Hallucinations are entirely mental. But the phenomena that sometimes appear to be hallucinations may be due to illusions of the senses within the organism. For instance, those who indulge in cocaine often have the feeling of having a veil over the face, or of having run into a cobweb or something of that kind. The presence of the veil or the cobweb on the face is probably not an hallucination, but is due to certain disturbances in the circulation, or perhaps in the nerves themselves, which affect the nerve endings of the face, causing them to tingle in a particular way, and this sensation is translated as coming from without in terms of something that has been felt before. Some of the appearances of muscae volitantes, or of specks before the eyes, or occasionally of wavy lines, are due to disturbances of the circulation within the eyeball which cause corresponding disturbances of the optic nerve, with consequent apparent visions. When the eyeball is pressed upon, the sensation first produced is that of light and not of pain, because whenever a nerve of special sense is irritated, it produces its own specific sensation in the brain.
The chilly stage in malaria is a typical example of a physical condition having an effect upon sensory nerves that more or less necessarily produces a delusion. The patient is actually at the height of his fever when the chilliness and shivering come on and when he demands a larger amount of covers in order to protect himself from the cold he will often have a temperature of 104 degrees Fahrenheit, or even higher. What has happened is that the little blood vessels at the surface of the body are shut up by the effect of the plasmodium upon the system. Whenever we are cold these little blood vessels shut up in order to protect the blood from being chilled by the external atmosphere. The shutting up of the little blood vessels deprives, for the time being, the terminal nerves in the neighborhood of some of their nourishment. Their response is to set up a tremor or shivering, which will mechanically tend [{775}] to open the blood vessels so that they may have their nourishment once more. Whenever we have a set of sensations that correspond to this connected set of events, we translate them as feeling cold. The outer air does feel cold to the body because the blood is not flowing through to the surface as it would normally in order to warm it. Hence the chilliness. This is not an hallucination; but an illusion with something of a delusion in it; until we know how things are. Nervousness may set our teeth chattering just as it may cause tremor through our sympathetic nervous system, disturbing the flow of blood through muscles and so disturbing control of them. Vehement emotion, anger, fright, and even those of less violence may cause similar effects. All these phenomena illustrate the close relation between mind and body.
APPENDIX II
RELIGION AND PSYCHOTHERAPY
Religion and psychotherapy have, of late, come to have many relations to each other and many interests in common, at least in the minds of a number of clergymen, and in popular estimation. There is no doubt but that religion can do much to soothe troubled men and women, even when their troubles are entirely physical in nature and origin. It at least lessens the unfavorable effect of worry in exaggerating such pathological processes as are at work. All diseases, functional and organic, are rendered worse by solicitude, while many troublesome symptoms become quite bearable if only the patient does not dwell on them too much but takes them as they come, carefully refraining from emphasizing them by over-attention. That is the very essence of psychotherapy. Religion, in the sense of trust in divine wisdom, can do much to originate and maintain this imperturbed frame of mind. People who are without religion, that is, without the feeling that somehow all their ills are a part of the great plan of the universe, the mystery of which is insoluble, but the recognition of which is demanded by reason, and who lack the assurance that somehow, in Browning's phrase:
"God's in His Heaven-
All's right with the world!"
—are more prone to give way to over-anxiety and consequently to make themselves suffer more in all their ills, than is necessary or even likely in the more favorable state of mind of those whose trust in Providence is thorough and efficient.
In recent years there has been in the general population a distinct loss of faith in the great religious truths that are so helpful in engendering a peaceful state of mind in suffering. Many have come, if not to doubt of the Providence of the Creator, at least to feel that we do not know enough about it to place any such supreme dependence on it in the trials of life as would make it a source of relief, or at least consolation, in suffering. This same spirit of doubt has paralyzed faith in the hereafter and in all that trust in it brings, to sufferers, of consolation to come for their ills if these are borne as becomes rational creatures whose suffering has a purpose, though we may not comprehend it. Some people are destined by their physical make-up or by accidental conditions to considerable suffering. There are many ailments that are incurable and are definitely known to be incurable. Some of these entail great suffering of body and even more suffering of mind. Such suffering becomes quite unbearable unless the patient is of a very stoic disposition, or unless the thought of a hereafter in which the sufferings of this life will have a meaning is present to console.
Great scientists in the midst of all our advance in science—one need but mention here such men as Lord Kelvin, Clerk Maxwell, Johann Müller, Laennec, Pasteur, Claude Bernard, though the number might easily be multiplied—have insisted that the existence of a Creator is absolutely demanded by what we know of the physical universe. "Science demonstrates the existence of a Creator," is Lord Kelvin's expression. The existence of a Creator implies, also, the existence of laws made by Him, by which His universe is regulated in every detail, nothing being left to chance. Chance is indeed only a term which indicates that we do not know the causes at work. If somehow the Creator's power has been sufficient to bring the manifold things of the universe into existence according to a plan in which there is no such interference with one another as would cause serious disturbance of the universal order around us, then He can be trusted also to care for even the minutest details of creation and of human life.