Sleep and Its Derangements

by William A. Hammond

The subject of the foregoing chapter is so intimately connected with the phenomena of dreaming, and I have expressed my views in regard to it at such length, that but few psychological points remain to be considered in the present discussion. What I have to say, therefore, in regard to the physiology of dreaming must be read in connection with the chapter on “The State of the Mind during Sleep,” in order that the whole matter may be fully understood.

It is contended by some writers that the mind is never at rest, and that even during the most profound sleep dreams take place, which are either forgotten immediately, or which make no impression on the memory. That this view is erroneous is, I think, very evident. If it were correct, the first object of sleep—rest for the brain—would not be attained. We all know how fatigued we are, and how indisposed to exertion the brain is, after a night of continued dreaming, and we can easily imagine what would be the consequences if such a condition were kept up night after night. To say that we really do dream not only every night, but every instant of the night, in fact always and continually when we sleep, but that we forget our dreams as soon as they are formed, remembering solely those which are most vivid, is making assertions which not only are without proof, but which are impossible of proof. For if, as Locke[65] remarks, the sleeping man on awaking has no recollection of his thoughts, it is very certain that no one else can recollect them for him.

The observations of Locke on this point are extremely appropriate, and, to my mind, very philosophical and logical. After insisting that, sleeping or waking, a man cannot think without being sensible of it, he says:[66]

“I grant that the soul of a waking man is never without thought, because it is the condition of being awake; but whether sleeping without dreaming be not an affection of the whole man, mind as well as body, may be worth a waking man’s consideration, it being hard to conceive that anything should think and not be conscious of it. If the soul doth think in a sleeping man without being conscious of it, I ask, whether during such thinking it has any pleasure or pain, or be capable of happiness or misery? I am sure the man is not, any more than the bed or earth he lies on, for to be happy or miserable without being conscious of it seems to me utterly inconsistent and impossible. Or if it be possible that the soul can, while the body is sleeping, have its thinkings, enjoyments, and concerns, its pleasure or pain, about which the man is not conscious of nor partakes in, it is certain that Socrates asleep and Socrates awake is not the same person; but his soul when he sleeps and Socrates the man, consisting of body and soul when he is waking, are two persons, since waking Socrates has no knowledge of or concernment for that happiness or misery of his soul which it enjoys alone by itself while he sleeps without perceiving anything of it, any more than he has for the happiness or misery of a man in the Indies whom he knows not; for if we take wholly away all consciousness of our actions and sensations, especially of pleasure and pain, and the concernment that accompanies it, it will be hard to know wherein to place personal identity.”

In a subsequent section of the same chapter, Locke asserts that most men pass a great part of their lives without dreaming, and that he once knew a scholar who had no bad memory, who told him he had never dreamed in his life till after the occurrence of a fever in the twenty-fifth or twenty-sixth year of his age.

Examples of persons who have not ordinarily dreamed are adduced by the ancient writers. Pliny[67] refers to men who never dreamed. Plutarch[68] alludes to the case of Cleon, who, in living to an advanced age, had yet never dreamed; and Suetonius[69] declares that before the murder of his mother he had never dreamed.

A lady who was under my care for a serious nervous affection declared to me that she never had had but one dream in her life, and that was after receiving a severe fall in which she struck her head.

And yet, notwithstanding the experience of every one that sleep often happens without the accompaniment of dreams, the great majority of writers hold the view that the brain is never at rest. Doubtless this opinion has its origin partly in the doctrine that the mind is a something altogether independent of and superior to the brain. They appear to be incapable of appreciating the fact that when the brain is in a state of complete repose there can be no mental manifestation, and that all intellectual phenomena are the results of cerebral activity. Another cause for their belief is the fact that they make no distinction between dreaming and thinking, whereas it is very evident that the two are not to be placed in the same category. Thinking is an action which requires cerebral effort, and which is undertaken with a determinate purpose. We will to think, and we think what we please; but it is very different with our dreams, which come and go without any power on our part to regulate or direct them. To think requires all the faculties of the mind; to dream necessitates only the memory and the imagination. In thinking, the brain is active in all its parts; in dreaming, it is nearly entirely quiescent.

Writers who contend for the doctrine of constant mental activity regard the brain as the organ or tool of the mind, a structure which the mind makes use of in order to manifest itself. Such a theory is certain to lead them into difficulties, and is contrary to all the teaching of physiology. The full discussion of this question would be out of place here; I will, therefore, only state that this work is written from the stand-point of regarding the mind as nothing more than the result of cerebral action. Just as a good liver secretes good bile, a good candle gives good light, and good coal a good fire, so does a good brain give a good mind. When the brain is quiescent there is no mind.

Lemoine[70] begins his chapter “On the State of the Mind during Sleep” with the assertion that “there is no sleep for the mind.” He is obliged, however, to admit that “when the organs of the body are benumbed by sleep, the mind appears to be in a particular state; it seems to be submitted to other laws than those which govern it during wakefulness; it seems to have lost for a time its most precious faculties.”