likely to be strong — the greater the displacement, the greater the mathematical non-correspondence of the points stimulated in the two retinas. To repeat : double vision is often simultaneous with stereoscopic depth perception. Double vision is not incom- patible with stereoscopic depth perception. What has been said about the other perceptions of depth, should be repeated about stereoscopic vision. Nature might have given the substitute reaction to each individual of the human race as an inherited gift. But there is little doubt that Nature did not do it, and that the Other-One has to acquire stereoscopic vision as one habit among all the other habits of the perception of the third dimension. Leaving now the discussion of depth perception as such, we turn to a brief statement about those space perceptions which are illustrated by so-called puzzle pictures. Here, — that is, in high class puzzle pictures, not in the bungled pro- ductions often published in Sunday papers — one of two possible perceptions is as likely to occur first as the other perception. But when one perception has once taken pre- cedence over the other perception, the latter does not easily take the place of the former. This is natural, since the nervous current once strongly established, more readily de- flects others, new ones, starting ones, than it is itself de- flected by these starting ones. Besides, preoccupation plays its role. Good puzzles of this kind do not require for their solu- tion, for making the change, any turning of the page on which the picture is printed. Once in a while such a puzzle picture can be obtained by photographing an actual situation. Such a situation is PUZZLE PICTUEES 261 then quite likely to cause practical troubles. The sketch here shown reproduces in its essential parts such a photographed puzzle. In a certain village of northern France the in- habitants, still somewhat affected by their experiences dur- A "WASTED" REACTION. ing the recent war, saw an appearance of the Vipgin Mary in their church yard, among the leafless trees. Show the picture of the church yard to the Other-One and ask him if he sees the Virgin. CHAPTER XI Nature Divides the Spectrum eor the Other-One's Space Perception at a Distance. The retina is essentially a group of sensory points of the skin whose sensitivity has been peculiarly differentiated. The original eye is a pigmented area on the skin, as shown in figure I. The dark pigment absorbs the rays of light more efficiently than the unpigmented skin. During the process of evolution this area becomes a pit, obviously for its better protection, as shown in our figure II. Later a glassy body develops from the skin, as shown in III, closes the opening of the pit, and concentrates the light in a region always opposite that region in the field of vision ^■9"""' ^"'^ y^ <^. Sk!, "•w'S-v>% Skin t U lU THE EVOLUTION OF THE EYE from which the light emanates. The sensory points of this area are now very sensitive to ether waves of light. Such waves easily produce chemical changes in the sensitive cells of the two retinas. But the problem with which Nature finds herself con- fronted is actually most complex. The object to which the organism is to react may not be different from the others because of its brightness, but on the contrary because of its darkness, its lack of light. The Other-One may be look- (262) TWO EXCITATIONS DUE TO LIGHT INTENSITY 263 ing for the blackboard in the schoolroom whose walls are painted white. Or the cave in which he usually finds shel- ter may — and surely does when seen from a distance — differ from the bluff in which it is located by its being a dark spot amidst brighter surroundings. Nature, therefore, could not be satisfied with differentiat- ing the sensitive cells in the retina merely so that they be- come sensitive to light. They must be sensitive to dark- ness too. A very particular (very complex and far from being exactly known, chemically understood) substance was developed by Nature in the sensitive cells. Following the example of others we call this chemical substance the Black- White substance. Its chief characteristic does not really consist in the fact that it is changed by light, but rather in the following more complicated fact. When neighboring cells of a retina are subject to differ- ing intensity of illumination, different chemical processes are set up, which are in some respect opposite. The re- sulting excitations, that is, are not merely differing in strength. Thus the very darkness of an object produces a very definite and really positive nervous process which passes along nervous conductors like any other nervous flux, and. produces motor effects just as any other. But why did we say that these positive nervous processes are in some respect opposite? What kind of opposition, not referring to the strength of each process, is this ? One can get an idea of the nature of this opposition by looking at the narrow moon sickle just before or just after the new moon. The large part of the moon which does not, like the sickle, receive the sun's rays, is illuminated by the "full earth" and should therefore in its totality ap- pear brighter than the dark sky. But when you ask the Other-One about this, he calls only the regions at the cir- 264 PSYCHOLOGY OF THE OTHEE-ONE cumference of the moon circle, bordering the dark sky, con- spicuously brighter than the sky. The regions marginal to the sickle he calls even conspicuously darker than the sky. We see thus that the intensities of the excitation Bright and of the excitation Dark are to a large extent independent of the absolute strength of the stimulating light and the stimulating lack of light. The strength of each excitation depends largely, if the other excitation occurs in the neigh- borhood, on the strength of that other excitation. We can say that there is observable, in adjacent regions of the retina, a phenomenon of contrast. And in this sense we can say that the two excitations in question, the one re- sulting from the stimulus light, the other from the stimulus lack of, or weakness of, light, are opposite processes. Into the details of the theories concerning this rather complex and far from perfectly understood pair of excita- tions we cannot enter in this elementary book. It must suffice to state that there is considerable evidence to the ef- fect that the excitation White and the excitation Black are chemically related in such a manner that they may be re- garded as parts, constituents, of one chemical substance, which may be called the Black-White substance. Let us restate then what we said before : Nature had to make a provision to the effect that (1) the presence or relative strength of a light stimulus and also (2) the ab- sence or relative weakness of a light stimulus (when sur- rounded on the retina by stronger light) could each call forth a qualitatively distinct excitation often called "proc- ess." There are then (thus far) two visual processes. And Nature provided the animal race with one substance in the retina. Within this substance the Black process and the White process may co-exist, and may co-exist in greatly varying ratios of the intensities of each. To these ratios THE BLACK-WHITE SUBSTANCE 265 the Other-One answers with "dark gray, medmm gray, or light gray." The substance may conveniently be called the Black-White substance. But Gray substance would also serve as a convenient name. The visual substance just mentioned enables animals to localize reflexly a darker object on a lighter background or a lighter object on a darker background. But think now of a dark yellowish or reddish apple hanging on a tree with the usual dark greenish-bluish foliage. It might easily hap- pen that the animal's, or the Other-One's, sensory points on the retina are then illuminated by the apple neither more nor less strongly than those other sensory points on the retina which are illuminated by the surrounding foliage. The ratio of the Black process and the White process would be uniform all over. There would then be no possibility of localizing the apple, of getting it. But the light rays thrown back from the apple, altho not differing in intensity, may, and usually do, differ from those thrown back from the foliage. They consist of ether waves of different frequency, say, of lesser frequency. It is easily understood, therefore, why Nature furnished the animal race a second visual substance, in which again two differ- ent excitations could be called forth, but in this case differ- ing according as the frequency of the ether waves was great or little. But where, then, is the division line between low frequency and high frequency in this respect? When we speak of the totality of all those ether waves which are capable of exciting the retina, we speak of the "spectrum." The spectrum is an artificially produced array (usually, but not exclusively, produced by letting a ray of light pass thru a prism) of all these ether waves, or kinds of light. The light possessing the greatest frequency of waves we throw on one end, that of the least frequency on the other end of the array. 266 PSYCHOLOGY OF THE OTHER-ONE Nature could have made the second visual substance similar to the first in this respect that the two excitations, or processes, could co-exist in the same sensory cell, and the ratio of their intensities would differ according to the frequency of the ether waves, as according to the intensity of the ether waves it differed in the first visual substance. We should have found, there, much of the one excitation and little of the other at one end of the spectrum, much of the other and little of the one excitation at the other end of the spectrum, and about equal amounts of each in the middle. That would have served the localization of the apple in the above case perfectly. But Nature did not do anything of the kind with this second substance, but de- cided to confine one excitation to one side of the spectrum, the other to the other side, and to deny both to the place between them, near the division point. Now, the frequencies of the ether waves in the spectrum do not spontaneously fall into two definite divisions. The change from greater frequencies to lesser frequencies is by infinitesimal, not by finite steps. Nature therefore had to [ Scarlet-Orange- Yellow-Olive-GTcen Peacock-Blue- Violet- Purple Spectrum Named Yellow Named Blue Two Excitations Named Red or Yellow Named Green or Blue , II Two Excitations draw the line between the two divisions of great and little frequency rather arbitrarily to suit her ideas about this second visual substance. And Nature experimented, so to speak, before finally deciding where to draw the dividing NATURE EXPERIMENTS WITH DIVIDING THE SPECTRUM 267 line ; she tried drawing it here and drawing it there, as we shall see presently. Above, the upper band, marked spectrum, represents the array of wave frequencies. If instead of writing the fre- quency numbers per second we have written familiar color names, this has been done only because the color names ap- peal more to the average person's fancy. These color names really serve here as nothing but frequency numbers, the lowest on the left, the highest on the right end of the band. Below this band there are two other bands marked on the right side I and II and each entitled "Two Excitations." These represent those two trials of Nature which we have evidence she made. One of them (II) she abandoned almost completely, leaving only the traces told further below. In I she drew the dividing line at the point Green. The ether waves to the right of this dividing line had to pro- duce the one of the two excitations in question, first the more strongly (as indicated by the sloping line) the farther we pass to the right from the dividing line, then again more and more weakly until at the end of the spectrum the in- tensity of this excitation fades away. On the left side we have the other excitation, also possessing a maximum be- tween two minima, more exactly between two zeros. The ether waves of the frequency represented by the dividing line do not call forth either of the two excitations. Let us here indulge in a little fable. We have seen previ- ously that the original purpose of any two differing excita- tions must have been the advantage of localizing objects. But at once another advantage offers itself, resulting from the existence of more than one excitation. Nature can now make an animal react to one of these excitations by one reflex movement and to the other by an entirely different reflex movement, — to give two among thousands of pos- sible examples, to the one by opening the mouth, to the other by closing the mouth, or to the one by a positive 268 PSYCHOLOGY OF THE OTHER-ONE localization, to the other by a negative locaHzation. Sup- pose some of the Other-One's ancestors at a remote stage of evolution, long before the existence of man, were able to speak, as in the fables, and were able even to foresee what names he nowadays would give to the different parts of the spectrum, and were given the task of choosing their own color names in such a way that they would suit best their offspring's modern color names. What would they do? We assume that they possessed only the excitations thus far mentioned and not all of ours. They would know then that the Other-One would most frequently react to one of these excitations (in the case I) by saying "yellowish-red" (scarlet) or "reddish-yellow" (orange) or "yellow" or "yellow-green" or, rarely, "green." That is, nearly always by using Yellow. They would naturally choose the name "yellow." They would further know that the Other-One would, at this later period of history, most frequently re- act to the second of the two excitations last mentioned by saying "faint bluish-red" (purple) or "reddish-blue" (vio- let) or "blue" or "blue-green" (peacock) or, rarely, "green." That is, nearly always by using Blue. They would naturally choose the name "blue." In the sense which we have just illustrated by a some- what fanciful story we could say therefore that animals at a very early time had only the "blue" and the "yellow" color vision, that they did not possess the Other-One's four- fold color vision (blue, yellow, green, red) about which vft shall have to say a little more in the next chapter. But Nature made at least one other experiment with dividing the spectrum. The lower band, marked II, shows where the dividing line was located in this attempt. The Other-One's remote ancestors with those fabulous abilities of speech and foresight which we attributed to them would SOME COLOE-BLINDNESS 269 have had to make a different choice, a less simple choice of names. The dividing Hne is here located in the part of the spectrum which their offspring now calls Olive. On the left he uses the names "yellowish-red," "reddish-yel- low," "yellow" and "greenish-yellow," that is, always Yel- low but very frequently also the term Red. On the right he uses the names "faint bluish-red," "reddish-blue," "blue," "blue-green," "green" and "yellowish-green," that is, very frequently either of the terms Green and Blue. Those an- cestors therefore would probably have chosen to respond to the ether waves on the left side by calling them indis- criminately either red or yellow, and to those on the right side by calling them indiscriminately either green or blue, using for themselves the former two as synonyms and the latter two as synonyms. The Other-One, transported back in history to that time, would have been astonished at this particular lack of dis- crimination and would have reported it in a letter to a friend by writing something like this: "Those ancestors of mine do not distinguish between red and yellow on the one hand, and do not distinguish between green and blue on the other. When one of them says that straw is yellow and the other says it is red, the first does not retort, but acts as if red and yellow were synonyms. And when a third person who just pricked his finger shows a drop of blood and exclaims : 'This looks like your straw.' they treat him as if he were a perfectly sane person. With re- spect to the words green and blue, and with respect to green and blue things, they act in the same queer manner." All that we have said about the Other-One's remarkable ancestors changes from fable into reality as soon as we look around and find that some of these ancestors are liv- ing with us today. We call them color-blind. They de- 270 PSYCHOLOGY OF THE OTHER-ONE serve the name because in certain situations they act as if they were bHnd ; for example, some of them may be as unable to localize by a reflex movement a certain red apple on a certain green tree as a blind person is unable to do that. We mean by color-blindness, physiologically, that the person in question has only the two visual substances thus far discussed, the Black-White substance whose two ex- citations depend on varying degrees of light intensity, and the second visual substance, a "color" or "chroma" sub- stance, whose two excitations depend on the range of the vibration frequencies of the light. A color-blind person has an incomplete color sense. The Other-One's complete color sense, as we shall later see, presupposes a third visual substance with two further excitations within it. When we said above that we had evidence that Nature made at least two trials of finding a suitable dividing line for the two excitations in the spectrum, we had in mind, not exclusively, but chiefly, the fact that these two types of color-blind persons exist ; one type to whom all parts of the spectrum to the left of what we call Green are alike, but different from those on the right ; another type to whom all parts to the left of Olive are alike, and all to the right of Olive are also alike, but different from those on the left. The latter type, fully established, is very rare ; the au- thor of this, however, had the good fortune of having a perfect representative of this type under his own observa- tion. But a very common relic of this condition still exists, — in every normal human being. It is a more important evidence of Nature's trial than a few rare cases of color- blindness. Ask the Other-One whether Red and Yellow, in spite of their dissimilarity, when compared with Green or Blue, do not seem to belong together, to be somewhat simi- lar, — and the answer will be in the affirmative. And like- ORDINARY COLOR-BLINDNESS 271 wise Blue and Green, in spite of their dissimilarity, when compared with Red and Yellow, seem to have something in common, seem to be similar. A third fact belonging here is the habit of the artists of putting the former into one class and calling them warm colors, the latter into an- other class and calling them cold colors. This habit brings out the same distinction. Much more common is the other type of color-blindness (in our fable mentioned first) which is represented by those to whom Scarlet, Orange, Yellow, and Olive are virtually meaningless distinctions, to whom it means nothing at all when the first autumn frost, leaving only a part of the foliage green, changes the larger part of the foliage in park and forest to yellow, orange, and even to a fiery red. Among a hundred men we are quite likely to find one of this kind. He does not object if you call all the autumn foliage simply yellow. We said intentionally "men," for we rarely find color-blind women. This color-blindness is a biological character which is sex-linked in a remark- able way. It is dominant (that is, observable) usually only in men, recessive (that is, not apparent) in women. And yet it is inherited, not thru a man (his father), but thru a woman (his mother). If a boy is color-blind, we usually find that neither his mother nor his father is color- blind, but that his mother's father is color-blind. If a girl is color-blind, we usually find that her father and also her mother's father are color-blind. We under- stand thus why a girl is rarely color-blind. That depends on a rare case of ancestral mating. We saw above (speaking of warm and cold colors) that the other type of color-blindness is in a mild sense a per- sonal experience to every normal person. Even less for- eign to everyone is this type. The normal retina may be 272 PSYCHOLOGY OF THE OTHER-ONE regarded as consisting of three concentric areas, a central disk, an intermediate zone and a peripheral zone. In the intermediate zone everyone has a colorblindness of this type, that is, all colors of the spectrum to the left of the point Green look alike, yellow, and all those to the right look alike, look blue. (Nothing in the spectrum ever looks here either greenish or reddish.) In the peripheral zone everything looks perfectly colorless, resembling an ordinary photograph or so-called half-tone print, some parts differ- ing from others merely in being brighter or darker. In this peripheral zone the retina has only the Black-White substance. In the intermediate zone the retina has the Black-White and also the Blue-Yellow substance. Only in the central disk has even the most normal in- dividual his complete color sense, which presupposes a third visual substance. What the properties are of this third visual substance, we shall tell in the next chapter. We owe to the German physiologist Hering the now gen- erally accepted suggestion that the Blue excitation and the Yellow excitation are, not only different, but antagonistic in the sense that they cannot co-exist in the same sensitive cell. (We remember that the Black process and the White process can co-exist.) No uniformly colored thing is to be found in nature which the Other-One calls yellowish and bluish. Either one, or the other, or neither. Never both. If we mix artificially on a color-wheel a yellow and a blue disk (making sure that we do not choose a greenish- blue), we can change the proportions of the sectors so that the result is called bluish, or yellowish, or neither, but not so that the result is called bluish-yellowish. Hering suggested that the two excitations making up this pair be called assimilation and dissimilation. Other terms, also frequently used and perhaps even more use- THE YELLOW-BLUE SUBSTANCE 273 ful, are recomposition and decomposition within the Blue- Yellow substance. When two forces act on a chemical sub- stance, one tending to decompose and the other to recom- pose, and these forces are equally strong, nothing, obvi- ously, would happen in that substance. So we understand why blue and yellow on the color-wheel cancel each other. Even with a minimum of chemical knowledge one can make this clear to himself. Suppose you pour together, in liquid form, water and its two components, hydrogen and oxygen. Now put a good stopper on your bottle and do not let anything either get out or get in. Certain influences, however, can act on the contents of the bottle. Heat, for example, would favor composition. An electric current would cause decomposition. But both influences ("stimuli") acting together and with equal strength on this mixture (the Blue-Yellow substance, let us say) of a compound and its components, could in the bottle (the sensitive cell) in- crease neither the compound at the expense of its com- ponents (the process of recomposition) nor the compo- nents at the expense of the compound (the process of de- composition). Recomposition and decomposition are an- tagonistic. And thus the Blue excitation and the Yellow excitation are antagonistic. Neither Hering nor anyone else has suggested whether the Blue excitation should be identified with the process of decomposition or with the process of recomposition ; and the Yellow excitation accordingly. That can be assumed arbitrarily either the one or the other way. The greatest value of Hering's theory of antagonistic chemical processes in the Blue-Yellow substance consists in permitting us to foretell that the Other-One will react in certain ways to certain situations, not yet described, and in finding that he actually does so react. These situations 274 PSYCHOLOGY OF THE OTHER-ONE we shall now describe under the names of (1) general adaptation, (2) successive induction, and (3) simultaneous induction. Suppose we stimulate any definite group of the Other- One's retinal sensory cells in the same, unchanged, man- ner for five minutes or longer. For example, we ask him to keep his head and eyes perfectly still and then put before him on his writing desk a large piece of yellow paper, or we make him look steadily at a wall painted yellow. Sup- pose the retinal cells on which the yellow stimulus acts suffer the excitation which consists in decomposition ol the Blue-Yellow substance. (Recomposition, then, is as- sumed to result whenever the stimulus is blue.) Now, since the yellow stimulus remains unchanged, and since (we remember that the "bottle" is securely stoppered) the group of retinal cells has no more succor than a be- sieged city, the decomposition can not go on eternally. After a while it must cease, simply because there is no "com- pound" left to be decomposed. But, if you were the Creator, would you not regard this condition of the Other- One as a highly undesirable predicament? Yet it is un- avoidable unless everything so far agreed on is changed entirely. There will inevitably come a time — no matter, whether in five, ten, or more minutes — when the Other-One no longer has, in that part of his field of vision, that ex- citation (the Yellow process) to react to. There will be a time when he tells us: "That paper (or wall) is no longer yellow." But the least you would want to do for him, if you had the Creator's power, would be to put off that predicament as long as possible, just as the commander of a besieged city, or a farmer entirely snowed in, would put off the moment of surrendering to the enemy, or to starvation. EECOMPOSITION AND DECOMPOSITION 275 The usual method is rationing of the supply. And so the eye is made in such a manner that it will give up at a steadily diminishing rate the recomposed material to the stimulus for being decomposed. The eye, we may say, spontaneously resists more and more the process of decom- position and thereby delays its complete cessation. The Other-One, accordingly, long before he tells us that the paper has ceased to be yellow, is found to remark again and again that its yellowishness has become weaker and weaker and weaker. Of course, the experiment with blue would have yielded the corresponding result. What we have just described, deserves to be called, and is called, a "general adaptation" to the exigencies of a situa- tion. Why it is called "adaptation," is immediately clear. It is called "general" merely because one of the other two phenomena to be described, the one called "simultaneous induction," is sometimes also called "adaptation" and then, for the sake of distinction, "local" adaptation. Suppose now, our above experiment being finished, we permit the Other-One to use his eyes freely. The region where all recomposed material of the Blue-Yellow sub- stance has been changed into decomposed material could then not function normally. A perfectly normal function does indeed presuppose a perfect balance between the avail- able quantity of the recomposed and the decomposed ma- terial. But when of the one kind there is absolutely nothing, the condition of the retina is extremely abnormal. How can it most quickly be made normal again ? The general supply store, so to speak, of any part of the body is the blood. For example, if a bone is broken and bone building material is needed, it can be, and is, ob- tained from the blood. But needed material can be ob- tained from the blood only slowly. We know that it takes 276 PSYCHOLOGY OF THE OTHER-ONE more than days — weeks and even months — to heal a wound or a broken bone. It might take hours or days to replenish the sensory cells. Now think of the farmer snowed in. If it takes too long to get a chemical substance, say soap, from the store in the town, and he has grease and wood ashes, he quickly makes the soap himself. And the sensi- tive cells have plenty of the raw material from which the compound needed can be made. The raw material in this case is the decomposed material. And there is enough of it in the cells. Indeed the very complaint is that there is too much of it. So Nature, in order to solve the problem, should have enabled the sensitive cells to restore spontaneously the bal- ance between the quantity of the decomposed and the re- composed material. And Nature has enabled them. And at once, therefore, when the yellow stimulus is removed, the eye spontaneously sets up the antagonistic process. But the antagonistic process, recomposition, is the Blue excita- tion. To it the Other-One can hardly help responding in the normal way. So he tells us : "Whatever patch in the room (other than that yellow patch) I now look at, on the ceiling, the floor, my arm (and where not!), it is blue." This phenomenon is called successive induction. The term "induction" was borrowed by Hering from physics, where we are accustomed to speak of electrical induction. And it is called "successive" naturally because the Other- One's remark that the patch in whose direction he looks is blue succeeds his remark that the patch in whose direction he formerly looked was yellow. Of course, if the first color name had been blue, the second would have been yellow. Yellow and blue are in the description of this phenomenon entirely interchangeable. ADAPTATION AND INDUCTION 277 The third phenomenon we promised to describe, can also be deduced from the theory simply as an economic neces- sity. If the farmer needs soap, needs it soon, and has plenty of the raw material, but cannot boil it in his own house (the yellow stimulus prevents the blue excitation in certain sensitive cells, — the "patch"), he may take the raw material to a near neighbor's house, boil his soap, and take it back home even before his soap supply has become com- pletely exhausted. The retinal "patch," while decomposed material more and more accumulates in it, sends it over its border, has it recomposed on the other side and sent back in a steady stream to be decomposed again. This will naturally result in two facts. First, along the border on the patch the rationing need not be as severe as farther inside. That is, along the border on the patch the Yellow excitation is stronger than farther inside. And just outside the border, in a marginal region, the Blue excitation occurs in spite of the absence of an adequate stimulus. The Other-One tells us that the marginal region of the patch is yellower than the inside of the patch, and that it is sur- rounded by a blue margin. This phenomenon is called simultaneous induction, because the blue outer margin and the yellow patch with its intense- ly yellow inner margin appear simultaneously. The marginal character of simultaneous induction can easily be concealed by avoiding patches and instead com- posing the field of vision of alternate yellow (or blue) and gray stripes, making them narrow enough so that the margin on one side just overlaps the margin on the other side and renders the coloring of each stripe uniform in its entirety. The Other-One, then, when asked whether he sees the field of vision composed of yellow and gray stripes, tells us that this is not so; but that the alternate stripes are yellow and blue. 278 PSYCHOLOGY OF THE OTHEE-ONB The theory, or rather hypothesis, of Hering, assuming two processes (excitations) of recomposition and decom- position in the single Bkie-Yellow substance, is a beautiful explanation of the four facts of antagonism, general adapta- tion, successive induction, and simultaneous induction. But the division of the spectrum which we have discussed in this chapter is not a mere hypothesis, but a fact referring to uncounted observations of the Other-One's reactions to visual stimuli when the latter are taken from the spectrum. CHAPTER XII Nature Makes a Second Division oe the Spectrum. Perhaps Nature made a mistake in preferring the method of dividing the spectrum between the two excitations, to the method of changing the ratio of the two excitations gradu- ally from one end to the other end of the spectrum. If Nature could use two excitations, co-existing, but varying in ratio, for all the shades from white to black, Nature surely could have used also two other excitations, co-exist- ing, but varying in ratio, for the scale of frequency of the ether waves. The mistake consists in preferring a merely two-fold division to a many-fold, indeed unlimited, division based on a ratio whose variations are unlimited. A poppy flower in a wheat field is then found to be not localizable because the ether waves coming from the flower and the wheat lie in the spectrum on the same side of the division line. In order to remedy this (generally not vital, but never- theless undesirable) defect, what can Nature do? We dis- cover that Nature, in order to improve the frequency dis- crimination of the ether waves, has actually made a second division of the spectrum within the "Yellow" region of the spectrum. For this purpos-e Nature has had to intro- duce a third visual substance. And she has selected this third visual substance in such a manner that within it again the phenomenon of antagonism exists. That is, the two different excitations within it are again of the nature of recomposed and decomposed material, each one changeable into the other. (279) 280 PSYCHOLOGY OF THE OTHER-ONE Now, in looking for a chemical substance which might serve as this third visual substance, Nature made a very- queer choice. She selected a substance which-^if it is not the Yellow excitation itself, that is, the part of the Blue- Yellow substance whose increase calls forth the response "yellow" — certainly is about the same thing as the Yellow excitation. This selection, we shall see presently, has a very strange consequence. First, however, let us look at a diagram showing the point of the spectrum where the division is made within the Yellow region. This region is shown in the band mark- ed A on the right, which is identical with the band marked I in our former diagram. Scarlet-Orange- YeIlow-0!ive-Grcen-Peacock-Blue-Violet-Parple Tints Yellow Blue First Two Excitations Red Green Red __^ ^ B Second Two Excitations The right half of the region of the Yellow excitation is called by the Other-One greenish, especially toward the right where its yellowishness is less pronounced. The left half of the region of the Yellow excitation is called by the Other-One reddish, especially toward the left where its yellowishness is weak. But the middle of this region naturally is not called by the Other-One either reddish or greenish, since there neither the Red process nor the Green process is in existence. He calls it purely yellow. Now let us return to the strange consequence of Nature's selection of something virtually identical with the Yellow THE RED-GEEEN SUBSTANCE 281 excitation, to serve as the third visual substance, as the Red-Green substance. We ask the Other-One to mix on a color-wheel a red (and not at all yellowish) disk and a green (and not at all yellowish) disk in such a manner that the result is neither red nor green. This can easily be done with just a little care and patience, for in the Red-Green sub- stance recomposition and decomposition exclude each other. He adjusts the sectors, taking less red if it still looks red- dish, less green if it still looks green. Finally he pro- nounces it to be neither red nor green. But if we ask him if it is now absolutely colorless, he tells us that that is far from being true. He tells that he would call the disk spinning before his eyes a kind of yellow, — not straw yel- low, to be sure, but some rather dark and muddy looking yellow, but yellow nevertheless. This result seems very strange, but loses its strangeness as soon as we remember how Nature selected the Red- Green substance. She made the Red-Green substance simply by taking the Yellow excitation and modifying it very slightly, if at all. Now when a red and a green disk are mixed on the color wheel so that neither the Red ex- citation nor the Green excitation (neither recomposition nor decomposition in the Red-Green substance) are allowed, a disturbance of some sort nevertheless is created in a sub- stance which is virtually the Yellow excitation. And this disturbance of the entire Red-Green substance seems to be passed along the nervous conductors with about the same effect as if the normal Yellow excitation had been created within the Blue-Yellow substance and were being passed along the nervous conductors. Having divided the Yellow region of the spectrum. Nature would — we should expect — divide the Blue region, too, of the spectrum and thereby introduce into the eye a further visual substance. She divides this region indeed, but dis- 282 PSYCHOLOGY OF THE OTHEE-ONE covers, we may say, that it is unnecessary to introduce a fourth visual substance. She discovers that, for some cause, the third, the Red-Green substance, suffers recom- position in one of the halves of the Blue region of the spectrum, and decomposition in the other half of the Blue region. The same Red-Green substance is therefore se- lected to serve also for the divisional discrimination of the two parts of the Blue region of the spectrum. The Other-One, as is indicated in the band B of our diagram, calls the left part of the region of the Blue ex- citation greenish, especially toward the left, where its blu- ishness is less pronounced. He calls the right part of the region of the Blue excitation reddish. But the middle of this region he naturally does not call either reddish or greenish, since there neither the Red process nor the Green process is in existence. He calls it purely blue. Speaking of the entire spectrum, we must say, in ac- cordance with B in the diagram, that the whole central part is by the Other-One pronounced to be greenish and both ends, right and left, reddish. Now we understand why the Other-One shows so much admiration for the great variety of coloring exhibited by spectrums, for example, by that spectrum which is a fre- quently seen natural phenomenon, — by the rainbow. One ex- treme he calls yellowish-red (scarlet). This extreme lies in our diagram on the left. Passing to the right, he tells us that the scarlet becomes more and more yellowish, until he inclines to give it the name of orange. Passing further to the right, the orange loses more and more its reddish- ness and becomes a color best described by the simple name yellow. Passing on, the yellow assumes a greenish tinge, becomes olive, and then green pure and simple. This hap- pens where the Green excitation is quite free of any ad- mixture of either the Yellow excitation or the Blue excita- THE RAINBOW 283 tion. Passing along in the spectrum, bluish-green appears, called peacock. Blue takes its place. A slightly reddish blue follows (violet) and with a somewhat more reddish blue (purple) the spectrum fades away. An interesting and notable fact is the absence from this spectrum of anything that the Other-One would call a pure red, that is, a red being neither in the least yellowish nor in the least bluish. Neither does nature's spectrum, the rain- bow, contain all the colors of