T-^(5) How would a dog show anger, grief, recognition, dream- ing? How would a one-celled animal show likes and dislikes?
(6) Give from memory some of the differences between your mind as a young child and your mind now. How do old people's minds differ from your own?
(7) Write out a list of the chief consciousnesses that have made up your experience to-day. How short a time do you think a consciousness could last? And how long a time? Give an instance of a sudden change from one consciousness to another of quite a different kind.
(8) What is the physiological function of the brain? If it is the function of the stomach to digest, and that of the liver to secrete bile, the brain must have a similar ofifice, as a bodily organ. That office is 7iot to secrete thought and feeling: what (9) What is your earliest notion of your own mind that you can recall?
(10) State definitely what assistance a physiologist would derive from a knowledge of psychology.
(11) What is meant by the ^explosion' of a nerve-cell? {H.^ 287; F., 145; H. H. Donaldson, The Growth of the References for Further Reading James, Textbook of Psychology, pp. 1-8, 78-120, 128-133, 151-160. Sully, The Human Mind, vol. I., chs. i., iii.; vol. H., appendix N. Titchener, Ontli^ie of Psychology, §§ 1-6, 100. Wundt, Lecttires on Hu77ia7i and Animal Psychology, Lecture I., CHAPTER II The Method of Psychology § 10. Observation. — The first thing which science demands of you is that you learn to observe. Obser- vation, the seeing of things or processes as they really are, is by no means easy. " There is not one person in a hundred," says Huxley, ''who can describe the commonest occurrence with even an approach to accuracy." The diffi- There are four reasons why observation should be observing difficult, (i) In the first place, we are all naturally careless; we like to take things easily, and dislike making a sustained effort. Observation requires great care. (2) Secondly, we are all biassed or prejudiced. Thus we may expect to see a certain thing, or want to see a certain thing. Under these circumstances, there is every chance of our seeing that thing when it is not there to see. (3) Thirdly, it is not till we have had a good deal of practice in observation that we know what to look for; in our first attempts we are 'all at sea,' — just as likely to make much of the unimportant as to single out the important things. (4) And lastly, when the object of observation is a process, something that continually changes, we may be confused and baffled by the change. If the process goes on slowly, we may grow tired of observing, and so overlook some of its stages; if it goes on quickly, we may not have time to notice them all.
24 (i) and (2) are well illustrated by the game of *hunt- the-thimble.' The thimble is least likely to be found if you put it out in full view upon a central table. This is because the seeker is too careless to note so small an addition to the familiar things already on the table, and because he is prejudiced by the idea that you must have hidden the thimble in some very ' unlikely ' place.
(3) is illustrated by the difficulty that we all have of making our companion on a country walk see a bird that has just settled on a tree a little way off. When he has found it, when he knows what he should have looked for, he is surprised that he did not see it at once.
(4) may be psychologically illustrated. Go into a dark- ened room, and look straight in front of you. You will see the blackness dotted and sprinkled with all manner of coloured points and flashes and patterns, which pass into one another Hke ' dissolving views.' Try to follow the changes, describing them aloud to yourself.
These difficulties may all of them be overcome, and how to however, with patience and practice. The reader ^^^^^^ who has worked in a physical or chemical laboratory will remember how ' hopelessly accurate ' physical measurements and chemical analyses seemed at first, but how in time it became as natural for him to be careful as it had been to be careless. If a man ''keep faithfully busy each hour of the working day," says Professor James, '' he may safely leave the final result to itself. He can with perfect certainty count on waking up some fine morning, to find himself one of the competent ones of his generation, in whatever pursuit he may have singled out." And the sci- entific man would not know so well what his diffi- culties were, if he had not been able to surmount th^m.
overcome \ 26 The Method of Psychology What an * experi- ment ' is.
§ 1 1. Experiment. — Wherever it is possible, science employs experiment in its observations. An experi- ment is simply an observation made under standard conditions. When an event happens in nature, it happens under all sorts of conditions, some of which are its conditions (the circumstances under w^hich it occurs), while others are of no importance for it, but are present accidentally, as it were, — merely because nature is so enormously complicated. In order to sift out the true conditions from their chance accom- paniments we perform experiments. We arrange the conditions under which the event shall occur, in such a way (i) that other investigators can repeat our observation, and (2) that they and we can vary one condition after another, and see how the event is affected by the change. Hence an experiment is both an observation that can be repeated, and an observation that can be explained. These two prop- erties of the experiment are indicated by the words * standard conditions.* In many cases an experiment enables us to reproduce and explain an event that in nature requires long ages for its accomplishment. Thus the geologist finds that certain rocks have been smoothed or hollowed, to all appearances, by the action of sand driven against their surface by the wind. Taking a piece of rock to his laboratory, and driving sand against it at high pressure by the ' sand blast,' he is able to satisfy himself that the wind and sand could produce the observed effects.
