CHAPTER V
THE ORGANISATION OF THE LOWER LEVELS OF THE MIND
In the level of the mind known as the subconscious or unconscious are stored all the ideas to which we have no direct access.
Some psychologists say that the memory of every impression which has ever been received by a sense organ is registered here as on a photographic plate, but this opinion is not universally accepted. We shall be quite safe in saying, however, that the memory of anything which has ever made a distinct impression on the mind is stored here and plays its part in the mental life.
Between the subconscious and the foreconscious is placed the great main censor-sieve of the mind, and it is this which is meant when the “censor” is referred to in psychoanalytical literature.
This censor-sieve is of the greatest importance in the mental economy, for upon its function the health of the mind is largely dependent. If its meshes are too loose, we get an uprush into consciousness of ideas which should never be there; and if too tight, the conscious mind is cut off from the source of its energy, the subconscious.
This sieve is constructed upon the same principles as the two others which we have already considered, but it has one fundamental difference, it is not under the control of the will; the dimension of its mesh is regulated, not by what I, at the moment, may happen to wish, but by what the main tenor of my character may determine.
The foreconscious, then, may be likened to a reference library, but the great storehouse of the subconscious is a vault in which the archives are kept; and although the bulk of them never touch the conscious mind, it is their indirect influence which determines the tone of the character.
The remotest level of the mind, whose functioning is purely automatic, has the control of all the vital functions of the body. Its thought processes direct the activities of the spinal level of the nervous system, whereas the other levels of the mind have the brain as their physical organ of manifestation, as is proved by the fact that a disease of the brain can throw the reasoning faculties out of gear and leave the purely physiological nervous functions intact, whereas a disease of the spinal cord may render inoperative the nervous processes of the bodily functions, though the mental processes are unimpaired.
The psychic processes of the automatic mind govern all the biochemical processes of the body; it is this level which controls the involuntary muscles, regulates the blood supply to any part of the body, controls the output of the ductless glands, and hence the chemical composition of the blood. It is these facts which may throw light upon the origin of many functional disturbances and upon the phenomena of mental healing.
Although the automatic level is not normally in touch with the conscious mind, it is enormously affected by the general feeling-tone of the mentality, and especially by the emotional states of the subconscious, hence the alterations of physiological function which take place in nervous disease.
This level of the mind was the first to be organised in the history of biological development. The dim mentation of the rudimentary beginnings of life was of the automatic order, being entirely concerned with physiological processes.
As organisms became more evolved, a higher type of intelligence was necessary for the carrying out of their life activities, and we get mentation of the type that is carried on in the subconscious level, the impulsive mentation of the instincts.
Level by level the mind builds itself up, in the race and in the individual; and level by level, under the influence of old age, disease or drugs, the planes of consciousness break down in the inverse order to that in which they developed, the more recently organised higher centres going first, and the automatic mind, the oldest and most stable, with æons of habit behind it, working on to the last, keeping the bodily mechanism running long after all that made the organism a man has withdrawn from its dishonoured vehicle.