nature, altho it may be said to contain nearly all of them. This red, lacking in the spectrum, can be produced easily enough on the color wheel. Jilst add to scarlet (which is a slightly yellowish red) a small sector of blue, enough to cancel the yellow- ishness of the scarlet without adding any bluish tinge. There being four excitations in the two "color" sub- stances (not counting here the Black-White substance), there must occur, in the Other-One's life, occasions in each of which he will not need more than a single one of the four color names invented to suit those four excitations. But there will also be occasions in each of which he will need two color names. One can represent this fact graph- ically by a square (this square appears incidentally on the right in the following figure) of which the four corners stand for the four color names when used alone, and the four sides stand for the four possible pairs of color names, red-yellow, yellow-green, green-blue, and blue-red. That the two pairs red-green and blue-yellow are impossible color names, we have already learned in discussing the fact of antagonism. The color square suggests a principle of classifying all the colors, that is, all the colored things of nature, by divid- ing them into those standing at the corners of the square and those standing at the sides between the corners. We 284 PSYCHOLOGY OF THE OTHER-ONE thus obtain the two groups of the "singular" colors (re- quiring only a single color name) and the "dual" colors (requiring a double color name). As we distinguish in the grammar of many languages a singular, a dual, and a plural. so we might feel inclined to suggest to the Other-One to use also plural color names. But he has no use for them, because of the fact that the four excitations fall into two pairs of antagonistic excitations. This fact prevents any three of the four from ever occurring at the same moment in the same retinal cell. And of course, it also prevents all four from thus occurring. Thus, there can be in the Other-One's world only singular colors and dual colors, and no plural colors. He speaks to us only of four singu- lar colors and of four classes of dual colors, each of these classes of dual colors containing infinitely many tints. It is interesting to note in this connection that only the names of the singular colors are of such ancient origin that absolutely nothing can be said of it except that these names must have their source in elementary biological needs: All other color words of the dictionaries, other than red, yel- low, green, and blue, have an etymological history. That is, they meant something else, a fruit, a flower, an animal, a mineral, and the like, before they came to mean a color. Think of orange, olive, violet, peacock, maroon as ex- amples. In some cases this is not so obvious, but never- theless true. Purple seems to have no meaning other than color. But it is actually an ancient corruption of the name of the mollusc which the Phoenicians collected in order to extract a bluish-red pigment. If we want to represent in a graph that part of the Other-One's color nomenclature which is indispensable as soon as we include also bright and dark discrimination, wr need a graph of three dimensions. The two dimensions of SINGULAR AND DUAL COLORS 285 the color square are insufficient because the one co-ordinate represents the Red-Green substance and the other co- ordinate the Blue-Yellow substance. We need a third co- ordinate to represent the Black -White substance. The simplest body to include all the three-dimensional color names ("color" in the broader sense, including white and black) is a regular octahedron. (A detailed study of the Other-One's color nomenclature would lead us to pre- fer a somewhat less regular, tho similarly shaped body. But in this book there is no room for these details.) Why is it an octahedron, that is, a body that tapers off into a 7^ "^AA e^ THK VISUAL EXCITATIONS EXHIBITED IN AN OCTAHEDRON. point whenever we proceed from the origin of the co- ordinates in any one of the six directions? In the left octahedron of the figure we see why this must be so for proceeding toward Red or Green. An ''intense" or "fully saturated" red is never excessively bright or excessively dark. Therefore, in increasing its reddishness, we limit the available space between White and Black until we end in the very point marked Red. The same statement holds for Green. And also, as we saw in the spectrum, the more we con- fine ourselves to the neighborhood of the Green point, the less there can be of the excitations Yellow or Blue, for the Green point is the very division point of the spectrum be- tween these two excitations. The same can be said of the 286 PSYCHOLOGY OF THE OTHER-ONE Red point if we think of the spectrum as a ring in which the right and the left end are joined in a single point of the ring. In the octahedron standing in the center we see why the color body tapers if we proceed from the origin of the co- ordinates in either the direction Yellow or Blue. The more saturated a yellow or blue, the less chance there is in the Other-One's experience for its being excessively bright, dark, red, or green. The octahedron on the right shows that the body tapers when we rise above or submerge below the "color square." An excessively bright or excessively dark object never ap- pears reddish, yellowish, greenish, or bluish, or in any dual coloring. So much for the fact of experience. However, any reason for this fact, any theoretical explanation, can- not be given either very convincingly or in very simple terms. We therefore pass over it. This octahedron (or a more irregular, but similarly shaped body which may take its place) is usually referred to, for purely historical reasons, as the "color pyramid." We pointed out, in the preceding chapter, that the three visual substances, which are represented in the three di- mensions of our octahedron, have their natural geometrical representation in the three "zones" of the retina. Nature, introducing the Black-White substance in the eye, spread it out over the region called the retina. The Blue-Yellow substance was introduced much later in evolution, and Na- ture, it seems, has not yet found the time to spread it, from the center in a radial direction, farther than the peripheral limits of the intermediate zone. And the Red-Green sub- stance has not yet been spread by Nature beyond the limits of the central disk. Only in this central region, therefore, does the Other-One possess the three visual substances EVOLUTION OF THE VISUAL. EXCITATIONS 287 represented in the octahedron. In the surrounding zone he is "color-bHnd" in the ordinary meaning of this term; that is, he has no Red-Green discrimination. And in the peripheral zone he has no frequency discrimination of Hght whatsoever. We also understand why the ordinary type of color- bhndness, discussed already in the preceding chapter, con- sists in the lack of the Red-Green (and not in the lack of the Blue- Yellow) discrimination. It seems logical that in- dividuals lacking an evolutionary character of the race, should be more likely to lack a character lately acquired by the race than a character older and, as stands to reason, more firmly established. A few color terms which we hear the Other-One use after he has gone thru certain occupations common in human society, should still be mentioned. "Complementary" is the name given to any two colors which can be mixed so that the result is "colorless," that is, neither reddish, nor yellowish, nor greenish, nor blu- ish. The name has an historical origin, referring to the fact that colorless compound light, like sunlight, can be physically split in infinitely many ways into pairs of colored light, and that any two "twins" of this kind can again be physically combined into the "complete" light, that is, the unsplit and colorless light. ("Complementary" is derived from the word "complete," not from compliment.) There is no scientific relation whatsoever between com- plementariness and antagonism. The former is a physical, the latter a biological term The only and fortuitous rela- tion between these terms consists in the fact that one of the many pairs of complementary lights of the physicist looks like the one pair of singular colors, yellow and blue. It is especially important to remember that there is no pair 288 PSYCHOLOGY OF THE OTHER-ONE of complementary lights which looks like the other pair of singular colors, red and green. If one light looks like the singular color red, its complementary light would look like the dual color bluish-green. And if one light looks like the singular color green, its complementary light would look like the dual color bluish-red. Sometimes we hear the Other-One speak of certain groups of colors as "primary, principal, fundamental, or original" colors. All these terms are entirely dispensable for the psychologist, to whom the distinction between singu- lar and dual colors is the only one needed. But naturally, if the psychologist were pressed to tell his idea of the Other- One's "primary, principal, fundamental, and original," as distinguished from the Other-One's "secondary and de- rived," color experiences, the psychologist could do nothing but call his four singular colors primary, etc., and the dual colors secondary, etc. But the technologist, the man engaged in industrial color work, such as color photography, color printing, etc., would find an entirely different group of colors most interesting, that is, most primary, principal, fundamental, and original, to him. In technology the chief problem is to find the smallest numbers of colors (that is, usually, pigments) which can be mixed in such varying manners that all the tints of nature as well as a colorless impression may re- sult. The smallest number fulfilling this condition is three. There are, however, infinitely many "triplets" of colors fulfilling this condition. Among them the technologist usu- ally, but not always, uses scarlet, violet, and green, be- cause of certain advantages with respect to the saturation of the resulting tints. These three then are to him his chief or "primary" colors. TECHNOLOGICAL COLOR CLASSIFICATIONS 289 A simple method of finding a triplet fulfilling these tech- nological conditions consists in selecting two singular, but not antagonistic colors, and adding that dual color which resembles the two singular colors left out. For example, blue, red, and yellowish-green. It is then easy to demon- strate that this triplet fulfills all the conditions. From yellowish-green we easily get, by adding some blue, the singular color green ; and also, by adding some red, the singular color yellow. Having then all singular colors, we can easily get, by combining them, all possible tints and also the colorless impressions. But all such triplets of colors, we must not forget, are of importance only in technology, not in psychology. The artist, the painter, again has a diflferent notion as to what colors are "primary, principal, fundamental, and original" to him. The painter would like to have as many different pigments handy on his palette as there is room for, since this facilitates his work. But the space on the palette is limited, and having to buy and store away many tubes or cakes is inconvenient and uneconomical. So he tries to restrict himself to buying a limited number of pig- ments. He rarely, if ever, restricts himself to less than six. So the Other-One, having asked a painter what his "primary" colors are, without which he would not care to begin any painting, is quite likely to have heard that there are six primary colors. To the psychologist this is of very little interest. Everything that we have said in the preceding chapters about antagonism, general adaptation, successive induction, and simultaneous induction, applies to Red and Green with proper modification as it applied to Blue and Yellow. And it applies, with the exception of antagonism, even to Dark and Bright. 290 PSYCHOLOGY OF THE OTHEE-ONE There are innumerable other facts which we might dis- cuss, concerning the Other-One's observed behavior of giv- ing this or that name or significance to this or that situa- tion to which his eyes are exposed. We select only one to mention here, the fact of "positive after-images." A color reaction of the Other-One due to successive induc- tion is often called a "negative after-image" because the induction stimulus causes the Other-One to give the "image," that is, the object seen, "afterwards" a name which is "negative" in the sense of being due to antag- onism or to the opposition of darkness and light. What, then, is a positive after-image? It happens that the Other-One calls the object, "after" it has disappeared from its former place in the field of vision, by "the same" name, implying its continued and unchanged existence. For example, we notice that the Other-One does this when he looks at the setting sun and then turns his head away ; or when the stimulus is the glow- ing filament of an electric light bulb. He tells us that the sun or the glowing filament seems to be still present. The positive after-image is in one respect the opposite of "general adaptation." In general adaptation the excita- tion ceases before the stimulation ceases. But in the case of a positive after-image, the excitation outlasts the stimu- lation. The stimulus must always be very strong if it is to cause a positive after-image ; or, if not very strong, very pro- longed. A weak stimulus gives only a negative after-image. A strong stimulus, however, gives both. The positive after- image is always followed by a negative after-image. Some- times the Other-One tells us that that negative after-image which follows a positive after-image, might more properly be given the name of a "flight of colors." AFTEB-IMAGES 291 The three visual substances, when strongly disturbed by intense stimulation, seem to pass thru a sort of "see-saw- ing" process before regaining their quietness. The Black- White substance see-saws thru an alternate prevalence of the Dark excitation and the Bright excitation ; and the two color substances see-saw thru an alternation of recom- position and decomposition. But the lengths of the periods of see-sawing are different for the three substances. The total result is a combination of excitations which varies from moment to moment, and in which it is difficult to find any orderliness. To it the Other-One is apt to find it im- possible to react otherwise than by simply calling it a flight of colors. The phenomena of adaptation and after-images may be written in their logical relations in the following form. General Adaptation Local Adaptation — Simultaneous Induction Successive Induction — Negative After-Imagery Positive After- Imagery The terms which, in the above form, stand side by side on the same level, are simply synonymous. The terms which stand directly above and below each other are thus placed to indicate that their relationship consists merely in the fact that the one suggests the other logically. It may appear strange to us that Nature should have chosen the visual substances and the excitations within them in such a mamier as to call forth these "wasted reactions," the color illusions described. But an excuse for Nature is the fact that these illusions are not as common in the Other- One's life as they appear to be from a theoretical study like this. They depend for their full development at any moment on a restful position of the eyes which is but rare- ly realized outside of the scientific laboratories where it is 292 PSYCHOLOGY OF THE OTHER-ONE specially fostered. Nature has overcome the difficulty created by the possibility of color illusions by making the eyes such movable and extraordinarily restless organs as they are. CHAPTER XIII The Other-One is Equipped with a Sense Organ Particularly Suited to Signals. In a previous chapter we enumerated the most interest- ing reflexes. We found among them a group of special importance, the reflexes of signaling. The signaling re- flexes are indispensable for social life. And we stated that the various species of animals had been equipped by Nature also with special reflexes enabling them to respond prop- erly to these signals coming from other individuals of the same species or of a different species. A reflex, we know, presupposes a chain of nervous con- ductors leading from a definite sensory point to a definite motor point. But it also presuppoBcs that this motor point is properly equipped with a nsotor organ. And it further presupposes that the sensory point is adequately equipped with a sense organ. We learned that in general the most efficient signals are acoustic signals. We therefore ask, now, what Nature has done in order to enable animals to respond properly to acoustic signals. When the acoustic signals are complex and the proper reflex (or habit) response depends on con- densation of the nervous functioning called forth by a multiplicity of acoustic signals, we speak of "perception," and here customarily of "auditory perception." We can, therefore, repeat our last question in the following form : How has Nature equipped that sense organ upon which the Other-One's social reflexes particularly depend, that sense organ which serves the Other-One's auditory perceptions, his "auditory organ" or, briefly, ear? (293) _. -..a 294 PSYCHOLOGY OF THE OTHER-ONE An acoustic signal is a trembling motion of an object capable of causing in the elastic medium surrounding it (air or water) a periodic density change. It is one of the laws of physics that a periodic density change will then oc- cur, after a very short time, also at any other place within the elastic medium, provided the distance of this other place is not excessive. Nature's first problem then consisted in modifying the skin of animals living in water or air so that density changes, that is, pressure changes, of the water or air could very easily bring about in sensitive cells chemical changes, — excitations. The so-called lateral-line organs of the fishes are such modifications of the skin. However, the pressure changes acting ordinarily on the lateral-line organs of the fishes are still very great in com- parison with the pressure changes which we call sound, caused by minute trembling motions of objects at distances often very considerable. Nature found that a sense organ of extraordinary sensitiveness could be constructed by let- ting the sensitive cells end in fine hairs and by exposing these hairs in such a manner that the slightest pressure changes in the medium surrounding the animal would ef- fect a bending of these hairs. A very simple sense organ of this kind is a cavity, located within the animal's body or near its surface, having a fur- like lining and being filled, of course, with the common fluid of the animal, with lymph. Our figure shows two views of such a cavity. In the left part of the figure the hairs are all in the normal condition, straight. At the left is a density wave approaching. It has already reached the interior of the animal, but not yet the cavity in question. The right part of the figure shows the effect on the hairs of the passage of the density wave thru the cavity. The wave A SENSE OBGAN FOB ACOUSTIC SIGNALS 295 is not likely to pass thru the lymph of the cavity with the same velocity with which it passes thru the substance of which the wall of the cavity consists. The velocity may be greater or less. That depends on the physical conditions of the animal's anatomy. What is important for us to keep in mind is merely that the velocity is not likely to be the same. In our figure the velocity in the lymph is supposed to be greater. The wave surface has advanced in the lymph farther to the right than in the wall of the cavity. The particles of the substance have been pushed together and the hairs between them have had to follow, bending to the right. Of course, the bending is exaggerated in the figure. Behind, that is, to the left, just the opposite is observable at this moment. The particles of the wall are being pushed TTTTTTTTrr^ MjdlLU^ AN EARLY STAGE IN THE EVOLUTION OF THE AUDITORY OK'GAN. together, into greater density. The roots of the hairs are here farther to the right than their tips. That is, the hairs are bent to the left. It is worth mentioning that this kind 296 PSYCHOLOGY OF THE OTHER-ONE of "hair organ" not only can be very sensitive to small density changes, but also is capable of being affected no matter in what direction the density waves pass thru the cavity, since the "fur lining" covers all walls of the cavity and is thus equally exposed in all directions. The Other-One's "ear," we shall presently learn, is much more complicated than such a hair lined cavity. But the essential features of this simple hair organ are present within it. There can be no doubt that the Other-One's ear, while functioning in a far more complicated manner, in accordance with the purposes of its anatomical struc- tures, functions at the same time in this primitive man- ner described. The complicated function, that is, does not preclude the primitive function. And when the Other-One, in the course of a disease, loses the more delicate and com- plicated functions of his auditory organ, he may still retain the organ's capacity for this primitive function. Many strange observations about the hearing of people who are hard of hearing or almost deaf, become thus understand- able. This primitive "hair organ" was further developed by Nature in the following manner. The cavity was enlarged. The "fur lining" was removed from the wall and floated within the cavity, not quite freely however, but attached to the walls in such a way as to form a sort of partition dividing the cavity into two rooms. To each of these rooms a window was given. These windows open upon a tunnel whfch leads out into the surrounding medium, the water or air in which the animal lives. But the distance from the outer air (or water) to one of these windows, both marked W in the figure, is somewhat greater than to the other window. The result is that the incoming den- sity wave never exerts its maximum pressure upon both THE EVOLUTION OF THE AUDITORY ORGAN 297 windows at exactly the same moment, but first upon the one, later upon the other, and so on alternately. Conse- quently the lymph in the cavity is pushed now in the di- TWO UNSTMMETRICALLY LOCATED WINDOWS. rection from the one to the other, then from the other to the one, and so forth, alternately. This motion of the lymph, however, in this case, is not to be regarded as the kind of motion spoken of in the primitive organ, that is, as molecular motion within the lymph. Rather it is a mo- tion of the whole mass of the lymph, up and down in the figure. In a cross-section avoiding the windows the cavity with the partition within reappears in another figure. On the left of the figure the partition appears in its undisturbed THE BENDING OF THE HAIRS ON THE PARTITION. position, and on the right of the same figure it appears bent down (exaggeratedly, of course, in the drawing). A kind of very delicate membrane (maybe a mass of threads like a brush rather than a membrane) is fastened to one side of the wall and touches the hairs so that their tips ad- here to it somewhat firmly. It is immediately clear, then, that the partition can not be pushed up and down by the 298 PSYCHOLOGY OF THE OTHER-ONE moving lymph without causing a bending of the hairs, which are rooted in the partition and have their tips in the upper, brush-like, membrane. We thus understand the "second method" of function- ing of the Other-One's auditory organ. Again it depends on a bending of the hairs of the sensitive cells. The great- er sensitiveness of the organ is secured by doing away with the necessity of the density wave passing thru the substance of the animal's body. Instead, the wave is led thru a passage, or tunnel, as we said, to the two unsymmetric- ally located windows. There is less loss of energ>' in the passage thru the tunnel than in the passage thru the body substance, and accordingly this second method of function- ing of the organ must be regarded as an improved, less primitive, more developed one. It is clear that for this second form of fimctioning much depends on the flexibility of the two windows. These win- dows should be protected against intruders like small para- sites living on the surface of the animal and capable of entering the tunnel. And in animals living in the air, like the Other-One, the windows should be protected also against the drying effect of the outer air. Nature, there- fore, has closed the tunnel with a membrane, the "ear drum" or "tympanum." The tympanum happens to be slightly funnel-shaped. But this shape is not very essential. That the protection afforded by the tympanum to the Other- One's "windows" of the inner, lymph-filled cavity is very important, is proved by much clinical experience concern- ing the results of a breaking of the tympanum. Would it not occur to you, having the Creator's power, that you might now utilize this drum, created merely for protective purposes, for the transfer of the sound energy directly to one of the windows? The advantage result- SECONDARY USE OF THE PROTECTIVE DRUM 299 ing would be that the amount of energy usable would no longer be limited by the amount of asymmetry in the loca- tion of the two windows relative to the tunnel. The trans- fer of the energy is easily accomplished by means of any kind of solid object attached both to the drum and to one of the windows. In the birds and lower vertebrates this solid is a simple slender rod, sometimes with a triangular USB OF THE PROTECTIVE DRUM FOR A SECONDARY PURPOSE. opening as seen in the figure. In the mammals it consists of three little jointed bones, the "auditory ossicles." One of them looks very much like a stirrup and is therefore called the "stirrup." Its plate is attached to one of the windows, the "oval window." The ossicle forming the middle link of the chain is called the "anvil" because it faintly resembles an anvil in shape. The third ossicle, which is attached to the drum, resembles a hammer still more faintly than the second can be said to resemble an anvil. It is called hammer chiefly because a thing acting on an anvil seems to deserve the name "hammer." Thus there is a "third method" of functioning of the Other-One's auditory organ. It differs from the other two by including the function of the chain of ossicles located in the air-filled cavity of the "middle ear," which is the name given to the space between the drum and the win- dows. From what we have said it is clear that the function- ing of the sense organ does not absolutely depend on the existence of the drum and the ossicles. Indeed, even when, as in a normal condition of the Other-One, they exist free 300 PSYCHOLOGY OF THE OTHER-ONE from all impediments, their significance seems to be the less, the greater the frequency of the sound waves acting on the sense organ. When the frequency is high, and the waves are therefore of small length (a few inches only), and the asymmetry difference of the windows is an ap- preciable fraction of the wave length, the ossicles are hard- ly needed. But for the lower tones, where the frequency is small and the wave length great, the mediating action of the drum and the ossicles seems to add much to the effici- ency of the organ. If you now examine the sense organ created, you dis- cover that it might be improved still further. Think of a fox whose ear is struck at the same time by the whistling of the wind and the cackling of a fowl. If he needs food, he ought to react negatively localizing the high tones of the wind and positively localizing the lower tones of the fowl. Or think of a dog whose ear is struck at the same time by the roaring of a lion and the much higher voice of his master. You cannot fail to notice the advan- tage which must result to the dog from the ability to per- form both reflex responses at the same time, to run away ^* S.b M. Mk ONK SENSORY POINT SERV- ING SKVER'AL MOTOR POINTS OR EACH ONE SEPARATELY. from the lion, but in the direction of his master rather than in any other direction which might also lead away from the lion. FREQUENCY OF JEKKS 301 In accordance with what we have already learned it must be emphasized that this ability, in general, by no means requires that both excitations originate in distinct sensory points. They might originate in one point. We have con- vinced ourselves previously that the neurons, at least some of the neurons of every animal, possess a specific (spe- cifically low) resistance. As a result of it two excitations originating in the same sensory point, say Sab in our fig- ure, may become separated, say at S%b. and may be con- ducted, further on, each virtually over its own path, one to Ma, the other to Mb. But it seems nevertheless necessary, in the case of the auditory excitations, since these depend for their distinctive qualities on the frequency with which the sensitive hair cells are disturbed, that of two kinds of auditory excitations originating during the same time the one must spring from one sensitive cell (or group of such cells) disturbed with one frequency, and the other excitation from another sen- sitive cell disturbed with another frequency. Why? — Simply because there is no concrete meaning in saying that a body trembles with two or more frequencies of jerks at one time. The total number of jerks during the unit of time is the frequency with which it trembles ; and there is only one such total number. If there must by necessity be during the same time an- other frequency of trembling causing another excitation, this must be caused to happen in another sensitive cell. But at some later time the other frequency of trembling may very well happen in the same, first, cell. Each of the sensory points may have — at dift'erent times — any one of the thousands of possible auditory excitations aroused with- in it ; it all depends on the frequency with which the sen- sitive cell happens to be jerked about at the moment. 302 PSYCHOLOGY OF THE OTHER-ONE Fortunately Nature's task of equipping the auditory cells is simplified by the limited need for localization reflex paths. In the eye every sensory point, we remember, has its own localizing reflex path. In the ear there are not thousands, but only two different localizing reflexes, one belonging to all the sensitive cells of the left ear in common, the other to all the sensitive cells of the right ear in common. This opens the way for easily assigning to any one sensory point a large number of reactions among the eight classes of fundamental reflex actions which we distinguished. Acting as the Creator's deputy, you now want to improve the auditory organ in such a manner that a compound den- sity wave acting on the windows will cause certain sen- sitive cells (located, we know, in the "partition" of the Ivmph-filled cavity) to be jerked about as many times as the frequency of the highest component tone, other cells as many times as the frequency of the lower component tone, and other cells with still lesser frequency if there are still further physical components. All that you have to do in order to bring this about is to lengthen that lymph-filled cavity. You must stretch it, change its shape from that of a sack-like cavity into a kind of tube, at one end of which the windows are located, and stretch, of course, the partition also lengthwise thru the tube. The reason for stretching the cavity and changing it into a tube is no other than that of obliging the density change of the external medium to spread its effect more or less over the partition, that is, over further or fewer sen- sitive cells, according as the density change of the com- pound sound wave happens to be vigorous or faint at each moment. In the more primitive, sack-like cavity virtually all the cells are at every moment indiscriminately under the influence of the external density change. Now, in the ELONGATION OF THE CAVITY AND ITS PARTITION 303 tube, at any infinitely small moment, some are and some are not under this influence, and at another moment others are and others are not. Some fifty years ago curious reasons were believed to have been Nature's purpose in stretching out the cavity and its partition. For example, it was believed that Nature had thus developed the partition into a sort of layer of harp strings or grand piano strings on which the sound wave could then "play by resonance" as you can play on the piano strings, without touching them, if you merely step on the pedal and, having previously raised the lid, sing or speak into the box. The piano then sings or speaks back. Thus the Other-One's "ear," it was said, takes up the sound and speaks, not back, but to the Other -One's nervous system. The more plausible reason for the stretching of the cavity and partition — simply in order to extend the sensitive sur- face of the organ in the direction away from the windows, that is, from the nearest possible point of attack — was first given by the French otologist, Pierre Bonnier, to whom belongs the honor of suggesting this idea altho he never showed in detail the consequences for auditory perception of this stretching of the sense organ. We then have here the "fourth method" of functioning of the Other-One's auditory organ. There are various ways of showing in a graph a com- pound sound curve. Our figure shows such a curve of density changes in the air produced by two (let us re- member "two") musical instruments of which one causes two "waves" while the other causes three during the same time unit, a small fraction of a second. There are also various ways of showing in a graph the shape which the partition, seen in section lengthwise, as- 304 PSYCHOLOGY OF THE OTHER-ONE sumes at the moments whenever the sound curve shows a maximum or minimum of air pressure. The next figure gives us one sample graph (reproduced from the writer's "Mechanics of the Inner Ear," U. of Mo., 1907) which corresponds to the sound curve of the preceding figure. The dotted line represents the place where the partition would be found while nothing at all was going on. If the motion of the lymph in the double tube-like cavity is to- ward the oval window (the stirrup window), the parti- tion yields upwards until it becomes so tightly stretched that it will go no farther up. This limit is of course shown in the figure with great exaggeration. If the motion of the 8 Y ^' f f TWO SERIES OF SOUND WAVES COMPOUNDED. >^ lymph is toward the other window (the so-called round window) the partition behaves in the same manner down- wards. THE COMPOUND WAVE SPREADS OVEB THE PARTITION 305 It is important, however, to keep always in mind that, whenever a reversal occurs, a lowering of the air pres- sure instead of a rising or vice versa, the piece of the parti- tion which reacts first to the reversal is that near the win- dows ; and only when this piece will yield no further to the onrush of the fluid, will a further piece of the partition yield, always proceeding in this manner from the left to the right, no matter whether the partition goes up or down. B C D C r G II 19 244 30 AN APPROXIMATE KEPRESENTATION OF WHAT HAPPENS TO THE PARTITION. This must naturally so occur in accordance with the physi- cal law that every motion occurs with the least possible ex- penditure of energy both in shifting the masses and in over- coming internal friction. And we remember that for this very purpose of extending the eflfect to a distance from the windows which is the greater, the greater the pressure change, the cavity and the partition have been stretched out in the direction away from the windows. Now, at A in the last figure we find in the upper limit an initial piece of the partition — thirty units in length, let us assume. We find this piece in the upper limit because the density change represented in the preceding figure has occurred periodically many times already. We do not con- sider at all the more complicated changes occurring in the 306 PSYCHOLOGY OF THE OTHEK-ONE partition at the very beginning of the sound, since they interest us much less. From the time A to the time B there is a pressure in- crease in the air of 24^ units. At the moment B, accord- ingly, we find an initial piece of the partition 24^^ units long in the lower limit. From B to C the pressure decreases 24j^ to 13^, that is, by 11 units. We therefore find at the moment C an initial piece of the partition 11 units long in the upper limit. From C to D there is a pressure increase from 135^ to I63/2, that is, by 3 units. We therefore find at the moment D an initial piece of the partition 3 units long in the lower limit. The piece directly following on the right is drawn as being still in the upper limit in which it was at C. It can hardly have changed its position appreciably, since no force has been acting on it meanwhile. The next piece, following on the right as far as the mark 24^/2, is drawn as being still in the lower limit in Vv-hich it was at B. The following piece is still in the upper limit as at the moment A. And the continuation of tlie partition farther to the right is unchanged since this sound wave is presumed to be not strong enough to affect it. From D to E there is a pressure decrease of 11 units. Accordingly, 11 units of the partition are sucked up. This upward movement, then, is what happens to the first three ; but the eight following (from 3 to 11) are already up. These eight are therefore left where they are, and eight more (from 11 to 19) are sucked up from their lower position at D to an upper position at E. Those pieces of the partition which follow on the right (from the mark 19 to the right) simply remain each in that position in which it was at the moment D. No force has acted on them meanwhile. FBEQUENCY OF JERKS 307 From the moment E to the moment F the air pressure increases from 5]^ to 30, that is, by 24^/2 units. Accord- ingly, so many units of the partition are pushed down, — the initial ones, that is those near the windows, first, the others soon afterwards. First those from the mark zero to the mark 19 are pushed down, then those from the mark 24>4 to the mark 30. From F to G the pressure falls 30 units. Thirty units of the partition are sucked up. At G we find these thirty units therefore in exactly the same position in which we found them at the start, at A, Let us not forget, now, that this graph shows us only in certain general outlines what goes on in the partition. The finer details of this occurrence have been sacrificed to the need of a first understanding of that which is most es- sential. Looking down the "columns," so to speak, of the last figure, we count in each column how many times the sen- sitive cells of that part of the partition have been jerked down and up. In the initial section we count 3 such jerks, in a following section 2 jerks, and in a farther section of the partition only one jerk in the time unit from A to G. It is clear, then, that three classes of excitations take their origin from the ear and pass thru the nervous sys- tem in those directions where they find favorable condi- tions of resistance. What at first astonishes us is the fact that not only the excitations "3" and "2," which we ex- pected to find, but also the excitation "1" are present. This, however, is entirely in accordance with the facts if we study the Other-One's auditory perceptions sufficiently in detail. If we sound two tuning forks, the Other-One will gen- erally tell us, provided he has enough training to answer our specific question, that he hears three different tones. 