I. Definition of suggestion — Suggestion and dreams — Distinction between the experimental processes by ideas and by peripheral excitement — The persons capable of receiving suggestions — The conditions of receptiveness: mental inertia, psychical hyperexcitability — Suggestion during hypnotism — Suggestion during the waking state — Different kinds of suggestion — Speech — Gesture — Muscular sense — Auto- suggestion — Relation between the idea suggested and the peripheral excitement — Error made by those who see suggestion in everything.
II. The method — Simulation — Voluntary suggestions — Unconscious suggestion — Comparison between the phenomena of suggestion and the facts of positive science.
III. Effects of suggestion — Modifications of vegetative functions — The suggestion of psychical phenomena — Classification — Positive suggestions hallucination, and action — Psychological analysis of their production — Law of negative suggestions— Law of psychical inhibition — Post-hypnotic hallucinations — Forgetfulness of the act of suggestion.
Definition of Suggestion. — We have seen that the hypnotic sleep approximates to natural sleep in its mode of production and in some of its symptoms. This comparison may serve as an introduction to the theory of the facts of suggestion. These facts are at first sight astonishing, unintelligible, and sometimes indeed they appear incredible. The question arises how it should be
possible for one person to exert over another the power of making him speak, act, think, and feel as it pleases the experimenter to dictate.
In order to make a systematic study, we must proceed from what is better known, to what is less known. As we have repeatedly said, the psychical phenomena of hypnosis can only be understood when they are compared with the dreams of natural sleep. The effects produced on hypnotized subjects by suggestion are nothing but a dream, produced and directed by the experimenter. This is a legitimate comparison, since it is possible to modify the dreams of a person who is naturally asleep. Maury performed some striking experiments on himself to illustrate this fact.* He begged a person to remain beside him in the evening, and as soon as he fell asleep to excite certain sensations in him, without telling him what they were to be, and to wake him after giving him time to dream. These dreams, produced by sensorial excitements, did not differ from those obtained from hysterical hypnotized subjects, by means of suggestion. On one occasion eau-de-cologne was given to him to smell; he dreamed that he was in a perfumer's shop, then the idea of the perfume aroused that of the East, and he dreamed that he was in Jean Farina's shop at Cairo. The nape of his neck was gently pinched, and he dreamed that a blister was applied to it, which recalled to mind the physician who had attended him in childhood. When a hot iron was brought near his face he dreamed of stokers. When he was asleep on another occasion, a person present ordered him in a loud voice to take a match, and he dreamed that he went voluntarily to find one.
Another resemblance of a different kind may be established between the psychical phenomena of natural sleep and those of hypnotic sleep. As one of the present writers has shown,* in the case of many patients the pathogenic idea, the first manifestation of delirium, may originate in the waking state, but it is generally confirmed by the dreams of natural sleep, in which it is re-echoed with added strength. Clinical observation therefore shows that the experiments so easily performed during the artificial sleep may be spontaneously realized in the normal sleep.
The region of suggestion has a wide range. There is not a single fact of our mental life which may not be artificially reproduced and magnified by this means. It is easy to understand how much psychologists may gain from this method, which introduces experiment into psychology.
Before going further, we must define the extent and limits of suggestion, by a more precise definition than the somewhat vague and summary one given above. Strictly speaking, suggestion is an operation producing a given effect on a subject by acting on his intelligence. Every suggestion essentially consists in acting on a person by means of an idea; every effect suggested is the result of a phenomenon of ideation, but it must be added that the idea is an epi-phenomenon; taken by itself, it is only the indicative sign of a certain physiological process, solely capable of producing a material effect.
This characteristic will generally enable us to recog-
nize what is and what is not suggestion, although this is often a very difficult question. Thus, when striking the tendons, or kneading the muscles makes it possible to form a contracture of the arm of an hysterico-lethargic patient, no suggestion is made, since the contracture results from a physical action, into which the subject's mind does not appear to enter. If, on the other hand, the experimenter approaches the subject, and says, without touching him, "Your arm is bent and stiffened, and you cannot straighten it," the contracture which occurs in consequence of these words results from a psychical action. The experimenter's command only produces its effect by traversing the subject's intelligence; it is the idea of contracture, entering into the subject's mind, which has produced the contracture, and this is really suggestion. From this point of view, it may be said that the theory of suggestion infuses new life into the old philosophic question of the action of the mind upon the body, and that at the same time it throws fresh light on the large group, still so obscure, of diseases of the imagination.
We give another example. Like contracture, paralytic movements may be produced in two different ways. If in a hysterical subject the fixed end of a vibrating tuning-fork is applied to certain points of the vault of the cranium, a transitory excitement of motor force takes place in the subject's arm which soon passes into complete and flaccid paralysis.* In this case the paralysis is the direct result of the vibratory movement transmitted by the tuning- fork through the thickness of the skull to the brain: the
subject's intelligence takes no part in it; the experiment, although made upon his body, has not affected his mind; there is no suggestion. On the other hand, if the idea is impressed upon the subject that his arm is affected by paralysis, the paralysis which ensues is of a psychical nature, since it results solely from the subject's conviction that he is paralysed. It does not result from a physical shock, or traumatism, but from a phenomenon of ideation. A suggestion has been made.
The analysis of this last example makes it possible to avoid a confusion made by some writers. It has been too readily admitted that every hypnotic process which has its seat in the brain, proceeds from a phenomenon of suggestion, and this has led to the opinion that lethargy, catalepsy, and hysterical somnambulism, which are perhaps due to reflex cerebral action, are the pure and simple products of suggestion. The fact just mentioned disposes of this error. The paralysis induced by physical vibration and the paralysis induced by suggestion probably both result from modifications of the cortical substance of the brain; they are consequently reflex cerebral acts. But the two cases are widely different. Paralysis by suggestion demands the aid of the subject's intelligence, and if the function of ideation were for any reason suspended, this kind of paralysis could no longer be produced. The study of hypnosis may be divided into two parts, distinguished by the different processes which are employed. The first part includes the hypnotic phenomena produced by physical excitements, or sensations, which were the subject of the two preceding chapters; the second part includes the hypnotic phenomena pro-
duced by ideas, that is, the theory of suggestions. These two modes of experimentation are parallel, and it is difficult to say which of the two has the widest extent.
