you have just read. This you will see in the ' mind's eye.' Perhaps, too, you will hear the word ' chair ' spoken in the mind's ear. Then will come a somewhat vague and shadowy picture of the chair, as it looks when your eyes are open, only that it will very likely seem to be inside your head, — as if you turned your eyes inward to see it. All this occurs with great rapidity, the changes coming in less time than it takes to write them down. Now try to hold the idea steadily. Your mind will suddenly ^ become a blank '; then the idea will crop up again, not just as it was at first, but with some part of the picture more prominent than the rest, or with some new picture of another chair blended in with it; then comes the blank again; and so on. Now look at the blank for a moment: you will find that it was not really nothing, no mind at all, but that it was made up of the black field before your eyes, of the pressure from your chair as you sat, of the sensations set up by the movements of the chest and abdo- men in breathing, etc. And the various processes in the blank shift and change as inevitably as the processes in the idea of the chair. Here, then, is a flow, a passage, a going on: not anything like a ' thing.'
The percep- (2) Close the book and look steadily at the table in front tion of a Qf yQ^^ 2,nA. try to think continuously of that. You will find that steadiness now is even more impossible than it was when the eyes were shut. There is a tendency to let the eyes wander, to let them follow the grain and pattern of the wood, or to travel over the various objects lying on the table. If you withstand this temptation, your mind becomes a blank very soon indeed: the table gets to be quite meaningless to you. Presently the blank ends: you remember that you * ought ' to have thought of the table, and resolve to do so; the eyes try to wander again; and so the whole history is repeated. Now look at the blank: it is filled up with press- ures from your chair, sensations from breathing, sensations of strain about the eyes, etc. Here too, therefore, there is a flow of proc.esses; the picture of the table, the feeling of 'ought,' the resolve, the pressure, the strain, all these are mental processes; they are, or they make up, your mind durmg the experiment. Mind ' goes on ' from moment to moment; it is never still.
§ 5. Mental Process. — We must now ask how it is that a mental process differs from the other processes that we have mentioned. If the mental process were in all respects the same as the chemical and the biological process, we should not be able to put the three into three different sciences: chemical decom- position, and the growth of the frog, and the course of an idea would all have to be treated by some one science. What, then, does the word ' mental ' mean "i We said just now that mental processes go on Mental 'inside of us.' The process in the test-tube and the onTn^Methe process in the aquarium are, clearly, going on outside ^^^y* of us. ^ Here, then, is one difference between the mental and the other processes. Still, it does not take us very far. For there are chemical processes also going on inside of us: processes of digestion, e.g. And biological processes of growth and decay are also going on inside of us; yet we do not speak of them as mental. The difference cannot, therefore, be merely a difference of inside and outside.
What we have to do is to distinguish somehow between the inside processes which are mental and the inside processes which are not mental. We had a similar task in § 2: all science is talk, we found, but not all talk is science. So here: all mental pro- cesses are*processes going on inside the body, but not all inside processes are mental. What is the difference between them 1 The characteristics that made talk into science were those of method and 10 Psychology: What it Is and What it Does and can be known by one person only completeness. What are the characteristics that make a process within the body a mental process? This is a question that has been answered in a great many ways. The simplest answer to it, per- haps, is this. A mental process is a process which can form part of the experience of one person only; the processes dealt with by other sciences can form part of everybody's experience. Not only does the mental process go on inside of you; it is so entirely inside of you that you are the only person who can ever get at it and observe it.
(which is not true of other processes); Illustrations will help us again. And as we have settled the point that psychology deals always with processes, and always too with processes within the body, we will take two of these processes as our illustrations.
We said that the process of digestion, going on inside the living body, is a chemical process. Under ordinary circum- stances, no one, neither yourself nor anyone else, can watch your digestive processes. But cases are known in which the wall of the stomach has been torn through, say, by a gunshot wound; so that digestion could be followed by the eye, just as the reaction in a test-tube can be followed. Now it is plain that, in such a case, other people could trace the pro- cess as well as you could: better, indeed, for you could watch your own digestion only by means of a mirror, whereas the onlooker could watch it directly. The mental processes, on the other hand, — the pain of the wound, the feelings of hunger and of satiety, — form part of your experience only; they can never enter into the experience of the onlooker.
The same thing holds of the process of growth. The growth of a bone or of a tumour within the body could be followed from day to day by means of x-ray photographs. But this growth would evidently lie open to your physician, or to anyone else to whom he should show the photographs, just as well as to yourself. The mental processes, the pains and pressures coming from the growth, would be yours and yours only.