308 PSYCHOLOGY OF THE OTHER-ONE But what is most important is the fact that each of our tone stimuH, "3" and "2," produces its own excitation. If the effect of the sound wave had been confined to the small area of the partition in the primitive cavity, if it had not been spread over the partition lengthened within the tube, the three jerks conspicuous in the sound wave would have resulted in a single corresponding excitation; and that would have been all. Several simultaneous excitations and several simultaneously determined reactions, like the dog's running away from the lion and toward his master, would have been impossible without this lengthening oi the sen- sitive surface. It will probably be of some interest even to the student who is not interested in the special problems of the function of the sense organs, to mention here a few of the secondary anatomical features which have resulted from the con- tinued lengthening of the tube containing the sensitive sur- lace. First, as the tube lengthened, it coiled up. Some explain this as due to a saving of space. But it is hard to see why the tube could not, on that account, find room in the thick bone of the base of the skull just as readily if it had grown along a straight line. It is a much more plausible argument that, in coiling up, the sensitive surface exposed itself to stimulation by the first mentioned, most primitive method more efficiently than if it had remained straight. Thus a sound wave passing thru the body can act on some part of the "fur lining" no matter in which direction the wave proceeds thru the three dimensions of space. Thus the advantage is regained which was im- paired when the "fur lining," as we remember, was taken from the walls of the cavity. A second anatomical feature which easily arouses the student's interest is the fact that a kind of skeleton, look- PECULIAEITIES OF THE AUDITORY ORGAN 309 ing in cross section like two pillars falling against each other and forming an arch between the sensitive cells, was introduced when the tube became long. In the birds, in which the tube is not yet very long, these pillars are absent. In our figure of a cross section of the tube in the mammalian auditory organ these pillars are very con- .spicuous. It is clear that, when the tube is very long, the initial sections of the partition near the windows undergo especially violent pressure changes. Such a skeleton, un- necessary in the birds, becomes then desirable. And in the initial sections it ought to be especially stiflf. So it is, for in the initial sections the pillars form a more acute angle than in the parts of the partition farther removed from the windows. A third feature worth mentioning even in this brief discussion is the membrane which is stretched at a slight distance above that side of the partition on which the sensitive cells are placed. There is, of course, a consider- able motion of fluid unavoidably also lengthwise in the double tube. This acts by friction on the partition and might cause damage. On the side of the partition (the lower side in the figure) where there are no sensitive cells, no damage is to be feared. But on the other side special protection is needed and given by the rather big membrane which in the figure appears above, stretching from wall to wall of the tube. In a sense, then, we can give the name of "the partition of the tube" to everything between this upper membrane and the lower surface of the partition as hitherto spoken of. The partition in this new sense is then a kind of hollow wall carrying in its interior the delicate hair cells, their supports, and the ends of the sensory neurons. 310 PSYCHOLOGY OF THE OTHER-ONE n oo ;a OS » aa S3 triH > . '-'Eh is I «o 2h a" Let us once more state the four different methods of functioning of the auditory organ, beginning with the most primitive method and ending with the most developed one. FOUR METHODS OF FUNCTIONING 311 But let us keep in mind, now, that all these methods of functioning are possible and actually occur in the same auditory organ, the highly developed anatomical structure called the Other-One's "ear" ; that the possibility and ac- tual occurrence of the most highly developed functioning does not exclude, in the very same ear, the possibility and actual simultaneous occurrence of any of the more primi- tive forms of functioning. 1. The Other-One's ear can function like a cavity lined with hair cells and exposed to any sound wave passing in any direction thru his body. 2. The Other-One's ear can function like a cavity in which the hair cells are placed on a floating partition, there being a "window" on each side of the partition, and a tunnel leading the sound more directly to one window than to the other. 3. The Other-One's ear can function like (2) with the difference that the sound waves are transported by means of a solid connection from a protective "drum" in the tunnel to one of the windows. 4. The Other-One's ear can function either like (2) or like (3) with the difference that the up or down motion produced in the partition is farther or less far extended over the greatly lengthened cavity and partition, according as each positive or negative change in the air pressure is more or less intensive. To the extent that pathological conditions interfere with any of these forms of functioning, the Other-One has to rely, and as a rule fortunately still can rely, on the others. We stated that Nature at the start equipped the auditory organ of animals with hairs, exposing them in such a manner that the slightest pressure changes in the medium surrounding the animal would effect a bending of these hairs. It has been shown some years ago by Emile ter 312 PSYCHOLOGY OF THE OTHER-ONE Kuile that in this most lately developed fourth form of functioning of the organ the hairs of the sensitive cells are bent back and forth. Our diagram shows these hairs indicated only by four short lines between two parallels. The upper parallel represents the fine brush-like membrane previously mentioned as touching the tips of the hairs. The lower parallel represents the surface formed by the sensi- tive cells in which these hairs are rooted. The sensitive HOW THE HAIKS OF THE HAIR CELLS AR-E BENT IN THE HUMAN EAR. cells themselves are not drawn in this diagram. But the "skeleton" supporting them, that is, the triangle formed by the two pillars, is shown, having its vertex, of course, in the lower one of the two parallels spoken of. The dia- gram shows how the hairs must bend when the two par- allels slide over each other in consequence of the partition being jerked out of one of its extreme positions into the other. It seems remarkable that in spite of all the changes which the anatomy of the auditory organ has undergone in evolution, the bending of the hairs still seems to be the most essential factor in stimulation. Having obtained, now, an elementary understanding of the functioning of that sense organ whose main purpose is the receiving of signals, we naturally turn in the next chapter to a discussion of the "vocal" organ by means of which the Other-One ordinarily transmits his signals. CHAPTER XIV The Other-One's Talking Machinery. An acoustic signal is a periodic change of density in the air. In order to understand clearly the Other-One's signal- ing apparatus we must first of all impress upon ourselves the fact that such density changes in the air can be pro- duced either directly in the air itself, by friction suffered by a stream of air, or indirectly by a vibrating solid which beats the air periodically. Density changes of the latter origin are not only very regular (owing to the regularity of the vibration of such a solid), but also rather strong. Density changes caused directly in the air by friction (for example, the breathing noise) are generally both weak and irregular in a physical sense. But both kinds of density changes can be greatly strengthened and can also, if they were before irregular, aperiodic, be made regular, periodic, by the mediation of an air resonator. An air resonator is nothing but a volume of air almost entirely enclosed within a solid container, but communicating with the outer air thru an opening in the container. The smaller the enclosed volume of air, the greater the frequency of its proper density changes, or, as we say, the higher the tone. And the larger the opening, the higher the tone. However, the size of the opening must have a certain reasonable relation to the volume, or the resonance will be very weak. All these facts mentioned can be easily illustrated with ordinary musical instruments of the wood-wind type. In a flute the density changes in the air are caused directly by 313 314 PSYCHOLOGY OF THE OTHER-ONE the friction of a stream of air blown against a sharp edge; and the air volume in the flute resonates, that is, makes the density changes regular and strong. In an oboe or clarinet a reed (that is, a solid body) is caused to vibrate by blow- ing against it ; and again the air volume in the instrument resonates, causing the density changes to be still more regular and stronger than they would be if depending mere- ly on the manner of the vibration of the reed. We have mentioned in a previous chapter that animals are equipped with a class of reflexes which enable them to use their breathing apparatus, the lungs, also as a blowing apparatus for causing periodic density changes of high fre- quency in the air. The muscles serving these reflexes are the diaphragm and the muscles of the chest acting on the ribs. The blowing apparatus is thus comparatively simple, as is to be expected. The friction apparatus, which we have to discuss next, is more complex. And the resonating ap- paratus, which will be discussed last, is most complex. Our figure shows in its most essential features the pas- sages thru which, during the Other-One's vocal activity, the air has to take its path in or out. (There are. how- ever, but few languages on earth in which sounds for signaling are produced by drawing the air in.) If the Other-One does not anywhere in these passages thru spe- cial muscular action obstruct the motion of the air, the friction is so slight that no sound is produced which de- serves to be called a speech sound (as in ordinary breath- ing)- Obstruction can be caused easily in the larynx by stretch- ing the so-called vocal cords so that they leave less room between them. Obstruction can. secondly, be caused in many different ways, as appears clearly from the figure, by the muscles of the upper lip, the lov.cr lip, the lower jaw, OBSTRUCTION IN LARYNX OR MOUTH 315 the tongue, and the soft palate. For simplicity's sake we may call the totality of all these latter organs "the mouth." But there is one great difference between causing the necessary friction in the larynx and causing it anywhere in the mouth. It is the same difference which exists be- tween the oboe and the flute. THE MOt'TH AND THB LARYNX FORMING THE HUMAN "OBOE." The parts constituting the mouth are not easily capable of vibrating, because they are virtually never, normally, under that tension which is physically necessary in order that a solid may vibrate. The motion of the air may be ob- structed, for example, by putting the lips together. But the lips do not then vibrate. The bugler may force them to vibrate, but only by pressing the mouthpiece of his bugle against them and thus giving them an artificial tension. Normally their tension is too weak for vibration. Or the motion of the air, to give another example, may be ob- structed by placing the tongue against the upper teeth or against the hard palate. There may then be much friction, but neither the teeth nor the palate can vibrate under such 316 PSYCHOLOGY OF THE OTHEE-ONB conditions. And if the tongue should vibrate, it does it with such a small frequency as to cause no sound of its own, but to add merely some roughness to a sound which originates elsewhere, as "r" and "1." Therefore the fric- tion produced anywhere in the mouth is comparable to the friction in blowing a flute. There is no solid body which is blown against and which in consequence vibrates. But when the cushions of which the vocal cords form the most advanced edges narrow the opening in the larynx, they do that thru the very tension of the vocal cords. The case is then quite similar to that of the oboe. There the reed, which obstructs the air motion, vibrates when air is forced thru. Here the stretched vocal cords vibrate when air is forced thru. From what we have previously said it is clear, then, that whenever the air is obstructed in the mouth, the resulting sound is relatively weak; and whenever the air is ob- structed in the larynx, the resulting sound is relatively strong. The sounds of the first class are therefore called voiceless sounds and those of the second class voiced sounds. In more popular terminology, the production of the former (voiceless) sounds may be called whispering, that of the latter (voiced sounds) singing or ordinary loud speech. The existence of a great obstruction in the mouth, as in pronouncing "s," precludes a sufficiently strong fall of the air pressure, on the passage from below the vocal cords up to above the vocal cords, to bring about vibration of the cords. But if the air is only moderately obstructed in the mouth, a certain amount of vibration of the vocal cords is simultaneously possible. We then have "voiced" speech sounds like "z, d, b, g, v, w." With a greater obstruction in the mouth and the then unavoidable failure of the vocal cords to vibrate, these sounds become the "voiceless" speech sounds "s, t, p, k, f, wh." VOICED AND VOICELESS SOUNDS 317 It is but natural, then, that in whispering, if we define this as voiceless speech, the sounds "z, d, b, g, v, w" are im- possible. They are indistinguishable from "s, t, p, k, f, wh." Ask the Other-One to whisper strongly, but really to whis- per, "zeal" and "veal," and they will sound like "seal" and "feel." However, it must be emphasized here as nearly everywhere in phonetic discussions, that all distinctions are relative, that there are intermediate steps between the ex- treme of whispering and the extreme of voiced speech. In the so-called stage-whisper, for example, the distinction is possible. Of course, when we said that somewhere the passage of the air must be obstructed in order to cause "by friction" a sound, we did not wish to give the impression that this friction was one perfectly simple physical process incapable of variations. The friction may be a steady process, as in pronouncing "s" or "sh ;" or it may deserve the name, rather than that of friction, of an explosion or sometimes the reverse, a sudden choking, as in pronouncing "k" or "p" in the beginning or end of a syllable; or it may be something between explosion and plain friction, like the re- peated weak explosions of "r" or "1," which, on account of their repetition, we do not recognize as explosions. Thus far we have been speaking of the sound only as it results exclusively from the friction which is caused by obstructing the passage of the air, forcefully expelled from the lungs, — with or without the aid of a vibrating solid body, that is, the vocal cords. We have not yet discussed the factor of resonance. But the variations of resonance are that very factor which makes "articulated" speech what it is. Without the manifold variations of resonance the Other-One would pos- sess virtually only (1) friction noises (a kind of whisper- ing, as we called it, but not "articulated" whispering) com- 318 PSYCHOLOGY OF THE OTHER-ONE parable to the noise of steam escaping with more or less force from a boiler and (2) musical tones comparable to the song of birds. And he would use the one or the other ac- cording to circumstances, but hardly both simultaneously. A glance at our figure shows how easily a great variety of resonating air volumes can be formed, and — whar 's especially important — not only a variety from moment to moment, but a variety of several air volumes at the same moment, a small volume here, a large volume there, each having its proper tone. Thus we understand the signifi- cance of the lengthening of the Other-One's auditory organ into a tube which we discussed in the preceding chapter, whereby different sensitive cells are enabled at the same time to be excited in different excitations. The tongue (t, in the figure) can be pushed forward to- ward the teeth or backward toward the soft palate (sp). It can be pushed up toward the hard palate (hp) or down, leaving little or much space between itself and the palate. The lower jaw can be lowered, enlarging in any desired manner the mouth cavity and enlarging also the opening between the teeth. The lips can be arranged so that the mouth cavity is prolonged forward. The lips can also make the opening of the mouth of any desired size. The soft palate can be pushed backwards in order to close the com- munication between the upper and lower pharynx (uph and Iph) and exclude thus completely the nasal cavity (n) from acting as a resonator. On the other hand, the tongue can so well fill the mouth cavity that the pharynx and the nasal cavity alone serve as resonators. When the Other-One sings like a bird, that is, without pronouncing at the same time words, he forms, more or less skilfully, one large resonating cavity of all those cavi-. ties at his service. This one resonating cavity is then merely adjusted in accordance with the frequency of the SONG AND SPEECH 319 vibrations of the vocal cords in the larynx (in front of the esophagus, e, in the figure). But in speech he forms numer- ous resonating cavities at the same time and locates the obstruction (or obstructions) wherever the resulting fric- tion will be near enough to the cavities to make them prop- erly resonate. It is clear, of course, that thus similar sounds or even identical sounds (that is, compound sounds consisting of the same components) can frequently be pro- duced by more arrangements within the vocal organs than one. The larger one of two simultaneous cavities may be located here and the smaller one there, or the smaller one here and the larger cavity there. The total sound might be about the same. It is important to understand this in order to avoid the needless differences of opinion which arise sometimes in phonetics as to whether a certain speech sound must be produced in one manner or in another. It might be produced in either manner equally well. To these several sounds caused by friction and reso- nance of the air cavities may then be added or may not be added the larynx tone. If the larynx tone is not added, we speak of articulated ("joined together") whispering. If it is added, but is not very strong and varies much, we hear the Other-One's normal loud speech. If the added larynx tone is overstrong, but still varies much, we call it shouting. If the added larynx tone is very strong, but held at constant pitch (vibration frequency) for a little while, to assume another constant pitch for a little while, and another constant pitch, we hear the singer's perform- ance, as in an opera or whenever the Other-One sings a song. What, now, is the difference between consonants and vowels? This is, perhaps, the first classification we learn in our earliest school life to make of different speech sounds. And yet it is a rather insignificant and almost 320 PSYCHOLOGY OF THE OTHER-ONE superfluous classification. We learn that vowels are those speech sounds which may form a syllable (a syllable is that group of sound qualities which occurs between two sound minimums and has only one maximum) while occurring alone and unaccompanied by consonants, and that con- sonants ("by-sounds" in the sense of accompanying sounds) are those sounds which never form a syllable while occur- ring alone, but must occur "by" a vowel. However, it is purely accidental that we do not in the English language have, for example, a syllable consisting purely of the voice- less sound "sh." There are other languages which have such syllables, and "sh" would then have to be called a vowel. This shows clearly enough the scientific irrelevancy of the distinction between English consonants and vowels. Psychologically interesting are all those cases where in speech the pronunciation of a sound is modified by the occurrence of another one just before or just after. It is but natural that, for example, the first syllable should be pronounced differently in the two words "do" and "doing," that the Other-One should in the latter case make the re- sonating cavities for the two syllables succeeding each other as much alike as this is possible without risk of being mis- understood. This is so justifiable an economy that virtual- ly nobody fails to develop his speech habits in accordance with it. In the study of languages we discover innumerable examples of speech economy which have become so con- spicuous that they have found expression even in spelling. Lazy people, of course, will economize without much at- tention to the question whether the Other-One's under- standing becomes impaired thereby or not. It is all right to say "cupmsaucer" if the Other-One's native language is English and if he can almost guess what we are saying. But if he is a foreigner and not perfectly accustomed to English, and we want him to understand us, we should rather pronounce "cup — and — saucer." ECONOMY IN SPEECH 321 But even lazy people sometimes get excited and may then expel the air from the lungs so forcefully that a mouth friction sound is heard in a word which does not possess the sound, but which word the excited speaker wishes to em- phasize, whereas in another word which he does not wish to emphasize he fails to produce, thru his laziness, the very friction sound which rightly belongs there. For example: Barber — The cholera is in the hair. Customer — Then you ought to be careful about the brushes you use. Barber — I didn't mean the air of the ead, but the hair of the hatmos- phere. When the Other-One is excited because you have told him that you are going to punish him, and he asks "Why?" he will probably let the vowel be preceded by the strong mouth friction sound "wh." — But if you ask him if he wears a fur coat in summer, and he smilingly replies "Why, nobody does that," he will probably pronounce the first sound as "w," with very little air friction in the mouth. The general features of speech in relation to personality have been well described by the Danish linguist Jespersen in the following brief paragraphs : "Every one has his own speech, differing from every other person's speech. This is true with respect to his vocabulary, his idioms, his syntax and his grammar ; but also with respect to his pronunciation. When we recognize a person by his 'voice,' that last term is not taken in the narrower meaning of 'larynx sound,' but in the broader meaning of his pronunciation as depending also on his pal- ate, tongue, teeth, lips, the elasticity of his cheeks, and even the muscular equipment of his breathing apparatus. "He who dissimulates his speech, pushes forward his lips, lowers his jaw, flattens his tongue, and so forth. "Very characteristic for a person's speech is also his tempo of speaking and the greater or lesser precision in 322 PSYCHOLOGY OF THE OTHEK-O^'E :he execution of the movements of his vocal organs, on which the clarity, comprehensibility and beauty — or the op- posite — of his speech depend. "Tho every one has his individual speech, that speech varies from time to time according to the situations in which he finds himself, just as his facial expression changes from time to time. "In general it can be said that those who speak a com- mon language have something common in their pronuncia- tion. Consequently it is sometimes possible, when one hears spoken words from such a distance that the separate words are not recognizable, to tell nevertheless what language it is. "Thus, too, it is frequently possible to tell of what coun- try or part of a country a person is a native, even tho he speaks a foreign language, since he may not have freed himself from the characteristic peculiarities of his native tongue, but may unintentionally use them in the other lan- guage, speaking — as the popular phrase goes — with a 'for- eign accent.' In reality this is not alone a matter of ac- centuation, or perhaps least of all a matter of accentuation, but rather a matter of moving his speech organs in the old accustomed way. "There is a kind of harmony among the motions of the vocal organs producing the several sounds of a particular language. For example, that language which pronounces *t' with the tip of the tongue far back in the mouth, most likely pronounces also 'd' and 'n' with the tongue thus withdrawn. And if 'b' is strongly voiced, one may be al- most sure that 'd' and 'g' are also strongly voiced. Thus, in certain cases, one may learn to imitate the pronuncia- tion of a foreign language beyond the possibility of a dis- tinction by merely flattening quite generally the tongue, or pushing it forward or withdrawing it, by retarding all lip movements, and so forth. INDIVIDUAL AND NATIONAL SPEECH 323 "In this sense it may be asserted that each language has its 'base of operations' in a particular region of the mouth, or that it has its particular 'pose' of the mouth organs. And just as the pronunciation of each individual represents and expresses the peculiarities of his personality, so the 'mouth pose' of each language has a definite relation to the national character. Nevertheless, no more than such a national character is the 'mouth pose' of a language easily and clearly describable in terms of scientific value." It is customary to say that a child learns the language of his parents "by imitation." It is more correct to say that he learns it by imitative (reflex as well as habitual) actions. According to the usage of language any action deserves to be called imitative (or "an imitation") which repeats the stimulus, or at lea«t produces something very much like that stimulus which gave rise to this action. We have agreed in this book to mean by a reflex or by an instinctive action about the same thing, that is, the func- tioning of one definite nervous path of the "short" and in- herited variety, a path which serves to place a perfectly definite motor point at the disposal of a perfectly definite sensory point. The motor "point" may be a "group" of muscles, and the sensory "point" may be a "group" of sen- sitive cells, and then we should prefer the phrase "instinc- tive action" to the word "reflex." But this distinction re- ferring to complexity or simplicity is a minor matter and really does not concern us at this moment. But while the functioning of ■ a definite nervous path (that is, a reflex or instinctive action) can be called a "right-sided" action, if it occurs on the right side, or an "imitative" action, if it repeats the stimulus, never can the abstract noun "right-sidedness" or the abstract noun "im- itation" be called a reflex or instinctive action. An action 324 PSYCHOLOGY OF THE OTHER-ONE is something concrete. Its functional basis in the nervous system is Hkewise something concrete. An abstraction can be used as the name of a concrete thing, but never can an abstraction be spoken of under the term standing for some- thing concrete, — unless we are tired of logic and try our luck by playing with intentionally introduced confusions. As we said in a previous chapter that "right-sidedness is not in itself a reflex, but a peculiarity of some reflexes," so we must say here that imitativeness is not in itself a re- flex, but a peculiarity of certain reflexes. Saying that im- itation is an instinctive action would be like saying "crea- tion is a fish" because a codfish is a creation. If we wish to express ourselves clearly, we shall be the clearer, the more frequently we speak concretely of this and of that special "imitative action" (which may be native or acquired) and the less frequently we speak generalizingly of "imitation." There is absolutely nothing in the sub- stances or the functions of the nervous system which can in any way be said to be correlative with the generalization (or abstraction) "imitation." Since speech imitating actions have led us to this discus- sion, we should, in order to make the matter still clearer, ask what kinds of imitative actions other than speech im- itating actions we find in the Other-One's life. In speech the Other-One reacts to sound and produces sound. This is auditory imitation. If a smell causes the Other-One to act so that a similar smell results, this is olfactory imitation. He does that, perhaps, as a perfumer's apprentice, journeyman or mas- ter perfumer. Fortunately nobody has given vent to his enthusiasm for the abstract terms "instinct" and "imita- tion" far enough to explain the perfumer's actions as due to his "instinct of imitation." ARE THERE IMITATm: INSTINCTS? 325 If the Other-One reacts to a taste so that a similar taste results, that is gustatory imitation. It is a good guess, in that case, that his vocation is that of a cook. If the Other-One reacts to a kinesthetic excitation in such a manner that he reproduces the kinesthetic excita- tion, that then is kinesthetic imitation. Very Hkely his vocation is that of a circus athlete. It is perfectly clear in the last as in the preceding cases that the imitation results from having obtained the knowl- edge that imitative actions are often useful, are often the basis of success, — success in a business, in a trade, in a skilful athletic performance, in what not. Nobody calls such a knowledge an instinct. Nobody imitates a smell instinctively. Does anybody im- itate a kinesthetic excitation instinctively? In an earlier chapter we have already had occasion to mention that many special circular reactions are inherited and may usually result from the kinesthetic excitation, re- sulting from one action, causing another action. If this kinesthetic excitation causes the same action from which it resulted, we have kinesthetic imitation. Does anybody inherit any kinesthetic imitative action? One might think that the inheritance of kinesthetic im- itative actions is almost self-evident from the fact that the sensory neurons of muscles and the motor neurons of the same muscles naturally run together in a single bundle, a nerve. But that is as accidental as running water pipes, gas pipes, sewer pipes, electric wires, and so forth to- gether in the same tunnel under a street or under a river. Within the central nervous system they separate and do not necessarily form "short paths." They form "reflex arches" only where the functional needs of the organism in evolution unite them, as in the case of all other sensory and motor neurons. 326 PSYCHOLOGY OF THE OTHER-0]S'E As a matter of fact there seems to be very little inherited kinesthetic imitation ; maybe no more than olfactory and gustatory imitation, that is, none at all. We remember the case of the child learning to pile up blocks. There is im- itation in so far as the child seems to imitate a model (a block standing) by creating a thing like it, only bigger (one block upon another). But the stimulation is visual, not kinesthetic. And the imitation is at the start purely accidental, since the efTective reflex, as we remember, is not in that case an imitative reflex, but is simply the visual localizing reflex. The child, with his hand already grasping a block, localizes another block by sight, and then drops his block on that location. Indeed, if a considerable amount of kinesthetic imitation were inherited, it would greatly retard the acquisition of useful habits of reaction. For example, the child, instead of learning how to build a house of blocks, would continue, thru the influence of such imitative actions, to move his hands up and down in the same manner without being in- fluenced by the fact that blocks other than the one in his hand are lying about. Kinesthetic imitative actions, if in- herited, would reduce man's biological significance in the world to something like that of mechanical toys in a child's world, capable only of performing the same jump in end- less repetition. Does anybody imitate a visual stimulation instinctively? There seems to be little evidence of special inherited re- flexes imitating visual stimulations. Neither do the earli- est learned movements seem to depend on visual imitation nor do the earliest imitative movements seem to be of the inherited type. The baby learns to creep, but— not by im- itation. He learns to stand up, but — not by imitation. He learns to walk, but — not by imitation. AUDITORY IMITATION 327 It is only after he has acquired these skilful movements of his hands and feet, that visual imitative actions become conspicuous. Then only we observe that the little child, already able to walk, joins us when we are standing with our back against the wall and takes his place at our side, leaning his back likewise against the wall. Then only, after a year of experience in hand movements without any visual imitative actions whatsoever, does he begin to wave his hands in imitation of ours, to put on his hat when we put our hat on. Then he places an open book on the music stand of the piano before he strikes the keys with his little fingers, because he has seen us open our music before striking the keys with our fingers. In all these early im- itative actions there is no more evidence of heredity being especially responsible for the imitativeness than there is in the actions of the perfumer. As the smell imitating per- fumer may nevertheless fail in his business (if we regard such failure as some evidence against the existence of re- flexes ), so the sight imitating child may fail in his busi- ness, in playing the piano, for example, in spite of his wonderful imitation. Summing up, then : there is scarcely any inherited visual imitation. That leaves us still more interested in the question how much auditory imitation the Other-One has inherited. There is this to be said, first, that without imitating sounds, the Other-One would surely fail in his business of living a human life. Auditory imitation is so essential that we al- most expect Nature to have made some provision for it by equipping the Other-One with special reflexes. The sound producing reflexes belong, we have said, to the signaling reflexes. Nature has equipped animals also with reflexes of responding to signals ; but the responses to signals are not necessarily imitative actions, as we have seen in many examples. Generally the reflex response to a signal is not 328 PSYCHOLOGY OF THE OTHER-ONE an imitative action. But it seems that to a certain extent Nature has equipped the Other-One with reflex responses to auditory signals which repeat with some accuracy the auditory stimulation. What is perhaps most remarkable about auditory imita- tion is the fact that it appears earlier than all other (no matter what their origin) imitations; and that it grows weaker as the individual grows older, whereas all other imitations seem to grow stronger with advancing age. Audi- tory imitation begins with imitative reflexes, and hardly develops into imitative habits (altho it develops into defi- nite speech habits) but rather dies out. All other imita- tions (think of making a fist before your enemy) develop from various non-imitating reflexes accidentally as imita- tive habits and grow stronger and stronger because the im- itativeness is found to serve a purpose. Auditory imita- tiveness has its maximum during the second year of life. Visual imitativeness is very conspicuous only about a year later and perhaps does not reach a maximum until old age. The infant imitates reflexly the speech sounds which are produced by others in his presence or by himself. The eight or ten year old child has almost ceased to imitate speech sounds. How slight the tendency to imitate speech has become in grown people, all those know from experi- ence, to their regret, who have ever learned or taught a foreign language. Grown people will do a hundred other things rather that repeat over and over again a phrase just heard as small children do, — the secret of children's rapid success. It is quite natural, however, that auditory imita- tion should be found so strong during the second and even a few of the following years and so weak later. The child must learn to speak early in life. And he learns by im- itating. When this learning of speech is once accomplished, AUDITORY IMITATION 329 imitative actions are no longer necessary. Aside from learn- ing speech in early childhood, auditory imitative actions have no biological value of their own. With visual imitation the case is quite different. It is true that all thru life a good many skilful movements are learned by visual (tho not reflex) imitative actions. How- ever, the visual imitative action itself, aside from all learn- ing, has an enormous biological value all thru life, in old age no less than in middle age and infancy. When we see a crowd gather in the street, we immediately (by habit) run to the spot ourselves, — not because we still have to learn how to run to a point seen, but because we have dis- covered that it is of immense value for our individual and our social life interests to do at any time as we see other people do, exceptions notwithstanding. Summing up, then, we may say that auditory imitative actions are virtually the only class of imitative reactions which are inherited and for whose inheritance there is some need; that even here one must not have an exaggerated idea of the exactness of the imitation resulting from the reflex equipment, since the reflex amounts to hardly more than responding to the signaling reflex of another person by a rather vague signaling reflex of one's own, producing varying sounds perhaps at random more frequently than imitatingly (as a dog responds to another's barking by its own barking, but only by chance imitatingly) ; and that these auditory imitative reflexes become so completely re- placed by sound producing habits that after ten years virtu- ally nothing is left of the original value and strength of these imitative reflexes. What we have said in an earlier chapter about "serial activity" as a special kind of concerted action finds its most important illustration in speech. All speech is concerted action, and among the various kinds of concertedness the 330 PSYCHOLOGY OF THE OTHER-ONE particular sequence of the sounds is obviously of especially great importance. Get ready to say "ga" but stop just be- fore the "g" explosion. Then do the same for the syllable "goo." You notice a great difference of position of the mouth organs and of tension of the various muscles altho the first sound is supposed to be the same. The muscles are clearly innervated and ready at once to produce both sounds, consonant and vowel. Which sound precedes in actual