Inferential theology would fall into the back-ground. The Bible would be studied more faithfully, more devoutly, more fruitfully. It might be hoped that many conscientious dissenters would no longer feel scruples in communion with their brethren of the Church; and that some good and able men would lend us their aid, both in the Universities and the Church, who are now kept apart by causes that could not separate men in heaven, and ought not to separate them on earth. HENRY G. LIDDELL. ON SLEEP AND DREAMS. BY THE REV. JOHN CUNNINGHAM, D.D., AUTHOR OF THE "CHURCH HISTORY OF SCOTLAND.” life? It is a great mystery. What is sleep? We must confess our ignorance. Though we sink into sleep every twentyfour hours, though we spend a third of our whole time in sleep, and though, as Shakespeare says, 66 our life is rounded by a sleep," we do not know what sleep is. Some physiologists have gone so far as to declare that sleep is our normal state, out of which we only waken at intervals into a condition of abnormal activity, and then naturally sink back. again into it; and that, therefore, it were wiser to inquire what is wakefulness than what is sleep. I suspect that both are normal conditions of all animal life but what is the difference between them? There seems, at first sight, to be a great and easily-recognisable difference; but, when we come to examine it it eludes our grasp. It is not that the one is a conscious and the other an unconscious state, for we shall presently see that in the profoundest sleep there is consciousness. It is not that there is, necessarily at least, less activity during sleep than during wakefulness; for our dreams are often more brilliant than our waking thoughts, and the feats of the somnambulist rival the feats of the wide-awake athlete. In truth, there is almost nothing deemed peculiar to wakefulness which does not sometimes occur in sleep. In sleep we think and feel, we may be sorry or glad, we may smile or weep, we may be profoundly happy or petrified with horror. There have been cases of men reading aloud while they were fast asleep. Soldiers have continued their march, postillions have ridden their horses, seamstresses have proceeded with their sewing, and even, it is said, clergymen have written on at their sermons after sleep had overtaken them. In what, then, does sleep differ from wakefulness? Physiologists and psychologists alike have been forced to confess they cannot tell. There is a difference, but they cannot exactly indicate it. The difficulty of distinguishing between sleep and wakefulness is increased by the fact that the one gradually merges into the other. There appears to be no well-defined line where wakefulness ends and sleep begins. Wakefulness imperceptibly gives way to sleep; sleep, in in like manner, yields to wakefulness. If there be any boundary between them, it is a debateable land- -a dream-landwhere lights and shadows, day-thoughts and night-thoughts, confusedly mingle. Sleep and wakefulness, in this respect, follow a general law. There are few sharp boundary lines in nature. Things which at their extremes are widely different approach till they meet and melt into one another. Who will sepa rate between the organic and the inorganic, between the sentient and the insentient, between the living and the nature's sweet restorer, balmy sleep" comes and lays us to rest. Sleep introduces us to the region of dreams, and dreams have ever been a subject of mysterious interest. Almost all primitive peoples have regarded dreams as Divine intimations. It was God whispering within them. "In slum"berings upon the bed," says Elihu,"God 66 dead? Every one may satisfy himself, by a kind law of our being, "tired by personal experience how gradually wakefulness gives way to sleep. Any night he may make the experiment and watch the process. He will observe that his thoughts become more and more dissevered from outside influencesthe sensational yields to the idealthe laws of association act uncontrolled by material objects, everything becomes shadowy, and so he glides into perfect sleep; but he never discovers the moment when he sleeps, both because there is no such moment, and because the farther he advances into the region of somnolency the more the attention relaxes, till at last it is swept away by the dreamy thoughts which now occupy the brain. It is thus we have every possible degree of sleep, from the light sleep of the nurse-which the slightest movement of her patient will interrupt-to the deep sleep of the worn-out man, which almost nothing will disturb. The most opposite causes seem to predispose to sleep. Heat creates drowsiness, and drowsiness leads to slumber. Cold at least, severe cold-has the same effect. The traveller in Arctic regions is frequently assailed by a desire to sleep, so strong that he cannot resist it, though he should be quite aware that it will be the "sleep which knows