Those liable to Suggestion. — Suggestion does not act with equal intensity on all individuals. If you assure a person who is awake, in normal health, and perfectly self-possessed, that she is hungry, she will reply that you are mistaken; if you try to suggest a visual hallucination by asserting that she has a book in her hands, she will declare that she does not see it. The assertion only produces in her mind a slight effect, which is quickly effaced. It produces an idea of the phenomenon, not the phenomenon itself. It is, in short, evident that the suggestion influences a sound person no more than the opening of her eyes would produce catalepsy.
In order that the suggestion should succeed, the subject must be either spontaneously or artificially in a morbid state of receptivity; but it is difficult to define with precision the conditions under which suggestion is possible. Two have been given, of which the first is the mental inertia of the subject. It has been said that in an hypnotic subject the field of consciousness is completely vacant. A state is produced, and since there is no obstacle — neither the power of arrest nor that of antagonism, — the idea suggested dominates the sleeping consciousness. This explanation has been given by Heidenhain, Richet, RIbot, and others, yet we doubt whether it is altogether in harmony with the facts. If the limitation to a single idea is realized in cataleptic subjects, it is much more rare in the case of somnambulists. We believe that the aptitude for suggestions is caused by a second phenomenon — by psychical hyper-
excitability, In our opinion, if the idea suggested exerts an absolute power over the intelligence, the senses, and the movements of the hypnotized subject, it is especially due to its intensity. But we admit that it is difficult to resolve the question, and we prefer to leave it open.
The number of persons liable to suggestions is immense; the liability is evinced, not only in cases of hypnosis and of natural sleep, but also in some forms of intoxication by alcohol, and haschich, and in the waking state. We only propose, however, to consider hypnotized subjects.
The aptitude to receive suggestions is strongly developed by hypnotism, but, as we have already said, it does not occur in all phases of hypnosis, only in catalepsy and somnambulism. The suggestions made to a cataleptic subject are simple, automatic, inevitable; the reason takes part in those of somnambulism; the subject discusses and enlarges on them, and sometimes even offers resistance. We shall have to consider these shades of differences whenever we have to do with interesting suggestions, and we shall for the most part content ourselves with describing the suggestions of somnambulism.
After awaking, the subject is still sensitive to suggestion; this fact has long been known, and is mentioned by Braid among other writers. Of late years it has been studied by Richet, Bernheim, Bottey, etc. It is possible, not only to make suggestions to subjects in the waking state, but also to persons who have not been hypnotized at all. Learned men have been agitated by these latter experiments, which have aroused in them doubt and
dissatisfaction. They have no difficulty in admitting that suggestions may be made to hypnotized subjects, since they are not in normal health, but they cannot understand how they should be made to individuals who are awake, not under hypnotism, and that this should be done by modes of action in daily use in our relations to one another. The question arises whether individuals capable of receiving suggestions in their waking state are in common life liable to submit automatically to the influence of others; whether they are weak in mind; what is their physical and moral state, and if there is anything peculiar in their waking state and hereditary antecedents. These are the questions stated by Janet, and they have not as yet received any reply. The possibility of making suggestions to normal subjects must, however, be admitted if, as one of the present writers has done, we refer suggestion to the act of attention. When attention is sufficiently intense, the period of reaction may disappear, and may even become negative; that is, the reaction may precede the excitement. An intense mental representation, whether arising spontaneously, or induced by suggestion, may therefore produce a reaction irrespective of any excitement.*
Different hinds of Suggestions. — If it is the characteristic of suggestion to address itself to the subject's intelligence, it follows that there are as many forms of suggestion as there are modes of entering into relations with another person.
The experimenter may begin by employing spoken or written suggestion. This is the simplest and most convenient means. In order to produce an hallucination,
it is enough to name the imaginary object, to say to the subject, "There is a serpent at your feet!" and the hallucination immediately occurs. Verbal assertion is the process most in use, since in this way everything which human speech is capable of expressing may be suggested, and it is also the most precise.
Gestures, which are often employed by some experimenters, are a very inferior means. They are undoubtedly fairly successful in the case of subjects who have been long under treatment. Without uttering a word, the hallucination of a serpent may be produced in such subjects by making an undulatory movement with the finger, or still more simply, by directing their eyes downwards. It also becomes possible to give orders by means of gestures, to constrain the subject to walk, to follow or approach the experimenter, to make him kneel down, etc. On pointing to a hat, the subject takes hold of it, and on pointing again to his head he puts it on. He may also be made to take something out of the pocket of another person. Pitres mentions the amazing quickness with which he has observed some subjects divine the meaning of the slightest movement of the fingers, lips, or eyes. But these processes are lacking in precision. Although it is probable that it is the psychical and expressive character of the gesture which generally acts upon the subject, that is, that it arouses ideas, we do not certainly know that no other cause is at work. The same must be said of passes, for when suggestions are made by their means, we do not know how it is done. But if suggestion by means of gestures is often vague, it may be very intense. When a verbal suggestion of movement is given to a subject.
the image of such movement is aroused in his mind; this image, however intense it may be, must always be less intense than the sensation given to the same subject when the movement in question is executed before his eyes. The result of the two experiments is therefore very different.* It has been repeatedly ascertained that if a dynamometer is placed in a subject's right hand, and he is ordered to hold it with all his might, this verbal suggestion only augments his normal dynamometric force by a few degrees; but if the action of firmly clenching his fist is imitated before him, his muscular force is not merely increased, but doubled; thus showing that in certain cases the suggestions given by gestures afford more intense results than it is possible to obtain by words only.
It is sometimes useful to combine suggestive gestures with verbal suggestion, or with the presentation of an object. For instance, a real object is presented to the subject, of which the nature is said to be different; he is caused to eat paper, while told that it is a cake; or it is suggested to him that one of the persons present has a false nose. Combining the word with the gesture gives definiteness to the suggestion.