production seems to depend, as in our discussion of serial activity in a previous chapter, on the relative inten- sity of the nervous flux going to the one and the other group of muscles. It is possible — indeed probable — that in the pronuncia- tion of such words as "god" and "dog" there is no differ- ence at all in the temporal order of the nervous activities involved, but a mere distribution dift'erence of the resis- tances of the nervous branches serving simultaneously as conductors, to the effect that, in the one case, the muscular "g" tension is stronger than, and thus becomes outwardly effective before, the "d" tension, and in the other case the reverse, — the "o" tension being of intermediate intensity in either case. This condition of relative resistances in each special case is, of course, habit in the particular language, and not inherited. But naturally, the statement of the last two paragraphs does not deny that kinesthetic excitations may also play a certain role in bringing about particular sound sequences. Kinesthetic excitations are especially likely to be of an im- portant service in determining the proper sequence of the sounds in very long words and whole phrases and sen- tences. The greater the temporal complexity of the sound, the less self-sufficient for the temporal order can be the manner of distribution of a nervous flux having a single source. SIGNALING AND LOCALIZING 331 Before leaving speech the peculiar relation between the localizing and the sound signaling reflexes should be point- ed out. In discussing the localizing reflex we mentioned that the "most movable" part of the body in each case is the one which performs the localizing movement. Usually this is, of course, an arm. During the second half of the first year this reflex begins to assume the particular form in which not only the arm is stretched out in the service of the localizing reflex, but the index finger too (but not the other fingers). Now. this is about the same time when the first articulated sounds (usual guttural and dental — ga and da) are reflexly produced by the baby. But the act of stretching the index finger, that is, pointing, is accompanied by a dental rather than a guttural sound — the baby point- ing and saying "dadada." We recall here the interesting fact that in all Germanic languages the demonstrative pronouns begin with a dental sound. This does not seem to be altogether fortuitous. Try yourself to accompany a pointing (localizing) move- ment by a dental or a guttural sound. The latter seems less natural, less easy. The explanation is probably a mere subdivision of the explanation of a more general fact, — the fact that gestures, especially those of the right hand, are likely to accompany speech, in adults as well as in the young. For nearly a century it has been known that the left hemisphere of the normal human brain functions in cer- tain cases in preference to the right hemisphere. The con- nections of the left hemisphere with the muscles of the right half of the body and also with all the speech organs are closer than those of the right hemisphere. A nervous current, therefore, which takes mainly the road to the speech organs and partly also to other muscles, finds less resistance to the muscles of the right arm than toward the 332 PSYCHOLOGY OF THE OTHER-ONE muscles of the left arm. In order to go to the left arm. it first has to go from the left to the other hemisphere. Thus its path becomes lengthened and of increased resis- tance. It is natural, therefore, that gestures accompanying speech must be gestures of the right rather than of the left arm. The case of the dental or the guttural sound fitting better together with the pointing movement, seems to be capable of a similar explanation. A sound which is produced by friction in the front part of the mouth seems to depend within the nerve centers on neurons belonging to and being found among that group of neurons which serves the ex- tremities of the body, like the pointing finger. The muscles of the throat, belonging to a different, an internal group of muscles, are quite likely to be served within the nerve cen- ters chiefly by neurons which belong to and are found among groups of neurons which do not serve frequently the extremities of the body, like the pointing finger. A nervous current is, then, more likely to call forth both a dental sound and the pointing of the index finger than a guttural sound and the pointing of the index finger. That is, this nervous current, when we measure the resistance starting from a certain nerve center, is found to travel over a longer and therefore more resistant path in the direction of the muscles back in the mouth than in the direction of the muscles in the front part of the mouth. Why movements of the speech organs are likely to be accompanied by gestures at all, of any kind, is a question which we shall hardly raise after having emphasized thru- out this book that every nervous current, even when coming from a single source, is widely distributed thru the nerv- ous system, and that any main activity is likely to be ac- companied by secondary — and generally, by the spectator, ACCENT AND GESTURE 333 overlooked — activities. But the question may still be worth raising in this connection why some nationalities gesticulate more than others. Some languages, especially the English, habitually put an enormous vigor into the enunciation of one definite sound of each word or sentence. The English language, that is, is a strongly accented language. According to the law of nervous deflection we expect, then, that the strong nervous flux leading to the enunciation of the accented sound should interfere more or less with the execution of such secondary actions as hand gestures. This is a plausible explanation of the absence, or at least remarkable infrequency, of gesticulation in speakers using the English language. In the French language, on the other hand, there is no ac- cent worth mentioning. The reflex gestures of the speaker are therefore fully preserved. Accent in speech is thus a substitute for gesture. This explanation seems more generally applicable than the popular one assuming racial differences of temperament as the exclusive cause of the difference in question. May- be there are some such racial differences. But taking into consideration the origin of the two peoples, such a differ- ence of "temperament" would remain ethnologically rather mysterious. CHAPTER XV Rhythm : Motions Grouped and Thus Repeated. Who has not had many experiences Hke the following: You are sitting at the open window thru which the regular- ly occurring puffs of a distant steam engine reach your ear. You see the Other-One sitting in another part of the same room. Suddenly you observe that he beats the time of the engine puffs, tapping with his finger on the table, or may- be with his foot on the floor. But that is not all. Indeed, that would not be at all remarkable. Why should not each of many regularly repeated auditory stimuli call forth an habitual motion, regularly repeated, of the Other-One's limb ? But you observe that the Other-One's tapping movements are not all equal. They seem to consist of groups of six, or of groups of three, according as you make finer or less fine distinctions. One of the six strokes appears to be especially vigorous and also to occupy a little more time than each of the other Jive strokes. It is executed more from the shoulder joint than the others. The two strokes following are executed with a much weaker movement of the hand. In them the upper arm at the shoulder joint takes hardly any part. The motion occurs from the elbow joint rather, or even merely from the wrist. The total time occupied by these two strokes is slightly less what you would expect, — slightly less than double the time of that vigorous stroke. That is, however, natural, since a long pendulum generally has a longer period than a short pendulum, and the vigorous 334 EHYTHM oo5 stroke is a sort of pendulum motion of the whole arm, the weaker strokes only of the lower part of the arm. In our example, the fourth stroke (the first of the second group, if we prefer) is comparable to the first altho pos- sibly it has the characters of vigor and length in a less pro- nounced degree. The fifth and sixth are comparable to the second and third. If you recognize a difference between the first and the fourth stroke, you call what you observe a perception on the part of the Other-One of a six-stroke rhythm. If you fail to recognize this difference, you call it a perception of a three-stroke rhythm. But what do you mean by rhythm? So much is clear that you do not mean by "rhythm," in the particular sense in which you use this term here, merely that the Other-One does something repeatedly. If that were the case, you could include the Other-One's heart beat in a discussion of "rhythm." But then the very reason for devoting to rhythm a special chapter of a psychological text-book would have disappeared. Then, indeed, you would vise the term "rhythm" merely as an (absolutely superfluous) synonym of the term for regularly repeated events on which mathematical science has long agreed, that is, the term "periodicity." We mean here by "rhythm" that the Other-One groups his motions by putting a special vigor, length, or perhaps still another property, every now and then, regularly, into one of these repeated motions. It is not really essential either that these motions are performed in succession by different muscles, or even different limbs, or exactly the same limb, the same muscle. You might observe that the engine puffs stimulate the Other-One to tap with one finger, using for each motion exactly the same muscles, that is, neither more nor fewer nor other muscles, merely a more vigorous contraction for the "accented" stroke of the group of strokes. That is one of the extremes. 336 PSYCHOLOGY OF THE OTHER-ONE Or you might observe that the engine puffs stimulate the Other-One, while he is standing, to raise his whole left leg and let it fall heavily upon the floor, and to tap then gently once with the index finger of his right hand and once with the index finger of his left upon the table. That is another extreme in the muscular activity. And there are also extremes in the stimulation as we shall see pres- ently. When instead of the regularly repeated, but unaccented engine puffs the sounds of an orchestra playing a waltz are the effective stimulation in the case, that also is a kind of extreme in so far as the stimulating orchestra marks the accents. On the other hand, you may observe that the Other-One engages in the same kind of remarkable activity when there is absolutely no accentuation or grouping or even repetition in the stimulation. For example, the Other- One may be standing at the window and looking out while a beautiful young lady, his partner in a waltz at yester- day's ball, passes on the street. The sight of that lady is the stimulus. That is the other extreme in the sense of a total absence of even repetition, not to mention grouping, of stimuli. In all these cases differing in muscular activity and in stimulation you speak of "rhythm." But the most re- markable case among them is the case where the sight of the lady is followed by a gentle tapping of the lone finger on the table, first a little stronger, then twice a little more softly, and so forth. In this combination of extreme con- ditions, with the peculiarities of the stimulation and of the reaction apparently entirely unrelated, incommensurable, the very problem of "rhythm" formulates itself in your thought : What is it that the Other-One's nervous system possesses which conditions such a strange mode of reaction, repeating grouped motions when there it neither grouping nor repetition in the stimulation? ORIGIN OF THE GROUPING" OF MOTIONS 337 There was a time when psychologists were quite ready — too ready — to answer this question by saying "Rhythm is one of the human instincts." As in the case of imitative actions, so in that of rhythmic actions this answer is no longer acceptable. It was excusable only as long as psy- chologists meant by "instincts" some mysterious property of the soul. It is inexcusable nowadays when the role played by the nervous tissue in conducting excitations from sense organs to muscles is sufficiently understood and when an "inherited action" has come to mean a definite "in- herited nervous path" from a definite sensory point to a definite motor point. The significant fact in rhythm is a tendency for any and all muscular activity to occur in groups made up of several actions and for these groups to be repeated. What, then, is the origin of the general tendency in the individual to perform muscular actions in a group ? What the correlative of the Other-One's grouping is in his nervous functioning, we simply do not know yet. But at least this question should be raised and can be answered with our present knowledge : Is this tendency toward a definite manner of grouping something inherited or some- thing acquired? In favor of answering "inherited" the fact has often been referred to that only those manners of grouping are likely to be observed in the Other-One which consist of making up the group in question of 2, 3, 4, 6, 8, and possibly 12 and 16, elements. "If the numbers counted are so strange- ly restricted," it was argued, "the restriction must be caused by heredity, for counting is in no way a restricted habit." The error in this argument is the assumption that "count- ing" has something essential to do with the rhythm forms. As a matter of fact, when you hear the Other-One count while performing group actions you might as well say that 338 PSYCHOLOGY OF THE OTHER-ONE that is evidence enough for his lack of rhythm. When we say that the Other-One possesses rhythm, we mean ex- actly the opposite ; we mean that we observe him per- forming a definite group activity without counting, and even while by conversation with him we intentionally make his counting utterly impossible. Another frequently heard, but inacceptable argument in favor of heredity is the assertion that every child is "rhyth- mical." But this argument shows only how little time those who advance it have given to the observation of children. It is true that "rhythm" is not the usual result of some years spent in the schoolroom as "knowing the multiplica- tion table" is. Nevertheless, all learning is not confined to the schoolroom, and children obviously do not inherit, but acquire their rhythm, at different ages, a few when they are three, four, or five years old, some more during the years of attending the first years of school, some much later. The only fact which we have to make clear, then, is the one referred to in the following question: If rhythm is an acquisition, including several acquired habits of action, why do we usually find among these habits only those of 2, 3, 4, 6, and 8-stroke rhythms, and virtually never, ex- cepting a few musical compositions of very few composers, the 5 and 7-stroke rhythm? We shall, therefore, give in this chapter a plausible an- swer to this question. And after having reported the facts giving this answer, we shall point out the further, very remarkable, fact that the rhythms when once learned — no matter of which number of strokes and by what muscles they have been learned — can be transferred to any one muscle (or several muscles) which may have been entirely inactive during, and unconcerned with, the acquisition of that rhythm. ORIGINS OF THE TWO-STEOKE RHYTHM 339 Of all the much talked of kinds of "transference of training," (from one sense to another sense, from one muscle to another muscle) this is the only transference of training of which it can be said both that the fact of its existence (as a true transference) is established without doubt and that the way in which it comes about in the nerv- ous system is thus far absolutely unknown and even un- guessable. No one has ever yet made the barest sugges- tion as to the manner of transference of this training with- in the Other-One's nervous system, tho no one has ever denied the actuality of this particular transference. First, now, let us report facts which help to give the an- swer to the former question. One of the most common (all thru life, excepting the first year after birth) activities of the Other-One, the very nature of which implies repeti- tion of grouped actions, is walking. In the exercise of this activity lies probably the chief opportunity and oc- casion for the acquisition of the plain 2-stroke rhythm. The Other-One can not walk without repeating the move- ment. But neither can he walk without composing his activity of two kinds of movements, a heavier and a lighter one. He can not walk hopping along on one leg But when he alternates the legs, one of the movements is al- ways heavier, or longer, than the preceding and following one. Thus we have a group of two actions. Whether we regard this group as composed of a heavy motion followed by a light one, or as composed of a light motion followed by a heavy one, (accent first or accent last) is quite arbi- trary, purely a matter of taste or of the momentary inter- est in this or that aspect of the entire phenomenon. Why is the movement of one leg by necessity heavier and more prolonged than that of the other leg? Simply in con- sequence of the Other-One's right-sidedness. The right leg is, so to speak, the skilful mechanician and the left leg 340 PSYCHOLOGY OF THE OTHER-ONE his unskilled helper. Balancing on one leg is easier on the left, because the skilful part of the process of keeping from tumbling does not consist in supporting the weight of the body (the helper can do that!), but in readjusting the weight distribution quickly from moment to moment by the raised (right) leg, as the tight rope walker balances him- self by shifting a heavy pole or loaded parasol held in his hands. We remember that walking equals balancing plus the functioning of the positive localizing reflex. Balancing is more natural on the left leg than on the right ; the localiz- ing action is more readily carried out with the right leg than with the left. In walking as in balancing the heavy part of the work is naturally assumed by the left leg, the skilful part by the right leg. (This is true even when the muscular development of the left leg happens to be weaker than that of the right. You also sometimes see a plumber at work who is a stronger man than his helper, yet the helper has to do the heavy work. ) It is no wonder that the officer who wants his soldiers to mark step, orders them to fall heavily on the left leg (not on the right), because that leaves the skillful right leg free to attend to the bal- ancing and falling forward of the body in the proper direc- tion. When we skate on ice and desire to slide a definite out- ward leading curve, we discover that we can do that more easily, with less risk of tumbling, on the left foot turning to the left than on the right foot turning to the right. The right leg, swinging in the air in the former case, is a better "balancing pole" than, in the latter case, the left leg. Of chief importance is the choice of the leg which does the balancing ; either leg can probably well enough do the mere- ly heavy work of supporting the sliding body. ORIGINS OF THE TWO-STEOKE RHYTHM 341 So, whenever there is any need or occasion for division of labor, the left leg does the heavy and the right leg the light (but skillful) work. And that the work of the less skilled member is likely to be a little more prolonged than that of the skilled member, is also evident enough. Walking, then, is all thru life a continuous training in performing repeated actions in a group of two, a heavier and prolonged action alternating with a lighter and slightly shortened action. If our anatomy were different, if, for example, we had three legs or four legs instead of two, we should miss this training. The quadrupeds miss it. Four legs, we know from observing dogs, horses, etc., do not co-operate easily in one definite manner ; that is, they do not co-operate in the same manner every time. Those ani- mals use now one gait, now another. Therein is found an obvious explanation of the fact that "the animals do not have rhythm." The animals have no chance of acquiring it. The four actions of the four legs do not succeed each other at such regular intervals that they could count as a regular repetition. Our hands give us no meaner opportunities for such train- ing than do our legs. Especially true is this in manual labor, that is, in the systematized work of civilized man, in domestic work or factory work. The savage, who does not perform much systematic labor, has fewer opportuni- ties of this kind. And the savage has less "rhythm." too, altho some people have the opposite opinion of him. But that savage who often practices dancing must of course be excluded from this statement. Dancing is systematic ac- tivity, and, among savages, is regarded as labor rather than recreation. Having two feet, and having two hands, and being right- sided (or left-sided, that makes no diflference) — therein lies the explanation of why the 2-stroke rhythm is common 342 PSYCHOLOGY OF THE OTHER-ONE among human individuals. Why, now, also the 4-stroke rhythm ? There are many systematic occupations in which the Other-One's activity is composed of an effective action fol- lowed by a mere "rebound." Take as an instance driving in nails. The hammer is swung down (or forward), but naturally rebounds upwards (or back). But this rebound must not be thought of here as a mere physical matter with which the muscles are unconcerned. The antagonistic mus- cles, drawing the hammer up, actually begin to contract be- fore the hammer has hit the nail, and are only assisted by the physical rebound. Nevertheless this action of with- drawing the tool is best named simply the rebound, because that name makes always clear what particular action is re- ferred to. Such a double action of effective motion plus rebound is clearly a further example of activities which lead to the acquisition of the 2-stroke rhythm. But let us recall that, when the Other-One has to drive in a nail, he is often observed to anticipate the strong ac- tivity in a weaker one, merely "feeling his way," so to speak, in order to make sure in what curve the hammer must swing to strike the head of the nail. Such a tenta- tive action again consists of a (relatively) effective motion and a mere rebound. The tentative action plus the strong action make up then a total activity consisting of four mo- tions. The four motions succeed each other at fairly equal intervals, so that we can speak of regularity of repetition. The first is the tentative hitting motion ; it ranks as the second strongest motion. It is followed by the tentative rebound, which is the weakest of all, ranking as the fourth motion in strength. Next follows the strong hitting mo- tion. And this is followed by the strong rebound, which ranks third in strength among the four. If we mark the four motions, according to their strength, by the letters ORIGINS OF THE FOUR-STROKE RHYTHM 343 A, B, C, D, their succession as above described is B— D — A — C. Here we have in the Other-One's Hfe a common enough activity of the class of habitual activities which lead to the acquisition of the 4-stroke rhythm. What we said in discussing the 2-stroke rhythm about the location of the accent may be repeated here. It is a matter of taste whether we regard the "group" as begin- ning with the accent (that is, the strongest motion) or end- ing with the accent or having the accent somewhere with- in the group. Of some significance, however, and worth mentioning is the fact that we can well speak here of a secondary accent in addition to the main accent. The motion "B," when group follows after group, has before and after itself the motions "C" and "D" which are weaker; it is therefore in a relative sense an accent. The 4-stroke rhythm may be divided into two kinds of 4-stroke rhythms, with and without a secondary accent, for there are also opportunities in life for acquiring a 4-action group habit where the sec- ond strongest action is not both preceded and followed by a weaker action, thus giving no rise to a secondary accent. In this necessarily brief treatment of the whole phenom- enon of rhythm, what has been said concerning the proba- bility of the Other-One's acquiring the 2-stroke rhythm and the 4-stroke rhythm must suffice for making it plausi- ble also that there are, altho rarer, opportunities for ac- quiring the 8-stroke and even the 16-stroke rhythms with or without secondary, tertiary, etc., accents. Our next prob- lem now is that of showing by examples what opportun- ities the Other-One has for acquiring the 3-stroke rhythm, the 6-stroke rhythm, and maybe the 1 2-stroke rhythm. One very obvious chance for changing a group of two actions into a group of three is offered by the necessity arising of performing such an action as that of nail driving 344 PSYCHOLOGY OF THE OTHER-ONE alternately toward the left and the right, or alternately up and down. The Other-One hits, let us say, a nail on a board before him below the level of his chest and carries out the rebound as previously discussed. But now, suppose, he has to hit a nail on the lower surface of a board before him above the level of his chest. A third movement, in the downward direction, has to be added to the other two merely in order to get ready for the work on the upper board. Let us call this added movement the "preparatory" movement. It is probably the weakest of the three. The hitting, the rebound and the preparatory movement then constitute the group of three. There certainly are in the Other-One's life, especially in industrial life, opportunities for having to change the direction of work alternately into the opposite direction. Here is another concrete example. Imagine a gardener having planted a double row of plants like the dots of our figure "Steps creating a 3-stroke or 6-stroke rhythm." In order to keep the loose earth, just thrown around the roots of each plant, from drying, it is necessary to compress it and thus render efifective the capillary attraction which draws the moisture from the lower soil. The quickest way — * v^--A-V/\--A^-Wv — ^ STEPS CREATING A 3 OR 6-STROKE RHYTHM. of doing the work is to walk along the center line of the double row and to step, with the full weight of the body, on each of the places which need compression, using, of course, alternately the right and the left foot. Now, try to walk ahead, doing this, and observe how your legs most naturally act during this procedure. While you are stand- ing on your right foot, the muscles of your right leg are OEIGINS OF THE THKEE-STEOKE RHYTHM 345 strained in such a way as to keep the leg straight and able to support the weight of the body, but not in such a way as to throw readily the weight of the body upon the other foot. For this a complete readjustment of the muscles of the right leg is requisite. To bring about the muscular re- adjustment, you most naturally let the body fall lightly up- on the left foot and let it swing back to the right. Thus you assume that new position on the right foot in which the tension of the various muscles is adjusted so that the full weight of the body can be thrown on the left foot force- fully and skillfully. The left foot now hits exactly the spot in the left row on the ground where the compression of the soil is needed. What, then, have you really done instead of stepping simply from the right foot upon the left? You have made two intermediate steps of a much less forceful kind, merely preparatory to the proper stepping on the loose soil. Be- fore you now step on the next spot in the right row, you make again two preparatory steps, and so you continue your agricultural work most easily (that is, most naturally) and most effectively. Between each two compressing move- ments there are always two different preparatory move- ments, both of an easy character. The 6-stroke rhythm can be understood most easily as the total activity including both the activities on the alternating sides. If, for instance, we consider the Other-One's ham- mer movement toward the left as being under special cir- cumstances accidentally of more consequence than the ham- mer movement to the right, and therefore as being stronger, we at once have a group of six motions among which the first has the main accent and the fourth a secondary ac- cent. But undoubtedly there are also opportunities in the Other-One's life for acquiring the habit of a group of six actions among which the first has the main accent and the 346 PSYCHOLOGY OF THE OTHER-OXE third and the fifth both have secondary accents ; or of six actions among which one has "the" accent, there being no secondary accents whatsoever. Thus far we have convinced ourselves that opportunities are not infrequent in the Other-One's Hfe for acquiring the 2-stroke, 3-stroke, 4-stroke, 6-stroke, 8-stroke rhythms. We use the pktral form "rhythms" advisedly, for it has already become clear to us that the Other-One does not acquire "rhythm" in the abstract, but particular rhythms of so many actions per group. Who, now, will suggest to us probable life activities of the Other-One in which five or seven regularly repeated actions are unified into groups having each an accent ? The fact that such activities are extremely rare explains to us at once why 5-stroke and 7-stroke rhythms are so rarely observed in playful activity, in music, in poetry and elsewhere in the Other-One's life. There is no need of the almost ridiculous assumption that creative Nature possesses such a dislike (reminding one of the "horror vacui" in medieval physics) for the numbers "5" and "7" that she left these out in making us a gift of "rhythm." However, while opportunities for acquiring the 5-stroke rhythm are actually rare in the Other-One's life, we should be able to create such opportunities artificially and inten- tionally if we are interested in the matter. What, for in- stance, would make up an activity of this kind? If any one suggests counting "1 — 2 — 3 — 4 — 5" and putting an arti- ficial accent every time, say, on "1," we may accept this as a possible method of acquiring this rhythm, for there would be regularly repeated (speech) actions of which every fifth would be the strongest. But this method of using a count- ing exercise in order to acquire the rhythm would turn out to be an exceedingly poor method. ACQUIRING UNUSUAL RHYTHMS 347 A good method has been found to be the following one, which employs a wooden frame, a square about two feet high, placed upon the table before the Other-One whom we desire to train. The frame has four buttons on the in- side, as shown in the figure, which may be furnished for experimental purposes with bells or recording devices of any desired kind. The Other-One is given a heavy spherical rubber mallet and asked to do a particular kind of work on the buttons of the frame. He is never told to count anything. Counting is never mentioned to him. All possible varieties of rhythm can be acquired by properly chosen forms of exercise on this frame (even the 11-stroke and the 13- stroke rhythms), — without any counting whatsoever. We tell the Other-One to hit the left button "tenta- tively," carry out the "rebound." hit the same button "strongly," carry out the "rebound," and then add a "pre- FRAME FOR LEARNING UNUSUAL RHYTHMS. paratory" motion in order to get ready to do exactly the same with only sides exchanged to the button on the right of the frame. Immediately after that it is done again on the left, and so forth alternately. The activity consists of five regularly repeated actions grouped, so that every fifth action in the repeated groups has an accent. When the Other-One has taken this exercise five minutes a day for four weeks, he tells us he now has "the 5-stroke rhythm" 348 PSYCHOLOGY OF THE OTIIEE-ONE comparable in every way to the 2-stroke and 3-stroke rhythms which he previously possessed. There is then no reason left for believing that those other rhythms were not also acquired. Merely occasions for acquiring them oc- curred at an earlier time in his life, — and occur with some probability some time in everybody's life. Or, we tell the Other-One to hit the left button, then carry out the rebound, then make a preparatory movement for doing the same thing toward the right button ; but, after having done it on the right and having made the sec- ond preparatory movement, not to continue on the left but to make an additional preparatory movement thru a quarter circle in order to get ready to perform the whole group of the six motions now up and down, as he made them before right and left. The exercise leads here after a few weeks to the acquisition of a 7-stroke rhythm which appears perfectly like any ordinary rhythm. The 5-stroke and 7-stroke rhythms can not, therefore, be said to be essentially different in origin and quality from the usual rhythms. The only thing that can be said of them is the fact that occasions for accidentally and incident- ally acquiring them are very rare. Musicians have begun to use the 5-stroke and the 7- stroke rhythms, in compositions of the highest quality. Maybe some poet will have the courage to follow in their footsteps. The fact, however, that musicians and poets have virtually abstained from using these rhythms, has nothing astonishing for us. Few are the musicians (for example, Tshaikovsky) who have these rhythms, and few are the lovers of music who have them. There is little in- ducement, then, for any musician to employ these rhythm forms in his compositions. But we hear them once in a while, and not' only in music of the European variety. The writer has seen Arabs in a FIVE-STROKE EHYTHM 349 religious street procession, with flags and brasiers in their hands, wr.lking along in dancing steps, five steps in a group. And he found there the confirmation of his previously es- tablished conviction that the alternate change of a lateral or vertical activity into a similar one in the opposite direc- tion (as above described) is probably the most influential factor in establishing rhythms of the odd number kinds. These Arabs in the procession face at every fifth step alter- nately the spectators on the right side and on the left side of the street, saluting now the one side, now the other. And the Arabic music band plays a "march" which, very fitting- ly, with perfect distinctness consists of five equally long tonal phrase elements to the measure. The musicians them- =?: M "■& f f ^ i>«i« 1- — U«eS - ARABIC MARCHING DANCE. selves dance while playing. The music is here reproduced. It is endlessly repeated. (There are no harmonies.) The old assertion that all '"true" rhythms contain only numbers made up of the prime numbers 2 and 3 as factors is clearly a myth. The word "true" in this sense is meaningless. The fact has already been stated that any particular rhythm, after having been acquired by the Other-One thru the acquisition of a particular habit of concerted (serial, or group) action,— amazing as this may seem — transfers itself with ease to virtually any arbitrarily chosen motor point, or motor points, of the body. The nervous system as a whole, that is, is after that habit acquisition capable of con- ducting, anywhere and anywhence within it, a particular succession of stronger and weaker stream waves with spe- cial ease. How that comes about is unknown. But the fact of this transference is only the more remarkable. 