Hallucinations Differentiated from Illusions and Delusions.—Hallucinations are vivid impressions on the consciousness which appeal to their subject as strongly as if they were really the result of sensory impressions, though those who experience them know, either at the moment, or on investigation afterwards, that they had no objective reality, that is, were not due to any external physical cause. Illusions are deceptions of the senses, due to the imperfection of the senses or the conditions in which the perception occurs. {604} Delusions are mental states in which ideas are accepted, or conclusions drawn, or information assumed to be gained, though the whole process is mental and has no relation to reality. (For illustrations of illusions see chapter with that title in the Appendix.)

Hallucinations lie in between illusions and delusions as a mode of deception. They are mental occurrences, but they seem to come from the senses and probably the best explanation for them is that a previous sensory impression is vaguely aroused and then finds its way into the consciousness as if it were coming through the senses. It has been suggested that they might be due to a reversal of the nervous process by which a sensation reaches the brain. The external object produces the sensation, this travels along a nerve causing a perception, this perception is stored in the memory, and then, when very vividly reawakened, causes impulses to travel backward along the nerve to the periphery with the production of a feeling very like sensation.

Frequency.—While hallucinations are often supposed to be only incidents in the life of the insane, or at least of those who are in the danger zone near mental disequilibration, carefully collected recent observations show that many perfectly sane people have experienced them, and some of them have been much disturbed by them for fear they portended loss of mental control or some developing pathological condition. A certain number of men and women have seen things that either had no existence or existed only for them and for the moment, and that evidently were due to some state of mind rather than to their senses. They have heard things that were not said or that were not audible to others, or that were only reproductions of their memory of previous sounds and quite naturally such mysterious manifestations disquiet them. It was the rule in the past to dismiss such phenomena without serious consideration, or at most to consider that they were only subjective manifestations not worth discussing, or to go to the opposite extreme and say that they were due to mental disturbances.

Of course, as a rule, hallucinations are an index of mental disturbance. No matter how apparently sane the patient, this must be the first thought and must be carefully excluded before proceeding with the case. The subject of hallucinations is larger than that, however, and it is a mistake to brush it aside in every case as if it were either very serious or of no importance and that in either case nothing can be done to relieve solicitude about it. Physicians can often do much, first to prevent hallucinations by getting at the physical causes of them; second, to prevent them from disturbing patients seriously by showing them how common are such experiences and by indicating their possible physical significance; third, by securing such mental discipline and control as will render their recurrence much less frequent; and, fourth, they can make the almost inevitable unfavorable effect upon the mind of the patient and then reflexly upon his body, much less than it would otherwise be, by sympathetically discussing and entering into the details of them enough, at least, to explain their significance or throw some light on their origin in physical conditions.

Hallucinations of vision, the seeing of things and persons that have no real existence at the time and place they are seen, are usually considered to be rather uncommon and to occur only in those whose mentality is seriously disturbed. Careful studies of the subject, however, show that at least one in ten {605} of educated people consulted have had some hallucinations of vision. Either they have wakened up, or they have dreamt that they waked in the early morning, and have seen some one whom they knew, but knew to be at the moment at a distance, standing near them. Such visions have gradually faded away or suddenly disappeared. Occasionally these persons have in full light had some appearance, wraithlike or otherwise, some manifestation that appeals to vision, yet that they knew at the time or learned afterwards was non-existent.

Many people are backward about confessing that they have had such experiences, for they fear that it will make them ridiculous or even cause them to be suspected of disturbed mentality. Just as soon as it is made clear to them that their admissions will be taken as evidence for a phenomenon to be discussed seriously, many more than would otherwise be thought confess to such hallucinations. Most of these, it may be said at once, are quite sensible people, a great many of them belong to the educated classes; all of them are trustworthy witnesses as far as good will goes, and the circumstances of their hallucinations are such in many cases that there cannot be a mere mistake, or error of judgment.

The frequency with which hallucinations occur may be appreciated from the investigation made some years ago at the instance of the Congress of Experimental Psychology. The following question was put to 17,000 persons, mostly residents of Great Britain, and answers received: "Have you ever, when believing yourself to be completely awake, had a vivid impression of seeing or being touched by living beings or inanimate objects, or of hearing a voice, which impression, so far as you could discover, was not due to any external physical cause?" The answers showed that 655 out of 8,372 men and 1,029 out of 8,628 women had experienced a sensory hallucination at some time in their lives. Some of them had had a number of them. That is, one out of ten in the educated classes has had some hallucination, and nearly one out of every eight women. An analysis of the statistics, however, brings out some interesting suggestions. There were nearly twice as many hallucinations related as having occurred during the year before the question was asked as in the preceding years. There was a definite reduction in the number that had occurred in all the preceding years, except the fifth and tenth, and these were evidently due to uncertainties of memory, so that five- and ten-year periods seemed about the length of time that had passed since the event.