Suggestive gestures address themselves to the sight. The other senses may also receive impressions. If a gong is gently sounded close to the ear of an hypnotized subject, he thinks that he hears bells; and if he is pricked or pinched, the image of stinging creatures may be aroused. But all these processes are inferior to that of speech. In all cases in which the idea awakened in the subject emanates from the experimenter's direct sugges-
tion, the subject is in a state of direct subjection to him. This state is not opposed to that which we may observe in the waking state; there is only an exaggeration of phenomena, which makes it easier to understand what occurs in subjects held to be of sound mind, who are unconsciously influenced by the will of another person substituted for their own. Indeed we have only to glance at social relations in order to see that individuals fall into two categories — the leaders and the led — that is, the givers and the recipients of suggestions.
It is characteristic of suggestion by means of the muscular sense, that it may be said to have its origin in the hypnotized subject. If his limbs are placed in a tragic attitude, a corresponding emotion is displayed; if his fists are clenched, he frowns with an expression of anger; if his limbs are disposed so as to begin any action, it is carried on by the subject, and in this way he may be made to climb or go on all fours; or if a pen or piece of work is put into his hand, he will write or sew. If his hand is raised, and the forefinger is bent, the idea occurs to him that a bird is perching on his finger, and this hallucination is developed. A slight movement by the experimenter will carry on this silent suggestion; the subject then imagines that the bird has taken flight, and he runs about the room trying to catch it. If the hands of a female subject are crossed upon her bosom, it suggests the idea that she is holding an infant. All these facts are included in the same formula; the attitude given to the subject's limbs is accompanied by definite muscular impressions, which arouse corresponding ideas in the brain.
Since every suggestion has its origin in a sensorial
impression which is experienced by the subject, it is easy to see that this impression may be produced by an external object without the intervention of the experimenter. This mode of suggestion is inconvenient, and therefore rarely employed, but it is sometimes spontaneously displayed. Bennett mentions the case of a butcher who wished to place a heavy piece of meat on a hook above his head; he slipped, the hook caught him by the arm, and he remained suspended. He was taken down half-dead, his sleeve was cut open, and, although he complained of great suffering, as soon as the arm was exposed, it was found to be absolutely intact; the hook had only penetrated his coat-sleeve. This is an instance of suggestion without an experimenter, and many others might be given. We shall speak presently of the paralysis induced in hypnotic subjects by suggestion. It is probable that some cases of hysterical paralysis, termed traumatic, — that is, caused by a shock, — are also due to suggestion, since the patient cannot divest himself of the idea that such a severe shock must produce paralysis.
These latter facts pass gradually into those to which the name of auto-suggestion has been given. There are cases in which suggestion has its origin in the subject's intelligence; in which the suggestion is made by himself. Instead of being the result of an external impression, as in the case of verbal suggestion, the suggestion results from an internal impression, such as a fixed idea, or delirious conception. A few examples will explain this better than dry definitions. A subject imagined that she was opposing by force the hallucination suggested by one of the present writers, and that she had given him a blow on the face. When her supposed
adversary entered the room on the following day, she imagined that she saw a bruise upon his cheek. This hallucination was derived from the former one, just as a conclusion is derived from its premisses, and it may be taken as a type of auto-suggestion. The subject must have unconsciously argued after this fashion: I gave him a blow on the cheek, of which therefore he must bear the mark. Another subject, coming out of a state of profound lethargy, which had only lasted for five or six minutes, imagined that she had been asleep for several hours. We encouraged the illusion by saying that it was two o'clock in the afternoon, although it was in reality nine in the morning. When she heard this, the patient felt extremely hungry, and begged us to let her go to get food. This was a kind of organic hallucination — the hallucination of hunger — suggested to the subject by herself. She unconsciously reasoned somewhat after this manner: It is two o'clock in the afternoon; I have eaten nothing since I got up, and am therefore dying of hunger. This imaginary hunger was soon satisfied by an equally imaginary meal. We suggested that there was a plate of cakes on a corner o£ the table, of which the subject might partake, and at the end of five minutes her hunger was appeased. These examples of auto-suggestion are derived from hallucination, and we now give one belonging to a different order of ideas. We approached a hypnotized subject, and addressed her as follows: "A serious accident has just befallen you. Do you remember it ? Your foot slipped in crossing the courtyard, and you fell upon your hip. You must have hurt yourself very much." The subject instantly felt a severe pain in the hip and began
to moan, and also, suggesting to herself the natural consequences of the fall, she gave herself a slight paralysis of the limb, and limped on awaking.
The general conclusion to be derived from all these facts and experiments is, that suggestion consists in introducing, cultivating, and confirming an idea in the mind of the subject of experiment. In reply to the inquiry. What is meant by an idea, and what latent force does it possess in order to affect some individuals so powerfully? we must repeat that the idea resolves itself into an image, and the image into a revival of the sensation. It consists in the psychical renewal of a peripheral sensation already experienced by the Subject. This enables us to understand its power; the idea is, strictly speaking, only an appearance, but there lurks behind it the energy excited by a physical, anterior excitement.
This point of view is confirmed by the fact that it is possible to produce, by simple physical excitements, that is, by sensations, almost all the effects which have hitherto been produced by suggestion, that is, by ideas. Thus, instead of producing or putting an end to paralysis by speech, it may be produced by a shock to the limb or on the skull (Charcot), and it may be terminated by employing the same process. The repetition of the vibrations of the tuning-fork represents the shock of traumatism. Hysterical anaesthesia may also be produced and destroyed by analogous processes.* The movements may also in some cases be produced by excitement of the scalp. We cannot here give full details, and only wish to show that suggestion may be referred to the
peripheral excitement in which it has its source. It is precisely because it produces in the nervous centres of some subjects the same dynamic modifications, that suggestion is able to effect all the phenomena which result from peripheral excitements. We are reminded of an old saying which is not yet obsolete, Nihil est in intellectu quad non prius fuerit in sensu.
In our day the power of suggestion has been so firmly established that some people have maintained that it is to this we must ascribe the action of aesthesiogenic and dynamogenic agents, etc., employed for peripheral excitements. The reality of the process of cure by these agents has been denied, and it is thought that suggestion will explain the singular phenomenon of transfer, discovered by Gelle, and afterwards studied by a commission of the Société de Biologie; what Carpenter ascribed to expectant attention is now ascribed to suggestion. This error is chiefly due to the idea that if suggestion will reproduce any given phenomenon which was previously ascribed to a physical excitement, therefore suggestion is its true cause. But this argument is weak. It might as well be said that since it is possible to satisfy a somnambulist's hunger with an imaginary meal, nourishment is at all times unnecessary for him.
