V. But it is conceivable, on the assumption of mind being a separate principle from matter, that the human soul may be capable of retaining its union with the body in a new, unusual, and abnormal relation. The hypothesis is startling enough. I adopt it only from seeing no other way of accounting for certain facts which, with the evidence of their reality, will presently be brought forward. I venture to suppose that the mind of a living man may energize abnormally in two ways: first, that a much larger share of its operations may be conducted exoneurally—that is, out of the body—than usual; secondly, that the esoneural mental functions may be conducted within the body in unaccustomed organs, deserting those naturally appropriated to them. Two or three instances have been already given, which favour, at all events, the supposition of the possibility of such an abnormal relation between the mind and the body being realized. But in most of the instances hitherto adverted to, the normal relation may be supposed to have remained.
VI. Thus all the ordinary phenomena of sensorial illusions at once are esoneural, and suppose the persistence of the normal relation of mind and body. The material organ to which the physical agencies preceding sensation are propagated being irritated, is to be supposed to excite in the mind sensuous recollections or fancies that are so vivid as to appear realities.
VII. In mental delusions, again, there is no reason for surmising the intervention of the abnormal relation. But what are mental delusions? They are a part of insanity. And what is insanity? I will summarily state its features; for some of the instances which remain for explanation are referrible to it, and because I delight to crush a volume into a paragraph.
The phenomena of insanity may be arranged under five heads: The first, the insane temperament; the next three the fundamental forms of mental derangement; the fifth, the paroxysmal state. The features of the insane temperament are various; some of them are incompatible with the simultaneous presence of others. When a group of them is present, as a change in natural character, without insanity, insanity is threatened: no form of insanity manifests itself without the presence of some of them. The features of the insane temperament are these: The patient withdraws his sympathies from those around him, is shy, reserved, cunning, suspicious, with a troubled air, as if he felt something to be wrong, and wonders if you see it; he is capricious, and has flaws of temper; being talkative, he is flighty and extravagant; he is hurried in his thoughts, and mode of speaking, and gestures; he has fits of absence, in which he talks aloud to himself; he is restless, and anxious for change of place. Of the elementary forms of insanity, one consists in the entertainment of mental delusions: the patient imagines himself the Deity, or a prophet, or a monarch, or that he has become enormously wealthy; or that he is possessed by the devil, or is persecuted by invisible beings, or is dead, or very poor, or that he is the victim of public or private injustice. The second form is moral perversion: the patient is depressed in spirits without a cause, perhaps to the extent of meditating suicide; or he feels an unaccountable desire to take the lives of others; or he is impelled to steal, or to do gratuitous mischief; or he is a sot; or he has fits of ungovernable and dangerous rage. The third form exhibits itself in loss of connexion of ideas, failure of memory, loss of common intelligence, disregard of the common decencies of life. Each of these three elementary forms is sometimes met with alone; generally two are combined. Sensorial illusions are common in insanity; auditory, unaccompanied by visual illusions, are almost peculiar to it, and to the cognate affection of delirium from fever or inflammation of the brain. To the head of the paroxysmal state belongs the history of exacerbations of insanity, of their sudden outbursts in persons of the insane temperament, of their preferential connexion with this or that antecedent condition of the patient, of their occasional periodicity.
VII. In congenital idiotcy and imbecility, the relation of the mind and brain is normal. Often the defective organization is apparent through which the intelligence is repressed. In many countries a popular belief prevails that the imbecile have occasional glimpses of higher knowledge. There is no reason evident why their minds should not be susceptible of the abnormal relation.
VIII. In sleep, the mind and brain are in the normal relation. But what is sleep, psychically considered?
It is best to begin by looking into the mental constituents of waking. There is then passing before us an endless current of images and reflections, furnished from our recollections, and suggested by our hopes and our fears, by pursuits that interest us, or by their own inter-associations. This current of thought is continually being changed or modified, through impressions made upon our senses. It is further liable to be still more importantly and systematically modified by the exercise of the faculty of Attention. The attention operates in a twofold manner. It enables us to detain at pleasure any subject of thought before the mind; and, when not on such urgent duty, it vigilantly inspects every idea which presents itself, and reports if it be palpably unsound or of questionable tendency. To speak with more precision, it is a power we have of controlling our thoughts, which we drill to warn us whenever the suggested ideas conflict with our experience or our principles.
Then of sleep. We catch glimpses of its nature at the moments of falling asleep and of waking. When it is the usual time for sleep, if our attention happen to be livelily excited, it is in vain we court sleep. When we are striving to contend against the sense of overwhelming fatigue, what we feel is, that we can no longer command our attention. Then we are lost, or are asleep. Then the head and body drop forwards; we have ceased to attend to the maintenance of our equilibrium. Any iteration of gentle, impressions, enough to divert attention from other objects, without arousing it, promotes sleep.
Thus we recognise as the psychical basis of sleep the suspension of the attention.
Are any other mental faculties suspended in sleep? Sensation and the influence of the will over the muscular system are not; for our dreams are liable to be shaped by what we hear. The sleeper, without waking, will turn his head away from a bright light, will withdraw his arm if you pinch it, will utter loud words which he dreams he is employing. The seeming insensibility in sleep, the apparent suspension of the influence of the will, are simply consequences of the suspension of attention.