It is evident then that in spite of the fact that an hallucination would seem to be very important and surely startling enough to be well remembered, it is yet easily forgotten, since even a year's interval made so much difference in the number that were remembered. The committee, after considering this easy forgetfulness in the matter, considered that to arrive at the actual total of visual hallucinations experienced by this group of 17,000 persons during the ten-year period in question, the numbers in the table should be multiplied by four. That means that probably very nearly one in three people have had an hallucination of some kind within ten years. The great majority of the visual hallucinations consist of apparitions of human figures. Other forms that are seen are so few, as Mr. Podmore has insisted in his "Telepathic Hallucinations, The New View of Ghosts," [Footnote 45] that they are almost negligible. A frank {606} discussion of these details with a person who is much disturbed by having experienced an hallucination is the best possible remedy for the physical and mental disturbance that may result.

[Footnote 45: The Twentieth Century Science Series, New York, 1910.]

Sir Francis Galton, well known for his investigation of many subjects and who may well be called the father of biometrics or statistical biology, in his "Memories of My Life" [Footnote 46] tells of his own investigations of the visions of sane persons. The fact that he delivered a lecture on this subject at the Royal Institution of London shows how seriously his studies were made and how much value scientists placed on them. Galton's well-recognized training in the careful weighing of evidence and his ability to strip phenomena of everything that might divert their significance from what they really were, add to the worth of his conclusions. Those who care to study the subject further will find his discussion in the Proceedings of the Royal Institution (London, 1882).

[Footnote 46: New York, 1909.]

There are few people beyond middle age who have not had one or more curious experiences in the matter of visions or appearances. Mostly these have been vague and have not proved a disturbing element in the minds of the subjects. Many more than are thought, however, have seen visions vividly and with a detail that makes it almost impossible for them to believe that what they saw was merely an externation of ideas already in their mind. In this matter it must not be forgotten that the dreams of many people, especially nervous people, often present themselves with marvelous vividness of detail. They see people or places in their dreams and reason about them quite rationally. Occasionally a dream will bring back details that have been forgotten. The dreaming state seems in some people to have wonderful power over the subconscious. Things that are not remembered at all in the waking state sometimes come back in dreams, and only then are recalled by the individual as representing past events in his life. He is apt to wonder where the details could possibly come from, since he had before no conscious memory of them. This same thing holds for the day-dreams or sudden visual appearances that come when the attention has been wrapped in something else.

A typical example of such visual hallucinations is the following incident told by a prominent London physician of himself:

One afternoon at tea time, before a meeting of the Royal Society, Sir Risdon Bennett (1809-1891, a well-known physician. President of the College of Physicians in 1876, and a fellow of the Royal Society), drew me apart and told me of a strange experience he had had very recently. He was writing in his study separated by a thin wall from the passage, when he heard the well-known postman's knock, followed by the entrance into his study of a man dressed in a fantastic medieval costume, perfectly distinct in every particular, buttons and all, who, after a brief time, faded and disappeared. Sir Risdon says that he felt in perfect health; his pulse and breathing were normal and so forth, and he was naturally alarmed at the prospect of some impending brain disorder. Nothing, however, of the sort had followed. The same appearance recurred; he thought the postman's knock somehow originated the hallucination. ... I heard the story at length, very shortly after the event, told me with painstaking and scientific exactness and in tones that clearly indicated the narrator's earnest desire to be minutely correct.

Those who are especially interested in this subject will find any number of similar stories, some apparently rich with meaning, most of them quite {607} meaningless, in the volumes of transactions of the English Psychic Research Society, in F. W. H. Myers' "Human Personality," in Podmore's "Naturalizing the Supernatural," in Flammarion's "The Unknown," or many other books published in recent years. It is quite easy to get sufficient material to bring reassurance to any patient that visual hallucinations, at least, mean nothing serious for the mind or body of the individual having the experience.