Moreover, this opinion does not possess the merit of simplicity which is claimed for it, since it is as difficult to understand why the simple idea of paralysis should paralyse, as to understand why a shock to the skull should produce the same effect. Besides, in ascribing everything to the idea, we ignore the fact that it is a secondary and derivative phenomenon. To maintain that the idea is everything, and the peripheral
excitement nothing, would be equivalent to maintaining that the idea is a phenomenon entirely independent of the sensorial functions; it is, in fact, a revolt against the grand theory of the relations between sensations and images which dominates modern psychology. Such an opinion is also opposed to physiology, which teaches us that several functions — the secretions of sweat, tears, etc. — may become active by means both of physical and mental causes, and that the reality of the one does not exclude the other.
We now come to the important question of the method.
Such a book as this cannot include within its narrow limits the innumerable details of hypnotic experimentation. Since it is necessary to restrict the exposition of facts, we think it well, by way of compensation, to throw light on the questions of method, which constitute the philosophic side of the subject.
The study of hypnotism bristles with difficulties, although this has not occurred to the numerous persons who have expected to find in these questions the occasion of a brilliant and easy success. Although nothing is more simple than the invention of dramatic experiments, which strike the vulgar with fear and astonishment, it is on the other hand very difficult, in many cases, to find the true formula of the experiment which will give its result with convincing accuracy.
Speaking generally, the method is the same in the study of physical phenomena, and in that of the phenomena of suggestion. In order to obtain constant results,
which may be verified at pleasure by any other observer, it is necessary to define with the utmost precision the physiological and pathological conditions of the subjects of experiment, and the nature of the processes by which it is performed. Whenever one of these two rules is violated, the method is incorrect. There is a risk of seeing the result announced falsified by another observer, who was unable to reproduce it; hence the questions become confused, personal discussions, which are necessarily sterile, ensue, and finally general disbelief is aroused.
The physical state of the subject must first be defined. We recommend the course pursued by ourselves, of choosing hysterical subjects who display the strongly marked characteristics of profound hypnotism. Any one who wishes to verify the new experiments in suggestion which we adduce, must occupy himself solely with these subjects. It is very important to indicate the physical state of the subject of experiment, and in no other way can there be any comparison of results. It is true that no morbid state is constantly presented under the same aspect. Each individual impresses a peculiar stamp on the morbid state to which he is subject. All diseases are displayed in forms which vary with the constitution of the subject, and it may even be said that each organic function presents individual variations. We cannot, therefore, be surprised that hypnosis is displayed under various and more or less characteristic aspects, but this is an additional reason for only comparing similar facts, unless we wish to fall into deplorable confusion.
It is less easy to define with precision the modes of operation, since the experimenter is often mistaken with
respect to the means which he employs. He believes that he is suggesting a given idea, but at the same moment he unconsciously suggests a second, which alters the first idea, or else the subject intervenes in an active manner, in order to simulate certain phenomena, thus deceiving the observer. Simulation and unconscious suggestion are the two rocks to be avoided in studying the facts of suggestion.
Simulation. — It must be admitted that simulation, always a difficulty in the study of hysteria, is no where so formidable as it is in this department of study. The experimenter is safe as long as he has to do with physical phenomena, but this is not the case with many of the facts of suggestion. It is very easy for the subject to simulate an hallucination or delirium. These are internal phenomena which cannot be seen, touched, and handled, like an objective fact; they are subjective phenomena, personal to those who experience them, and consequently they may readily be assumed. Before studying them, it must be proved that they exist. Before observing the characteristics of an artificial hallucination, we must ascertain that it is really experienced by the subject.
The danger is not averted by proving that the subject is really hypnotized, for, as we have already said, simulation and somnambulism do not exclude each other. Pitres has ascertained that even when the subject is asleep she may still deceive. We must, therefore, exact from the facts of suggestion themselves the proof of their reality.
Strictly speaking, we might appeal to moral proofs; but these proofs are only valuable to those who know the subjects; they are strictly personal. Moreover, those who are satisfied with moral proofs should remember
Hublier, whose good faith is undoubted, and who was deceived by his somnambulist subject for four consecutive years. It would be wise to accept the lesson of caution presented by this fact.
The method to be pursued in such cases is already told, and it may be summed up in one word: it is the experimental method, and includes the most improved processes of clinical observation and physiological research.
In earlier times magnetizers were content to observe, and many in our day imitate them in this respect. After producing a given psychical phenomenon by suggestion, they observe, and then describe it. We hold that this is only a preparation for the experiment, which remains incomplete. Passive observation is not enough to assure us of the subject's sincerity, nor can the reality of the hallucination suggested be proved, if we only observe what the subject does, and listen to what he says. The investigation must be carried further, and the phenomenon of suggestion must be subjected to systematic examination, in order to separate it from the objective signs. It is in this way that experiments have shown that hallucinative vision is modified by optical instruments just as actual vision is; that hallucination with respect to a colour produces the same effects of contrast in colour, as if it were actually seen; that artificial anaesthesia produces the same phenomena of colour as the spontaneous achromatopsia of hysterical patients; that the motor paralysis induced by suggestion is accompanied by the same physical signs as a paralysis due to organic causes. These hidden characters, which are revealed by experiment, are evidently of a complex
nature; in order to understand them we must be acquainted with physics, psychology, and the physiology of the nervous system. The effects of contrast produced by colour-hallucination is inexplicable, unless we understand the theory of complementary colours. Again, we cannot understand the clinical signs of motor paralysis produced by suggestion, unless we are acquainted with the nature of organic paralysis; and so it is in other cases. There is no risk of the subject's inventing the characteristics as a whole, in order to deceive the experimenter, and we may therefore be assured that there is no simulation, and this for two reasons: first, want of knowledge, and, secondly, want of power. The objective signs mentioned just now are therefore very valuable; they apply to every case, and offer an irrefutable proof of the reality of the experiment.
In short, the method to be pursued with respect to facts of suggestion is this: the artificial psychical phenomena must be matter for experiment, with the aim of rendering these subjective disturbances objective.