We can put this answer in a different way: in a but they sentence which, at first sight, seems to contradict whole world. what we have ju&t said, but which really throws light on it. We may say that every object dealt with by any science whatsoever, — whether it be thing or process, whether it be inside of the body or outside, — can be transformed into a mental process. For everything can be looked at in two ways. It can be looked at as it is in the world, where one man can see it as well as his neighbour: or it can be looked at as it is in someone's personal experience. Looked at in the first way it is a physical thing or a chemical process or a physiological process or what not; looked at in the second way it is always a mental process.
Think of sound, for instance. The physicist says that sound is a certain kind of movement of the particles of the air we breathe. The physiologist says that sound is a com- motion in the cells of a certain part of the brain, — a com- motion first set up by the action of the air particles on the ear, and then carried inwards to the brain along the nerve of hearing. The psychologist says that sound is a sensation, a mental process.
The three sounds seem to be very different. The air The three movements go on quite independently of us; there is phys- ^?^^. ^: ical sound when the air moves, whether we are present to physioiogi- hear it or not. And the commotion in our brain goes on cai, psycho- quite independently of us: the physiologist who has made models of the ear and performed experiments on animals tells us what happens, and we believe him; but we do not know more than anyone else about the processes in our ear and brain. But the hearing, the sensation of rap or thud or 1 2 Psychology: What it Is and What it Does tone, is a particular experience: everyone hears for himself, and no one can have any sensation but his own. This last sound, therefore, is a mental process.
Nevertheless, we can make the physical and the physio- logical sounds into mental processes. For after all, if we are to have a science of physics, we must have an idea of the physical movements; physics is simply a statement of the ideas of people who have worked at physical problems. Hence we can say, ^^ Sound is a certain movement of the air-particles": that is physics. But we can also say, "This., or this is my idea of the movement of the air-particles ": and that is psychology. And similarly with the brain commotion.
To make the point quite clear, go to a physical text-book (TV., 337) and read the definition of sound there given. Then ask yourself what idea this definition calls up. Your idea will perhaps be made up, in part, of mental pictures of the words of the definition {cf. above, p. 7); but you will also see, probably, in the mind's eye, some picture of the actual movement. Ob- serve this picture carefully, and try to describe it in words. Compare your own idea with those of two or three of your friends. You will find at once how individual it is, how entirely it is your own experience and not that of anybody else. Even if the words in which two of you describe it should, by some acci- dent, be identical, — and this may happen quite easily when you are not used to psychological observation, — each will still feel certain of the fact that the picture described is his picture and his only; it cannot be transferred from the one to the other, or handed round for inspection. You will find, that is, that the physical sound has become an idea of physical sound, a mental process.
In this way anything and everything can be made into a men- tal process. Just now we saw that a chair — which, if we look at it as a physical object, is sufiiciently solid and unchanging — be- comes a process, or rather a group of processes, when we look at it psychologically, i.e.^ look at our idea of it. It would be worth the reader's while to test some other cases: try heat, e.g,^ or light, or animal, or rock. The result will be precisely the same.
The brain is § 6. Mind and Body. — Mental processes run their mind. - coursc ' withm — better, m connection with — the living body. But they are more closely connected with some parts of the body than with others. Men- tal processes appear only when there is a commotion (or, as it is technically called, an excitation^ in a cer- tain portion of the brain. Hence the brain is some- times spoken of as the 'organ of mind.'
The brain (ZT., 290) is a rounded whitish mass of soft tissue lying in the cavity of the skull. It is made up of nerve fibres (delicate strings of tissue; H., 356) and of nerve ceils {H., 359). The cells are found in groups or clusters within the brain mass, and also form a layer or rind covering the whole. This layer is called the cortex (bark or rind). It is only when certain cells of the cortex are excited that we have a mental process; the fibres serve simply to join groups of cells together, and so to convey excitations from one part of the brain to another.
Nerve fibres {H., 201, 278, 295) are found not only in The nervous the brain itself, however, but also throughout the body, ^y^^^^- Nerves run into the brain from every organ of the body: from eyes, nose, skin, heart, muscles, bones, etc. And nerves run out from the brain to the muscles. In both cases the nerve fibres act merely as telegraph wires, carry- ing messages from cells in the bodily organs to cells in the brain, and from brain-cells out again to muscle-cells.
Suppose, e.g., that as you are reading a fly settles on your Physiological forehead, and you raise your hand to drive it away. On the ^^^ psycho- physiological side you have the following processes, (i) The weight and movement of the fly act as ' stimulus ' to certain skin- cells fi'om which nerves run inwards to the brain. ' Stimulus ' is the technical word for the physical object or process that can excite a sense-organ and so give rise to a mental process. (2) The stimulation of these skin-cells sends an ' excitation ' travelling along the nerves. (3) The excitation arrives at a group of cortical brain-cells, and explodes them. (4) A new excitation, due to the explosion, travels along fibres running within the cortex to another group of cells, from which nerves cesses.