So the formation of shores and of river beds, which in nature is an exceedingly slow process, can be shown in a few minutes experimentally, by pouring a stream of water upon a mixture of different kinds of earth.
/ § 12. Psychological Observation. — Psychological Thediffi- observation has all the difficulties of scientific obser- psychoiogi- vation in s^eneral, and some added difficulties of its ^^^ observa- ^ tion own. Our mental processes are so familiar to us, we think we know ourselves so well, that we are liable to be very careless and very prejudiced in our account of our own mind. Again, even if we take the psychologist's warning to heart, and resolve to look at ourselves carefully and impartially, we are at a loss to know what to look for: what we have always taken most for granted may be altogether imaginary, and quite unlike the reality. And lastly, of all the processes that we could set out to exam- ine, mental processes are the least tangible and the most elusive.
Moreover, psychological observation is observation or intro- by each man of his own experience, of mental pro- ^^^^ ^°" cesses which lie open to him but to no one else. Hence while all other scientific observation may be called inspection, the looking at things or processes, psychological observation is introspection, the looking inward into oneself. Now ^ observing ' is a mental process. When we are observing a thing or process in the outside world, we do not thereby interfere with it: the fossils are there, and the tadpole goes on growing, whether or not we have turned them into mental processes, formed ideas of them. But when we are observing a mental process the case is very different. We are now interfering with what we are watching: our consciousness a moment ago, before we began to introspect, was made up of cer- tain processes; now we have introduced among these 28 The Method of Psychology a new process, — the mental process of observation. Surely, that is a poor method of observation which changes the very thing that we want to observe! and their To get ovcr this difficulty, you must wait to introspect until the processes that you wish to examine have passed by. Let them run their course undis- turbed: then call them back by memory, and look at them. They are now dead, and cannot be changed by your observation. Only take care that you do not wait too long before recalling them If ^ post mortem examination is to be of any use, it must be made soon after death. And decay sets in among mental pro- cesses as well as in dead bodies; we may * forget ' them entirely, or they may get overrun by all sorts of other and more recent processes, so that we can- not live them over again just as they were.
The chief reason for the occurrence of the ' blanks ' in the introspection of § 4 was that you were trying to observe your ideas while they were going on. How fatal this mis- take is you will reaUse at once if you seek to introspect a feeling during its course. Try to observe your enjoyment, while you are enjoying yourself: the observation drives the enjoyment out of mind altogether. You do not drive an idea out of mind in the same way, by the wrong use of introspection; but you alter it and interfere with it very considerably.
Here, as before, the difficulties, formidable as they seem, can be overcome by hard work. Since you carry the material for introspection about with you, you can practise it at all times and in all places; and practice makes perfect. For some little while you will be baffled; but presently, very likely when you are least expecting it, you will come face to face with a § 13. The Psychological Experiment 29 concrete process and find yourself observing it, — and then you are on your way to be a psychologist.
Many of our most interesting mental processes are very hard to catch, and, unless one seizes upon them promptly, will be gone before there is an opportunity to introspect them. One may, however, cultivate an attitude of alertness towards one's psychological experiences, may learn (as it were) to meet them half-way, — or rather to pounce upon them before they have lapsed from memory as well as from the present consciousness.
We are often warned by moralists against ' giving way to a Morbid morbid introspection.' But ' morbid introspection ' is very differ- introspec- ent from the introspection of the psychologist. What the moral- ist condemns is a continual occupation with the affairs of self, to the neglect of the wider interests of family or society or nation, — an exaggerated notion of the importance of one's own acts and motives, and the consequent failure to see oneself in a right social perspective. In other words, he is looking at the practical side of life; whereas the psychologist's interest is scientific. The psychologist introspects his own mind not because it is worth more than others, but because it is the only mind accessible to him. \ § 13. The Psychological Experiment. — Experiments inpsychoi- are more needed in psychology, perhaps, than in any ments are other science. For the facts of nature are, at any rate, open to all observers alike; whereas the facts of mind are never open to more than one person. If then the results of introspection are to have any scientific value, — if we are to have any assurance that they hold equally for all minds, — they must evidently be obtained under standard conditions: so that every enquirer may repeat for himself the obser- vations recorded by other enquirers as true in their particular cases.
needed 30 The Method of Psychology and can be performed.