A singular problem, however, occurs with reference to simulation, which has not yet been examined by any observer. The rules which we have just laid down in order to counteract simulation are very efficacious when the simulator does not experience in any degree the assumed phenomenon. For instance, if the subject asserts that he has a visual hallucination, when he sees absolutely nothing, the manifold proofs furnished by optical instruments, complementary colours, etc., will easily expose the fraud. But it is open to question whether simulation in a subject liable to suggestion may not effect all which is effected by suggestion itself.
Let us take an important instance. Motor paralysis can be given to some subjects by means of suggestion, and it is a question whether the subject, with the purpose of deceiving the experimenter, may not simulate a motor paralysis, and whether this assumed paralysis may not present the same objective characters as that which is produced by suggestion. We think that this is possible, for in paralysis by suggestion the real cause of functional impotence is the idea of a paralysis, and it matters little whether this idea proceeds from suggestion by the experimenter, or from simulation by the subject; it is only essential that it should be sufficiently intense as to affect the motor power. It is in this way that we hold that simulated phenomena may in some cases be absolutely confounded with real phenomena.
This question of simulation in an individual liable to suggestion is, in fact, only one aspect of a much larger question: that of the action of the will on phenomena of suggestion. It may be asked whether an individual liable to suggestion can voluntarily create, modify, and destroy effects on himself comparable to those developed by suggestion. We are acquainted with facts which enable us to reply in the affirmative. We have seen subjects who could at pleasure, and in the waking state, call up the hallucinative image; when looking attentively at a sheet of white paper, they could cause it to appear red, blue, green, etc., and the colour thus evoked would be sufficiently distinct to give birth in due succession to the complementary colour which the subject could indicate correctly. This remarkable visual phenomenon differs from artificial hallucination in one respect; it requires a voluntary effort, continued for a period vary-
ing between twenty seconds and a minute, while a suggested hallucination occurs almost spontaneously. We met with another instance of voluntary suggestion in psychical paralysis. A subject to whom complete paralysis of the arm had been given was able to free herself from it after endeavouring for five minutes to move the paralysed limb.
Unconscious Suggestion. — We have not yet had occasion to speak of this last kind of suggestion, which has a tendency to introduce itself like a parasite into the experimenter's mental suggestions, so as altogether to vitiate the results. It should be known that some hysterical subjects become when hypnotized so sensitive and such delicate re-agents, that no word or gesture escapes their notice; they see, hear, and retain everything, like registering instruments. Suppose that the experimenter has produced a visual hallucination; he then wishes to ascertain whether this sensorial disturbance has produced any modification in the sensibility of the integuments of the eye, which were insensitive before the experiment. Before making the examination, he says to one of his assistants, "I am going to see whether the cornea and conjunctiva have become sensitive." The subject hears what is said, and it may easily, although not certainly, happen that the words act as a direct suggestion of the symptom in question, so that the experimenter runs the risk of taking for an effect of hallucination what is the effect of suggestion. The subject acts in good faith, as well as the experimenter; there is no simulation, and yet there may be a considerable error.
The risk of unconscious suggestion is not found in
the subjects of profound hypnotism in all degrees of hypnosis; it is slighter during lethargy and catalepsy, and does not exist at all in the case of some subjects, who are in these states unable to receive any suggestions whatever. It is during somnambulism that unconscious suggestion is most frequently present, and when the experimenter has to do with a somnambulist, he should always remember this source of error, and guard against it. The moral proof derived from the subject's good faith is useless, since we are not concerned with simulation. It is well for the experimenter to work in silence, not to prepare his experiments in the presence of his subject, and to execute them before a limited number of spectators. One or two are enough. We cannot too often repeat that only the first experiments are convincing, since, strictly speaking, these alone are performed on a virgin subject, safe from unconscious suggestion. Every time that the experiment is repeated, there are probably more spectators who comment upon it aloud; they unconsciously make suggestions which vitiate the purity of the phenomenon, and greatly diminish its value. In addition to this there is another source of error, namely, that when the second experiment takes place, the subject remembers the former one. For instance, if a given phenomenon has been produced once by the employment of a given agent, on the second occasion the presence of this agent, or even its image, may recall its sensation, and so disturb the experiment in hand.
For these reasons, among others, we have always been careful in our papers on hypnotism to give the results of the first experiment, although these results were often less exact and complete than those which followed.
We believe that the experimenter who follows the rules just laid down, who accurately defines the physical and mental condition of his subjects, who takes measures completely to eliminate simulation and unconscious suggestion, will obtain verifiable results.
We must not omit a final precept, equally applicable to the research into facts and to the performance of experiments, and that is, to bring together the phenomena of suggestion which are already known, and which make part of positive science. Many experimenters have disregarded this important precept, and have written pages on suggestion which are only a collection of amusing anecdotes, adapted rather to pique curiosity than to afford instruction. Paul Janet has forcibly remarked on the serious consequences of this omission: "In recent works on the subject of suggestion, all more or less intended for the public, since they were published at conferences, lectures, or in reviews, we have observed that, instead of first relying on the most common and elementary facts, assuming that these were already too well known, which is by no means the case, they have been chiefly anxious to dwell on extraordinary facts which strike the imagination. This is intelligible enough, since in addressing the public, success is the first object. The writer doubtless loves truth for its own sake, but he is not unwilling to make it effective. If the audience or the reader is prepared, the effect is weakened, and it becomes greater in proportion to its unexpectedness. This tendency to throw into relief the extraordinary and the unexpected is excellent from the literary and dramatic point of view, but it has many inconveniences when we are concerned with science
for when the amazement is too great, it inclines the mind to unbelief, and diverts it from examination. Enlightened minds have long held aloof from the study of magnetism, precisely because of its marvellous and mysterious character. And now, although the new facts rest, or appear to rest, on a really scientific method, yet their resemblance to those of magnetism tends to produce an analogous disposition to hostility and dislike. At the same time, by a reciprocal and contrary effect which is no less vexatious, others regard these singular phenomena, of which they cannot divine the cause, as if they were invested with the same prestige of the unknown and the mysterious as those of magnetism. The one leads to the other, and since the public is unacquainted with the methods of science, they confuse the subjects together, so as to fall back into the error which it was sought to avoid."*
The method to be pursued consists, as we have said, in at once showing that suggestion is not a distinct phenomenon in the history of intelligence, an isolated, disconnected fact, explained by nothing, and as it were suspended in mid-air. It is necessary to insist on the close relations existing between the phenomena of suggestion and the admitted facts which form part of positive science; the connection between them must be made clear, since these phenomena are only an exaggeration and a pathological deviation.