350 PSYCHOLOGY OF THE OTHER-ONE When the nervous system is once in possession of this peculiar capacity and tendency, we say that the Other-One has "rhythm," or, more correctly, that he has a particular rhythm, which may "crop out" at any time in any muscles of his body. Whenever he happens to execute this rhythm in response to a perfectly regular (that is, known by us to be perfectly regular) succession of stimuli, tones, drum beats, ticking noises, or what not, he is likely to answer a question in this respect by telling us that these sounds are not all alike, that they themselves "have rhythm." Since we know better, and since he will probably contradict him- self after a while, we have here a new example of those reactions which are "wasted" and which, therefore, are called "illusions." Rhythm experiences are often, and quite rightly, mentioned in the text-books as samples of illusions. We all probably have had such illusions of rhythm while riding at leisure on a steamboat or in a train. We find ourselves able to change the rhythm of the train at our own sweet will. The stronger our own habits of group activity are (for instance, if we are passionate dancers), the more readily come these wasted reactions, these illu- sions. An especially interesting transference of rhythm is the transference to the function of the speech organs. We call the result poetry, without, however, wishing to convey the idea that this is the only characteristic or even one ab- solutely indispensable property of everything which goes properly under the name of poetry. In all his games and recreations the Other-One enjoys the ability to perform easily an apparently difficult feat, or, as in the circus, to see other persons or animals perform easily apparently difficult feats. So he enjoys poetry. Mere- ly to speak in prose correctly and logically does not appear very difficult to the Other-One. To act rhythmically does TEANSFEBENCE OF RHYTHMS 351 not either appear very difficult in producing meaningless sounds. But a combination of rhythm in speech with good grammar, syntax, and logical sense seems so impossible that when it is successfully accomplished, it is very enjoyable. Of course, there is rhythm also in prose. But it is not applied with such long continued regularity as in poetry, where the regularity is called the "meter." Wrong ideas are often entertained with respect to the rhythm of music. Only in dance and march music is the rhythm of music comparable in regularity to that of poetry with a definite meter. In all other artistically performed music the rhythm is much more comparable to the rhythm of prose than to that of poetry. That all music is written in measures has a purpose other than that of securing a "meter." The written musical measure is a pseudo-rhythmi- cal group, introduced merely for the practical purpose of adjusting the time relations of the tones to some standard and aiding several performers in finding out how to play together. Quite erroneous would be the idea that the fact that peo- ple dance is one of the results of a transference to the feet of any particular rhythms previously acquired. Such a transference is, of course, not impossible ; but it would be much truer to say that the Other-One has rhythm because he often dances than to say that he dances because he has rhythm. The main origins of the dance can be found in special (real or imaginary) human needs, as a study of anthropology reveals, not in an irresistable impulse to apply rhythm to otherwise unrhythmical locomotion. On the other hand, dancing, having once established itself as a habit in the Other-One. becomes one factor of great im- portance for developing in him particular rhythms. The value of rhythm for increasing the efficiency ot labor has often been spoken of in books. But while rhythm has 352 PSYCHOLOGY OF THE OTHER-ONE such a value, this value is usually overestimated by the authors. As with respect to the dance, so it may be said with respect to the performance of systematic labor that more frequently the Other-One can be said to have rhythm because he often labors than that he labors efficiently be- cause he has rhythm. The workmen of countries with a somewhat retarded civilization (the Orient) are often quoted as making their simple labor performances more efficient by forcing it, thru the medium of song, to be rhythmical. The writer, in mak- ing observations relative to this question, reached the con- clusion that the song usually serves, mainly or even ex- clusively, an entirely different purpose. For instance, when three laborers tamp the clay into a form in order to con- struct the wall of a building, they sing. But they sing quite obviously not in order to make their work rhythmic. Their work is not rhythmic. The raising of the heavy tamp is so slow, and its downward motion so quick, that there is nothing rhythmic in the individual laborer's work. And they succeed each other in tamping — so much is true — , but the succession is so irregular that one can not speak of anything rhythmical there either. Nevertheless they sing. But each one sings while he is doing his share of the work. And the other two laborers, during their brief pause in their work, pause generally in their singing too. The song, then, is a signal meaning (al- tho the words sung literally do not have to mean this) : "I have done my share of the work; now do you yours." And the second laborer raises his tamp in response to the signal, in turn also takes up the song and thus gives the signal to the third laborer that his time has come to do his share. It may happen that the third then raises his tamp, but makes three or four quick and weak impressions on the clay, here and there, rather than one heavy blow if the latter is less LABOR AXD RHYTHM 353 needed at the moment. He lengthens the singing a httle. Signahng to each other and thereby encouraging each other to continue their heavy task, — that is the purpose of the song rather than to increase the efficiency of their labor by forcing it into a (here virtually impossible) rhythm. CHAPTER XVI How THE Other-One Talks and Writes to Himself. There is no need of describing in detail, in a psychology text-book, the invention of script. Only this let us recall that signaling by drawing a design of an object is a very natural invention. If the traveler in the wilderness, for ex- ample, hides provisions and wants his friends, who will come later, to find the hiding place, he carves or paints the outline of an animal used for alimentation on the tree or rock beneath which the provisions are hidden. Of this nature are also the famous Egyptian hieroglyphics. These visual signals, once invented, quite naturally be- come substitutes, as occasion arises, for auditory signals. That is, they become phonetic characters in which the ab- breviated picture represents the sound of the whole word that is the name of the object. If your voice does not carry the word "meat" across the valley to your friends on the other ridge, you send a written message, the phonetic symbol which represents that word, across to your friends. Soon the phonetic symbol comes to represent, no longer that whole word, but only the chief sound, usually the in- itial sound, of the word. Phonetic script is then invented. Phonetic script is a kind of frozen speech, just as in a later (but actually much simpler) invention the disk of a talk- ing machine is a kind of frozen speech. Altho speech is nothing but a development into compli- cated habits of the original signaling reflex acting on the other animal's auditory organ, it assumes a new role in the Other-One's life thru being used by him in order to signal to himself. It is not necessary for us to support by far 354' SPEECH AND SCKIPT 355 fetched evidence the assertion that the Other-One often signals to himself, often speaks to himself. Everybody knows that. But what is the use of doing that? Its use is, in philosophical terminology, generalization and abstrac- tion. It is our business here to understand it as a nervous function. 1. A child, in the presence of such things as bread, fruit, edible roots, meat, impressing his eye, learns to pro- nounce the word "food." Instead of handling these things in accordance with his reflexes and already acquired habits, he speaks the word which his parents and other people of his environment use as the common name of these things. 2. On the other hand, when the child's ear is struck by the .sound "food," he learns to respond (if otherwise than by repeating '"food") by such particular muscular activities as are adapted either to the preparation and cooking or the consumption by the mouth of bread, fruit, edible roots, and similar articles. The word heard takes the place of the things seen in the nervous functions which result in hand- ling. From now on, whenever the word has struck the ear, the muscles which co-operate in properly handling these things get ready to work rather than other muscles get ready to handle other things which also impress the eye at the time. The nervous paths serving the latter impres- sions are at a disadvantage in not being "cleared for action" (by deflection or by preoccupation) thru the word signal commanding them. Under (1) we mentioned the speech action "food," under (2) the speech sound "food." We know, however, that the sound resulting from the speech action stimulates the ear of the very person who speaks. Thus the motor action of speaking and the resulting excitation of the ear become a double link inserted between the mere sight of the article of food (among other things) and its proper handling 356 PSYCHOLOGY OF THE OTHER-ONE (among other ways of handling). This insertion of a new Hnk into the chain of functions is not an unnecessary, un- economical complication. It is a helpful link because it is "the same link" however different the visual appearances of the articles of food (they are all called by this par- ticular name "food") and however different the ways of handling and preparing them before swallowing (they are all called "feeding"). Thus stimuli most different and re- actions most different are all brought together into one sensory-motor class. This classing together, in the terminology of logic, is "generalization." In the life of animals generalization is virtually absent because, without speech, such classing to- gether of functions is very unlikely to occur. But let us not think that it is absolutely lacking in animals. A dog, for example, classes together certain sights ("outdoors," in contrast with "indoors") and certain actions, and per- forms the latter only outdoors. Nevertheless, the differ- ence between human beings and animals may well be de- scribed by saying that the latter do not generalize, or by saying, as we did in the first chapter of this book, that the former are thoughtful and the latter are thoughtless, which refers to exactly the same observable facts. Let us imagine another instance. A child has a solid article in his hand, or between his teeth, or in a pocket, or beneath his feet. An adequate stimulus causes him to trans- fer it from his place to a place farther away occupied by another person. The child, transferring the thing, is stimu- lated by the sound "give" and pronounces himself, imitat- ingly, this word "give." But the child also learns to respond to the auditory stim- ulation "give" by a motion transferring whatever is trans- ferable. GEXERALIZATIOX AXD ACSTEACTIOX 35 < Later he is busy transferring, hears the word "give," re- peats it by pronouncing it himself, responds to his own voice by transferring, and thus has within his action of transferring a speech function which seems to be a perfect- ly superfluous accompaniment and superfluous representa- tive of the action of transferring. Transferring transferring continued Transferring saying "give" sound of "give" transferring continued This representative, accompanying its constitueni, v/ould indeed be an unnecessary complication of nervous activity, were it not for the fact that the additional function is practically the same however diiterent the manner of mo- tion transferring the article in question : by stretching out the hand, throwing, kicking, dropping from an elevated place, rolling down a hill side, not to mention sending it by a messenger, by mail, or by any other device of modern transportation. This establishment of a definite function identical in spite of untold variations of the motor activities which it represents — they are all called giving — is obviously also a generalization. Or, in the terminology of logic, it is an abstraction. Abstraction, then, is a special case of gen- eralization — generalization, not with reference to objects, but with reference to relations (spatial transference, in the instance discussed). The difference between the biological functions in ordi- nary generalization and in this special kind of generaliza- tion, abstraction, might be described thus. In ordinary gen- eralization the object handled is of main significance. The manner of handling it is of importance only in so far as the object is distinguished from objects of a different clas? by the proper mode of handling it, — for example, "food" is an object to be eaten by the responsive animal. In ab- straction the mode of handling is of main significance. The object itself is important exclusively in so far as, if there 358 PSYCHOLOGY OF THE OTHER-ONE were no object whatsoever, no handling of it could have occurred. The purpose of our present discussion is not to give a lesson in logic. Our intention is to show briefly, but con- clusively, that practically no generalization or abstraction is possible without speech, and to make clear by concrete examples what is meant biologically by such terms as gen- eralization and abstraction. In order to make the signifi- cance of speech in the Other-One's individual life — over and above its social significance in signaling for co-opera- tion in actual labor — still clearer, let us discuss a third con- crete sample case taken from life. The Other-One, after having had both the speech experi- ences above described of "food" and of "give," happens to meet a beggar who "signals" to him with the words "food, give." The Other-One then looks about until his eyes are arrested by an article belonging to the class "food." A piece of bread may serve to bring this about. He then ap- proaches the bread and would now respond to its sight simply by the most firmly established habit, by taking it and eating it, had his ears not been stimulated by the sound of the word "give" too. So he responds by giving the piece of bread to the beggar. Similar experiences take place quite frequently in every child's as in every grown person's life. Suppose the ad- dress has been "food, give, hungry." The child thus learns to react to the signal "hungry" in the same way as to the sentence (if these two words may be called a sentence) "food, give." He learns to react to the word "hungry" by looking about for edible things, taking hold of them, and transferring them to the other being. There is new economy by means of a new "abstraction," one word taking the functional place of several. ABSTRACTION IS AN ECONOMY 359 What a wealth of possible actions is thus placed under the control of the single speech function "hungry !" The Other-One, when fully experienced, hearing this word, looks about until an edible thing strikes his eyes. But if this does not happen to his eyes, other reactions follow in a more or less definite series. He may put his hands into his pockets to search for food. He may walk home in order to find food there. He may open his chest or cabinet, take money from it, and go to the store where food is for sale. Or he may go out to his fields, cut his wheat, and store it away under the roof of a barn in order to be able to give food at a later time when the sound hungry may strike his ear again. Not having any wheat mature on his fields, he may take out his horses and implements and plow the ground on which wheat is only to be sown. He may attend, as a stu- dent, an agricultural college where he learns how to grow wheat most successfully on his farm. He may vote in favor of his government spending money for the support of such a college. Further think of the innumerable pos- sible activities which make provision for the transportation of the food from place to place, from the producer to the consumer! To enumerate even those activities which are more directly controlled by the word hungry, would require a volume. Of the activities which we have mentioned, some are rather remotely dependent on the abstraction "hungry." The more remotely they are dependent on it, the more numerous, of course, are the other abstractions on which they are also — more or less directly — dependent, so that, then, the actual motor response becomes more and more the resultant of many components, of all the activities controlled by all the abstractions. We have thus far spoken of the word "hungry" only as denoting a sound, stimulating the ear and controlling by means of the nervous paths diverging from the ear a vast 360 PSYCHOLOGY OF THE OTHEE-OXE number of highly comphcated motor responses. We said above, that the word hungry was often heard together with the words food and give. At such a time it must have been imitated by the child in question. It is plain, however, that the same word, hungry, is also heard in other situations, especially at the time when the members of the family as- semble to take their meals together. At that time the child's sensory points of the stomach are likely to be ex- cited by the physiological condition called liunger technical- ly by the physiologists. Accordingly, the child learns to say "hungry" in response to that sensory excitation. Whenever he responds thus, he produces the sound of the word, and the sound acts on his own ear. Quite naturally, then, the speech function "hungry" becomes an intermediate link between the sensory excitation of physiological hunger and that vast number of responses above mentioned, in- cluding such things as the deposit of a ballot in a box, all serving, with greater or less directness, to dispel hunger not only in others but in himself. It is not difficult, then, to understand the value of ab- stractions to the Other-One. They serve to make ready, in- stead of the simple reflex corresponding to the stimulation or a simple habit having taken that reflex's place, an enor- mous number of complex motor responses among which for actual execution a selection is made, that is, is condi- tioned, by the other sensory factors of the situation and by the motor tendencies of the abstractions belonging to them. The functioning of abstractions (his "thoughtfulness" in popular terminology), which is the distinguishing feature of man's life as compared with that of animals, is made possible by the acquisition of speech. The speech functions here described are habits in no es- sential manner different from other habits. The mere fact that the muscles in question are the muscles of our speech MOTOR HABITS AND MEMORY 361 organs and not those of our hands and feet, does not es- tablish an essential distinction between these and other habits. The laws of nervous function governing the forma- tion of habits are the same for the "generalization and ab- straction" habits and for other habits. In ordinary life we distinguish them often by calling the other habits simply "habits," or motor habits, or manual habits, or postural habits, and denying the name "habits" altogether to the habits of generalization and abstraction, giving them in- stead such names as memory, or reasoning power, or thought. This division into two classes has its advantages from the sociological point of view ; but it has little to com- mend it from the psychologist's point of view. It would be a complete misunderstanding of the func- tioning of speech in the generalizations and abstractions of an adult, if we should think that in every such case he must be heard to speak or mutter to himself in a manner audible to others. We know that sometimes he can be heard to speak to himself. But the muscular contractions may be far too weak to result in actual sound production. And yet their action as kinesthetic stimuli may be strong enough to bring about the effects which their action as sound stimuli would have brought about. It goes without saying that the kinesthetic and sound stimulations which are al- ways (normally) the simultaneous results of speaking, come to take each other's place with absolute definiteness on the sensory side of all habit functions in which either the one or the other plays a role. Moreover, it is not even necessary, in order that the speech organs may play their parts in generalizations and abstractions, for their muscles to contract at all. It is quite possible, tho not as yet a proved fact, that nervous cur- rents, after having passed into muscles (motor points) may directly under certain favorable conditions pass over into 362 PSYCHOLOGY OF THE OTHER-ONE the sensory points of the same muscle fibers without caus- ing them to contract at all, — and then pass on from these sensory points in the usual manner. If that is true in cer- tain cases, these muscle fibers would act simply as if they were higher centers within the nervous system. Nothing is thus far definitely known about this question. In the development of generalized (abstract) nervous functions an enormous step in advance is made when man- kind invents script. The written language can accomplish much that is denied the spoken language. First, it enhances the preservation of the Other-One's generalizations for his own later use. Secondly, it removes practically all the limits of space and time from mutual signaling among sev- eral individuals, and therebv also removes all limits from placing one individual's generalizations at the disposal of other individuals, thus saving them in the case of innumer- able generalizations the time necessary for their invention. As to the preservation of any generalization for the in- dividual's own use. it is plain that, as long as generaliza- tion is mediated only by the spoken language, it depends exclusively on the properties of his own nervous system. Just so long will the generalization persist, as a path of low resistance, established by the speech function, leads from the sensory points of. say. hunger to a common central point, and another one from a common central point to that vast number of responses previously indicated. But such a path of low resistance can continue to exist only if it is constantly re-established, so to speak ; for we know that a path whose resistance has been lowered by individual experience tends to resume gradually its original high re- sistance. "The experience is forgotten." After the individual has acquired — by a simple replace- ment of response — to the sight of the written word the same manifold possibility of responding as to the sound of the PRESER^T^NG THE GENERALIZATIONS 363 same word, the time limit of preserving the generalization depends no longer on the delicate properties of his nervous system, which is so easily influenced by new exp'^riences as well as by normal and abnormal physical processes like fatigue and disease, but on the physical properties of the material on which he has written the word. It is true that, quite recently, one has learned by phonographic records to preserve the spoken word. But the limitations of this method are obvious, and, whatever may be its significance for the future, in the past at least the individual has had to depend for the preservation of his generalizations on the written word, the memorandum-book. Of course, we use here and in the following the term "word" in a very wide sense, including therein all written symbols of any kind, especially those of mathematics, even all kinds of geometrical drawings, and the diagrams and symbolic letters of physics, chemistry, and all other sciences. Secondly, we stated that by the substitution of the written for the spoken word communication of the individual's generalizations to other individuals has transgressed almost all limits of space and time. As we read a letter despatched from the opposite side of the globe, we learn what gen- eralizations were most powerful in the nervous system of the individual who signed the letter, at the time — weeks ago — when it was written. As we peruse the book of an author long since deceased, we learn what generalizations of his own he thought desirable to communicate to his con- temporaries and those who were to live after him. As we uncover the tombs of the Egyptian kings, we learn what generalizations chiefly determined their actions thousands of years ago, while they were preparing for the common destiny of all individual life, for death. Posterity, opening our books, may learn what generaliza- tions affected our nervous system so strongly that, in addi- 364 PSYCHOLOGY OF THE OTHER-ONE tion to using thern in our individual life, we had them re- produced in the printer's office. Thus all mankind becomes a unit, spatially and temporally. The individual's experi- ences are no longer useful to him and to the few people of his direct environment alone. All other individuals of the present and future may profit by them. Science is the sum total of all those generalizations which the experience of mankind has invented, selected, and collected as the most useful for the control of the muscular response called forth by sensory excitation. The statement of the last sentence calls for further elaboration since the work of a scientist, especially to those not very familiar with it, seems to be altogether different from that of the ordinary man, say, the farmer plowing his field, — seems to belong to a category of activity other than that of motor (muscular) response to sensory excitation. When, in the evolution of civilization, the writing of words and other symbols of generalization has firmly es- tablished itself in a sufficiently large group of men, in a tribe or a nation, the written symbols become a special class of important objects to v/hich, however artificial their ori- gin, man has to learn to respond in order to be successful in the struggle for life, as formerly he had to learn to respond to those objects alone which have their origin in nature. Moreover, young people selecting a class of objects to which to devote their lives as specialists may now not only select from the natural objects, but may choose even this class. Their life work, then, consists in responding to writ- ten symbols by writing symbols and, of course, also by pronouncing them, as in oral teaching. The scientist's work, aside from experimenting, that is, testing the value of his generalizations by skillful appeals for an answer to nature, consists in combining, on writing paper, symbols al- GENERALIZATIONS EIVAL NATURAL OBJECTS 365 ready existing into new groups and inventing for each group of generalizations which has been demonstrated by experi- ment to be a useful combination of symbols, a new name, that is, a new symbol of generalization. All this is, clearly, motor activity in response to sensory excitation. The only distinguishing features are these, that the scientist's motor activity does not require muscles of any great strength, and that it does require an enormous amount of learning, of variations of response, before it can begin to be of any value to humanity. Let us take an example from the most ancient of all the sciences, which, notwithstanding its age, is still and will always be the foundation of all others, — from arithmetic. No one doubts that the most ancient symbols for larger and smaller groups of things were diagrams of familiar objects. The Roman numerals V and X, for example, are diagrams of one hand with fingers spread out and of two hands united in opposite positions at their wrists. Even if these dia- grams, originally, signified only a quantity portable in one hand and a quantity portable in both, they would already be generalizations, for many are the things or substances which can be carried by hand. If not at once, at a later period, these diagrams came to signify five and ten. They are then a step further removed from natural experience ; they have assumed to a further degree the meaning of a generalization (or, if you prefer, of an abstraction). When a person counts, up to five or any other number, he enounces in regular order one of the words of a series which he must previously have learned, while he removes to a position of repose, say, with his finger on the table, or with his turning eye in the subjective field of vision, just one more each time of the objects counted. When written symbols like our Arabic figures are substi- tuted for the spoken words, nev/ generalizations are made possible. 366 PSYCHOLOGY OF THE OTHER-ONE What is the significance of the plus sign? If we write it in 7-f 8, we invite the reader to count a group of seven things of his own choice and another group of eight as if they were only a single group of countable things. The plus sign, then, is a generalization for any kind of sensory- motor activity arranging the things as if they were a single series and covniting them thus. The minus sign is a gen- eralization of a similar kind. In 7 — 4, for example, we express the question : How many times more do you count after 4, till you enounce 7? The minus sign, then, is a generalization for any kind of sensory-motor activity ar- ranging the things of one series as if they were two series. The multiplication sign presupposes the experience of the plus sign. By writing ^y^7 we invite the reader to perform the work of adding 7 plus 7 plus 7. Modern mathematics has greatly increased the number of such gen- eralizations, — think only of logarithms, not to mention high- er mathematics. Yet by degrees they can all be reduced to the relatively simple activity of counting a series of things. Another example of a scientific generalization might be taken from mechanics. Remember the formula y2mv', gen- erally used in measuring our experience of "force." Man, in his intercourse with nature, learns how to resist moving objects and also how to utilize the motion of objects (a hammer, for example) for his own purposes. He learns that he has to exert more muscular energy if the object resisted is heavier, and also that his work is more effective if he uses a heavier tool. He generalizes his experiences of resistance to objects and of work by the aid of objects — experiences to which he has already given the general name of "force" — by pronouncing the word "mass" in order to express their quantitative aspect. In writing this word he abbreviates it by writing simply m. THE GENERALIZATIONS OF MECHANICS 367 By further experience man learns that he has to exert more muscular energy and also that his work is more ef- fective, if the object in question moves more quickly. These experiences, in addition, he generalizes in writing by unit- ing the symbols "mass" and "velocity" in a single formula, connecting them by a sign of multiplication. At our present time, however, one does not write simply my,v, but m'X-u, multiplying v with itself. This is done be- cause the formula myiv', in algebraic relations with other formulas expressing other important experiences with heavy bodies, is in general more convenient. Still, this greater convenience was only gradually recognized by scientists. Two hundred years ago the question was debated in heated controversies between the most distinguished scientists whether the symbol mv or the symbol mv' was a more use- ful tool of generalizing human experience, or, as they ex- pressed it, — talking as if force were a measurable thing among the other objects in nature, instead of a mere gen- eralization invented by man — "whether force was propor- tional to velocity or to the square of velocity." At present the latter formula is generally preferred, but slightly modified by the addition of the factor 1^2 • This simplifies again the algebraic operations, for the formula y2im' can be put down directly as equal to a certain other very important formula of mechanics. The usefulness of the equation thus formulated is the only reason why our scientists have become accustomed to using exclusively the formula y^mv' in their generalizations of the quantitative aspect of the qualitative generalization of "force." (We may mention, by the way, that the use of the equation in question gradually brought about a change of name of the generalization l^nw, so that it is nowadays called "work" in the text-books of physics.) 368 PSYCHOLOGY OF THE OTHER-ONE Force, therefore, is by no means, as some speculative philosophers would make us believe, a reality given by na- ture, and truly measurable only by a single formula, but a mere abstraction created by man to suit his needs, and ex- pressed by that combination of algebraic symbols which best suits his needs, practical and theoretical, — an abstrac- tion from experiences so varied and complex that with- out this generalization we could not respond to the quantita- tive aspect of any one of them with any definiteness, we could not measure them. In school and all through life we find ourselves compelled to respond to traditional audible and visible symbols of generalization as well as to the situations presented by nature. We gradually learn to respond to these kinds of stimulations most successfully : we acquire scientific habits. An example of a habit of responding to symbols of gen- eralization — or rather an example of a large group of such habits — is the multiplication table. To the phrase "seven times nine" we at once add, by habit acquired, the word "sixty-three," without having first to do any counting, thus saving a large amount of time. In a similar way one learns, long before he acquires the multiplication table, to combine words into sentences and sentences into periods, and to draw conclusions expressed in further sentences, without first having to devote time and energy to perceiving the things which are meant by those generalizing words and sentences. The enormous advantage of substituting this handling of words for the cumbrous handling of things is clear enough. but the danger of speculation is clear too, — the danger of combining words and of thus drawing conclusions, that is, of expecting the things to agree with the last group of words manufactured by us, for no better reason than this, that we know our succession of sentences to have been con- HANDLING WORDS S69 structed according to the rules of grammar, syntax, and logic. This danger does not exist in the case of the multiphca- tion table. Here, in our most elementary quantitative gen- eralizations, things always agree indeed with our conclu- sions. But our purely qualitative generalizations are so in- exact that the things, when we perceive them, often turn out to be quite different from what we, guided only by our habits of handling words, expected to find them. CHAPTER XVII If the Other-One is Born Blind, or Deaf, — What Then? That the loss of any sense organ involves many diffi- culties in the Other-One's life we know from experience. And that is also to be expected as soon as we understand that his life is a continuous reaction to excitations occur- ring in his sense organs. But a detailed discussion of these general difficulties would be out of place in an introductory text-book like this. It would lead us into the medical and other sciences. A reason, however, for discussing here certain conse- quences of a loss of certain sense organs is the fact that this loss may seriously interfere with the Other-One's liv- ing as a member of human society. The signaling reflexes, we have seen, are of particularly great interest to the psychologist because of the role they play in establishing social relations among the individuals. While discussing the relative value of the visual and auditory signaling re- flexes, we had to point out that, contrary to our first ex- pectation, the auditory signaling reflexes seem to be more significant than the visual signaling reflexes. Keeping this in mind, we no longer wonder at the fact — not statistically proved or provable, but generally acknowledged — that deaf people are more likely to be unsocial, morose, suspicious of their fellow men, than blind people. Of course, if people in adult life lose one of these two senses, they are during the period directly following the loss more conspicuously 370 LOSS OF THE SENSES 371 affected by the loss of sight than by the loss of hearing. This is natural, for the former loss requires in general a much more profound change in the manner of performing one's daily routine work. But after this adaptation has occurred, and the individual has become to some extent rec- onciled to his loss, the change in personal character above referred to as distinguishing the deaf from the blind is obvious enough and is clearly the result of the great sig- nificance of auditory signaling for social life. But in this book our chief interest in the loss of various sense organs has its basis in the fact, discussed in the last chapter, that the Other-One's supremacy on earth among all the species of animals depends on his acquisition of language. Without his language that feature distinguishing man from the animals, that is, the use of generalization and abstraction, his "thoughtfulness," would not exist. And in order to acquire language, all sense organs are not of equal importance. Having once acquired a spoken or written language and having learned to use it for generalization and abstraction, the Other-One may then lose his sense organs needed for the acquisition of speech, or of its equivalent, script. And still he would continue to use generalization. It is not the adult, therefore, who concerns us here in this discussion of the effect of the loss of sight or hearing. It is the child who becomes blind before learning to read and write and the infant who becomes deaf before learning to speak the lan- guage of his family, who interest us here. Briefly speaking (but allowing for a certain extension of the time of loss beyond the time of birth, as hinted at in the last sentence), we may ask : How dift'erent will the Other-One be if he is born blind, or born deaf, or born both blind and deaf ? 372 PSYCHOLOGY OP THE OTHER-ONE The signaling reflexes which the Other-One possesses are far too few and too simple to serve as the mediating link, studied in the preceding chapter, which establishes that nervous function deserving a special name and given the name of "generalization." The Other-One must learn to speak, he must acquire a relatively extensive complex of habits, "language," in order to generalize. For acquiring language habits he depends largely on "imitative reflexes," since schools, in which language is, or languages are, arti- ficially taught, are a very recent invention of mankind. In spite of all the vague glorifications of the "instinct of imita- tion," man, as we have convinced ourselves, virtually has no other imitative reflexes than the auditory ones. Without having the sense of hearing, therefore, man can not by re- flexes imitatingly acquire a language. If the Other-One is born deaf, he never acquires a lan- guage unless he is sent to school. Being born blind, on the other hand, does not interfere with his learning to speak the language of his people. The lack of schooling, there- fore, has a much more profound effect on the deaf-born than on the blind-born. The lack of schooling condemns the deaf-born child to remain intellectually on the level of animals. When we use here the term "intellectual" or "in- tellect," we use it as an abstraction referring to the con- crete fact that a being uses in his life, to a larger or lesser extent, generalizations and abstractions. He who deprives a deaf-born child of schooling, deprives him of what makes him a human being, of his "intellect." He degrades him to the level of animals. If in a modern civilized state the question could be raised at all, whether it is more indis- pensable to have schools for the deaf or schools for the blind, the answer is easy to give. The school for the blind raises an intellectual, "thoughtful," human being to a mere- BLIND OR DEAF 373 ly higher level of intelligence. The school for the deaf raises to a human level a being who would, without it, re- main on the level of the animals. The fact just stated has always been recognized in human tradition. In former centuries, it was customary to say, on hearing of the birth of a deaf child, that the parents were the unfortunate possessors of a being which had in- herited their material form, but to which the Creator had refused a "soul." In other words, they had an animal look- ing like a man. That people should have expressed the expectation that a being would never in his life use generalization and ab- straction, by saying that he had been given no "soul," would strike us merely as a rather ridiculous kind of superstition, if that manner of referring to these unfortunates had not had its serious practical consequences. When a being is so unsocial as a deaf being generally is, so unresponsive, so unteachable, there is no great inducement for his people to make the sacrifices involved and give him a schooling. But since this disinclination of the parents to the establishment of a school for their deaf children, or to the appointment of a tutor for a deaf child, was still fortified by the use of the abstraction "lack of a soul," it is no wonder that the educa- tion of the deaf-born child was something unheard of in ancient and medieval education and is not an outstanding feature in the history even of modern education. Who but a fool, it seems, would think of appointing a tutor for animals, — and deaf-born children used to be regarded as animals. The men who could free themselves from tradition, look the facts in the face, and recognize that deaf-born children were as teachable as others, that they merely had to be taught by diflferent methods, may well be counted among the geniuses of mankind. That alone, however, is not the rea- 374 PSYCHOLOGY OF THE OTHER-OXE son why we mention the names of some of these men be- low. We mention them also because in the history of the education of the deaf we have a beautiful illustration of the fact, innumerable times repeated in human history and psychologically interesting, that a vague rumor that some- thing apparently impossible has been done somewhere some- how, and that therefore it can be done, has often encour- aged a man to rediscover something independently and to claim the priority of the discovery quite honestly, without being the first discoverer. It is commonly believed that the discoverer of the pos- sibility of educating the deaf-born was the French priest De I'Epee. But, that almost exclusively his name is con- nected with this discovery, is due only to the fact that he was the first who, in addition to instructing the deaf, also instructed those who were willing to become teachers of the deaf. And these teachers of the deaf carried the name of their teacher all over the world and made it famous. The honor of the first discovery, so far as our present knowledge reaches, belongs to a Spanish Benedictine monk, Pedro Ponce, called de Leon, who died in 1584. How this discovery struck those contemporaries who in spite of the insufficient means of spreading ideas in those times heard of it, can be seen from the phrases used, in a book describ- ing the totality of the work of the Benedictine order and published about 1600. "Our monk, fray Pedro Ponce de Leon," says the author, Antonio Perez, himself a Bene- dictine, "created that marvelous art of giving speech to the dumb. Thereby he has won the admiration of all who have heard of it, abroad as well as at home, on account of this wonderful display of genius. Yet he never succeeded in instructing others in the art. However, we know how much more difficult even than to practice oneself it is to train other masters in one's profession." PONCE AND BONET 375 The honor of being the country of the second discovery of the art also belongs to Spain. And not only this, but also the honor of the publication of the first text-book for giving this instruction, and an elaborate and very suitable text-book, too. In the year 1620 appeared in Madrid the book by Juan Pablo Bonet whose title in literal translation is "Reduction of the letters, — and art of teaching the mute to speak." The book has been translated into English, French, and German. The rather curious title means that the author wants to make clear that the teacher of the dumb must himself begin with acquiring a knowledge of phonetics, because he has to teach his pupils the often vary- ing sounds represented in script by each single letter of the alphabet. There can be no doubt that Bonet had heard it rumored that someone somewhere had succeeded somehow in teaching the dumb to speak. But he honestly redis- covered the method and rightfully claims the honor of his discovery. His first pupil was the brother of a nobleman, the Constable of Castile, whose secretary he was. The pupil had been deaf since the age of two years. Bonet's book consists of two parts. The first part begins with the history of the art of writing and gives an exposi- tion of phonetics, a little imperfect from the modern point of view, but nevertheless quite remarkable. The second part discusses the causes of mutism, the auxiliary use of the manual alphabet, lip reading, the formation of the separate sounds and their production in series. He gives a complete Spanish grammar adapted to the special needs of the deaf-mute pupil, and this part of the book is to be used as the regular text-book by the pupil as well as the teacher. The method is similar to that which goes nowa- days under the name of the Berlitz method of teaching for- eign languages. The text-book contains even a chapter on arithmetic. 