Hallucinations in the Past.—It must not be thought, however, that this subject of hallucinations is new. Literature is full of it and from the earliest times we find traces of it. Egyptian, Babylonian and Chaldean writers mention them. Nor indeed is the scientific consideration of the subject new. Aristotle speaks of them and it is evident that many of the old writers thought of them as psychic incidents on some physical basis, or at least due to some predisposition in the individual or in some special state of his senses. Two generations ago Johann MÜller, the great German physiologist, discussed the whole subject at length in a monograph, and considered it of so much importance for physicians that he introduced a rÉsumÉ of it into his great text-book of physiology. His explanation of the occurrence of visual hallucinations is not only a striking illustration of the thoroughly scientific character of his treatment of the subject, but it serves to show how well men considered these subjects long before the present fad for the study of abnormal psychology or mental influence came in. His discussion of the subject is sufficient of itself to make any patient understand his hallucinations and keep them from bothering him better than anything else I know:

The subjective images of which we are speaking have sometimes, however, both color and light; different particles of the retina, of the optic nerve, and of its prolongations to the brain, being conceived as existing in special states of action. This happens rarely in the state of health, but frequently in disease. These are the true phantasms which may occur to the sense of hearing and other senses as well as to that of vision. The process by which "phantasms" are produced, is the reverse of that to which the vision of actual external objects is due. In the latter case particles of the retina thrown into an active state by external impressions, are conceived in that condition by the sensorium; in the former case, the idea of the sensorium excites the active state of corresponding particles of the retina or optic nerve. The action of the material organ of vision, which has extension in space, upon the mind, so as to produce the idea of an object having extension, form and relation of parts, and the action of such an idea upon the organ of vision so as to produce a corresponding sensation, are both equally wonderful; and hence the spectral phenomena or visions are not more extraordinary than the ordinary function of sight. (Vol. II, p. 1393, Eng. transl., 1842.)

Apparitions and their Explanation.—In spite of suggested explanations on physical grounds, some of these apparitions that appear to people seriously disturb them. They cannot get them out of their minds. They are sure that they portend evil. Hence worries, and the more nervous the people are and the more worried already, the more likely is such a thing to recur and then to be made much of. Only through their minds can these people be treated, and it must be made clear to them not only how common are hallucinations, but that there is an easy psychic explanation of most of them. Sir Arthur Mitchell, K. C. B., in his book "About Dreaming, Laughing and Blushing," [Footnote 47] tells a story and then gives his explanation of it in such a way as to illuminate many of these occurrences:

[Footnote 47: Longmans, London, 1900, page 21.]{608}

Perhaps I should illustrate how I think that apparitions may be nothing more than dream hallucinations. A. B., a gentleman of culture and strong character, called one hot day, after a hearty lunch, on an ecclesiastic in a high position, who happened to be engaged in his library at the time of the call. A. B. was shown into a room opening off the library, and requested to wait. He sat down beside a table, and with his elbow resting on it, he leant his head on his hand. While in this position he saw a man in clerical costume come through the door communicating with the library, without any opening of the door. A. B. was absolutely certain that he had seen an apparition, and was surprised and hurt when I expressed a doubt. He called on me to explain, and I said that it was at least possible that he had been asleep for some moments, that if he had slept at all, however short the dream of the sleep, he must have had a dream, if I am right in thinking that there is no dreamless sleep, and that thus what he regarded as an apparition might be nothing more than a dream hallucination. He assured me persistently that he was continuously wide-awake, but I assured him that these moments of sleep often occurred without any consciousness that they had occurred. He refused to be deprived of his ghost, and I refused to believe in the supernormal when the normal was sufficient.

Such wraith-like appearances are supposed to occur especially in connection with the deaths of persons at a distance. Startling stories are told, particularly of those who are very near relatives, husbands and wives, mothers and sons, and, above all, twins, who have been very closely associated with one another during life. There are a large number of stories of this kind, however, that have been collected by the Psychic Research Society and other agents with strong evidence in their favor, in which the appearances have had no ulterior significance at all and have evidently been mere figments of the imagination, the externation of images from memory so vividly that they seem to be the reseen. Reassurances in this matter are the best possible source of relief from the sense of impending ill for many patients. The physician who wishes to relieve such symptoms must familiarize himself with some of the many stories that have been investigated and that serve to prove that these and like appearances must not be taken as significant of anything more than a definite tendency, that exists in human nature at moments of day dreaming or when one's attention is suddenly turned from a book in which one has been absorbed, to see externally what is really passing through the imaginative memory.

