THE MEDIUMS’ BOOK

Allan Kardec

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Theory of Hallucination.


111. Those who do not admit that there is an incorporeal and invisible world, fancy they can explain everything by the word hallucination. The definition of this word is well known ; it means the error, the illusion, of one who believes himself to experience perceptions which he does not experience in reality; it comes from the Latin word, hallucinari, to err ; but the learned have not yet, so far as we know, explained the cause of the fact expressed by this word.

As optics and physiology appear to have no secrets for their devotees, how is it that the latter have not yet explained the nature and source of the images, which, under certain circumstances, present themselves to our consciousness? They would fain explain everything by the laws of matter; let them then deduce from those laws a theory of hallucination, capable of giving a rational explanation of the facts comprised under that term.

112. The cause of dreams has never yet been explained by science, which attributes them to an effect of the imagination, but does not tell us what imagination is, nor how it produces the clear and distinct images which sometimes appear to us. Scientific men are too much given to explaining an unknown thing by another thing as little known, leaving the problems they deal with very much as they were. It is often said that dreams are a recollection of the occupations of our waking state; but, even admitting this solution, which is no solution at all, there still remains the question, what is the magic mirror which thus preserves the traces of things, and, above all, how are we to explain the visions we sometimes see of real things, never seen by us in our waking state, and about which we never thought? Spiritism alone can give us the key to this strange phenomenon, which is only overlooked because it is so very common, like all the other wonders of nature that we are so apt to trample under foot.


The votaries of science have disdained to trouble them-selves about hallucinations; but whether real or not, they nevertheless constitute an order of phenomena that physiology ought to be able to explain, under pain of avowing its insufficiency. If; some of these days, a scientific man should undertake to give, not a mere definition, but a physiological explanation, of this class 6f phenomena, we shall see how far his theory covers the whole ground; he must not omit the very common facts of the apparition of persons at the moment of their death, and he must show us the source of the coincidence of the apparition with the death of the person. If this coincidence had occurred but once, we might attribute it to chance; but the fact is of frequent recurrence, and chance is not recurrent. If the person who saw the apparition were already possessed with the idea that the party appearing was about to die, we might attribute the apparition to imagination ; but it generally happens that the person seen is not in the thoughts of the seer at the moment of the apparition, so that imagination has nothing to do with it. Still less can the imagination theory explain the presentation of the circumstances of a death, the idea of which never entered our heads. Will the partisans of hallucination assume that the soul (supposing they admit the existence of the soul) has moments of over-excitement, and of abnormal power? If so, we agree with them, for this may be the case ; but, when what is seen is proved by events to have been real, we must drop the theory of illusion. If the soul, in its excitement, sees an object which is not present, it must transport itself to that object; and if our soul can transport itself to an absent person, why should not the soul of an absent person transport itself to us? Let those who adopt the theory of hallucination explain all this; and let them not forget that a theory which is opposed by facts is necessarily false or incomplete.


While awaiting the explanation demanded, we ask attention to the following considerations on the subject.

113. Facts prove that there are veritable apparitions, which spiritism is perfectly competent t6 account for, and which can only be denied by those who admit of nothing beyond the bodily organism but, besides real visions, do what are called hallucinations also occur? We reply, that such do undoubtedly occur. What, then, is the source of the latter ? It is the spirits themselves who assist us to explain this point, for our explanation appears to us to be fully implied in the answers given by spirits to the following questions: -

-Are visions always real, or are they not sometimes the effect of hallucination ? When one sees in a dream or otherwise, the devil, for example, or any other fantastic appearance which has no real existence, is not such an appearance a product of the imagination?

"Yes, sometimes, in the case of persons whose minds are excited by stories which leave a strong impression, and which they carry in their memory until they fancy they see what has no real existence. But we have already said that a spirit, with the aid of its semi-material envelope, can assume any and every form for manifestation. Thus, a mocking spirit can appear with horns and claws, if it pleases him so to play with your credulity ; just as a good spirit can show himself with wings and a radiant countenance."

-Can we regard as apparitions the faces and other images which often present themselves when we are halt asleep, or when we merely close our eyes?

"As soon as the senses grow torpid, the spirit disengages itself, and is able to see, whether far or near, what it could not see with the bodily eyes. The images then seen are frequently visions, but they may also be an effect of the impressions that the view of Certain objects has left on the brain, which retains traces of them as it does of sounds. The spirit, when disengaged, sees, in its own brain, these imprints which are fixed therein as in a daguerreotype. From their variety and their intermingling are formed fantastic but fugitive wholes, which disperse again almost immediately, in spite of the efforts made to retain them. It is to an analogous cause that you must attribute many fantastic apparitions which have nothing of reality in them, and which frequently occur during illness."

It is certain that memory is the result of impressions preserved by the brain ; by what singular arrangement is it that these impressions, so numerous and so varied, are not inextricably confused? That is an impenetrable mystery; but it is not more strange than the crossing of the sonorous undulations which pass athwart each other in the air, and vet are none the less distinct. In a healthy and well-organised brain, these impressions are clear and precise ; In a state less favourable, they become faint and confused, which produces loss of memory and confusion of ideas a result that appears less extraordinary, if we admit, with phrenologists, a special destination of each part, and even of each fibre, of the brain.

Images which come to the brain through the eyes leave in them an impression, so that we may remember a picture, as though we had it before us; but this is always an act of memory, for we do not see the object thus present to our mental eye. In the state of emancipation, the soul looks into the brain, and finds those images therein ; those, especially, which have struck it the most, according to its personal idiosyncrasy, prepossessions or disposition. Thus, it finds again, in its brain, the impress of religious events, of diabolical, dramatic, or worldly scenes, the figures of fantastic animals, which it has seen at some previous period in paintings. or has heard or read of for recitals also leave their impress. Thus the soul really sees; but what it sees is only an image daguerreotyped on the brain.

In the normal state, these images are fugitive and ephemeral, because the cerebral organs perform their functions freely; but in illness, the brain being always more or less enfeebled, the equilibrium of the organs is lost. some of them retaining their activity, while others are partially paralysed : hence the permanence of certain images, which are not effaced, as when in a normal state, by the pre-occupations of external life. This is veritable hallucination, and the determining cause of fixed ideas.

It will be seen that we have explained this anomaly by a well-known physiological law, that of cerebral impression but we have also had to assume the intervention of the soul. If the materialists have not yet been able to give a satisfactory solution of this phenomenon, it is because they do not admit of a soul ; and they will say that our explanation is worth nothing, because we assume the very point which is contested. Contested by whom? - By them; but admitted by the immense majority of mankind, ever since men have lived upon the earth ; and the negation of the few cannot be accepted as authoritative.

Is our explanation a sufficient one? - We give it for what it is worth, for want of another, and as one which may he regarded as a convenient hypothesis, while waiting for a better one. Does it explain all cases of vision? Certainly not ; but we defy physiologists to give, from their point of view, any explanation that can do this; for, when they have pronounced their sacramental words, excitement and imagination, they have not advanced the solution of the problem a single step. Therefore, as all theories of hallucination are insufficient to explain all the facts referred to, it follows that those facts imply something else besides hallucination properly so called. Our theory would fail if we applied it to all cases of visions, because there are cases which contradict it ; but it may, nevertheless, be true in regard to some kinds of visions.

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