376 PSYCHOLOGY OF THE OTHER-ONE Two further facts will be mentioned here in order to show how advanced the thought of Bonet was. He uses for the instruction of his pupils such modern aids as a flexible leather model of the tongue. And the modern edu- cational psychologist reads with astonishment the follow- ing heading of the tenth chapter : "Reason why normal children are so slow in learning to read, and discovery that this is due to the difficulty which we create by teaching them the names of the letters first." In the year 1622 another Spanish teacher of the deaf, Manuel Ramirez, became known and claimed for himself the discovery of the art of teaching the dumb to speak. In 1657 Franciscus Mercurius van Helmont, son of the famous Flemish physician and chemist, published a book concerning the education of the deaf, but concerned him- self only with lip reading. In 1660 Wallis, a mathematician and also author of an English grammar which begins with an elaborate treatise on phonetics, thought that he was the first inventor of the art, having succeeded in teaching several deaf-mutes to speak. In 1670 an Italian, Lana, claimed to be the first to have taught mutes to speak. In 1690 the Swiss physician Amman, who spent the latter part of his Hfe in Holland, had to treat a girl for deafness and succeeded in teaching her to speak. In 1692 he pub- lished a book "Surdus loquens" and, as usual in these cases, thought that he himself was the first inventor of the art. In 1748 the Portuguese Pereira became famous in Paris as teacher of deaf-mutes. The history of his career is in- teresting. He happened to read in a book by the Benedic- tine monk Feyjoo a notice about Pedro Ponce. Thereupon TEAOHEKS OF THE DUMB 377 he tried to teach mutes, succeeded, and later was praised by many as the first discoverer of the art. In 1761 Ernauld, of Bordeaux, presented to the French Academy of Sciences a communication in which he men- tioned some previous teachers of deaf-mutes, but declared himself the inventor of a new method of teaching lip read- ing. He did not use a manual alphabet at all, but based his instruction on Hp reading. This application of lip read- ing he regarded — and to a slight extent probably with justi- fication — as his own contribution to the art of teaching the deaf. De I'Epee published his book in 1776. He died in 1790. He was the first teacher of deaf-mutes who became the father of a training school for teachers of deaf-mutes. Sev- eral teachers trained by him established themselves success- fully in Italy. Emperor Joseph II of Austria sent the Abbot Storch to Paris in order to import the methods of teaching the dumb into his dominions. Another author of much merit concerning this phase of education, Andres, in a letter written in 1794 to the wife of the Spanish ambas- sador in Vienna, characterizes the work of the French priest by calling it "unquestionably the most methodical and per- fect," while upholding the priority claim of his country- man, Pedro Ponce. A slightly prolonged occupation, like the one to which we have just submitted, with this matter helps to impress upon us the enormous significance for the "human intellect" of language, that is, of speech and script. Nothing can show this significance as clearly as the enthusiasm of those who by one accident or another were led to, and by patience succeeded in, teaching the dumb to speak, transforming as by a miracle animals into human beings. But on the other hand, it also impresses us with the enormous difficulty of convincing the great crowd of which humanity consists, that 378 PSYCHOLOGY OF THE OTHER-ONE herein lies the main difference between animal life and human life. "Do animals think?" is a question often asked. But few have always been those who could see that this was the same question as "Do animals speak?" The art of teaching the dumb to speak, once discovered, ought to have spread thru the great crowd of humanity like a religious gospel. It ought to have become a common- place at once, because of the psychological implication of the fact of human intelligence with this art. But the great crowd did not see the implication. The miraculous art satisfied the crowd's curiosity for a few years and was soon entirely forgotten, with the result that the art had to be re- discovered so many times. Even modern psychology, altho it has given considerable attention to language, is only slow- ly beginning to recognize that the "human intellect" is human language, that what is popularly called "mental" and popularly opposed to "physical or physiological," is merely that which in scientific psychology is found to be onaracterized by consisting mainly of language functions. Compare "memory" with "manual habits." In habits of "remembering" language functions prevail over the func- tions of other motor organs. That is the only difference. We have above mentioned only incidentally the substi- tutes or surrogates for normal speech and script, invented for the use of those deprived of one or both of the higher senses. An introductory psychology is not the place to dis- cuss details which are mainly of technological importance. Let us make only a few remarks about them. The manual alphabet serves as a surrogate for speech. But it is a visi- ble kind of speech instead of an auditory one. It has all the general drawbacks of visual compared with audible signals. It can not rely, either, on the advantage of ap- pealing to imitative reflexes, which is possessed by auditory stimulations. The execution of complex manual signals is. SUBROGATES FOR SPEECa 379 further, very slow in comparison with the execution of signals by the vocal organs. Nevertheless, even the ac- quisition of nothing language-like but the "speech" by means of the manual alphabet will raise a dumb person above the level of an animal, give him a certain degree of human in- telligence. The raised script of the blind serves as a substitute for visible script. Its importance for the intellect of the Mind, however, is only relative, since the blind, possessing speech, possess thereby also the use of generalization and abstrac- tion without being taught to read and write raised script. The intellectual level of an uneducated blind-born person is essentially the same as that of an uneducated normal person, whereas the uneducated deaf-born person, as we have seen, is comparable to an animal. Most difficult, naturally, is the education of those who have lost both the higher senses at birth or not much later. In these cases signaling is possible only by appealing to the sense of touch. The first speech surrogate therefore is based on writing a short word with one's finger on the palm of the hand of the person to be educated and induc- ing him (since the "localizing reflex" causes him to imitate the stimulation only with remote exactness) to imitate by writing thru habit on his hand the same word with his own finger. Later the process of education becomes more simi- lar to that of the dumb. To what height one can develop the intellect even of a person who has lacked virtually from birth both sight and hearing, is illustrated by the example of our countrywoman Helen Keller, who has become fam- ous even as an author. In this connection it is well to point out why the senses of sight and hearing, to which we have repeatedly referred as the "higher senses." deserve this name. It is not that these sense organs or their functions have any property 380 PSYCHOLOGY OF THE OTHEE-OXE which elevates them physically, chemically, or biologically above the other senses. They are rather those senses which can be spared most readily without destroying the possi- bility of life. They are higher only in the sense that the particular feature distinguishing man from animals, the human intellect, that is, the nervous function of general- ization and abstraction, is by far more dependent on the function of the organs of sight and hearing than on that of the other sense organs. But even this dependence is not absolute, since the intellect can be developed, by the in- vention and application of the proper kind of educational art, even in those who lack these two senses. The higher senses, then, are simply those senses on which the development of the intellect depends in the natural and usual course of events. These are the senses which man- kind particularly needs for "being thoughtful." CHAPTER XVIII The Other-One Walks in his Sleep. Disturbances oe Personality. Abnormalities. There are variations in the Other-One's customary mode of reacting to stimuli which belong to a class different from that of willing and learning. They are technically called "symptoms of neurosis." That is, they are abnormal. They result from an abnormal or diseased condition of the nerv- ous system. Our chief interest in abnormalities lies in the fact that they may illustrate some of the normal func- tions hitherto discussed in so striking a manner that ex- amples from the behavior of the Other-One, as he normal- ly stands before us, are not of equal illustrative value. The layman thinks, when he thinks of psychological ab- normalities, first and mainly of the "somnambulist," in liter- al translation, sleep-walker. The somnambulist is popular- ly supposed to have been disturbed in his sleep by the moon. Therefore he is also called a "lunatic." And institutions for the confinement and treatment of people suffering from nervous diseases are in some regions even ofiicially still called "lunatic asylums." A most perfect sample descrip- tion of the symptoms of a certain type of nervous disease is found in Shakespeare's "Macbeth." "Since his majesty went into the field," the gentlewoman reports to the doctor, "I have seen her rise from her bed, throw her nightgown upon her, unlock her closet, take forth paper, fold it, write upon't, read it, afterwards seal it, and again return to bed; yet all this while in a most fast sleep." — Shakespeare here gives us in the gentlewoman's talk an exact sample of the popular attitude in a case like 381 382 PSYCHOLOGY OF THE OTHEK-ONE this. The uncritical observer of the somnambuhst always exaggerates when he tells what he cbjerved. "She is in a most fast sleep." As a matter of fact, we do not call that sleep when the Other-One is so active as one is in writing and sealing letters. What the gentlewoman really ought to say in accordance v^-ith the truth would be something more moderate, like this : "Considering that we regard al- most everybody at that time of the night as asleep unless he is dressed for and doing special night duty, as a watch- man's ; and considering further that a minute before writ- ing she actually was in bed and a few minutes later she was in bed again ; and considering that she did not say to me 'How do you do,' as she does when she meets me ordina- rily, but passed me as if I were a wooden pillar; and con- sidering that she treats us (speaking to the doctor) just now with the same slight attention ; and considering that she talks now before us of such suspicious things as the spots on her hands, and of the unexpectedly large quantity of blood which the old man had, and that she rubs her hands as if they needed a cleaning — I should say that she was not then and is not novv' exactly what one would call 'awake to the situation.' If we were her enemies, she would already have given herself away." In the popular (not recognizable as scientific) psychology sleep is not a purely relative amount of being active, or rather of being inactive, but is a specific "state of the soul." To the "popular" psychologist the most curious fact then seems to be that here a "soul" is found to be "not fully awake" or "asleep" or "subconscious" in a body which is not lying in bed, but standing up and even walking about. Therefore "somnambulism." To the psychologist who is a man of science it makes no great ditlerence whether you call that observation sleep or, better, relative inactivity, or give it no name at all. All SOMNAMBULISM 3 PQ that interests him is the fact that the Other-One's reactions observed are reactions very unusual in such a situation. Usually a person who has his eyes open says "How do you do" when entering a room in which there are acquain- tances. Lady Macbeth, altho her eyes are open, addresses her acquaintances no more that she would address a piece of furniture. A murderer fearing discovery of his deed ordinarily abstains from loud comments on the quantity of blood of his victim. Lady Macbeth makes such remarks in the presence of others. What the psychologist observes is that the stimuli are not adequate to the reactions, that the reactions are those which one would expect of Lady Macbeth only in an entirely diflferent situation. We have, therefore, a case perfectly similar to that in a previous chapter where a man stands still on a busy street where everybody walks, and answers the traffic policeman "It's your move." Lady Macbeth is obviously "preoccupied." But the difference between her preoccupation and that which occurs in a normal person — as in that chess enthu- siast — consists in the fact that normal preoccupation rarely lasts more than a few minutes, in exceedingly rare cases (where it becomes a "joke") as long as a few hours. But in a case like that of Lady Macbeth, in a neurosis, the preoccupation lasts days, weeks, or months, and even years. In saying that it lasts so long we do not wish to be under- stood as meaning that it lasts in unvarying strength. There may be ups and downs in that preoccupation. Neverthe- less, it often seems to be the same preoccupation after weeks or months, having fluctuated meanwhile, but with- out having been clearly interrupted and fortuitously re- created. If we hold the contact improvement in the synapses of any higher centers responsible for any symptoms of pre- occupation, it follows that these neuron terminals must have 384 PSYCHOLOGY OF THE OTHER-ONE in these abnormal cases an inherited tendency to "stick" after having extended in consequence of a nervous flux passing thru them. Normally they would recede within a few seconds or minutes after the cessation of the nervous currents. These neurons in the case of this neurosis seem to have lost this ability to recede again. The consequence is that, whatever nervous current passes thru the nervous system, finds thru these synapses a path more conductive than it ought to be. The result is that certain reactions occur with a frequency out of proportion to their proba- bility as reflexes or established habits. One naturally asks, then, "Is this loss of ability on the part of neurons to withdraw their terminal branches after cessation of the flux with the normal speed, restricted in the individual to a particular nerve center?" The clinical observations show that it is not so restricted, but that this is an abnormal property of all the higher centers. The particular kind of preoccupation, like "talking of blood and wiping the hands," depends merely on circumstances (of specially effective stimulation applied under specially favor- able conditions of the organism). Under other circum- stances establishing a preoccupation of this patient other reactions would have appeared as the symptoms. But the tendency toward abnormal preoccupation is a general tend- ency of the nervous system belonging to that individual. Making use of the ancient term "hysteria" (very absurd in its literal meaning, which is womb trouble), this neurosis is often pronounced to be a "tendency toward hysterical symptoms." It is actually as common in men as in women. Examples of the clinical observations referred to in the preceding paragraph are the following, reported by the French psychologist Pierre Janet, to whom we owe the most elucidating studies of this matter. A lady forty-three years old has terrible fits in which convulsions and bowlings ABNORMAL PEEOCCUPATION 385 mingle together for fifteen or twenty hours as a reaction to such simple stimulations as the mentioning of a calendar date before her, as the pronunciation of the words "love," "affection," "happiness," as a dog barking on the street, the sight of a cat passing by on the street, the pronuncia- tion of the words "dog" and "cat," and many others to which no normal person would respond by convulsions and bowlings. It all becomes plausible when we know her his- tory, in which a certain event occurred in which stimuli of this very kind belonged to a total situation calling forth a mixture of extreme disappointment and anger with fate, thus establishing preoccupation in a particular sensory-mo- tor direction. A dear friend had died. Only one souvenir from him, an old dog, remained. Then the dog died, in his turn, on a carpet. And the lady lay down on the carpet on which the dog had died, and remained there for sixty days without consenting to sit at table for a meal or to take the usual care of herself. The case is essentially the same as that of the chess player, an extraordinary readiness for a certain kind of sensory-motor function. Only every as- pect of it is more extreme. In another patient the reactions and the stimuli differ, not because the tendency toward preoccupation is a differ- ent one by heredity, but because the life history is a differ- ent one. The sight of a fiame, sometimes of a match only, brings about a particular fit in a patient who has been af- fected by a conflagration. And, as the peculiar power of a special stimulus, so the nature of the reaction, altho first seeming entirely irrational, explains itself as soon as the patient's life history is known. "There's method" in what seemed irrational madness. A patient presents an intense tremor of the right hand. It is finally discovered that the tremor started from a long continued practice in so-called automatic writing in order to question spirits. The tremor 386 PSYCHOLOGY OF THE OTHEE-ONE is nothing but the quick execution of writing movements. Put a pencil in the patient's right hand, and the tremor is transformed into writing. If the poHceman had asked the chess enthusiast for a match, or for the time, there would probably have been no occasion for a joke, because there would have been no occasion for "method in madness." A patient in her nocturnal somnambulism makes a pecu- liar movement up and down with her foot, makes also a turning movement at her right wrist and simultaneously says all the time: "I must work, I must work." — One evening, as a girl of sixteen, she had heard her parents bewail their poverty. She was very much moved, and from that time had at night her "somnambulism." The trade of the girl was that of making doll's eyes, and, for this purpose, she worked a lathe by treading a pedal with her foot and turn- ing a fly-wheel with her right hand. If she had only tossed in bed as we all do now and then, we would not call it somnambulism. But our tossing is neither more nor less mysterious. Only our tossing would not illustrate such an extreme case of preoccupation. A man is paralyzed on his left side. He explains it as caused by a tremendous shock. But the real explanation is abnormally extended preoccupation, for which his nervous system certainly had a congenital predisposition. Travel- ing by rail he had done an imprudent thing: while the train was running, he had gotten down on the outer step. At that moment he became aware that the train was about to enter a tunnel. It occurred to him that his left side, which projected, was going to be knocked and crushed against the tunnel. He swooned away, but happily at that moment was pulled back by others into the carriage. His left side was not even grazed. Nevertheless, the muscles on that side no longer contracted. The preoccupation here obviously consisted in the synapses leading every nervous HYSTERICAL SYMPTOMS 387 current which normally would reach those muscles, into a certain high nerve center whence it could further distribute itself in almost any motor direction rather than into the "paralyzed" muscles. That the congenital tendency of certain people to suffer from preoccupation of an abnormal character exists in their whole nervous system and is not merely a tendency con- fined to a part of the nervous system, is proved by other facts than the definite relation found between the special sensory-motor disturbance and the fortuitous life history of each patient. It is also proved by the transferability or transmutability of the symptom. It is often easy, thru some psychological process or other, to cause such or such a de- terminate symptom to disappear. Besides, the symptom often disappears of itself, in consequence of an emotion, of some surprise, or even without reason. But when a symp- tom has disappeared, especially when it has disappeared too quickly, another neurotic symptom often takes the place of the first. The patient is "cured" of vomiting and now suf- fers from delirium. He had a contracture in the neck, a stiff neck, and now has a contracture in one hand. A man had hysterical coughing and now has crises of sleep, sleeps a week or longer continuously. A man had a foot con- tractured and was cured thru a somewhat mysterious pro- cess which frightened him. He now can walk freely, but has lost his voice. When, after three months, his voice returns, he has stomach trouble and abdominal contractures. Another man had contractures of the trunk and now, being cured of the first trouble, no longer responds to anything acting on his eyes, — he is virtually blind. All this is comprehensible. There are several "preoc- cupations," but owing to the law of "deflection," which is effective in the neurotic as in the normal person, the nerv- ous current which happens to be strong, prevents the other 388 PSYCHOLOGY OF THE OTHER-ONE currents from reaching any considerable strength of flux and thus keeps the other "preoccupations" from developing for the present to any conspicuous height. Any preoc- cupation is anyway, as we pointed out, nothing constant, but is fluctuating in strength, in these abnormal as in normal cases. But as soon as any particular form of the patient's preoccupation goes down in strength, there is no longer that deflecting current, and another particular pre- occupation has a chance to develop to great height. But, when we say that this abnormal tendency for the terminal branches in a synapse to "stick" after having ex- tended, affects the whole nervous system of the neurotic T)atient, we do not after all mean exactly the whole nerv- ous system. There are undoubtedly differences between the lower and the higher centers. We have already pointed out, in speaking of normal preoccupation (absent-minded- ness, as we also called it), that it is not easily observed in those who do merely routine work consisting of reflex-like habits. At least, it never lasts in them more than a few seconds. For the very same reason as in those normal cases, in these neurotic cases where there is abnormal pre- occupation, the troublesome symptoms occur in the habit functions only, and with the most pronounced frequency in the very highest habit functions. The reflexes are vir- tually free from these troubles, and the more so, the more they have preserved their original character as reflexes, the less they have become dependent on higher nerve centers. Among the most extreme examples illustrating that the very highest centers are those where preoccupation most readily plays its role, are those where "abstractions" make up the main part of the nervous function. Invite the Other-One to do something, to raise a hand, to step for- ward, or anything much more complex, if you wish. If you succeed, by talking to him convincingly (which may HYSTEEICAL SYMPTOMS 389 or may not be easy), in stimulating in him the nervous function which, for want of a briefer name, we call the "abstract idea that this is necessary for his religious salva- tion," you will be surprised how quickly he carries out your request that he raise his hand. If, on the other hand, you convince him of the abstract idea "that there is no such thing as a hand," you will be surprized with what an ab- solutely negative smile he will refrain from raising his hand at your request, which then would be senseless. Every nervous process would be side-tracked, so to speak, away from the hand muscles. So it happens that a patient may be preoccupied with the abstraction "there is no such thing as whistling on my part." You then observe — and such cases are not rare — that your patient can eat, drink, speak, pout, spit, and what not, with his lips, but he can no longer whistle with them altho he used to do it formerly. Or, in a similar case, a patient, while lying in bed, can raise his legs, bend them, turn them, can push your hands back with his feet, can lift you up if you bear down with all your strength on his knees. But put him on his feet and ask him to stand or walk, — and he collapses. His legs are completely "para- lyzed." He is preoccupied with the abstraction "there is no such thing as walking on my part." Reflexes, however, are the less interfered with, the less they have become modified into habits. For example, the application of a little ice on the patient's fore-arm brings about the usual reflex response, the immediate contraction of all the vessels of the hand. This has never been modified into a habit. But the neurotic patient, altho perfectly friendly toward you and convinced of your best intentions and his own indebtedness to your kindness, may entirely fail to respond to your request to make a sign by words or motions as soon as you, having blind-folded him, place a 390 PSYCHOLOGY OF THE OTHER-ONE little ice on his fore-arm. He is there "anesthetic" so far as his habits are concerned, but not with reference to pure reflexes. Preoccupation, that is, the synaptic condition meant, does not easily occur in these pure reflex paths, in the lowest centers. Certain muscles, then, as well as certain sense organs still are in the service of the reflexes, while the same sense organs or muscles may no longer be in the service of many, most, or perhaps virtually all habits, because they have been enslaved by a few abstractions. For this reason further facts become clear which would otherwise surprise us. Neurotics of the kind under discussion do not suffer any deterioration of their muscles in consequence of paral- ysis. This deterioration is a serious matter in the case of paralysis caused by a lesion within the nervous system. The paralyzed muscles, never contracting, gradually shrink, are absorbed, and if the nervous lesion is cured after months or years, it little helps the patient who has lost the muscles needed. Most tragical are such occurrences in children having suffered from infantile paralysis, a disease which destroys whole bundles of neurons. The unfortunate pa- tients, still in their period of growth, thru the indirect con- sequences of the nervous lesion often become cripples for life. No shrinkage of the "paralyzed" muscles occurs in these neurotics. There is enough muscular contraction — tho too weak to be observed or not observed because occurring during the night — to prevent the deterioration of the mus- cles. The muscles are still in the service of the purer, little modified, reflexes. Anesthesia, too, in all sense organs, when due to a ner- vous lesion, has its serious indirect consequences. For ex- ample, if the limb of an animal is made anesthetic by cut- ting certain nerves, this limb, quite intact at first, can not HYSTERICAL SYMPTOMS 391 be preserved. It is not long in becoming covered with sores, and little by little the animal itself bites it off. There are patients who complain that their hands are constantly burned or wounded. They are not able to avoid injuries. They have a spinal lesion which makes them insensible to cold and heat. Where the "anesthesia" is merely a symp- tom of abnormal preoccupation, such indirect troubles are not likely to occur. The reflexes still protect the patients to a high degree. The difference between reflexes and habits — the function- ing of lower and higher centers — may lead to consequences very ridiculous or very tragical according to the circum- stances and the ability of those dealing with the patient to understand his case. Take the following example. A pa- tient is anesthetic (thru preoccupation) on one side and has normal sensibility on the other. We blind-fold him and pinch him on one side, and he tells us where we pinched him. We pinch him on the other side, and he does not tell us where we pinched him. But since his original re- flexes are not destroyed, we can build up a new habit, — and perhaps thru the medium of higher centers which happen to be little affected by the existing preoccupation. We re- quest him, we persuade him, to say "Yes" when he feels and to say "No" when he does not feel. This is a habit formation, but of the kind of "quick learning" which we call "willing." If the patient is a little simple minded, not intellectual, we succeed. The new habit happens to be free from the interference of the preoccupation ; and whenever we touch the "anesthetic" side, the patient says "No." The observer ignorant of psychology will then show little patience with that patient. "He is no patient at all," he will say, "he is an habitual liar or pretender. A person who tells us that he feels nothing when he is pinched on a cer- tain spot and yet says "No" in response to being pinched, 392 PSYCHOLOGY OF THE OTHEK-ONE while blind-folded, on that spot, is a person who lies to us." The non-psychologist does not understand that these are two different habits, of which one may well suffer from the preoccupation of the patient and the other not. Of course, in a person of high intellect the whole experiment is not likely to succeed, or is likely to succeed only a short time, since the new habit will quickly fuse with the old habit. The intellectual person "will see the nonsense of the request." But what succeeds in others, may succeed in him if the conditions become more complex. All thru the history of medicine the accusation goes that hystericals are habitual liars. An hysterical person may be a liar just as a non-hysterical person may be a liar. But he should not be regarded as a liar because he is hysterical and ought not to suffer the moral contempt of others on account of being ill. Tragical illustrations belonging to the same category are plentiful in the application of the criminal law, if one studies the history of the criminal law from this point of view. The case of insufficient condensation previously discussed in the case of discrimination on the skin can be referred to here. We would object if someone would call us a liar because we say that what he placed on our skin "feels like one point and yet feels like two," as subjects not infre- quently are heard to say in such an experiment. We have pointed out in a previous chapter certain other laboratory experiments in which we tend to react unreason- ably. In stereoscopic vision we may say, "I see two pencils and I also see that the pencil is farther than the finger." We would object if someone would tell us: "You are a liar, for seeing the greater distance of the pencil is a sub- stitute for seeing it double. You can not see the replacing thing and the replaced thing at the same time." HYSTERICAL SYMPTOMS 393 In the same previous chapter we mentioned one further reason (among innumerable actual reasons) why hysterical patients are exposed to being wrongly regarded as insin- cere. In that former case the trouble was due to failure of the eyes to move as incessantly as they normally do. Such failure may result from drugs. The "double vision" of the alcohol intoxicated person is proverbial. But stiffness of limbs or organs, "contractures," have been mentioned as common symptoms of the neurosis of preoccupation. If the eyes are motionless from the latter cause, such troubles as those just mentioned become a reality. Another result of lack of motion of the eyes deserves to be mentioned in this connection. The somnambulistic, hysterical, patient often tells us that he sees people surrounded by an "aura" or that he sees ghosts. We can see the aura too if we stare at a person long enough ; but it is difficult for a normal person to do that. These are nothing but unintended and uncomprehended experiments, made by ignorant people, in simultaneous and successive visual induction.. We owe it to Janet more than to anyone else to have made it clear that the state of hypnosis is nothing but a state of abnormal preoccupation like those described above, only artificially and intentionally produced instead of re- sulting from an accident in life. As is to be expected, peo- ple differ greatly in the ease with which they can be hypnotized. Some have a nervous system whose synapses greatly predispose the owner to becoming preoccupied with affairs of little intellectual significance. We then call them hypnotized or hysterical. If their affair is a highly intel- lectual one (think of the "absent-minded professor") and the preoccupation results from intense normal work and not from a congenitally abnormal nervous system, we do not call them cither hypnotized or hysterical. But the cases are essentially the same. 394 PSYCHOLOGY OF THE OTHEK-ONE The physician Robert Mayer, famous in the history of science, ran into a friend's house without knocking at the door, exclaimed "It is true, it is true," and would not listen to an}i:hing for a long time. His friend thought that Mayer had gone insane ; he had entirely forgotten that many weeks before they had discussed the question whether water in a bottle could be warmed by merely shaking the bottle, and that he himself had rejected that idea as absurd. But Mayer continued to be occupied by that same question. Any change in the Other-One's habits may be called a change in the Other-One's personality. The reaction after every process of willing or learning is a symptom of a change in his personality. Where the change of habit is profound and abnormal, we speak of a disturbance of the personality ; even of the splitting of a personality in those cases where the change periodically recurs. But there is no essential difference between the most astonishing splitting of a personality and the simplest hypnotic or somnambulistic performance. And in the description of all these cases such terms as the "division of a soul" into parts, a "conscious," a "subsconscious," a "coconscious," etc., one, are better avoided. That such terms are so popular, is, of course, due to the fact that even those people are able to use them glibly in their speech who have never devoted time and energy to a serious study of those problems of human be- havior which fall within the province of the natural sci- ences. Abnormal nervous functions of any kind interest us in an introductory text-book of psychology only in so far as they illustrate the normal anatomical and physiological properties of the nervous system. That property of the sy- napse which leads to preoccupation has already been illus- trated by abnormalities. The other normal anatomical and physiological properties of the nervous system are not so ABNORMALITIES OF THE NERVOUS SYSTEM 305 strikingly illustrated by abnormalities and there is, therefore, less reason for discussing the other abnormalities. It is worth while, nevertheless, to enumerate again all the vari- ous anatomical and physiological properties of the nervous system which form the basis of the systematic description in this book of the Other-One's life activities, and to point out what abnormalities may result from them in conse- quence of bad heredity or of pathological conditions aris- ing during life. It is not to be expected that a being born with an ana- tomical deficiency of reflex paths would live long. That anatomical possibility, therefore, need not concern us psy- chologists much. But a human being may be born with a deficiency in its possible equipment with higher centers and continue to live. Indeed, we are, perhaps, all born with such a deficiency. The result may be either the one or the other or both of the two abnormalities mentioned present- ly, which are so common that we simply call them indi- vidual differences. Higher centers have a great importance for the concerted- ness