The immediate conditions of mental processes are brain processes. Hence it is these that we should record and vary, if we were able to perform a direct psychological experiment. Plainly, however, we cannot get at our brain processes; the brain is locked up in the skull, and can be affected only in- directly, by way of the external organs of the body which are connected with it by nerve fibres.
Still, experiment is possible. The processes that go on in a particular part of the brain are condi- tioned (i) by the excitations coming in along the nerves that lead to it, and (2) by the state of all the rest of the brain. The excitations are dependent, in their turn, upon the stimulation of the external bodily organ from which the nerves start; so that by varying the sthnuhis in a definite way, we can vary the brain processes in a definite way, — just as well as if we had access to them directly. On the other hand, we try to keep the rest of the brain in the same state throughout an experiment by arranging (i) that disturbing stimuli shall be shut off, and (2) that the observer's ' frame of mind ' shall remain the same.
Suppose, e.g,, that we wished to find out by experiment how our idea of a printed word is formed, — whether we read it letter by letter, or take in its form as a whole, or take in the form and certain letters. The immediate conditions of the idea are cortical processes in the back of the head, where the excitations carried in by the optic nerve are received. These are out of our power. But they depend (i) upon the excitations coming in through the eye, and (2) upon the state of the rest of the cortex. (We saw in § 6 that the cell- clusters which receive, and the cell-clusters which send out § 13. The Psychological Experiment 31 excitations are connected by nerve fibres; the same thing is true of all the different receiving clusters, those connected with the eye, ear, mouth, skin, etc.) Now we can control the excitations, because we can present to the eye any kind of word-stimulus that we care to use, altering or omitting par- ticular letters of the word, etc.; and we can record the nature of the stimulus in every case, so that other psychologists are able to repeat our experiments. We try, further, to keep the rest of the cortex steady (i) by shutting out other stimuh. Thus we work in a darkened room, and flash the word on a screen, all else remaining dark. And (2) we do all we can to preserve an equable frame of mind; knowing that if the thoughts are allowed to wander, new processes will be arising in various parts of the cortex, and the equilibrium of the brain will have been upset.
It is clear that in most cases two persons are needed for the performance of a psychological experiment. The ' subject ' or ' observer ' introspects; the ^ experimenter ' arranges the condi- tions. Thus the subject would introspect, in the instance given, to see what contribution the various stimuli made to the forma- tion of the idea under investigation; the experimenter would arrange the instruments for flashing the stimuli, would do his best to keep the subject in an even frame of mind, and would record the character of the stimuli given and any indications that the observer might show (by incidental remarks, by restlessness, etc.) of steadiness or unsteadiness of thought.
In this way, introspection can take place under Community standard conditions; the psychologist can experi- ^hus^Lsured. ment. The conditions to be repeated and regulated are those of (i) stimulus and (2) frame of mind. If they are properly described, any psychologist can satisfy himself of the correctness or incorrectness of a result obtained by any other psychologist: he can make precisely the same observation under pre- cisely the same circumstances. If a number of psy- chologists, after many experiments, reach the same 32 The Method of Psychology Experimental introspection the psycho- logical method.
The first psychologi- cal labora- tory.
result, that result is a psychological fact of scientific value.
§ 14. The Method of Psychology. — It follows, from the two foregoing Sections, that the method of psy- chology is the method of experimental introspection. Only by looking inward can we gain knowledge of mental processes; only by looking inward under stand- ard conditions can we make our knowledge scientific.
Even when we are examining a mind as if it were an object in the outside world, — when we are trying to understand the mental processes of a child or a dog or an insect as shown by conduct and action, the outward signs of mental processes, — we must always fall back upon experimental introspection. For our own mind is our only means of interpreting the mind of another organism; we cannot imagine processes in another mind that we do not find in our own. Experimental introspection is thus our one reliable method of knowing ourselves; it is the sole gateway to psychology. / Psychology is a very old science: we have a complete treatise from the hand of Aristotle (b.c. 384-322). But the experimental method has only recently been adopted by psychologists; the first psychological laboratory was opened by Professor Wundt at Leipsic in 1878-9. It now seems certain that there is no mental process that cannot be observed experimentally. There are many that have not yet been satisfactorily investigated; but the reason is simply that the use of the experimental method requires training and practice, and that twenty years is too short a time for the re-making of a whole science.
