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.

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


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


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 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 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 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


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 Mueller, 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 resume 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.]

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 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


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 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 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


Habit Headache facebooktwittergoogle_plusredditpinterestlinkedinmail