of the functioning of certain reflexes. We gave these concerted reflexes the name of instincts. A congenital de- ficiency in a person's equipment with higher centers in a certain region of the brain might thus be regarded as the cause of a weakness of certain instincts which in other in- dividuals may be strong. But let us remember that the con- certedness of most human actions is not congenital at all, but acquired during life. We remember, secondly, that in order to acquire a par- ticular habit, we must first of all have that particular "long path." In the reduction of the resistance of that path con- sists the formation of that habit. Now. we know that one person acquires easily only these habits, another person easily only those habits. The chief source of the individual 396 PSYCHOLOGY OF THE OTHER-ONE difference is undoubtedly the congenital anatomical differ- ence. If the Other-One's nerve centers in those regions in which the reflexes in question have their paths, are only poorly equipped with long paths, then those particular re- flexes can be modified into habits only with difficulty, that is, thru mediation of long paths too long in the first in- stance. That must be one of the chief causes of individual differences. The person who is born with a general deficiency in his equipment with higher centers, the microcephalic person, for example, who has very little brain substance, is a born idiot. But we are all of us in a relative sense born idiots. There are sensory-motor functions which we can not easily acquire in perfection, tho we see some others succeed in them. Very important for acquiring and retaining habits is the degree of the positive and of the negative susceptibility of the neurons. There are undoubtedly great congenital dif- ferences in this respect between individuals. Some per- sons learn everything that they learn at all, very quickly. Others learn slowly, needing more repetitions. But one must not think in connection with the speed of learning that, whenever a person learns something slowly, the sus- ceptibility of his neurons is small. He may learn slowly because he "understands" slowly, because he lacks a good anatomical equipment of certain higher centers especially implicated and has to rely on very indirect "long" (too long) paths. The greatest difficulty in interpreting the re- sults of experiments in human or animal behavior results from the fact that they rarely are based (perhaps rarely can be based) on a preliminary analysis of the nervous functions involved. It is clear that an observed speed of learning, for example, may be the outward sign of any one or more of several properties of the nervous system. ABNORMALITIES OF THE NERVOUS SYSTEM 397 We saw that deflection is a very important nervous func- tion. But it does not seem plausible that deflection as such, in general, can be stronger in one individual than in an- other. Indirectly, thru anatomical causes, deflection among particular nervous currents may be weak in a particular person, because there can be no deflection without a certain "contact" or relatively close, not too indirect, connection of the paths of the current to be deflected and the deflecting current. With respect to shortening a long path after its resist- ance has been reduced, there is a possibility of congenital individual dift'erences. Unless the individual has undevel- oped neurons existing in the region where a short-circuit- ing might occur, no shortening of the path is possible. We were discussing disturbances of the personality and now return briefly to that problem. We must ask, now, what influences occurring during life might change a per- son in the same or a similar way as a different constitu- tional inheritance would have made him a dift"erent person. With reference to the synapse, it seems that great nervous fatigue and also certain drugs aggravate a natural predis- position for abnormal preoccupation. Hysterical symptoms and a changed personality often make their first appearance after exhaustion or intoxication. Anatomical interferences are easily understood. A wound, say, the passing of a bullet thru the head, or an inflamma- tory disease, or a breaking down of some (not necessarily all or most) cells thru age, may completely destroy cer- tain nervous paths. The effect is, of course, then of the same kind as if it were an inborn anatomical deficiency. An individual may not be originally, but may become at a certain time in his life, idiotic, demented, in a more or less relative sense. If we can still notice that he formerly ac- quired an "intellect," but that that acquisition no longer 398 PSYCHOLOGY OF THE OTHER-ONE functions properly, it is customary to say that lie has "paranoia," tb.at '"his reason goes astray." On the other hand, an inflammatory disease, or natural old age decay, or a poison created somewhere in a diseased part of the body and carried by the blood thru the nervous system, or a drug taken into the body and acting on the nervous system, may not destroy the substance of the neurons, but may alter them so that they may gain or lose, permanently or temporarily, in conductivity ; or so that they lose all or much of their susceptibility, or, maybe, have more of it. Particular disturbances of the personality of the individual must result. Tl.e change in conductivity must make certain reactions uncommonly frequent and strong, or uncommonly rare and weak. This may occur alternately, as in manic-depressive insanity. The change in susceptibility must make the individual quicker or slower in "learning" and "vv-illing." Epilepsy, which in its extreme form shows itself in con- vulsions, may be an abnormal general conductivity of the nervous tissue, breaking forth momentarily and subsiding again quickly. Instead of this or that muscle contracting, all contract in an extreme degree for the time being. Disturbances of personality interest us especially as illus- trating normal nervous properties and functions. But they can themselves be understood only if one has a clear idea of the normal function of the nervous system in the whole living body. Otherwise abnormal psychology is a mere col- lection of curiosities. CHAPTER XIX The Psychology of the Other-One and the Sciences Other than Psychology. Science is one, intrinsically undividable, whole. That is, all divisions of it are arbitrary, fortuitous, due to the limi- tations of one person's energy and interest. The man of science who is asked to define a particular science and justify its separation, never feels satisfied with his own answer. When a university man and a man engaged in a trade or business who perhaps has never attended the high school happen to get acquainted on the street, in a store, in a rail- road car or a similar place, the question is usually asked : "What do you teach?" And after the teacher has answered it, the next, almost inevitable, question is : "What is that ?" And then we have to give an answer which we really dis- approve of and even feel ashamed of because we know that it is unclear. But we give it nevertheless because we know that a clear answer would be a whole college course ; and evading the answer altogether would seem discour- teous. So we speak out. "All about the earth," says the geologist. "All about sound and light and electricity," says the physicist. "All about animals and plants," the biologist. "All about the soul," the psychologist. What else could he say in that situation ? What troubles the psychologist in giving the answer is this, that he is really in no more special manner interested in the soul than other people who are not psychologists. (399) 400 PSYCHOLOGY OF THE OTHER-ONE But what can he do when he has to give a brief answer? It does not help him if, instead of "All about the soul" he says : "I teach all about the mind." The majority of modern progressive psychologists would deny that as psychologists they are particularly interested in the mind, in mentality, in consciousness, or whatever synonym of "soul" you choose. That period in the history of psychology, when those terms stood in the center of discussion, is passing away, never to return. In recent years men have lamented (using an expression which sounds like a joke, but is meant as a serious com- plaint) that psychology has "lost its mind." Just as a fu- neral oration is fair testimony that the man in whose honor it is spoken is dead, so this complaint is fair testimony that psychologists are no longer concerned, chiefly, with the mind. It is a curious fact that what is nowadays technically called psychological, would appear often in the language of a hundred years ago the very opposite, the unpsycholog- ical. Inasmuch as we all, even the professional psychol- ogists themselves, still live in the general literary atmos- phere of our ancestors of a hundred, and even hundreds, of years ago, a discussion of the fact stated in the preceding sentence is desirable. The old, and still popularly accepted, meaning of the word "psychological" is de<-ived from the literal meaning of the Greek word "psyche," that is, soul. Unless you can or will mention a soul, you would then not consider the matter as "psychological." Out of such general questions arise in many instances specialized questions which thru- out the history of mankind have puzzled the lawyers and the legislators, and naturally even more the theologians, — such questions as this, whether the unborn child has a soul, or wheLhcr the ■"infant," tlic net }c't speaking, child has a HISTORY AND PSYCHOLOGY 401 soul. Think, for example, of the untold misery that has been brought over countless human beings by answering in the one rather than in the other way the question, whether the mother drowning her newborn baby has committed mur- der of another soul or a partial suicide of her own soul or neither. Or the question whether the unbaptized soul of the infant goes to hell, an impossibility in case the infant has no soul yet. We are beginning to think more and more lightly of questions like these, which were a heavy burden to the conscience of our ancestors. How has this change come about, in popular thinking, and even more pronounced- ly in the thought of men of science ? History is one of the social sciences. To the naive thinker, however, history is the science which records the deeds of individual great men. History is then chiefly a record of the deeds of heroes, of prophets, of kings. Remove Achilles, Agamemnon, and the other names of heroes from the IHad. What would be left ? Remove the name of Christ from the history of the Church. What would be left? To the naive thinker history is the product of the whirling processes going on in the individual great soul. Human society is both the clay which is being moulded by such a soul and the tool by means of which the particles of that clay are pushed forward by that great soul. The only really interesting thing is the great soul that does it. It used to be customary to refer to the view opposing this naive one by the curious phrase of a materialistic view of history. This, however, is only an example of what we find to be generally true : the modern psychological view in every one of its applications has had to submit to being branded, sometimes by friends, sometimes by foes, as the materialistic, that is, seemingly, the entirely unpsychological view of humanity. There are many reasons for this mis- branding. 402 PSYCHOLOGY OF THE OTHER-ONE For example, it was concluded that the world, if it was not controlled by souls, must be controlled by the stomach and sex organs, by hunger and love, as Goethe said in a little poem, and that the complete development of this principle would lead to the glorification of riotous living and self-indulgence. As a matter of fact, the materialistic view of history is, or should be, something very different. It simply regards history as the mutual reaction of groups of organisms, — organisms which are equipped by Nature, not only with digesting and propagating functions, but with equally fundamental altruistic functions. These latter func- tions — call them reflexes, instincts, or what not — establish the very grouping of the organisms. Human societies can thus be understood as originating from natural laws, — not in the sense of groups of souls tho, but in the sense of groups of organisms. Accepting this view, we readily understand why the trend of history is in the direction of democracy. Let souls (of which we never experience any but our own) be as different in degree and kind as a despotic mon- arch is apt to imagine them to be. Human organisms — that we know by experience and therefore cannot imagine other- wise — have more likenesses than differences. The proof is easy. Fill a museum of human life with the specimens of the human race that are for all practical purposes alike. You cannot do it. No museum would be large enough. But you can place in a museum, for comparison, a Darwin and an idiot, or a man seven feet tall and a negrito four feet tall. It is the differences which we exhibit in museums because the differences are rare. In real world-wide human life the differences among individuals are entirely swamped by their likenesses. To him who accepts the scientific view that human society is a group of organisms, it is an absurd proposition to divide even as small a group as, say, a hun- dred into only two classes, placing ninety-nine in the one CRIMINOLOGY AND PSYCHOLOGY 403 the subjected class, and a single member in the other, the governing class. No considerable number of individual organisms can ever live depending on the accidents of the life of one. With souls that may be different; but in science souls no longer play their former role. We spoke of history. Let us speak of other social sciences. Modern criminology would never have come into existence if our psychological thinking had not passed from its former stage, during which mankind's very proper in- terest in Man was mainly an interest in his soul, to the modern stage where our psychological interest turns to the functioning of man as an organism. The old-fashioned idea of a crime is that of an interference with one soul's independence by another soul. The proper punishment then consists in pushing the latter soul as far to starboard as it arbitrarily pushed the former to larboard. Thus the balance of the spiritual world would have been re-establish- ed. That it was the only purpose of punishment to set the world right again in this almost mathematically exact manner by spiritual mechanics, the writer was taught in his student days by a professor of philosophy who called him- self proudly the last Hegelian. Modern criminology, how- ever, adopting the modern psychological way of thinking of man as an organism, not as a soul, regards a crime as a case of poor adjustment of one organism to the others and also — not less — of the other organisms to the one, and punish- ment as one of the means of improving this biological ad- justment. All the social sciences will have to take the same road. Economics has one foot already on it, but it seems to have the other foot still on the old road forming an endless circle which leads nowhere. We still see too much interest shown among economists in speculative discussions of subjective terms, such as "value," which in no way contribute to the 404 PSYCHOLOGY OF THE OTHER-ONE real problem of finding how human organisms produce, ac- cumulate, and distribute things which help to strengthen the functions of these organisms. \J Sociology, that is, the mass of knowledge of a social kind to which we apply the term "sociology" in the restricted sense, perhaps has had unusually good luck. Coming into existence rather late, let us say during the last fifty years, it seems always to have had the advantage of the pressure resulting from the immediate social needs of mankind. Sociologists, that is. have always felt so strongly the need of social reform, the need of betterment of the lives of the very organisms with whom they rubbed shoulders in the crowd on the street, that they did not find much time for talk about souls. Nevertheless there are sociological books whose very chapter headings make one shudder, so far re- moved are they from the warmth of life, — such headings as "Intuitive Perception," "Intuitive Reason," or "Female Intuition." That is Hegel revived. A further social science is the science of religion, or, as it is often called, the psychology of religion. Who doubts that religion is one of the strongest forces in society? And yet, for thousands of years the intellectual interest of men, of students, has been restricted to the unsocial, artificial problems of religion, the questions as to the interrelation of souls, — for example, the question how one soul may contribute to the eternal salvation or eternal damnation of other souls, briefly speaking, to theology, which is not a social, but a purely individualistic affair, one intellectual game among the many which fill the history of philosophy. The modern psychological way of thinking has brought us back to the solid ground of appreciating religion as a social phenomenon, exemplified by Christ going among his fellow men, an organism among organisms, and comfort- ing and encouraging those whose burdens in society were RELIGION AND PSYCHOLOGY 405 heaviest, making it easier for them to carry the burden when its removal under the existing conditions was impossible. It is easy enough, then, to answer the question what use the social sciences have for psychology. They simply are psychology in the modern sense of the word ; and on the other hand, psychology is social science. We psychologists must often hear the (unjustified) re- proach that ovir psychology is nothing but physiology or neurology or some similar "unpsychological," materialistic science, against which you would better protect the un- suspecting, pure soul of the college freshman. But we psychologists have no difficulty in distinguishing our in- terests from those of other biological departments. We study the organism as an organism, it is true, but only in so far as its functions have distinctly social significance. We do not study the stomach, because its function is an in- dividualistic affair with which society is not directly con- cerned. It is the physiologist's business. We do not study the breakdown of nerve cells under the influence of exces- sive athletic training. That is an individualistic affair, the business of the medical man. But we are concerned with the possibilities of developing habits and with the limita- tions, if there are any, which Nature may have placed upon the development of habits. We are convinced that habits are the mysterious entities so much and so vaguely talked about under the name of social forces. A hundred years ago Johannes Mueller, the father of modern physiology, made the famous remark : Nemo psy- chologus nisi physiologus." That was a valuable statement at his time when psychology was still mixed up with spec- ulative philosophy and very little psychology in the modern sense existed. Today a still more valuable statement would be this: "Nemo psychologus nisi sociologus." 406 PSYCHOLOGY OF THE OTHER-ONE The psychologist, however up-to-date, is not a material- ist. He does not deny the existence of the soul. He may deny, however, that it is his business to waste his time in trying to make the soul an object of scientific inquiry. We do not deny the soul ; but we do not devote our time to it. We find enough, and more than enough, to do studying the body. For instance, when we study memory, we do not study the soul. We find out, for example, how many times the speech organs have to pronounce a series of words placed before the eye until they will pronounce the whole series correctly with only the first word appearing before the eye. That is a study of the organic functioning of the body. It is unfortunate that no human being can be always safe and sane in his ways of thinking. Even if I could master all the scientific achievements of the day, which obviously one individual can not, these scientific achievements them- selves are only a small part of that complete understanding of the world which a divine being would possess. Owing to the individual and general limitation of scientific knowl- edge, moments arise in everyone's life, less frequently in one's, more frequently in another's, when no amount of ra- tional thought, but faith in the destiny of this world, relig- ious faith alone can give him comfort. Religion is needed, then and therefore. But remember, it is extra-scientific. Now you will perhaps ask: If psychology is not the science of the soul, but one of the many sciences of material bodies, will it always be possible to define it so that I can distinguish it from the other sciences ? The answer is simple. Don't distinguish it. Don't define it. You don't have to define it any more than you have to define physics. That is physics in which those are interested who are called physicists by consensus of opinion. For the purposes of mankind that is not only a sufficient, but a better definition DEFINITION OF PSYCHOLOGY 407 than any more detailed one you might substitute. We have hinted, in the first chapter and in this chapter, at a defini- tion of psychology in terms describing its subject matter. But really the best definition, the one that serves human society best, is this : Psychology is that in which psychologists are interested as men of science. This definition has also this great advantage for the psy- chologist that now the other sciences can no longer unload their unsolved problems on psychology by shrugging their shoulders, so to speak, and saying : Here is a problem whose solution concerns us, — concerns us more than anyone else. But it seems to be a problem of the soul, therefore we must wait until the psychologists solve it. You see how hopeless the case then would be. If it is a problem of the soul, then it is no scientific problem at all and the psychologist will never pay any attention to it. But if it is an objective problem, a real problem, then it is a problem of that science which is directly concerned with it. If the lawyer has a problem, and if no one else cares for it enough to attempt its solution, then it is a lawyer's prob- lem, a problem of jurisprudence ; and it is primarily the lawyer's business to solve it. Don't be lazy and call it a psychological problem. If the engineer has a problem, say, whether the man in the locomotive cab should wear overalls or an apron, don't be lazy and call it a psychological problem. If no psychol- ogist and nobody else can be made to take an interest in the question but you, then it is a problem in engineering. If the economist has a problem, say, why people want to buy things that they have no use for, don't say: "Excuse me, this is psychology. It is a problem of the soul. It is mysterious. We can't solve it. We are waiting for the psychologists." If it is your problem because you seem to 408 PSYCHOLOGY OF THE OTHEE-ONE be primarily interested in it, then it is a problem of eco- nomics. Go ahead and solve it. One must not think that this gives an unfair advantage to the psychologists, relieving them from practically all re- sponsibility for the welfare of the world. Not so. We psychologists have similar troubles. We are often inclined to think, this is a problem in physics, this is a problem in chemistry, this is a problem in neurology, and so forth, and to wait until the physicists, the chemists, the neurologists have solved it. But it won't do. Those men take but little interest in our problems. You can't expect them to take more. So we have to do what everyone has to do, to solve our own problems ourselves. You do not wonder, then, altho you perhaps wondered before, why the modern psychologist needs so much equip- ment of apparatus, machinery, tools. Maybe you thought that a psychological laboratory ought to look like a saint's chapel or like the interior of the Egyptian temple which you saw on the operatic stage, in the Magic Flute. Such places seem to be well suited to an investigation of souls. But that is not our task. CHAPTER XX The Mysteries of the Soul. Ask a college freshman on his registration day what he thinks his psychology teacher ought to teach him. The answer is likely to be "How to hypnotize people." Now, this is not mentioned in order to convey the idea that a psychologist is not concerned with hypnotism. We are. But this subject is so trite, and the task of hypnotizing a person is ordinarily so devoid of the satisfaction which comes from performing a task both difficult and useful (neither of which can usually be said of hypnotizing) that the psychologist feels no more enthusiasm about it than a kitchen chef would feel when given the task of boiling the potatoes for a banquet. But with the layman it is a different story. It is thrilling. Why is there this great interest in hypnotism among the lay population? Because to them it is not a mere material event, as easily reproduced by anybody as any simple event, as sawing a branch from a tree, for example, but a demon- stration of the powers of the soul. Like everything con- cerning the soul it is mysterious. And like everything mys- terious it is thrillingly interesting. Hypnotism is a relation between two human beings, two human bodies, two organisms. It is therefore a relation essentially the same as that of teacher and pupil, for ex- ample; or that of traffic policeman and driver; or that of a politician and his constituents ; or that of the governor of a state and the people of the state ; or that of an army officer and a soldier; or that of a priest and a confessing (409) 410 PSYCHOLOGY OF THE OTHER-ONE sinner ; or the relation between two sinners, or between two private soldiers, or that between one citizen and another one living next door. When we here enumerate these dry ex- amples chosen at random from the multitude of human re- lations, they may at the first moment seem to be unsuited to our discussion, to involve nothing of the kind of a problem of souls. But with the least amount of reflection you will convince yourself that, except very recently, all these have always been treated, in the history of mankind, as problems of the interrelation of souls. And as problems of souls they have been mysterious problems, open to attack, not by the methods of science, but only by the methods of magic. The most extreme case is that of religion. Let us there- fore courageously subject it first to our scrutiny. Religion is to the individual who has it (and we all have religion, altho perhaps under different and curious names and at different times and periods of our lives different quantities of it) — religion is the great problem, the great mystery of oi:r soul. How to procure satisfaction, salvation for our soul under the tribulations of life, that is the question. Does mankind draw the consequences from the fact that we know thru our senses no soul whatsoever, and that the only soul which we experience in our immediate consciousness is the own soul? If we drew the proper consequences, we would be — that is, mankind would always have been — per- fectly tolerant in matters of religion. The reverse is true. Thruout history we find religion being spread by fire and sword, by torture and death. By these methods people be- lieved themselves able to save, not only their own souls, but also thousands and millions of other souls. Innumerable human lives were sacrificed in order that their souls be saved. Now assume, for comparison, the attitude of the modern p.'^ychologist. He will make no attempt at proving to you MYSTEEIOUS PROBLEMS 411 that you have no soul. Your soul and the question of its existence are your own business. Because your soul is your own business, can never be any other's experience or business, and must therefore be forever mysterious, forever closed to the inductive methods of science, closed to the infinitely repeatable sensory-motor test of scientific pro- cedure, therefore the psychologist minds his own business and leaves your soul alone. Your religion is to him a set of peculiar reactions of your body, consisting in the writing and speaking of particular words and the performance of particular observances, such as going to church. The psychologist is much interested in these actions of your body. He tries to find out to what extent they are inherited, to what extent they are habits acquired during life, what forces, physical or social, contribute to the for- mation of these habits, what help your body can derive from these inherited and acquired functions in its struggle for existence. And then he will give you his advice. You need not accept his advice. He will hardly urge you to accept it. for he knows how little he knows this complex machinery called the human body and its functions. As to forcing you by torture or death to accept his advice, the idea is ridiculous to him who knows how little he knows. The psychologist, altho he may have written a big volume on the psychology- of religion, can not help being tolerant. He has as much doubt as he has knowledge. It is the man who is interested in souls who is intolerant. Not having, since no one can have it (as we stated), scientific knowledge of other people's souls, he has no scientific doubts about their souls either, but regards them dogmatically as recasts of his own soul and acts according- ly. Is not that exactly what we call intolerance, when we expect everything to be like our own? He whose interest is centered in souls thinks, when he has forced others to speak 412 PSYCHOLOGY OF THE OTHER-ONE his prayer, pronounce his creed, kneel before his altar, that he has saved their souls, and fails to admit that he has merely forced their bodies, — without in the least trying to investigate the purpose, the end of his intolerant acts so far as the welfare of these bodies is concerned. Religion is one of the poles of the axis around which our intolerance swings in its mysterious whirl. Government is the other. Nsiive thinkers have sometimes concluded that the easiest way of freeing the world from intolerance would be the abolition of both religion and government. Those who boast of being atheists, usually also boast of being anarchists. A certain phase in the French revolution comes to our mind as a typical example. If you still are in this naive stage of thought which often accompanies the enthusiasm of youth trying to reform the world quickly, we shall not take you seriously because we are convinced that you will sooner or later pass over that stage. What we must point out is that political terrorism, too, has its main and inexhaustible source in the human tendency to think of other human beings, not as bodies open to scientific in- vestigation, but as souls, as mysterious beings, to be govern- ed either by magic or, if magic fails as it naturally must, by torture and death. In all the history of mankind it has always been regarded as the crime of all crimes to be against the de facto govern- ment, to be a rebel, to try to change the government by sub- stituting for those persons who have the power, some other persons. If those who govern would be regarded and re- gard themselves merely as the servants of the people, why should it be a crime to change servants? We do it here in the United States every few years. But what is the divine right of kings if it is not the assertion of a mysterious soul given to the king by God, quite different from the souls MYSTERIOUS PROBLEMS 413 of subjects, but whose difference is quite beyond the pos- sibility of scientific investigation. Where the divine right is still quite unchallenged by the critical spirit of science, as among half civilized people, the king is expected to perform magic feats (in France until the eighteenth century). Why not, — if his soul is of a superior kind? One of the Prussian kings, even in the nine- teenth century, made himself famous by speaking of "the limitations of judgment characteristic of mere subjects." Among more highly civilized people, where recognition of the fact that the body of the king (or say President, it makes no difference) is a very common human body inter- feres with regarding the soul as superior, an impersonal soul is often substituted and worshipped. It is the "state" or the "nation" or the "country" or the "honor of the flag," as we say, that plays the same role. Not the state in the sense of the totality of the human beings living within a certain territory in the year — choose your own. That would be a truly scientific conception in the investigation of which the psychologist would be glad to share. But the state in the sense of a soul-like reality, unknowable thru our senses, but which we must worship with out bodies as the subjects of a king worship their king. In the story of William Tell it is said that the Governor whom the Emperor had sent to Switzerland invented a good method of making the Swiss submissive. He had a pole erected on the market place of one of the towns and his hat placed on top of the pole. When the Swiss people walked by, they had to take off their hats and bow. What were they to worship? The body of that piece of felt crowning the pole? Of course not, but its soul, the imperial idea. You see that even a piece of felt may have a soul. The story ap- pears fanciful to us. It probably is fancy, a mere legend. 