Let us take an instance to show that experiment is possible under very unfavourable conditions. We said in § 6 that it is § 15. General Rides for Introspection 33 only when the cortical cells which receive incoming excitations are exploded that a mental process arises. But it is plain that, when once these cells have been exploded by an excitation coming from the outside^ they can be exploded later from the inside. Thus we should never know what greeii was unless a certain stimulus had been presented to the eye and the green- cells of the cortex, if we may use that phrase, had been exploded by the excitation sent inwards along the optic nerve. But when once we have 'seen' green, w^e know what green is: we can remember green, or imagine it, even if we are looking at black or red. The green-cells are, in this case, exploded from within (by change of blood supply, etc.); there is no external stimulus. Here, then, the circumstances are as unfavourable for experiment as they can well be; we seem to have no control over the exci- tation, the bodily condition of the remembered or imagined green.
Nevertheless, we can experiment. For we can (i) keep dis- tracting stimuli away, and (2) introspect the memory-green or fancy-green in an even frame of mind. These are standard conditions; they can be accurately recorded by the psychologist who introspects; and they can be repeated by other psycholo- gists after him.
§ 15. General Rules for Introspection. — The rules Special and for introspection are of two kinds: general and ofintrospec- special. The latter refer to the regulation of stimu- *^°"- lus, and differ in different investigations; the former refer to the frame of mind, and must be observed in all investigations alike.
Suppose, e.g.^ that you were trying to find out how small Special rules a difference you could distinguish in the smell of beeswax; of mtrospec- that is, how much greater the surface of the stimulus must be made if the sensation of smell is to become noticeably stronger. It would be a special rule that you should work only on dry days; for beeswax smells much stronger in wet than in fine weather. Or if you were trying to discover how well you could call up the smell of beeswax in your mind, without having the wax under your nose, it would be D 34 The Method of Psychology General rules: attention.
a special rule that you should perform the experiment in a perfectly odourless room, so that the excitation set up from inside the brain should not be interfered with by foreign stimulations set up in the smell-cells of the nose. Again, if you were trying to distinguish all possible tints of blue, it would be a special rule that you should work always by the same illumination: always by dull daylight, or always by the same electric light, etc. For a blue seen in sunlight is different from the same blue seen in dull dayhght.
The general rules of experimental introspection are as follows: impartiality, (i) Be impartial. Do not form a preconceived idea of what you are going to find by the experiment; do not hope or expect to find this or that process. Take consciousness as it is.
(2) Be attentive. Do not speculate as to what you are doing or why you are doing it, as to its value or uselessness, during the experiment. Take the experi- ment seriously.
(3) Be comfortable. Do not begin to introspect till all the conditions are satisfactory; do not work if you feel nervous or irritated, if the chair is too high or the table too low for you, if you have a cold or a headache. Take the experiment pleasantly.
(4) Be perfectly fresh. Stop working the moment that you feel tired or jaded. Take the experiment vigorously.
The reasons for these rules should be obvious. Attention to the stimulus makes it clearer, and holds it in mind longer. Moreover, if the attention wanders, other processes than that under investigation come into consciousness, and inter- fere with the experiment. The same thing happens if you are uncomfortable. Discomfort draws your attention from comfort, freshness.
Quest io7ts and Exercises 35 the object of the experiment to the source of the uncomfort- able feehngs. And fatigue means that your brain is not in good working order.
Summing up, then, we may say that the rule of psychological work is this. Live impartially^ attentively^ comfort ably, freshly ^ the part of your rnental life that you wish to understand. As soon as it is past ^ call it back and describe it.
Questions and Exercises [The exercises will be best performed in class, or by several students who are working together, as comparative results are desirable.]
(i) Numerous methods may be devised to test accuracy of observation. You may, e.g.^ draw a plan, to scale, of some room familiar to you; putting doors, windows and furniture in their right positions. Or draw from memory the distortion that an oblong table suffers when you look at it from one corner. Or draw pictures from memory of an oak-leaf and an elm-leaf. Or have some simple geometrical construction, some arrangement of dots and lines and curves, drawn on a blackboard: look at it for 5 sec, and then try to reproduce it on paper.