14 Psychology: What it Is and What it Does How we know the relation of brain to mind.
run to the muscles of hand and arm, and (5) explodes these. Their explosion (6) sends the necessary excitation to hand and arm: hand and arm move. (7) This movement serves as ^ stimulus ' to muscle-cells, from which yet other nerves run in- wards to the brain. (8) The stimulation of these muscle-cells sends an excitation travelling along this second set of in-going nerves. (9) The excitation arrives at a group of cortical cells, and explodes them; stage (3) is repeated, but at a different part of the cortex. On the psychological side you have: at stage (3) an idea of the fly, and at stage (9) sensations which tell you of the position and movement of your hand and arm. No mental process is present at any of the other stages; not even at stage (5). It is only when the cortical cells which receive the in- coming excitations are exploded that a mental process arises.
The fact that the brain is the organ of mind has been estabhshed by two Hnes of evidence. In the first place, we find all through the animal kingdom that size and complexity of brain are matched by range and complexity of mental processes. And, secondly, we find that disturbance of certain parts of the brain indicates a certain form of mental dis- turbance, and conversely, that particular forms of mental disturbance indicate disturbance of particu- lar parts of the brain.
We cannot go into the details of this evidence here. The following facts, however, may be noted.
(i) The brain of man is, by absolute measurement, an organ of great size; it is heavier than that of any other ani- mal, with the exception of a few of the very largest (elephant, etc.). It is also relatively, i.e., when compared with the weight of the whole body, heavier than the brain of any other animal, with the exception of a few of the most highly developed small mammals (some monkeys, etc.). And we know that the mental life of man is richer than that of any other animal. (Donaldson, Growth of Brain, 121.)
(2) The physician finds from experience that pecuHar disorders of a patient's ideas, as shown, e.g., by forgetfulness of the names of a certain class of things, indicate disorder of a special part of the cortex, — say, the pressure of a blood-clot upon a particular area of the nervous substance. Hence the mental symptoms justify his opening the skull at a certain place. He finds the clot, and removes it; and with its removal the patient's ideas become normal again.
(cy:§ii5.)
But how^ do we know anything about the ^ range and How do we complexity of mental processes all through the animal other people kingdom'? How do we know, for that matter, — since ^^^^ minds? we can know only our own mental processes, — that anyone except ourselves has a mind at all 1 Before we attempt to answer this question, let us be quite sure as to what the question is. We can never know any mental processes but our own; we cannot experience our neighbour's experiences. No one can take his friend's grief out of his friend's mind, and put it into his own. But we can know about the minds of others, because we can form ideas of their minds. ^^ I know just how he felt when he got that letter! " we say: or ^^ I knew that he would think as I did about it." In other words: it is quite possible to know that other people have minds, al- though it is impossible to experience what they expe- rience, to make their mental processes our mental processes. How do we know, then, that other men, and the animals, have minds 1 In the first place, there can be no doubt of the The argu- '-T'l r ment from matter as regards other men. The whole of our society, common life — family life, social life, civic life, national life — is based upon the assumption that 1 6 Psychology: What it Is and What it Does we all have minds, and would be impossible if the assumption were falsified by the facts. All these forms of life, that is, are the productions of more than one mind. All of them, e.g.^ presuppose Ian- guage. And language is a mental product that requires at least two minds for its making. We should never have made words to talk to ourselves. All of them, again, presuppose laws. Now a single mind may form a habit; but it takes at least two minds to make a law. The argu- But, sccondly, there is other evidence, which leads mentfrom ^^ ^^ asscrt that all the animals, and not men actions. ' only, possess minds. This is evidence drawn from conduct or behaviour. Our conduct indicates the state of our mind, the character of our mental pro- cesses, at a given moment, just as the direction in which the weather-cock points indicates the direction of the wind. If we find, then, that certain outside circumstances set up certain mental processes in us, and that under these same circumstances we act^ in a certain way: and if we find that under similar out- side circumstances an animal acts in a similar way: then we are justified in concluding that the animal has similar mental processes. Thus there can be no doubt that a dog feels grief and anger, recognises his master, dreams in his sleep, etc.; under fitting cir- cumstances he * shows all the signs ' of feeling and recognising and dreaming.