414 PSYCHOLOGY OF THE OTHER-ONE Make sure, however, that we do not do the same today, only under another name. If we get into patriotic hysterics, the professional poli- tician can subject us the more easily. In poetry one can not object to talk of the soul of a nation, or of such synonyms as the "honor" of a nation, which to some is as convenient a substitute for soul as it used to be to the duellists of former centuries who had to fight whenever their "honor" was hurt. Religion and poetry (or art in general) are the two forms of human activity which have a right to be unscientific — or rather extrascientific — so long as they are not antagonistic to scientific, objective social progress. But let this talk of the soul, the honor, the Kultur, the destiny of a nation and its needs get beyond the playful use in poetry, let it get into international diplomacy, let it begin to determine your ac- tions towards other beings, and your actions will be as atrocious as those for which the world war has given us plentiful examples. If nations could be made to see that all nations are con- gregations of organisms of the same species, and that what each calls its soul, its honor, its civilization, its tradition (the particular one of these terms used makes no difference) is only a set of organic habits on the whole neither better nor worse than the habits of another group, peace would reign on earth as it has come to reign in our smaller com- munities. Let us recapitulate what we have said thus far. In re- ligion and in politics the worst intolerance, the most in- human atrocity is found correlated with the most one-sided preference of spiritual, subjective, idealistic terminology. Can you blame the psychologist when he, who regards the study of human life as his particular sphere of interest, confesses to you that he prefers to think of a human being MYSTERIOUS PROBLEMS 415 as a bodily organism rather than as a soul, of a nation as a society of such organisms rather than as a collective soul? From our earliest youth, almost from infancy, we become saturated with habits of denoting human beings as souls, and thus we are led into the alleys of the maze of mystery from which few find their way out into the light of modern, rational, scientific thought, and from which many, very many, it is to be feared, never even see a dim and distant reflection of such light. When you ask a person who manifests any considerable interest in psychology what it is that he is specially inter- ested in, he usually replies that it is hypnotism, or thought transference, or mind reading, or fortune telling, or char- acter reading. If this were not the twentieth century, but the eighteenth, we could have added sorcery, magic, en- chantment. These and similar mixtures of fact and fable are the mysteries of the soul. To hypnotize a person, it is necessary, according to the popular notion, to obtain first a peculiar property of the soul, a kind of spiritual magnetism that can at a distance act on another soul, can reproduce itself in another soul as magnetism can reproduce itself in another piece of iron, and which one may obtain therefore from another person who already has it, if that person is willing to give. No doubt that not a few college students are either entirely or at least partially driven by such notions and the motives connected therewith when they enroll in a course in psychology. Some people who offer themselves to play the ridiculous role of being hypnotized, do so from this kind of curiosity, because they wonder how it feels when that magnetism goes thru one. They are not to be blamed at all. If we grow up under conditions implanting such notions in us, it is entirely proper and an indication of a perfectly normal and desirable curiosity and ambition, to learn about and, if possible, ob- 416 PSYCHOLOGY OF THE OTHEK-ONE tain such a wonderful power. On the other hand, it is easy to read the disappointment in their faces when they learn that everybody can hypnotize just as everybody can kindle a fire, can give an Indian whisky to drink, or can rock a baby to sleep. Why call it mysterious? The following happened at a time when mysterious phenomena were most commonly referred to under the term "animal magnetism", when — in a certain European country — telegraph wires were already found along many of the important highways, but when railway lines were still very rare. The manager of an "animal magnetism show" traveled with his "medium" in a coach from one city to another. Unfortunately, when they arrived, they could not give the performance on the promised date because the medium had become sick. The manager explained the sickness very readily. No wonder she got sick : She, that is, this "lump of animal magnetism," had been com- pelled to "move for miles and miles parallel and in close proximity to an electric wire," that is, the telegraph wire. Many of our contemporaries who laugh at the foolishness of this explanation would probably be quite willing to ac- cept equally foolish explanations of facts if they are only clad in terms which have the character of mysteriousness in the way in which the populace of today is accustomed to think. Is there anything mysterious in a mother's rocking or singing a baby to sleep? It is just as difficult to rock a baby to sleep as to hypnotize a person. Nevertheless, no mother has ever claimed, and no other person has ever admitted, that she had a mysterious power over the baby's soul. The baby is placed in a comfortable position, the light is dimmed and all other avoidable stimuli are kept away. The subject to be hypnotized is treated in the same manner. The baby is rocked. Bodies to be hypnotized, however, are usually MYSTERIOUS PROBLEMS 417 too large and heavy to be rocked easily, since the hypnotizer is not a giant. Therefore the latter substitutes for the rock- ing talking. Speak to a person under such conditions as persuasively as you can about nothing but sleep and dreams, and he finally assumes the sleeping posture as far as it is possible in the given situation and becomes preoccupied with maintaining this posture. If you have any experience in it, you know that, when you rock a baby to sleep, the most risky part of the per- formance is the moment when you stop rocking. The ces- sation of rocking requires a new adjustment of the baby's body and is therefore of the nature of a new stimulus. To this stimulus, the cessation of rocking, the baby is likely to respond by throwing about its arms and legs, by crying, and by similar activities which we familiarly call waking up. What is to be emphasized, however, is not this waking up as such. If we must regard the cessation of rocking as a stimulus to which the baby's body responds by a new ad- justment, it is clear that before the new and changed ad- justment there was another adjustment. That is, the baby's body, asleep as we say, is nevertheless keeping adjusted, is in this way positively responding to the rocking, altho asleep. That is one of the false notions most people have, that sleep is the opposite of every class of activity. The sleeping body is not absolutely inactive. It is one-sidedly active. It is pre-occupied. Now substitute for the baby the hypnotized subject. Talking takes the place of rocking. It is plain, then, that the hypnotized body, too, is still positively adjusting him- self to, reacting to, the hypnotizer's talking, — altho already asleep. Now the hypnotizer begins to change the content of his talk. Instead of talking about sleep and dreams, he begins to talk about raising an arm. opening the mouth, and similar reactions of the nature of visible motion. But re- 4:18 PSYCHOLOGY OF THE OTHER-ONE member, the hypnotizer is one of those stimuH with whom the subject to be hypnotized is already preoccupied. It is not mysterious, then, that these motions are executed. If I stand before an audience, raise my finger, look at it myself and say in a loud voice "Look at this finger," every one looks at it. There is no mystery in that. It is no more mysterious when a hypnotized person obeys an imperative demand and bites into a raw potato, smacks his lips, tells you that it is a delicious apple. If a clerk in the grocery store or a professional entertainer in the circus acts in that way, you call him silly, a fool, or a clown. Why, — be con- sistent and call the hypnotic performance by the correspond- ing name. It fully deserves it. The only difference is this, that the clown is the actor who supplies the ridiculous element of the case, whereas in the hypnotic performance you, the spectator, little as you may suspect it, supply the ridiculous element. The pre- occupied person can not be expected to act rationally while he is preoccupied, but you, the spectator, might have better sense than to apply the notion of a soul acting thru the medium of a spiritual magnetism, when all that happened before your eyes was the social relation, the most familiar fact in the world, between two bodily organisms. Think of two organisms, and the whole performance loses its mys- tery, becomes trivial. Think of two souls, and it is myste- rious. But what is truly mysterious is the fact that you, a usually rational spectator, should apply this silly notion of a magnetism of souls. The popular craving for hypnotism and whatever is connected with it becomes comprehensible when we recall that it is a craving for power, — for power over other souls, power to compel them to do what we want them to do. And people long for still another power over souls which consists in knowing them, in knowing their thoughts and MYSTERIOUS PROBLEMS 419 feelings, in knowing their character, in order to adjust themselves to such knowledge. If we could all realize that knowing another person can mean only knowing his organic habits, we would go about obtaining it in the proper way, by gradually accumulating experience, tho this process must be slow. But we think falsely that knowing another person means knowing his soul and crave for a short cut by mysterious means. In practice, the requirement of know- ing another soul has played its greatest or rather its most disastrous role in criminal procedure. Criminal procedure until most recent times has always had for its aim the restoration of the spiritual balance of the world by meting out punishment in proportion to the quantity of evil thought, of evil character, contained in the evil-doer's soul. That legal punishment is one of the means of social adaptation, of mutually adapting the habits of the individual human organism and of the society of such or- ganisms, is a very recent insight which has not become quite universal yet. In the traditional procedure the only im- portant problem for the judge was to know the accused per- son's soul, his "thoughts." When the prisoner's thoughts were known, it was an easy matter to adjust the punishment to them. Any person whose intelligence was equal to the multiplication table could do that. But how to know the other person's thoughts, — that was ^ a problem ! Have you ever tried to read another person's mind? Suppose you were the judge and you had to read the other person's mind. Of course, you remember the classic examples of King Solomon. Go and do likewise. But you would soon begin to doubt, under the stress of actuality, whether Solomon's wisdom was not fable rather than fact. Mind reading is easy only when its truth or un- truth is of no serious consequence, when it is a mere sport. It becomes difficult in proportion to its seriousness and its 420 PSYCHOLOGY OF THE OTHER-ONE real value. You can easily understand, then, why these judges of former centuries, despairing of their mysterious power of mind reading which they were supposed to pos- sess, should have felt inclined to resort to a more feas- ible, altho cruel, method, — judicial torture. To listen is often easier than to read. Why not here? Instead of reading, those judges decided to listen to, the prisoner's mind. If the prisoner's mind would not move his tongue, there were means of loosening the tongue — ap- plication to the prisoner's body of the thumb screw or the boot or the rack or the wheel. A person of the twentieth century, who is accustomed to scientific ways of thinking, and who regards the prisoner as an organism whose habits have to be studied, investigated by all possible means, among which listening to the prisoner's speech function is only one and not the most important means, wonders why former centuries should have placed such enormous weight in legal practice upon the prisoner's confession or lack of confession. But it becomes plausible enough when you consider that the judge in former times was not a sociolo- gist, but a mind reader who by mind reading and a little knowledge of the law had to keep an imaginary, ideal, spiritual world from losing its balance. Fiat justitia, pereat mundus. Let justice be done, even tho the real world, that is, mankind, should perish. Recall the horrors of the torture, the horrors of the pro- cedure especially of such courts as the Spanish inquisition or the witch-craft courts of the 17th century in Europe and in New England, — the horrors of any and all criminal pro- cedure down to the nineteenth, maybe even to the twentieth century. These atrocities were due to the fact that the judge was serving as a mind reader, and that the accused was regarded primarily as a soul. Not even the most inhuman, most MYSTERIOUS PROBLEMS 421 bestial butcher (a butcher, of course, is not inhuman because of being a butcher) would treat a pig in that way. Why not ? — Because the pig would be merely an animal, not a soul ; and therefore not only the energy, but the dignity of the torture would be wasted on it. There are few cases reported in the history of mankind where animals, that is, "soulless" beings, have been executed ; they seem to have entirely escaped judicial torture. Even that rooster, some- where in Switzerland, that was burnt because eye witnesses seemed to prove that he had committed, about the year 1700, the devilish act of laying an egg, escaped previous tor- ture before being burnt at the stake. Nowadays we think we are more enlightened. We have abolished the rack. But how do we kill a prisoner con- demned to death ? We tell him that in a few weeks he must die, but we leave him in suspense as to whether tomorrow or next week. Then suddenly we give final notice, lead him in a formal procession to the electric chair and have a little chat with him as a crowning ceremony to our procedure. It does not occur to us that, if the welfare of society demands that a certain human organism be put to death, the only humane method would be putting him to death without tell- ing him anything about it, or intimating as little as possible about it. and doing it in his sleep when he is not suspecting what will happen the next moment. Humane methods, however, we leave to the butcher. The executioner mvtst be atrocious out of respect for the prisoner's soul. The modern psychologist is not the man to whom you should appeal if you want information about your soul. The psychologist is not interested in your soul but in cer- tain functions of your organism, in those which are directly of social significance, whereas he leaves to the physiologist, and the workers in branches of science related to physiology, the study of those functions of your organism which, like 422 PSYCHOLOGY OF THE OTHER-ONE digestion, or tissue growth, or the color of your hair, -ire not directly of social, but almost exclusively of individual significance. This book could have attempted to make clear the gradual change of his interests and its result, the present direction of the psychologist's interest. For example, )t could have pointed out how men who started with a con- siderable enthusiasm for studying the soul became disgusted with this study, because they discovered that it led no- where, just as this same study of the soul, continued for thousands of years in the history of mankind, practically led nowhere. However, it is generally more difficult to prove the nega- tive, the absence of something, than to prove the existence of something. So we chose the method which is easier and more quickly convincing, and tried to show you that our interest in other human beings as souls positively is highly dangerous for human society, that the most cruel acts of man against man are those committed in the name of man's mysterious soul, that a rational, a humane treatment of its individual members is to be expected much more by a so- ciety which regards itself as a group of organisms than by one which regards itself as a mysterious collective soul. You cannot, then, blame the psychologist if he refuses to be considered an expert in matters spiritual, if he proclaims that his work is a study of the human organism in certain functional aspects, as previously delimited. QUESTIONS AND PROBLEMS Chapter 1. 1. What role does the Self play in modern psychology? 2. Is the psychology of the Other-One a denial of his conscious- ness? 3. How do engines, plants, animals, and the Other-One differ? 4. What are the delimitations of psychology toward the other sciences? 5. What is the chief cause of animal locomotion? 6. What is the direct (not indirect and later) effect of a stimulus on living bodies? 7. What kinds of stimulation and what kinds of response are there? 8. What kinds of differentiated tissues must be distinguished? 9. What is the shape of neurons, and why? 10. What is the relative importance of gray and white matter? 11. What is the function of a ganglion cell? 12. What need is there of a second form of animal behavior? Chapter 2. 13. What kind of snail are we considering? 14 Write a snail story in which you use the following terms as often as you wish, but in proper sequence: (l) body weight axis, (2) stimulus, (3) expansion, (4) conduction, (5) con- traction, (6) excitation, (7) normal body shape, (8) deforma- tion, (9) direction of body, (10) normal tissue density, (11) normal chemical constitution, (12) fever. 15. Why is the kind of nervous system which suggests itself most readily quite impossible? 16. Why must a moth, and all higher animals, have nervous tis- sue? 17. In what respect may the answers to questions 15 and 16 ap- pear contradictory? 18. A nervous excitation causes, not only continuous muscular contraction, but what contraction also? (423) 424 PSYCHOLOGY OF THE OTHER-OXE 19. What is meant by sensory and motor points of the body? Are they geometrical points in the bod^-? 20. Why do we call certain actions reflex actions? 21. What is the origin of the term "nerve center"? 22. What should we mean by central neurons, central sensory points, central motor points, peripheral points? Chapter 3. 23. What is a local reaction? 24. What is a concerted action? 25. What distinction between causes must be made in concerted action? 26. Give examples showing the relativity of the distinction he- tv.een local and concerted action. 27. Does reference to localness of an action imply inactivity of the rest of the body? What does it imply? 28. Do we mean by concertedness merely simultaneity? 29. What did the student who wrote "Odgen" write instead of "lapse"? 30. In the divisions of the bell of the jelly-fish, why is there little probability of much difference in frequency? 31. As in the preceding question, why is there some probability of some difference in frequency? 32. What is the disadvantage of a difference in frequency? 33. What insures simultaneity of contraction? 34. If the frequencies of the divisions, cut from each other, are 16, 12, 13, 14, 15, 13, 15, 14 per minute, why is the frequency of the united whole not the average, 14? What is it? 35. What, in the jelly-fish, serves as "conductor of the orchestra"? 36. Give an example of serial action. 37. Give an example of circular action. 38. How would you causally explain circular action? 39. Why can the explanation of circular action not be universally accepted as a causal explanation of serial action? Chapter 4. 40. Is unification of the animal the one chief purpose of the existence of a nervous system? 41. What is the most general demand made on the architecture of the nervous system by concertedness of action? QUESTIONS AND PEOBLEMS 425 42. In what respect can good conductivity from any part of an animal to every other be undesirable? 43. What are the two methods used by Nature in averting the predicament of "too universal conductivity"? 44. Which alone of the two methods referred to in the preceding question contains a constructive element valuable to the architect? 45. Why is the mere reflex path formerly mentioned not suf- ficient to enable a moth to alight on a twig or leaf? 46. What is the most useful diagram enabling us to represent short nervous connections between corresponding peripheral points and longer connections between non-corresponding points? 47. What is the unit by which we measure (count) the resist- ances of various paths in the diagram of nervous architec- ture? 48. How are resistance and conductivity related? 49. What is meant by "levels" in the nervous system? 50. Why are we (wrongly) inclined to represent a nerve center by a "point" from which neurons radiate? 51. Can excitations move thru any nervous path in either direc- tion? 52. What facts of human behavior prove that excitations do not within the nervous sj'stem proceed toward sense organs? 53. What relation has the "synapse" to the last two questions? 54. How can the length of a conductor be responsible for a great delay of reaction, altho its length is virtually nothing in comparison with the velocity of the excitation? 55. What is the relation between the explanation of serial ac- tivity and the question of the number of nervous levels? 56. What is the advantage, in a diagram illustrating the last question, of representing "higher" nerve centers by arches with multiple legs rather than by radiating lines? 57. What are the three parts of the problem solved by choosing for the nervous system a design of "arches over arches"? 58. Compute the distribution of the flux in a nervous system dif- fering from that for which the computation is made in the text only by the substitution for each of the three motor neurons (Mi M , Mi M., Mi M ) of a pair of shunted 426 PSYCHOLOGY OF THE OTHER-ONE neurons. — Answers for the peripheral neurons: in-flux 1564; out-flux 49 and 49, 595 and 595, 138 and 138. But give the an- swers also for the central neurons as in the text. Chapter 5. 59. Give examples showing that the Other-One's absent-mind- edness is related to his just preceding occupation. 60. What is the synapse theory of preoccupation? 61. How may warming up be related to absent-mindedness? G2. What relation do lower and higher centers seem to have to absent-mindedness? 63. What is the positive aspect of a failure to act? 64. Give examples of the positive and the negative aspect of pre- occupation. 65. What facts of behavior may be called competition of stimuli? 66. What advantage does Nature obtain thru competition of stimuli over what would result from the law of the resultant? 67. What physiological experiment proves the deflection of a weaker nervous current bj' a stronger one? 68. In what respects can a neuron be compared with a storage battery? 69. How does deflection differ from what the physiologists call inhibition? 70. What two functional peculiarities does the usage of language combine under the term "instinctive" activitj'? 71. Why must the "deflection center" in an instinctive activity be a "higher" center than the "overflow center," which is responsible for the concertedness? 72. Why is a room painted uniformly, lacking all decorative features, and placed in an absolutely silent locality by no means the ideal school room? 73. What are the three actual meanings of the social term "in- attention"? 74. What is the cure for inattention? Chapter 6. 75. What reflexes are joined, and how are they joined, in the candy-eating habit? 76. In what three ways do motor functions become related (log- ically) in the formation of habits? QUESTIONS AND PBOBLEMS 427 77. Give an example not found in the text for each class referred to in the previous question. 78. What two terms are suggested in the text for the classes vi'here there is not simply substitution? 79. Does the antagonism of muscles play any role in habit forma- tion? 80. What two manners of reducing the resistance of a complete nervous path must be strictly distinguished? Which of these conductivity changes establishes itself most quickly and which lasts longest? 81. What three conditions are given in the text as essential for forming a habit replacing the motor function of one reflex by that of another? 82. What function discussed in the preceding chapter gives an advantage to simultaneous over successive stimulation in habit formation? 83. Illustrate the four meanings of "forgetting" referred to in the text by four stories not found in the text. 84. What does the text mean by positive and negative suscep- tibility of neurons? 85. In what ways (mentioned or not mentioned in the text) may "preoccupation" corrupt a "learning curve" or a '"forgetting curve"? 86. What facts make it unavoidable to distinguish a specific conductivity (or resistance) of certain neurons from their general conductivity? 87. When do we call several stimuli similar, judging purely from the Other-One's motor activity, which we observe? 88. How does "similarity" depend on "specific resistance"? 89. How can a long path, after its resistance has been reduced, become shortened? 90. How may the shortening of the nervous path corrupt the learning curve? 91. Why is the difference between "persuading or tempting" and "training" the same as that between "willing" and "learn- ing"? 92. Why do sociologists use the term "freedom" more frequently than physicists? 93. What concrete fact gives rise to the abstract term "strength of will"? 428 PSYCHOLOGY OF THE OTHER-ONE 94. Under what conditions could the workman mentioned in the text (and under what conditions could he not) "will"? Chapter 7. 95. What is the origin of the term "phrenology"? 96. Why does an animal have "ganglions"? 97. Why does not a worm show an upper and lower series of ganglions as clearly as it shows a right and left series? 98. Has a starfish one brain or five brains? 99. What is a brain? 100. Has a crayfish a brain? 101. Has a fish a brain? 102. Why has no animal its brain in the tail? 103. When in evolution a single ganglion increases in relative size continuously, what is the meaning of this growth? 104. Discuss the relative significance of three methods of com- paring the average brain weights of two animal groups. 105. In the proper comparison of brain weights, how can one manage to get along without measuring the body surfaces? Chapter 8. 106. What is the localizing reflex? 107. What is the logical opposite of localizing on the skin? 108. How many dimensions are there in the localizing reflexes of the eye and the ear? 109. Did you find in the text an old problem which is no prob- lem? 110. What is negative localization? 111. What is the grasping reflex? 112. In what respect does the Other-One depend on combining the localizing and the grasping reflexes? 113. Enumerate the adjusting reflexes of the more conspicuous sense organs. 114. When do we not, and why do we not, localize a sound thru the medium of the localizing reflex? What do we use in- stead? And what is the use of having an auditory localizing reflex anyway? 115. What is the signaling reflex? 116. What advantage has acoustical over optical signaling? 117. Which are the muscle groups serving the Other-One's acoustical signaling? QUESTIONS AND PKOBLEMS 429 118. What muscular contractions make up the sleeping reflex? 119. What is the stimulation in the case of the sleeping reflex? 120. State the two causes (other than incidental fatigue of his nervous system) of the sleeper's failure to converse with you readily. 121. Enumerate the eight forms of behavior which the text re- gards as fundamental and therefore inherited. 122. What is right-sidedness, and why is it discussed in this chapter? Is it a reflex, a habit, or neither? 123. Why is it impossible, by observing people a short time in their infancy, to foretell whether they will turn out right- sided or left-sided? 124. Is walking an inherited concerted action? 125. What reflex must combine itself with the habit of balancing in order to develop balancing into walking? 126. The following habits are examples of actions falsely enum- erated as "instincts" by various writers: Curiosity, esthetic expression, communicativeness, eating and drinking (as per- formed by humanbeings), cleanliness, parental care, rivalry, co-operation, hiding. Try to reduce each to such phy- siological reflexes as you probabl}' have heard of, and as far as possible to some among the eight classes of inherited be- havior emphasized by the text. 127. When do we refer to reflexes or habits as "emotions"? 128. Reduce the following examples of so-called emotions to wasted habits or wasted reflexes in the manner of answering question 126: Anger, shame, sorrow, tenderness or love, envy, wonder, cordiality, admiration, hatred, doubt, exuberance. 129. Is play a reflex? What is play? Related to "exuberance"? Chapter 9. 130. Give a reason, other than the limitation of muscular ac- curacy, why Nature has established a rather large thresh- old of sensibilit}' on the skin. 131. Why is the threshold the smaller, the greater the curvature of the surface region? 132. What reflex action or actions are replaced by the answer "Two" in cutaneous discrimination? And by the answer "One"? 133. How many dimensions has cutaneous space perception? 134. Make plain that space perception is a species of motor con- densation in the nervous functioning. 135. Why is an "illusion" like an "emotion"? 430 PSYCHOLOGY OF THE OTHEE-ONE Chapter 10. 136. What proves the existence of inherited visual space percep- tion? 137. Demonstrate the dependence of nervous condensation on the size of the interval between stimulated points. 138. Hov^ do you explain that there is no real distinction possible between the "substitution" and the "addition" of a new re- action? 139. What habits has the Other-One with respect to angles in perspective? 140. What happens when areas in the visual field compete with mere points? 141. What examples can you give of two-dimensional or of color perceptions for which a third-dimensional localiza- tion is substituted? 142. Why does the Other-One call the moon larger when it is near the horizon? 143. Give examples of reflex actions (adjusting the sense organ) to which a localization in the third dimension is habitually added. 144. Is "single vision" or "double vision" simply a matter of mathematical correspondence or non-correspondence of retinal points stimulated? 145. Give examples of division of labor between corresponding retinal points. 146. Give an example of complete co-operation of corresponding retinal points. 147. Give examples of "wrestling" and of more or less com- promising between corresponding retinal points. 148. What is the essential difference between the two visual images (both being two-dimensional space perceptions) of the two eyes? 149. How do you describe in words and in a drawing the lateral displacement for a farther and for a nearer object in stereo- scopic vision? 150. Why does the perception of a puzzle picture change with difficulty? QUESTIONS AND PROBLEMS 431 Chapter 11. 151. Why must there be two kinds of excitations to be called forth by the intensity of the light? Why is one kind not sufficient? 152. What is the relation between a visual process and a visual substance? 153. How could a second visual substance be helpful to the animal world? 154. What proves that Nature, before dividing the spectrum in one definite point, experimented with different divisions? 155. In what sense is every normal retina color-blind? 156. What does it mean that the Blue excitation and the Yellow excitation are antagonistic? 157. What is meant by general adaptation of the retina? 158. What is successive induction? 159. What is simultaneous induction? Chapter 12. 160. What mistake does Nature appear to have made in creating the second visual substance? And how did she remedy the defect? 161. It seems that Nature created the third visual substance somehow as God created w'oman. How? •162. How are the singular and dual colors related to the four excitations (or visual processes)? 163. What singular color does not exist in the rainbow? 164. Why are there only singular and dual, and not also plural colors? 165. Why does complementariness of colors interest the psychol- ogist but little? 166. Why do the primary, principal, etc., colors of technology in- terest the psychologist but little? 167. How does a "flight of colors" come about? Chapter 13. 168. What is the simplest kind of auditory organ? 169. What changes are needed in the auditory organ in conse- quence of leading the sound waves to the organ thru a tunnel? 432 PSYCHOLOGY OF THE OTHER-ONE 171. What is the original purpose of the ear drum? 172. Why are the cavity and the partition lengthened? 173. What advantage results in pathological cases from the fact that the ear can function in more primitive and more ad- vanced ways simultaneously? Chapter 14. 174. What must happen to the stream of air exhaled in order to produce density changes directly, or to cause a solid body to vibrate and in turn produce the density changes? 175. What makes weak and irregular density changes strong and regular? 176. Which two may be said, generalizingly, to be the places where the stream of air is easily obstructed? 177. In what sense, and why, does great obstruction in the mouth preclude the production of "voiced" sounds? 178. What do we call speech during which the larynx never ob- structs the stream of air? 179. Of what use in sound production is the mouth, and every- thing connected with it, aside from obstructing the passage of the air? 180. If whispering is one extreme, what is the other? 181. What is a syllable? 182. Are the consonants consonants and the vowels vowels in all languages? 183. Give examples showing how natural economy, laziness, and excitedness may influence the pronunciation. 184. What can be said about individuality in speaking? 185. Imitativeness is not a reflex, but — ? 186. Are there inherited kinesthetic, olfactory, or gustatory im- itative actions? 187. Are there inherited visual or auditory imitative actions? 188. How do auditory and other imitations change during life? 189. How is "serial activity" illustrated in speech? 190. Do the localizing and the sound signaling reflexes seem to be related? 191. What may happen when one speaks an unaccented lan- guage? QUESTIONS AND PROBLEMS 433 Chapter 15. 192. What do we mean, in psychology, when we call repeated motions rhythmical? 193. What used to be the chief argument for the belief that grouping in action was inherited? 194. What do you think of another person's "rhythm" when you hear him counting? 195. What habits of "rhythm" are rarely acquired? And why is that so? 196. By what procedure can an odd group most easily be de- veloped from an even group? 197. Why is rhythm the most wonderful — perhaps the only true — example of transference of training? 198. What differences may be noted of the rhythm in dancing, poetry, music and prose? 199. Do laborers sing in order to make their work rhythmical? Chapter 16. 200. What is generalizing as a bodily function of the Other- One? 201. What is the value of abstractions to the Other-One? 202. In what ways are generalization and abstraction aided by the invention of script? 203. What entirely new vocation is made possible as soon as generalization and abstraction have become established in the human race? 204. Give examples of special importance showing that, and to what extent, the progress of science depends on generaliza- tion and abstraction. 205. Is the acquisition of generalizations and abstractions dif- ferent from the acquisition of other habits? 206. What is speculation? Chapter 17. 207. Why are schools for deaf-born children more indispensable than schools for blind-born cliildren? 208. What superstition existed in former centuries concerning deaf-born people? 209. What is the history of the education of the deaf? 210. Do animals think? 434 PSYCHOLOGY OF THE OTHER-ONE 211. What corresponds in scientific psj'chology to the popular opposition of the mental and the physical in habits? 212. How does the education proceed of those who are born both blind and deaf? 213. What justifies our calling sight and hearing the higher senses? Chapter 18. 214. Why is the literal meaning of "somnambulism" a misunder- standing of "sleep"? 215. In what respects are the actions of Lady Macbeth unusual? 216. Give examples of life histories demonstrating that abnormal preoccupation is not restricted to the functions of a par- ticular high nerve center. 217. What does the transferability or transmutability of hysterical symptoms prove with respect to the question just hinted at (under 216) and with respect to deflection? 218. What proves that abnormal preoccupation does not readily extend to the functions of the lower centers? 219. What are the two fortunate indirect consequences of the freedom of reflexes from preoccupation? 220. Give various reasons for the wrong belief that hystericals are fond of telling lies? 221. How is hypnotism related to somnambulism? 222. What is personality? 223. Make a list of the anatomical and physiological conditions of a normal functioning of the human nervous system. Then derive from it a list of all possible abnormalities. Chapter 19. 224. What is the wrong and the right meaning of a materialistic conception of history? 225. What is the speculative and the scientific conception of criminology? 226. What has kept sociology from submerging in speculation? 227. What is a psychology of religion? 228. Why is it unnecessary to define psychology? Chapter 20. 229. Why would a general knowledge of modern psychology have prevented the cruelties of religious persecutions? QUESTIONS AND PROBLEMS 435 230. Why would a general knowledge of modern psychology prevent international atrocities? 231. Why would a general knowledge of modern psychology save people from the craving for hypnotism and similar phenomena? 232. Why would a general knowledge of modern psychology have prevented the cruelties of the criminal law. 233. What is human society and how does it concern the psy- chologist? INDEX Absent-mindedness, see pre- occupation. Abstraction 357-369, 371, 3««. Adaptation 274, 275, 278, 289-291. Adjusting the sense organs 187-195, 215, 243. Afferent 47. After-images 290, 291. Anatomy 8. Anesthesia 390, 391. Anger 214, 215. Angles 232, 235, 238. Animals 6, 371, 380, 421. Antagonistic colors 272, 276, 278, 279, 283, 287, 289. Antagonistic muscles 122. Arches 44. Aristotle 226, 227. Art 215, 414. Attention 101, 114117, Auditory excitations 301, 307. Automatic action 143. Binocular vision 245, 251, 260. Bird 164. Blind 371, 379. Blind spot 246. Blood 275. Bonet 375, 376. Bonnier 303. Brain 152, 156-161, 163, 167. Brain weight 169. Centers 47-49. Centers, functional differences of low and high, 95, 113, 12b, 388. Cerebrum 163-167. Check valves 76-77. Chemistry 138. Circular action 63. Cold colors 271. Color blindness 270, 271, 287. Color etymology 284. Color pyramid 2St). Color zones 272, 286. Competition of stimuli 99-102, 106. Complementary colors 287. Computation of nervous flux 86. Concerted action 50-66, 329. Condensation 120, 225. Conditioned reflex 119. Conductivity 16, 17, 70, 12, 74, 80, 87, 125, 130, 135, 136. Consonants 319, 320. Contractility 16. Cortex 25. Crayfish 160, 161. Criminology 403, 419-421. Current, nervous, 108, 135. Dancing 349, 351, 352. Deaf 296, 311, 370-379. Deflection 103-106, 110, 114, 117, 397. Delayed reaction 46. (436) INDEX 437 De I'Epee 374, 377. Demented 397. Democracy 402. Depth 240, 244, 256. Descartes 4. Differentiation 15, 17, 134, 136. Dimensions of space 182, 183, 222, 223, 240, 244, 256. Discrimination 219, 221, 234. Distribution of flux in the nervous system 85. Dual Colors, 283, 284. Dumb 372-379. Ear 293, 295, 297, 308-312. Earthworm 154-157. Economics 403, 407. Economy in speech 320. Effectors 47. Efferent 47. Emotion 211-215, 226. Engines 6. Epilepsy 398. Esthetic emotion 215. Evolution 168. Excitation 14, 17, 28-31, 107, 290. Eye 246, 262. Eye ball 179. Fatigue 201. Fighting 196, 197. Fish 161. Flight of colors 291. Forgetting 132-134. Freedom 147, 148. Frog 163. Gall 152. Ganglion 155-157. Ganglion cell 20, 23, 26. Generalization 356-369, 371. Gesticulation 333. Genius 117, 174. Glands 14, 47. Government 10, 412. Grasping 186. Gray matter 24. Growth 6, 7. Habit 93, 119, 167, 168, 388, 395. Habit formation 123, 127, 130, 396. Hering 272, 276, 278. High and low centers, see centers. High and low creatures 7. High and low senses 379, 380. History 401. Horopter 250. Hunger 12, 402. Hypnotism 393, 394, 409, 415- 418. Hysteria 384-393, 397. Idiocy 395, 396. Illusion 226, 227, 231, 291, 292, 350. Imagination 232. Imitation 323-329. Inattention 116-117. Induction 274-278, 289, 291. Inhibition 109-110. Innervation 79. Instinct 110, 114, 176, 210, 395. Integration 67, 158. Intellect 372, 373, 377-380, 397. Intelligence 168-175. 438 INDEX Janet 384, 393. Jelly-fish 56-61. 68-72, Jespersen 321. Joy 214, 215. Kinesthetic 148. Labor and rhythm 351-353. Language 7, 322, 323, 372, 377, 378. Larynx 314, 316. 319. 321. Learning 124, 130, 131, 145, 147, 396, 398. Levels of connection, 74, 75, 78. Local action 50-66, 71. Localizing 177-186, 193-195, 198, 216, 219, 331. Locomotion 11, 12. Magnetism, animal 415, 416. Marriage 9. Materialism 405, 406. Measuring 3. Mechanics 366-368. Memory 378. Moth 38. 39. Motor condensation 120, 225, 231, 236, 238. Motor points 42. Mouth 315-318, 321, 323. Mueller 405. Muscles 14, 47. Muscle sense 61-63, 148, 149. >Iusic 137, 138, 346, 348, 349, 351. Naming 219. Nationality 322, 323, 333. Negative localization 185, 198. Negative response 96-98. Nerve cell 18, 20. Nervous system 36, 69, 73, 76, 81-84. 394-398. Neurons 18-27. Neurosis 381, 383, 384, Obstacle 27, 33. Overflow 113, 114. Paralysis 386, 387, 389, 390. Paranoia 398. Perception 219-227. Periodic motion 39, 40. Peripheral points 49. Personality 394. 397, 398. Persuasion 146. Phrenology 151, 152, 169. Physiology 8, 405, 421. Plants 6. Play 215. Poetry 346, 348, 350, 351. Ponce 374, 377. Preoccupation 94, 115, 117, 125, 130, 134, 147, 201, 383, 384, 388, 393, 394. Primary colors 288, 289. Psychology, Definition of, 8-11, 405-408, 421, 422. Punishment 10, 419. Puzzle pictures 260. Qualitative 369. Quantitative 369. Reaction time 45, 46. Receptors 47. Reflex 45. 50, 176, 388. Reflex arches 47, 48, 73. Religion 5, 404, 406, 410, 414. Repetition 131. Resistance 16, 70, 72, 74, 80, 87, 125, 126. 130, 135, 136. Responses 14, 15. Resultant of stimuli 100, 102. Retinal co-operation 245-256. Rhythm 335. INDEX 439 Rhythmical motion 39, 40. Right-handedness 203-205, 332. Schools 10, 372. Scnpt 354, 362, 371, 377. Self 3, 4. Sensitivity 15, 16. Sensory condensation 121. Sensory points 42. Serial action 62, 78-80, 85, 330. Sex 169-174, 196. Short-circuiting 142. Signaling 195-200, 293, 331. Similarity 136-138. Singular colors 283, 284. Sleep 96, 116, 200-202, 382. Snail 28-36. Social 196. Sociology 8-10, 148, 404. Somnambulism 381, 382, 386, 393. Song 318, 352, 353. Sorrow 212-214. Soul 3-5, 373, 382, 394, 399, 406, 411, 414, 421, 422. Sound 294, 304, 308. Space perception 219-227, 229, 231. Specific excitation 111. Specific resistance 134 138, 301. Spectrum 265, 278, 279-283. Speech 321, 322, 361, 371, 377. Speech organs 199, 200. Starfish 159. Stereoscopic vision 245, 256. Stimulus 13, 14, 290. Stumpf 138. Susceptibility of neurons 130, 132-135. Syllables 320. Synapse 78, 81, 93, 95, 125. 130, 134, 145, 383, 384, 386, 388, 393, 397. I Synergies 138. Temperament 333. Temptation 146. Ter Kuile 311, 312. Thoughtfulness 7, 356, 371-373, 378, 380. Threshold 217-219, 221. Transference of training 338. Turning 28-36. Uexkuell 102. Visual excitations 264, 265, 272, 278-284, 291. Vocal cords 316. Vocal organs 199, 200. Voiced sounds 316. Voiceless sounds 316. Vowels 319, 320. Wakefulness 202. Walking 205-210. Warm colors 271. Warming up 94, 131. Wasted reflexes 195, 212, 215, 226, 227. Whisper 316, 317. Will, 6, 7. 145-150, 398. Woman 169-174. Worm 145-157. Publislied by the MISSOURI BOOK COMPANY, Columbia, Missouri. A BRIEF MANUAL OF PSYCHOLOGY DEMONSTRATIONS to accompany as illustrative material an elementary course in The Psychology of the Other-One. By Max F. Mever 118 pages. f£B This book is DUE on th^ last date stamped below 5 mi^ JVl 1 Q 1938 AUG 4 A93^ DEC ^^ " '"" IAN 5 1945 JAiV 2 7 mi M||^91950 DEC as 1^t Form L-9-15m-7,'31 MARl 81950 SEFD LD-Ui?a MM ivm lilut F J I BEC'D LD-URl Hov '^ u ly //■ 3 1158 00023 7833 7^ UC SOUTHERN REGIONAL LIBRARY FACILITY |H|!|iP||i'1|l'1l#i|P|l|''''''|''|''f{|| AA 000 509 877 7 iniilM iinminiiinHiT 11 lii.Ll; iU -l!!!!lil!!l!lliniiili!l!ii!!llliiiliii!!!li|p I ■'■■'' ' liiii ! it i ! r