no waking." Vacuity of thought is generally regarded as favourable to sleep, and yet intense thought, and even intense anxiety, have the same result. It is thus that felons not unusually sleep soundly the night before their execution. The explanation of this, however, most probably is, that the mind is worn out by the violence of its own emotions, and kind nature comes to its relief. Physicians tell us that anything which determines the blood to the brain induces sleep, and also that an excessive loss of blood has the same effect. From such opposite quarters does sleep come: but at the same time we must remember that it is a normal condition of our being; that it has a tendency to recur periodically; and that weariness is undoubtedly its great predisposing cause. When we are wearied and jaded with the duties of the day, openeth the ears of men and sealeth "their instruction." Homer frequently introduces the gods as inspiring dreams both good and bad; and in this he is followed by almost all the ancient poets, who so far only gave a poetic utterance to the popular faith. Philosophers, in more recent times, have adopted the belief of these ancient bards. Baxter, in his Essay on the Phenomena of Dreaming, after rejecting all the theories which represent dreams as originating in the mind itself, and debarred by his Christianity from calling into play mythological deities, resorts to the supposition that they are suggested to us by spiritual beings of some kind or other. In no other way, as he thinks, can they be accounted for. And, as dreams have thus been attributed to a supernatural origin, so have they very generally been regarded as possessing a prophetical character. The farther back we ascend, this belief becomes stronger, but it is far from extinct in the present day. In the courts of the ancient eastern kings there was always to be found an interpreter of dreams. Joseph held the office in the court of the Egyptian Pharaoh ; and Daniel in that of the Chaldean Nebuchadnezzar and, though the function has now declined from its pristine dignity, the "spey-wife" still explains to credulous maidservants the meaning of their dreams. Nor need we wonder that our dreams have thus been ranked with the supernatural. There is the gloom of night, and the mystery of sleep; and, when our eyes are closed upon the world, and we no longer hear the voices of our fellow-men, then mysterious voices whisper within us and weird-like shapes move before us; we visit strange countries, converse with old comrades, get a glimpse of things not yet come to pass ; and everything is so real, so life-like, and at the same time so unlike our usual thoughts, that we readily accept of any explanation which refers our dreams to the Divine. But there has always been a sceptical philosophy in the world, which repudiates the supernatural, and traces all things to the operation of ordinary law. The Greeks, who speculated about everything, speculated about dreams, and had their ways of accounting for them. Democritus taught that all material things were constantly throwing off filmy simulacra of themselves, and that these assailed the soul, while it lay helpless in sleep, and formed the images of our dreams. The Latin Lucretius afterwards worked up this idea in his great poem. The Platonists, on the other hand, held that the mind itself might evolve dreams; and Cicero, whose tendencies were all toward the Academy, defends this opinion, in his interesting book on Divination. Many other old theories about dreams might be quoted; but, instead of getting ourselves entangled in these ancient speculations, I think it better to follow the track of modern thought. One of the questions which has at all times been greatly agitated is-Do we always dream during sleep? This question is as old as the days of Aristotle; and equally illustrious names can be quoted on either side of the controversy. Hippocrates, Leibnitz, Des Cartes, Cabanis, Abercrombie, and Sir W. Hamilton, maintain that we always dream Locke, Reid, Macnish, Carpenter, and Brougham, are of opinion. that sound sleep is dreamless. In order to reach a satisfactory solution of the question, I shall endeavour first to answer it in this simpler and more definite form - Are we ever perfectly unconscious during sleep? I imagine that, when the question is thus put, few will hesitate to answer that we are never entirely unconscious even during the profoundest sleep. I question, indeed, how far utter unconsciousness is compatible with the existence of mind. I cannot think the mind is like a piece of mechanism, which may exist though it does not move: the essence of mind is thought; and therefore the cessation of consciousness seems to be tantamount to the cessation of mind. I therefore apprehend that even in swoons there must be some remnants of consciousness, though we may not be able to reach them. There must always be a feeble