Rudimentary It is not surprising, perhaps, that we should find signs of minds. mind in the higher animals; animals whose nervous system is built on precisely the same pattern as our own. But we find them quite plainly, too, in the conduct of animals whose § 7- Psychology and Physiology 17 structure is very different from ours, e.g., in that of insects. More than that: we find them persisting in the conduct of the very lowest animals that there are, the one-celled animals whose movements cannot be followed except by help of the microscope. These creatures manifest their * likes' and dislikes/ just as we do. At the same time, while we grant that they have minds, we must guard against sup- posing that the mental processes whose signs we see in their actions are at all like our own. Mental processes grow more and more distinct as the nervous system grows distinct from the rest of the body; and animals that are ' all of a piece ' — any part of whose body can act as nerve or muscle or stomach or lung — cannot have any but the most confused and vague mental processes.
It has been seriously argued by some psychologists that mind appears wherever life appears; not only in the animal kingdom, but in the vegetable as well. This is a question which we can- not stop to discuss here. At any rate the plant-mind, if there is such a thing, must be so extraordinarily rudimentary and so totally different from our own that it is hopeless to try to form any idea of it.
§ 7. Psychology and Physiology. — It has some- Mind is not times been said, on the ground or the tacts stated brain; in the foregoing Section, that psychology is nothing but a branch of physiology. Just as the lachrymal glands secrete tears, it is urged, or the sweat-glands in the skin secrete sweat, or the liver secretes bile, just so does the brain secrete mental processes, thoughts and feelings. As it is the function or office of the stomach to digest food, so it is the function of the brain to think and feel.
This argument is not sound. It is important that the psychologist should understand physiology, and especially the physiology of the nervous system; 1 8 Psychology: What it Is and What it Does but psychology is not a part of physiology. The reason why the psychologist is interested in the body is this: — ^ but body is In cvcry science we try to explain things. Facts of mind Cannot be methodically arranged and harmonised until they are explained. Now to explain a thing is simply to state the circumstances under which it appears. These circumstances are termed the con- ditions of the thing's appearance. Apply this to psychology. Certain disturbances in the body, be- ginning in a bodily organ and ending in the cortex, are the circumstances under which mental processes appear. Bodily processes, that is, are the conditions of mental processes; and the statement of them fur- nishes us with the scientific explanation of the mental processes. We can deal with mental processes by themselves; but to make our psychology complete we should add to our account of mind an explana- / tion of it, that is, an account of its bodily conditions.
The prin- That is why the psychologist ought to know |)hysiparaiieiism * ^^^SY* Wherever a mental process occurs, there must be a bodily process to serve as its condition. But this is not saying that the brain produces mental processes: it is merely saying that the mental runs alongside of the bodily, — that, as a matter of fact, the bodily is the condition of the mental. To say more than this is to leave science for ungrounded speculation.
It is important to understand clearly what scientific ex- planation means. Hence it will be well for the reader to test the definition just given by instances taken from vari- ous sciences: to see, e.g., how the physicist explains the § 8. The Divisions of Mind 19 formation of dew, or the geologist the appearance of dif- ferent kinds of rocks.
It may seem strange at first sight that an occurrence in one science (physiology) should be called upon to explain an occur- rence in another (psychology). But the process of digestion (physiological) is chemically explained; the shape of the bones of the skeleton (anatomical) is physically explained (by the law of the lever, etc.); and so on.
§ 8. The Divisions of Mind. — When the zoologist ciassifica- sets to work to classify animals, his material, what he has before him to work with, is simply the separate individual animals found in the world. By putting together the creatures that are more or less alike, he is able to make an orderly arrangement of his material: he groups the separate animals into grades and orders and families and. genera aftd species.
So it is with the psychologist. Mind is a stream of processes, going on as long as the body goes on living. The psychologist disentangles these pro- cesses, and puts together into groups those that are more or less alike. In this way he is able to classify his material; he passes by stages from the total mind to the single processes of which mind is composed.
The total mind, the mind that extends over the The three whole lifetime, falls (i) into three parts. We call j^jnd. them the child mind, the adtilt mind and the sejiile mind. Each part has well-marked peculiarities which distinguish it from the others, although we cannot say precisely in what years of life the first two give place to their successors. The change is gradual, and occurs at different times in different lives. (2) Each of these part-minds consists of a series of Conscious- consciousnesses. By conscioitS7iess we mean 'mind ness.
20 Psychology: What it Is and What it Does now '; the mind of the present moment. It is clear that, as you pass through life, you pass through a succession of ^now's': now it is time to get up, now time for breakfast, now time for work, and so on. The mind at every ' now,' whether it be in childhood or in manhood or in old age, is a con- sciousness. You have a getting-up consciousness, a breakfast consciousness, etc. Sometimes conscious- nesses pass into one another by slow degrees, and sometimes very suddenly.