On this subject we shall have to point out numerous parallels between the facts of suggestion and those of physiology, of psychology, and of mental disorder. The comparative study of suggestion and of psycho-
logical phenomena will show us that the hypnotic subject is not governed by special psychological laws, and that the germs of all his symptoms may be traced in the normal state. The comparative study of the phenomena of suggestion and of mental disorder will, moreover, show that the psychical disturbance caused in the subject by suggestion has many characters in common with the spontaneous disturbance found in an insane person; that, for instance, the hallucination of hypnotism does not essentially differ from the ordinary forms of hallucination.
It is by means of these repeated comparisons that the experimenter finds his bearings in the study of hypnotism, in which such care is necessary. Reliance on the achieved results of positive science acts as a check and guidance, and hypnotism, instead of being merely an amusement for the idle, becomes a useful method of experiment in psychology and in mental diseases.
Suggestion acts on the subject's nervous system, and produces modifications analogous to those which are produced by peripheral excitements. But we are far from knowing all the effects produced by the idea which is introduced by means of suggestion into the subject's brain; it is, indeed, probable that we are not acquainted with the thousandth part of them. Far from wishing to conceal this incompleteness of the theory of suggestion, we think it well to call particular attention to it. The study of suggestion has only just begun, and many surprises are doubtless in store for us.
We think it probable that when suggestion is employed in the case of a subject adapted for it, it is capable of producing all the actions connected with the nervous system. This is, however, only a probability, since direct proofs are wanting, and if it were proved, we have still to learn the extent and limits of the influence of the nervous system on the rest of the organism. The question of suggestion merges in this case in an important and still somewhat obscure question of physiology.
A fresh chapter in the history of suggestion has been lately opened. Various observers have been studying suggestions which do not exert any action on the subject's physical life, but on the so-called vegetative functions, circulation, calorification, secretion, digestion, etc.
We do not propose to dwell on well-known facts, such as purging by means of suggestion, since such facts present no special feature, and we know that in the normal state these effects are produced by certain forms of mental emotion.
The most important of the organic disturbances produced by an idea is an experiment on vesication, performed by Focachon, a chemist at Charmes. He applied some postage stamps to the left shoulder of a hypnotized subject, keeping them in their place with some strips of diachylon and a compress; at the same time he suggested to the subject that he had applied a blister. The subject was watched, and when twenty hours had elapsed the dressing, which had remained untouched, was removed. The epidermis to which it had been applied was thickened and dead and of a yellowish white colour,
and this region of the skin was puffy, and surrounded by an intensely red zone. Several physicians, including Beaunis, confirmed this observation, and the latter made photographs of the blister, which he presented to the Society of Physiological Psychology on June 29, 1885.*
Shortly afterwards, on July 11, 1885, Dumontpallier informed the Société de Biologie of experiments performed on hypnotized hysterical subjects, whose temperature he had raised locally several degrees; this is a curious fact, to which another is analogous, namely, that the temperature is lowered in the correlative region of the body during the suggestion of these physical phenomena.
During the same séance, Bourru and Burot, professors of the Rochefort school, published records of epistaxis, and even of blood-sweat, produced by suggestion in a male hysterical patient, who Was affected by hemiplegia and hemi-anaesthesia. On one occasion, after one of these experimenters had hypnotized the subject, he traced his name with the blunted end of a probe on both his forearms, and then issued the following order: — "This afternoon, at four o'clock, you will go to sleep, and blood will then issue from your arms on the lines which I have now traced." The subject fell asleep at the hour named; the letters then appeared on his left arm, marked in relief, and of a bright red colour which contrasted with the general paleness of the skin, and there were even minute drops of blood in several places. There was
absolutely nothing to be seen on the right and paralysed side. Mabille subsequently heard the same patient, in a spontaneous attack of hysteria, command his arm to bleed, and soon afterwards the cutaneous haemorrhage just described was displayed. These strange phenomena recall, and also explain, the bleeding stigmata which have been repeatedly observed in the subjects of religious ecstasy who have pictured to themselves the passion of Christ.
Charcot and his pupils at the Salpêtrière have often produced the effects of burns upon the skin of hypnotized subjects by means of suggestion. The idea of the burn does not take effect immediately, but after the lapse of some hours. It is still very doubtful whether all organic functions may be thus modified by means of suggestion.
Quite recently one of the present writers * succeeded in showing, by means of processes analogous to those of Mosso, that any part of the body of an hysterical patient may change in volume, simply owing to the fact that the patient's attention is fixed on that part. This important observation is not only an addition to the foregoing, but explains them by showing what influence may be exerted in hyperexcitable subjects by a simple phenomenon of ideation on the vaso-motor centres, which are concerned in all experiments of this kind.
Among the effects of suggestion only one class has been the object of regular research: that of psychical phenomena. These have been studied by preference because they were the first which charlatans sought to turn to their advantage. To these we now propose to turn
our attention, endeavouring to define and classify them with the utmost care.
If, before going into details, we consider the subject as a whole, it will be seen that we have to study the part played by ideas in the modification of the intelligence; that we must observe what this factor produces when it acts alone. It is generally admitted by psychologists that the idea is only a secondary factor, that it is for the most part a resultant, a point of arrival; that psychical phenomena are in some sort developed from below in an upward direction. They do not begin in the upper centres of ideation, but are completed there.* So also the phenomena of suggestion which, by an inverse mechanism, are developed from the higher to the lower plane, are more superficial and ephemeral than spontaneous phenomena. It is possible to suggest to a subject that he is very hungry, but this feeling, which is dictated by an idea, will not be so deep as that which is due to an organic necessity. So, again, the personality of the subject may be transformed, and he may be changed into a dog or a wolf; but when this borrowed personality is engrafted on the true one, the character is not fundamentally changed. If the suggestion is to produce any permanent modifications it must be often repeated, and it will then, at least in some cases, end by producing habits. A subject to whom suggestions of motor paralysis had been repeatedly made, said that in dreams she often saw half of her body paralysed. Experimental suggestions of crime ought not to be lightly made, since we cannot always tell what traces they leave behind them.