glimmer of light, if it is to be blown again into a flame: there must always be a trace of life, however faint, if reanimation is to take place. But there are more specific arguments which greatly strengthen these general ones. It is allowed on all hands that sensation is greatly blunted by sleep. The eyes are closed, the ears are partially stopped, the whole surface of the body loses some of its sensitiveness, and even the sensations which reach us from other parts of our system are not so vivid as when we are awake. The famished escape from the pangs of hunger; and those who are perishing for thirst forget for a little the agony of the parched throat. But, though sensation is blunted, it is not destroyed. If the sleeper has assumed an uncomfortable position, he feels the discomfort, and turns himself in bed. If a whisper fails to awaken us, a cry will; if we do not hear a step softly treading our room, we cannot help hearing if, perchance, the tongs rattle on the fender. A hand gently laid on the bed-clothes may not disturb us, but a hand somewhat roughly laid on our shoulder will make us quickly start up with confused thoughts about thieves. This proves there is sentiency, though it is not so sharp-edged as when we were awake. If there were no consciousness, no sentiency-(as Macnish in his Philosophy of Sleep unguardedly affirms)-a cannon might be exploded in our room without awakening us. Indeed, when once we were sound asleep, there would be no possibility of rousing us at all. It is because consciousness and sense remain that the connexion is maintained between the sleeper and the external world. We have thus a basis for dreams. But a dream, in the usual sense of the term, is something more than a state of dull, sluggish, consciousness. It is a lively train of thought, resembling our waking reveries, but at once more vivid and more incoherent. If the question be-Are such trains of thought constantly passing through our minds during sleep?-I think there can be no hesitation in answering in the negative. I do not see why we should not believe that in sleep, as in wakefulness, the mind is sometimes more and sometimes less active. In neither state is it ever entirely without thought and consciousness, and in both it is sometimes intensely busy, and at other times in almost perfect repose. In short, there may be every gradation of thought and feeling, from the highest consciousness down to the very verge of unconsciousness. There is reason to believe that in deep sleep the latter state is approached-thought lies still, and fancy, so lively at other times, folds her wings, and partakes of the universal repose. It is certain that those who sleep soundly seldom remember their dreams, and I apprehend that we remember our nightthoughts just as we remember our vivid day ones, and quickly forget all others. We shall be confirmed in this belief if we watch a person in profound sleep. The whole frame lies motionless, every feature is in perfect repose; there is nothing to indicate that thought is busy within; and energetic thought generally works its way out, and manifests its presence. It is very different in broken sleep, and in the transition-state between sleep and wakefulness, which, I suspect, is the true dream-land. The frequent changes of position, the shades of expression which pass over the countenance, as with men in a reverie; sometimes the mutterings, sometimes the uneasy groans-all indicate that thought is earnestly at work, giving pleasure or reflecting pain. This opinion is greatly strengthened by the following curious case, stated by Dr. Pierquin. It fell under his notice in one of the hospitals of Montpellier, in 1821. A young woman had lost, from disease, a large portion of her scalp, skull-bone, and dura mater, and a corresponding portion of her brain was consequently bare and open to inspection. "When she was in reported as such by herself, the pro"trusion was considerable; and, when "she was perfectly awake, especially if "engaged in active thought or sprightly "conversation, it was still greater. Nor "did the protrusion occur in jerks, alter"nating with recessions, as if caused by "the impulse of the arterial blood. It "remained steady while the conversation "lasted." This singular case is very interesting, as not only illustrating the action of the brain under the influence of thought, but also as leading to the inference that the mind is nearly quiescent in certain stages of sleep. The facts of somnambulism are frequently quoted in opposition to the opinion I have maintained. The somnambulist may be in a sleep so profound that almost nothing will awaken him; he may show the current of his thoughts by his actions-by dancing, singing, climbing to house-tops, performing a hundred extraordinary freaks, for hours together, and in the morning have not the slightest recollection of his night's adventures. Such cases