States of con- But a group of animals may live under favourable or un- sciousness. favourable conditions: there may be enough or too little rain for them, scarcity of food or abundance of food, etc. The conditions of consciousness may vary in the same way; the brain may be well-nourished or ill-nourished, etc. So we have different states of consciousness, as they are called. Besides the normal, 7vaking consciousness, we have abnormal states of consciousness, the chief of which are seen in the dreaming and the hypnotic consciousnesses. Within the wak- ing consciousness we have a well-marked difference between the attefttive ^idiie, the state in which we are fully absorbed or interested in something, and the state of inattention.
Remember that, just as the same animals may live under different conditions, and be fat or lean, healthy or unhealthy, so the same consciousnesses may appear in different states. That is, the mental processes may be the same in attention that they are in inattention; it is only their state that differs, — their clearness and definiteness, and (if we may say so) their power to hold their own against other processes.
So we may see an accident or dream of it. In the first case it has a great hold over us; in the second we forget it soon after waking. The state of the accident-processes differs in the two consciousnesses.
The concrete (3) Every consciousness is made up of a number process. ^^ concrete processes: ideas, feelings, wishes, resolu- § 8. The Divisions of Mind 21 tions, etc. Each of these, every idea or resolve or feeling that forms part of our conscious experience, is a specific item of that experience, — corresponding to the separate animal, horse or eagle or what not, of the zoologist.
(4) Once more: just as histological observation The mental shows that the animal is not made up of a single uniform substance, but that the organism is com- posed of a number of different tissues, so does psychological observation show that no concrete mental process, no idea or feeling that we actually experience as part of a consciousness, is a simple process, but that all alike are made up of a number of really simple processes blended together. These simple processes are called mental elements. They are very numerous: there are probably some 50,000 of them: but they may all be grouped into two great classes, as sensations and affections.
Reversing our order, then, we may build up mind as The up- follows. We set out with the two classes of elementary bmidmgof processes, sensations (red, cold, bitter) and affections (pleasant, unpleasant). These can never be experienced separately: a consciousness is never a single elementary process, but always a group of concrete processes. While the chemist can get H and O as well as H2O, the elements as well as the compound, the psychologist can never know sensations and affections except by abstraction, by directing his attention upon one part of a concrete process and ignor- ing the rest of it.
Above the elements stand the simplest forms of real mental experience, the concrete processes (ideas, feelings, etc.). These unite, again, to form consciousnesses, which appear in various states, according as their bodily conditions vary. Finally, a certain series of consciousnesses makes up 22 Psychology: What it Is and What it Does Elements.
Laws of connection.
Bodily con- ditions.
a child or adult or senile mind; and these three part-minds, taken together, make up the whole mind of the individual man.
§ 9. The Problem of Psychology. — We are now in a position to say just what the problem is that the psychologist is called upon to solve. He must (i) give an exact account of the elementary processes^ of sensation and affection. He must then (2) state the lazvs which govern the connection of the elements into concrete processes, and the connection of con- crete processes into consciousnesses. He must also declare whether these laws hold alike of the child, adult and senile mind, and of the animal mind as well as of the human, or whether there are different laws for each stage of mental development. Lastly, (3) he must give the bodily conditions under which the elementary processes appear, and those under which a change occurs in the state of consciousness.
This threefold problem is a great deal too wide to be solved in a single book. All that we can do here is to sketch briefly the answers to the most important questions involved. But it is well to realise, at the beginning of one's study of mind, how large and how varied a field psychology covers.
Additional Questions and Exercises (i) In thinking of the chair as directed in § 4 do you see it in your head, or do you see yourself sitting in it, or is it some- where in space, away from you? If you see it in space, where precisely does it seem to be? Can you make it move from place to place at will? Can you see it on your eyelids? Can you see it as if it were in the room behind you?
(2) When you are thinking of the table, and have iht feeling of 'ought '' and the resolve to hold the table steadily, what are the processes that actually make up your consciousness? Can Questions and Exercises 23 you split up the feeling and the resolve into simpler processes? Think of various things that you ought and mean to do. and see if you can discover what the feelings and resolves are made up of.
(3) What difference would it make in the list of processes, psychological and physiological, in § 6, if instead of simply wav- ing my hand to drive the fly away I actually touched my fore- head? Draw a diagram (pattern in James, Textbook^ p. 117).
(4) What other products of our common life are there, besides language and law, which compel us to believe that our fellow- men have minds?