A careful study of suggestion shows that this word does not imply a single fact, but two principal facts which may be said to form the cardinal points of the whole theory. There are two fundamental kinds of suggestion; the one produces an active or impulsive phenomenon, such as a sensation of pain, an hallucination, an act; the effect of the other is to produce a phenomenon of paralysis, such as the flaccidity of a limb, the loss of memory, anaesthesia of the senses. These are two quite different processes, and may even be said to be opposed to each other, since the one undoes what is done by the other. It is impossible to refer them to the same psychical law, and to apply to them the same explanation.
Let us first consider the positive suggestions, of which the hallucination and the act are the most important. It has already been observed that all suggestions are addressed to the subject's sensorial organs, and that the co-operation of his intelligence is necessary in order to attain the end in view. We must go further, and establish the fact that each suggestion includes two things: first, an impression is made upon the subject, which is, according to circumstances, a sensation of sight, of hearing (verbal suggestion), of touch, or of the other senses. This initial impression, which may be termed the suggestive impression, has the effect of arousing in the subject's brain a second impression, which may be termed the suggested state, such, for instance, as the hallucinatory image. The first impression is the means, the second its object. In reply to the question how the first impression, which is directly produced by the experimenter, can arouse the second, which is wholly from within, and without any direct influence from the experimenter, we
should reply that this is owing to the association of ideas. Suggestion in its positive form is only the setting in action of a mental association previously existing in the subject's mind.
Suppose, for example, that the subject is told to look at the bird on her apron. As soon as the words are uttered she sees the bird, she feels it in her hand, and can sometimes even hear it sing. Inexperienced persons may think it extraordinary and even inexplicable that an imaginary image can be created in the subject's brain by mere words; but it is nevertheless a fact that the association of ideas is the cause of the suggestion, of hallucinations. The words uttered by the experimenter are associated with the mental image of a bird by education, by repetition, in a word, by habit; therefore it produces this image, and the hallucination is effected. It is a law that when two images have frequently been received together, simultaneously or in quick succession, the presence of the one tends to revive the other. The production of the hallucinatory image by means of verbal affirmation is only a fulfilment of this well-known law. We should be able to show, by considering it more closely, that this mode of suggestion belongs to the group of associations by proximity.
Instead of making use of speech, the subject's sense of sight may be employed. When his eyes are mobile and follow all our actions with docility, we make with the hand the appearance of some flying object, and the subject soon exclaims, "What a beautiful bird!" This singular effect of a simple gesture is also due to the association of ideas. The rude imitation by which the hand represents the movement of some flying object has
raised up the image of a bird. In this case the association which comes into play differs from the former one; it is an association due to resemblance.
It is in this way that psychology explains the mechanism of hallucinatory suggestion, which essentially consists in acting on an association. It is only a special case of the great law of which this is the formula: — When an image is aroused in the mind, it tends to reproduce all the images which resemble it, or which were found with it in an anterior act of consciousness. In a word, one image suggests another. Paul Janet observes on this subject: "Some Scotch psychologists, Brown for example, have even proposed to call this law the law of suggestion, a term which would be much more appropriate than the other. I have no doubt that the expression of suggestion, introduced by Braid into his theory of hypnotism, is derived from this source." *
Just as the association of the word with the image explains the suggestion of hallucinations, so the association of the image with the movement explains the suggestion of acts.
When a given movement is executed before the eyes of a subject, such as clapping the hands, the representation of this movement is produced in his mind. When, without moving himself, the experimenter bids his subject clap his hands, the representation of the same action is aroused in his mind by the association of words with ideas; if in both cases alike the subject performs the act in question — in other words, if the image is translated into movement — this is because custom has associated the image with the movement. It is, as it
were, the beginning or first stage of the movement which it represents, and owing to this fact the subject automatically executes whatever he is ordered to do, even if the act should be dangerous, immoral, or merely ridiculous. Eichet tells us that on one occasion, when performing experiments on the friend he had hypnotized, he compelled him to pick up the piece of chalk he had thrown under the table twenty times. In fact, the suggestion of acts is perhaps, of all the phenomena of suggestion, the one which approximates most closely to the normal state; it simply consists in the servile execution of an order. We have, however, an observation to make on this subject. We are compelled to connect these facts of suggestion, impulses, and hallucinations, with the facts of positive science which may serve to prove and control them. Yet we are far from believing that this method will give a complete explanation of the phenomena in question. It is a proof of excessive confidence to assume that everything is explained, and a word is enough to show that the matter is still full of obscurity. Admitting that the suggestion of a movement is explained by the association of the movement with its image or representation, it is a question whether as much can be said of the suggestion of an act. When the subject's brain is charged with this idea, "On awaking you will steal the handkerchief of some given person," and the subject when he awakes does actually commit the theft, we cannot suppose that there is nothing in this except an image associated with an act. The subject has, in fact, appropriated and assimilated the experimenter's idea. Instead of passively executing the order given by another, the order has passed into the active state, that is, the subject feels a
desire to steal — a complex and obscure state which no one has hitherto been able to explain. We shall return to this subject presently, in order to examine it more closely.
Since we find so much that is enigmatical in the region of impulsive suggestions, which are the clearest and most intelligible, this is still more the case when we approach the subject of inhibitory suggestions. Here the most superficial psychologist will find himself on new ground. The facts of paralysis by means of suggestion completely overthrow classic psychology. The experimenter who produces them with perfect ease does not really know what he is doing.