there undoubtedly are, but they must be regarded as abnormal, and as proving little regarding the phenomena of ordinary sleep. In ordinary sleep the body is generally motionless, in somnambulism it is active; and the same may be true in regard to the mind. Somnambulism appears, in some respects, to be like the mesmeric sleep, in which there is perfect agility of body, and a certain alertness of mind, though coupled with a subjectivity to every kind of hallucination and imposture. In truth, it almost looks like a misnomer to speak of these states as sleep at all-the mind seems simply to be in some degree detached from the senses, and thrown into a new frame of thinking, as an organ, by the different arrangement of the stops, may be made to emit a new set of sounds. But Sir William Hamilton quotes his own experience as evidence that the mind is busy with dreams during the soundest sleep. He caused himself to be wakened at different periods of the night and always found himself dreaming. It might be said in answer to this that Macnish tried the same experiment upon himself, and with the very opposite result; as he wakened he could not catch the least trace of a receding dream. But, though there were not such opposing testimony, the case of Sir William Hamilton would not be decisive. A person going to bed with the knowledge that he was to be operated on-aware that he was to be wakened at some period of the night, and that, to make the experiment successful, he must start from sleep as quickly as possible, and turn his eyes in upon himself, would not be likely to enjoy that deep sleep which dreams do not invade, but would almost to a certainty have his mind agitated and filled with thoughts about the business on hand, thus destroying the necessary conditions of a testing experiment. But, besides, could Sir William Hamilton be certain that the dreams which he found in possession of his brain when he awoke were not confined to the short period of transition from sleep to wakefulness? There are plenty of dreams on record-dreams which appeared long to the dreamers and embraced a multitude of scenes and circumstances-and which yet could not have occupied many seconds. And, moreover, as has already been said, the transition-period seems to be the most fruitful of dreams. But Sir William Hamilton acknowledges that on some occasions when he was thus suddenly roused, he was "scarcely certain of more than the fact that he was not awakened from an unconscious state," which corroborates the opinion that consciousness exists in very various degrees of activity. We may therefore rest in the conclusion that in sleep we are always conscious, though not always imaginative. But how comes it that our night thoughts are so different from our day thoughts? Why should the same mind act so differently in sleep and wakeful ness? These questions I think admit of a satisfactory explanation. The two chief characteristics of dreams are the substitution of ideas for sensations, and incoherency without any perception of it. Let us look at each of these characteristics. Dreams are nothing more than trains of thought. We think when we are asleep as well as when awake, and these sleeping-thoughts we call dreams. But there appears to be something more than mere thoughts. We see, we hear, we smell, we taste, touch, handle. We pass through the streets of a great city, gaze at the noble buildings, admire the splendid equipages, hear suddenly the salutation of a friend, walk with him, talk with him, part with him; and every thing is as real to us, and as firmly believed, as if it were actual. How is this? How do we manage to impose upon ourselves? How do our thoughts contrive to cheat the conscious mind out of which they spring? To penetrate the mystery we must remember that the mind has two states of consciousness -sensations and ideas. Sensations are the pictures of outward nature, and ideas are the pictures of sensations. Sensations are the images of objects thrown upon the mind with every shade of brilliant colouring, but fading the moment these objects are gone; ideas are the photographic light-and-shade impressions of these left on the memory: and as, when photographs are placed in the stereoscope, the effect of reality is produced, so there are circumstances in which ideas, by a wonderful illusion, produce all the effects of sensation. We seem to see not mere pictures but the actual scenes. I have already shown, in a previous paper (see Macmillan's Magazine, No. 30, April 1862), that even in our waking state ideas are sometimes mistaken for sensations, that we believe ourselves to see or feel what we merely imagine, and that all ideas as well as sensations bring their outward objects before the mind. When we think of anything it is always as of something outside of ourselves. What we think of-what we are conscious of is not the thought itself, but its object. When |