Our conviction is, that the results proceed entirely from imagination acting with a peculiar condition of the brain, and that this peculiarly passive and impressible condition of the brain is induced by the fixed gaze upon the disk. These are the only agencies which we believe to be necessary, in order to give us an explanation of the phenomena in question. In saying so, however, we are aware that such data will seem to some inquirers insufficient to account for the effects we have described. It may be said: 'We know that imagination sometimes produces singular results, but can hardly see how it explains the facts stated.' We have only to request that such inquirers, before they throw aside our explanation, will give attention to a few remarks on the power of imagination in certain conditions. We propose, 1st, To give some suggestions on this point; 2d, To notice the relations of imagination with reason; and, 3d, To inquire how far the physical means employed—the fixed gaze on the disk—may be sufficient to affect the mental organ, the brain, so as to alter its normal condition.
1. Our usual mode of speaking of imagination, is to treat it as the opposite of all reality. When we say, 'that was merely an imagination,' we dismiss the topic as not worthy of another thought. For all ordinary purposes, this mode of speaking is correct enough; but let us ask, Why is imagination so weak?—why are its suggestions so evanescent? Simply because it is under the control of reason. But if the action of reason could be suspended, we should then see how great, and even formidable, is the imaginative power. It is the most untiring of all our mental faculties, refusing to be put to rest even during sleep: it can alter the influence of all external agents—for example, can either assist or prevent the effects of medicine—can make the world a prison-house to one man, and a paradise to another—can turn dwarfs into giants, and make various other metamorphoses more wonderful than any described by Ovid; nay, these are all insufficient examples of its power when left without control; for it can produce either health, or disease, or death!
To give a familiar instance of the control under which it is generally compelled to act: You are walking home in the night-time, and some withered and broken old tree assumes, for a moment, the appearance of a giant about to make an attack upon you with an enormous club. You walk forward to confront the monster with perfect coolness. Why? Not because you are a Mr Greatheart, accustomed to deal with giants, but because, in fact, the illusion does not keep possession of your mind even for a moment. Imagination merely suggests the false image; but memory and reason, with a rapidity of action which cannot be described, instantly correct the mistake, and tell you it is only the old elm-tree; so that here, and in a thousand similar instances, there is really no sufficient time allowed for any display of the power of imagination.
A tale is told—we cannot say on what authority—which, whether it be a fact or a fiction, is natural, and may serve very well to shew what would be the effect of imagination if reason did not interfere. It is said that the companions of a young man, who was very 'wild,' had foolishly resolved to try to frighten him into better conduct. For this purpose, one of the party was arrayed in a white sheet, with a lighted lantern carried under it, and was to visit the young man a little after midnight, and address to him a solemn warning. The business, however, was rather dangerous, as the subject of this experiment generally slept with loaded pistols near him. Previously to the time fixed for the apparition, the bullets were abstracted from these weapons, leaving them charged only with gunpowder. When the spectre stalked into the chamber, the youth instantly suspected a trick, and, presenting one of the pistols, said: 'Take care of yourself: if you do not walk off, I shall fire!' Still stood the goblin, staring fixedly on the angry man. He fired; and when he saw the object still standing—when he believed that the bullet had innocuously passed through it—in other words, as soon as reason failed to explain it and imagination prevailed—he fell back upon his pillow in extreme terror.
2. The point upon which we would insist is that, in the normal condition of the mind and the body, the power of imagination is so governed, that a display of the effects it produces while under the control of reason, can give us but a feeble notion of what its power might be in other circumstances. To make this plain, we add a few suggestions respecting the nature and extent of the control exercised by reason over imagination; and we shall next proceed to shew, that the activity of reason is dependent upon certain physical conditions.
We shall say nothing of a metaphysical nature respecting reason, but shall simply point to two important facts connected with its exercise. The first—that it suspends or greatly modifies the action of other powers—has already been noticed in our remarks on imagination; but we must state it here in more distinct terms. We especially wish the reader to understand how wide and important is the meaning of the terms 'control' and 'overrule' as we use them when we say: 'reason controls, or overrules, imagination!' When we say that, in nature, the laws which regulate one stage of existence overrule the laws of another and a lower stage, we do not intend to say that the latter are annulled, but that they are so controlled and modified in their course of action, that they can no longer produce the effects which would take place if they were left free from such control. A few examples will make our meaning plain. Let us contrast the operations of chemistry with those of mechanism. In the latter, substances act upon each other simply by pressure, motion, friction, &c.; but in chemistry, affinities and combinations come into play, producing results far beyond any that are seen in mechanics. On mechanical principles, the trituration of two substances about equal in hardness should simply reduce them to powder, but in chemistry, it may produce a gaseous explosion. Again—vegetable life overrules chemistry: the leaves, twigs, and branches of a tree, if left without life, would, when exposed to the agencies of air, light, heat, and moisture, be partly reduced to dust and partly diffused as gas in the atmosphere. It is the vegetative life of the tree which controls both the mechanical and the chemical powers of wind, rain, heat, and gravitation; and it is not until the life is extinct that these inferior powers come into full play upon the tree. So, again, the animal functions control chemical laws—take digestion, for example: a vegetable cut up by the root and exposed to the air, passes through a course of chemical decomposition, and is finally converted into gas; but when an animal consumes a vegetable, it is not decomposed according to the chemical laws, but is digested, becomes chyle, and is assimilated to the body of the animal. It is obvious that animal life controls mechanical laws. Thus, the friction of two inert substances wears one of them away—the soft yields to the hard; but, on the contrary, the hand of the labourer who wields the spade or the pickaxe becomes thicker and harder by friction.
The bearing of these remarks upon our present point will soon be obvious: we multiply examples, in order to shew in what an important sense we use the word control, with regard to the relation of reason with imagination. As we have seen, chemistry overrules the mechanical laws; vegetation suspends the laws of chemistry; a superior department of animal life controls influences which are laws in a lower department; again, mind controls the effects of physical influences; and, lastly, one power of the mind controls, and in a great measure suspends, the natural activity of another power—reason controls imagination. A second fact with regard to the action of reason must be noticed—that it requires a wakeful condition of the brain. Some may suppose that they have reasoned very well during sleep; but we suspect that, if they could recollect their syllogisms, they would find them not much better than Mickle's poetry composed during sleep. Mickle, the translator of the Lusiad, sometimes expressed his regret that he could not remember the poetry which he improvised in his dreams, for he had a vague impression that it was very beautiful. 'Well,' said his wife, 'I can at least give you two lines, which I heard you muttering over during one of your poetic dreams. Here they are:
"By Heaven! I'll wreak my woes
Upon the cowslip and the pale primrose!"'
If we required proof that the operation of reason demands a wakeful and active condition of the brain, we might find it in the fact, that all intellectual efforts which imply sound reasoning are prevented even by a partial sleepiness or dreaminess. A light novel may be read and enjoyed while the mind is in an indolent and dreamy state; music may be enjoyed, or even composed, in the same circumstances, because it is connected rather with the imaginative than with the logical faculty; but, not to mention any higher efforts, we cannot play a game of chess well unless we are 'wide awake.'
Now we come to our point:—Supposing that, by any means, the brain can be deprived of that wakefulness and activity which is required for a free exercise of the reasoning powers, then what would be the effect on the imagination? For an answer to this query, we shall not refer to the phenomena of natural sleep and dreaming, because it is evident that the subjects of the experiments we have to explain are not in a state of natural sleep; we shall rather refer to the condition of the brain during what we may call 'doziness,' and also to the effects sometimes produced by disease on the imagination and the senses.