A Disappearance.—A very interesting commentary on some of these appearances is to be found in Mark Twain's story of a disappearance, which could probably be duplicated many times if experiences in this line were collected and collated. Mr. Clemens, sitting on the porch of his residence one day, saw a stranger of rather peculiar appearance come up the walk toward the front door and he expected to hear him ring the bell and have the servant come to the door and usher him in, and then perhaps be called to see him. About the middle of the walk, however, the stranger disappeared and Mr. Clemens was quite surprised to come to himself, rub his eyes and conclude that he had had one of these curious visions or hallucinations, in which the Psychic Research Society would surely be interested. He had plainly seen the stranger enter the gate, come up the walk, and then disappear. He was so impressed by the disappearance that he roused himself to go into the house to get his notebook, so as to make notes of what had happened before the details escaped him. To his surprise he found the stranger in conversation {609} with the servant in the house. There had simply been a lapse in Mr. Clemen's vision of him. He had had a disappearance phenomenon instead of an appearance. The story will be found to amuse patients who complain of appearances disturbing them, though Mr. Clemens always told his disappearance story very seriously, and it is as interesting a psychic phenomenon as any told of the wraith-like appearances.

Treatment.—Considering how frequent are such phenomena, the physician must be prepared to treat those who are disquieted by them. A wraith-like appearance, for instance, will disturb many people very seriously and often for days, sometimes for weeks, make them nervous, excitable, and impair their appetite, disturb their digestion and sleep and often such unfortunate occurrences are prone to come just when they are run down in weight and when they need the help of every factor that makes for improvement of health. Simply to dismiss such an appearance as if it were quite imaginary, that is, non-existent in some form of reality, or quite baseless and trivial, serves no good purpose, for, as a rule, the persons concerned are deeply impressed with what they have seen. The only way to remove the unfavorable impression produced by it is to discuss it straightforwardly on the basis of what we have come to know as the result of recent investigations and the collation of the literature which has been published by the various psychical research societies and authorities on the subject. We know now that while occasionally such wraith-like appearances seemed to have a definite significance, because of something that happened simultaneously or shortly afterwards, this is mere coincidence and there are literally thousands of such cases in which a well authenticated wraith-like appearance was followed by no serious consequence, was never shown to mean anything beyond a curious psychic phenomenon, and was evidently merely due to some personal subjective influence, some externation of an image in the memory, unusual, but not at all unique, or even very rare, and evidently due to a curious peculiar externalizing power with which certain intellects are gifted.

Auditory Hallucinations.—Hallucinations of hearing are more common than those of vision. Many people have had the experience of waking up thinking that someone was calling them. A great many people are sure that they have, at some time or other, heard a voice when no one was near enough to them to have said anything. They have even recognized the voice. Some people, when thinking deeply about a person, have the voice of that person occur to them so clearly that they cannot quite make out whether they have actually heard it or whether it has only been very vividly reproduced in their memory. Such experiences are so common as to be well known, though many people hesitate to tell the stories of them, for hearing voices is rightly looked upon as a frequent preliminary symptom of insanity.

Hallucinations of hearing are the most common early symptom of insanity. The hearing of voices must always arouse suspicion at once. It must not be forgotten, however, that a great many recognizedly sane people who have remained so for life, have thought that they heard voices. Of course, we have no definition for insanity, and it is difficult to draw the line. We have no definition for health either, yet we have a practical working standard for the recognition of it, as also for insanity. These hallucinations then, both of vision and hearing, deserve to be discussed seriously, and in {610} nearly every case, even though there is some mental disturbance, the physician can in this way benefit his patients and keep them from being overmuch distressed by their hallucinations.

There is an expression in such common use that it is evidently the result of an almost universal experience, according to which men sometimes explain, after having acted in a particular way, that "something told them to." What they mean, of course, is that a conclusion formed in their minds the reasons for which they could not understand, but which yet had force enough to cause them to follow it to a practical application. When we hear of Socrates being advised in life by a demon, a so-called familiar spirit, we are apt to wonder whether by this term is meant anything more than just this curious feeling of aloofness from ourselves that we sometimes have when we are trying to make up our minds, or, indeed, not infrequently when we are deeply engaged in any intellectual occupation. As discussed in the chapter on Unconscious Cerebration, our minds seem in a certain way to act independently of us. Occasionally they draw us to conclusions quite different from those which we previously expected to reach. There seems to be a something within us that works quite of itself and beyond our will. Whether under these circumstances there may not occasionally come so vivid a feeling of this power within us impressing itself upon us, that it seems to come from without, must always be taken into account in the effort to get at the real significance of these curious hallucinations. Only thus are we able to come to the relief of patients who are bothered by them.