Take an instance of systematic anaesthesia. The subject was told, "On awaking you will be unable to see or hear, or in any way perceive M. X —, who is now present; he will have completely disappeared." Accordingly, when the subject awoke she saw all the persons who surrounded her with the exception of M. X —. When he spoke, she did not answer his questions, and when he laid his hand on her shoulder, she was unconscious of the contact. He put himself in her way, and she walked on and was alarmed to encounter an invisible object. We are ignorant how this phenomenon is produced and can only accept the external fact; namely, that when a subject is assured that an object present has no existence, the suggestion has the direct or indirect effect of establishing in his brain an anaesthesia corresponding to the object selected. But it is still a question what occurs between the spoken affirmation, which is the means, and the systematic anaesthesia, which is the end. We cannot, as in the case of halluci-
nation, assume that the word spoken to the subject, and the phenomenon produced, are connected by association. If it is true that the image of a serpent is associated with the words, "Here is a serpent," it cannot be said that the incapacity for seeing M. X —, who is present at the time, is also associated with the words, "M. X — is non-existent." In this case the law of association, which is so useful in resolving psychological problems, is altogether unavailing. This is probably because this law will not explain all the facts of consciousness, and is less general than it is supposed to be by English psychologists.
Similar reflections apply to another instance of paralysis by suggestion, or motor paralysis. It is possible to suggest to a hypnotized subject that her arm is paralysed. It is only necessary to say repeatedly with the requisite authority, "Your arm is paralysed," and functional impotence is soon displayed. The subject begins by signifying a denial of the fact, she tries to raise her arm, and succeeds in doing so. She is repeatedly told, "You cannot raise your arm; it will fall again," and paralysis gradually comes on, and presently extends to the whole arm. The subject can no longer move it, and its flaccidity is absolute. Such is the singular phenomenon of motor paralysis by means of suggestion. It is as difficult to understand as the anaesthesia to which it corresponds. We do not think that it can be explained by any psychical facts now known to us.
Perhaps this whole class of facts is subject to a general psychical law of which the most advanced psychologists have not yet discovered the formula and which may have some analogy with an inhibitory action.
According to this hypothesis it may be provisionally admitted that in order to paralyse the subject the experimenter produces in him a mental impression which has an inhibitory effect on one of his sensorial or motor functions: it should also be clearly understood that, strictly speaking, it is not the mental impression which produces the inhibition, but the concomitant physiological process. Moreover, it must be remembered that the word inhibition explains nothing, and does not dispense with the necessity of seeking the true explanation. Hypnotic suggestions may be classified as follows: — Some are only effected during sleep, and disappear with a return to the normal state; others continue during the waking state; others, again, are produced in the waking state.
Thus, the hallucination of a bird may be given to a somnambulist, and this hallucination will disappear when the subject is awakened by breathing on his eyes. As soon as he returns to the normal state, he is completely free from any imaginary vision. This is the case with fresh subjects and with those who are only moderately receptive, in whom suggestion does not outlast the hypnotic sleep. It is possible, however, to protract the suggestion after the awakening by strengthening it with a different suggestion. If the precaution is taken of telling the subject to whom the hallucination is given that he will still see the object in question when he awakes, the assertion is often enough to ensure the existence of the suggestion in the post-hypnotic state.
It is not usually necessary to make a special suggestion in order to produce this effect in subjects thoroughly under the influence of profound hypnotism. Every effect
which has been suggested without fixing any term to it, and which has a continuous form, may persist for a shorter or longer period during the waking state. This is especially the case with hallucinations, paralysis, etc. We are thus presented with a curious experience, calculated to interest the psychologist. The subject is awake, has returned to what may be called his normal state, is able to reflect, reason, and direct his conduct; and yet, under these conditions, he is influenced by the hypnotic suggestion.
The suggestion which persists during the waking state presents one interesting characteristic; it appears to the subject to be spontaneous. As a general rule, the process which produced the suggestion seems to leave no trace of its symptoms, and the subject who after awaking is still a prey to the hallucination which was suggested, does not remember the way in which it was produced. We have not in a single case met with a subject who said spontaneously, "If I see a bird at this moment, it is because you assured me that I saw one when I was asleep." The memory of the uttered word has completely disappeared, while its effect remains in the hallucinatory image. Hence it follows that hypnotic hallucination has always the appearance of a spontaneous symptom. Some curious consequences ensue. A subject is told that one of the persons present wears a coat with gold buttons, and the word arouses the sensible image of buttons of a yellow colour. If the subject is afterwards asked of what the buttons are made, he may reply, "They are made of copper." The buttons which he has before his eyes are yellow, and he supposes that they are copper; he has completely for-
gotten the word gold which figured in the verbal suggestion.
The same may be said with respect to suggestion of acts. On awaking, the subject obediently performs the act which he was ordered to do during the hypnotic sleep, but he does not remember who gave him the order, nor even that it was given at all. If asked why he is performing this act, he usually replies that he does not know, or that the idea has come into his head. He generally supposes it to be a spontaneous act, and sometimes he even invents reasons to explain his conduct. All this shows that the memory of the suggestion, so far as respects its utterance, is completely effaced.
The same rule applies to paralysis by suggestion. The subject who is affected by a monoplegia, when he awakes does not understand how the accident occurred; he remembers nothing of the verbal suggestion, nor does he suspect that the incapacity to move his arm is due to a conviction of the want of motor power. In short, the suggestion is effaced from the subject's mind as soon as it has produced its effect, and the symptoms appear to be evolved independently of their cause. The existence of this partial failure of memory may perhaps allow us to compare the artificial results of suggestion with the phenomena which are spontaneously displayed in normal individuals and also in the insane, in their acts, phenomenal impulses, hallucinations, etc. We now come to the detailed study of the facts of suggestion. It is impossible to examine all of them, and we must be content with selecting a certain number of typical cases for careful study. We shall successively consider hallucinations, impulsive acts, motor paralysis,
and paralysis of the senses. The phenomena just indicated are the simplest which can be obtained by means of hypnotic experimentation, and in studying them we may be said to study the most elementary properties of the phenomena of suggestion. If space permitted, we should follow up the study of these elementary facts of suggestion by enumerating the complex facts derived from them. Thus, we might connect with the hallucinatory image all the facts included under the name of intelligence — sensation, the association of images, memory, reason, and imagination. With a suggested act are connected sentiments, emotions, passions, voluntary action, and all the phenomena constituting the psychology of movement, with which we are as yet imperfectly acquainted. Finally, paralysis by suggestion is connected with the phenomena of psychical inhibition of which the study has not as yet even begun.