If two or three persons have recently witnessed an accident or a theatrical performance, or have been present at a social gather- ing, let them write out a detailed account of what they experi- enced, and compare notes. Or let a 'number of people walk a certain distance down a country road, or a street, and afterwards write out their experiences, and compare notes.
(2) Four newspapers describe the same gown as {a) gold brocade, (J?) white silk, {c) light mauve, and {d) sea-green, with cream or ivory sheen on it. How could this difference of opinion have arisen?
(3) Newton is said to have discovered the law of gravitation by observing the fall of an apple from the bough. Was this a simple observation, or could it be said to have anything of the experiment about it?- (4) How does the psychological experiment resemble, and how does it differ from, the physical or chemical experiment?
(5) Try to introspect an idea while it is going on. Intro- spection is a mental process, or rather a group of mental pro- 36 The Method of Psychology cesses. Hence the consciousness which contained the idea is intruded on by other processes from the moment that you begin to introspect. What are these other processes that make up introspection? In other words: what changes do you find set up in consciousness by your attempt to introspect an idea (say, that of an elephant) while it is still passing through your mind?
(6) You may test the power of bias in this way. Make a series of coloured papers, choosing those that are as nearly as possible of the same brightness, that range from pure red to a pronounced bluish red. Cut a circle, of about 2 cm. diameter, from each sheet. Give the observer a rolled tube of black card- board to look through. Tell him that you are going to show him a series of reds, beginning with pure bright red and passing into very dark red; and ask him to say when the first really dark red comes. Now lay the circles one by one on the table, in the order from red to bluish red, letting the observer see each in turn for some 2 sec. See how far the series can go before he says: ^' The reds are not getting darker; theyVe getting bluer! " Or take a long piece of wire. Let the subject close his eyes, and give him one end to hold. Tell him that you are going to put the other end in a candle flame, and ask him to say when he senses the heat. Take the other end in your hand; walk up to the table on which the subject knows the candle stands, and strike a match, — but do not light the candle. Notice by the seconds' hand of your watch how long it is before the subject senses the imaginary heat. If the experiment fails, he is already so far an impartial observer; but probably it will not fail.
(7) What are the characteristics of a good ' subject '? Of a good experimenter?
(8) Can you get from psychological observation and experi- ment any advantages, in the way of mental training, which you cannot get from observation and experiment in the other^ sci- ences?
References James, Textbook, pp. 160-175. Sully, Humaii Mind^ vol. I., ch. ii. Titchener, Outline^ §§ 9, 10, 33. Wundt, Lectures, Lect. I., § 3. Wundt, Outlines, § 3.
CHAPTER III Sensation § 1 6. Sensations and their Classification. — A sensa- tion is an elementary mental process. It cannot be^ split up, by the most persistent introspection under the strictest conditions, into any simpler processes.
It is a characteristic of sensation that it comes to Definition of consciousness by way of a special bodily organ, a ^^"^^^^°"- sense-organ. Or, in more technical language, its bodily condition is the stimulation of some particular bodily organ. We are accustomed to think that there are five of these sense-organs: eye, ear, nose mouth and skin. Scientific investigation has shown, however, that there are more than twice that num- ber.
Remember that a sensation never occurs quite alone in our mind; consciousness is always made up of more than one pro- cess. We can, however, get an approximately pure sensation by experiment. We shut off distracting stimuli, and focus our attention upon some single process in consciousness {cf. § 8).
Remember, too, that the 'particular bodily organ' may mean either (i) the external organ, like eye or ear, or (2) the part of the brain cortex to which the nerves from eye or ear run {cf.
As every sensation is set up in some definite The different bodily organ, we shall, naturally, classify sensations sation. by grouping them under the organs through which they come. We shall thus have eye sensations, nose sensations, skin sensations, etc., to describe and dis- 37 38 Sensation cuss. There are, however, some organs that give us * more than one set of sensations: thus the ear, which we think of as giving us only sensations of hearing, really gives us a very different sensation as well, — the sensation of giddiness. And there are different organs that furnish similar sensations: thus not only the skin, but the joints also, furnish the sensation of pressure. The reason is simple. What we call the ear contains two different cell-groups, connected by nerves with different parts of the cortex; while skin and joint contain similar cell-groups, connected with the same or similar parts of the cortex. We shall, of course, take account of these facts in making out our list of sensations.