Explanation by Sound Reproduction.—Auditory hallucinations are probably not more than reproductions of sounds heard before recalled vividly and apparently heard again at moments when attention is not attracted to actual auditory sensations and we are in receptive mood. Some of them are very startling because they are apparently warnings of future events, as is proved by their fulfillment. These, however, do not seem to be more than coincidences noted with regard to similar events connected with Premonitions, Dreads and Dreams (see chapters on these subjects). There is, for instance, a well authenticated story published by the English Psychic Research Society of a woman who was about to take a dose of what she thought was some ordinary home remedy, when she distinctly heard a voice telling her to taste it. The dose to be taken was a tablespoonful, and when she tasted it she found that by mistake she had placed her hands on a bottle containing a rather strong poison and a tablespoonful of it would almost inevitably have killed her. Unfortunately, such occurrences are so rare and the reason for them is so hard to find that their consideration as anything more than coincidences seems out of the question. Every medical journal almost brings the story of someone who has taken a dose of medicine that proves fatal, and there is no warning. If such warnings came with definite frequency, it would be easier to appreciate their significance.

There are similar stories with regard to other warnings. There is the story of the young man who in a storm drove under a shed for protection. Just as he did so he heard his mother's voice—she had been long dead—distinctly say "Drive out!" Ho drove out at once in the teeth of the storm, so deeply impressed was he, and was scarcely beyond the entrance when the shed fell, crushing everything within it. Similar warnings of impending {611} accidents are rather frequent in certain people's minds, yet it is hard to think of them as anything else than premonitions. These somehow take on the character of auditory hallucinations in certain sensitive minds. Compared to the whole number of accidents, however, such incidents are extremely rare and follow no law, and while there are those who like to think that perhaps such phenomena are due to the solicitude of some being in the other world, this is extremely doubtful. In that case, as St. Augustine suggested, they would be much more frequent and have a clearer significance than is at present the rule. St. Augustine, discussing the possibility, was sure that he would have had communications from his mother. Most men would re-echo his feeling.

Coincidences.—Most of these stories as they have been analyzed by careful investigators are indeed such trivial unmeaning things that it would be too bad to let people be bothered by them. They have occurred, however, from time immemorial. Veridical warnings are a commonplace in the literature of all countries. Undoubtedly some may suggest the action of a Higher Power, but the more one knows of the conditions in which they happened, the people to whom they came and their ultimate effects, the less will they seem providential. It is evident that under certain conditions they may be produced even at moments when men are not particularly excited and when they think that they are perfectly calm and self-possessed. Each story must be discussed in its own merits. The only thing to do, then, is not to make too light of them and, above all, not to treat them as merely imaginary or as utterly illusory; for they are often natural phenomena, the reasons for which and the conditions of their production we do not as yet fully understand. If patients can be brought to this viewpoint, they may even become interested in searching out just what it was that caused each particular hallucination. Over and over again it has been found that a moonbeam or a peculiar unexpected reflection of the sun, or the light shining through an unnoted aperture, or any or several of these in connection with a mirror has been the main cause of the wraith-like appearance. When they happen during the day it is sometimes at the moment of passing from very bright light to a darker hall that the occurrence takes place and evidently there is some physical occasion for the appearances in the eye itself. Unusual noises of various kinds are responsible for the auditory hallucinations.

Dangers of Serious Considerations.—There is one serious aspect of these hallucinations and supposed warnings—they tend to paralyze action. If a person allows himself to become firmly persuaded that doubts and premonitory possibilities must be weighed and solved before he may dare to act with assurance, then action becomes almost impossible. Premonitions may serve to bring people into danger, or at least keep people from having such presence of mind as will enable them to get out of it, as they otherwise would. Doubts lead to inaction and make a state of mind that is eminently miserable. The patient's one hope is to put aside resolutely such hallucinations if they rise to the level of a disturbing doubt or a paralyzing premonition and to discipline himself against being influenced by them. In many persons this is a difficult matter, but it represents the only efficient path to the regaining of mental health and strength.{612}