The brain and the spinal cord have every attention from the yogi, because the yogi knows them as the two great centres of the whole nervous system of the body. The effect of the nerves on the body cannot have its importance exaggerated. Dr. G. E. Hall, of Toronto, explains that a stimulated nerve fibre oozes a secretion called acetylchaline, which, in excess, is poisonous and has been proved by experiment to create ulcerated stomach and some diseases of the heart.
Anger, which is a strong emotion, sends its messages from the brain, down the nerves, and stimulates the nerve endings to discharge acetylchaline in excess. This poisons the body, and the result of anger is low spirits and misery. Is it, then, the absurd invention of a weird cult to insist on the composed body and mind? It is nothing more than the practical application of common sense.
One may consider oneself composed, but might this not be due to nervous reactions being repressed in his conscious life? When he is asleep the conscious is off duty, the guard is gone. The average sleeper, without knowing it, of course, changes his position between twenty-five and fifty times a night. That is no composure of body and mind.
The rhythm of the breathing exercises is reflected to some extent in the accepted scientific fact that the brain generates electricity under the influence of rhythmic chemical action, whereby the thinking process is carried on, and other bodily functions. Dr. T. J. Case, of Chicago, says that the nerve-cells pulse electrically at about ten beats per second, and a break of rhythm means that there is some affliction at the area where the rhythm is broken. That rhythm is fundamental to life is indicated in many ways, as for instance in breathing and in the love of music and dancing. Dr. Rex B. Hersey has charted a man's emotions, and finds that they run in cycles of crests and depressions over an average period of four to five weeks. Yoga recognizes nature's demand for rhythmical living and trains the student accordingly.
That Yoga believes so strongly in the potentialities of the mind can readily be understood when it is realized that the subconscious, while giving evidence of phenomenal powers, is not yet by any means understood. Hypnotism, one method of exploring the subconscious, has revealed that the subconscious absorbs things we have never dreamt came within our ken, and when stimulated it will reveal them in the most minute and accurate details. Working through the conscious, however, its hidden knowledge is often revealed in distorted shape, to the individual's confusion, much as dreams juggle with the impressions left by the day.
The hidden mind profoundly influences the conscious mind, so Yoga strives to understand the subconscious.
The effect of the mind on the body is being established with increasing force by the progress of medical science, and many statements are corroborated by authoritative statements of fact made in The Force of the Mind, by Dr. A. T. Schofield, M.D., M.R.C.S., an admirable work, to which I am deeply indebted.
As to the influence of the mind on the body, we have Sir James Paget writing to Sir Henry Acland in 1866 that one of his patients might surprise the whole medical profession by being relieved of her maladies were there some force of assertion which would create the will to bear, forget, or suppress the turbulences of the patient's nervous system.
Modern medicine can no longer afford to ignore those potentialities of the mind that Yoga has always recognized, and that it has harnessed in a course of real therapeutics. Yoga recognizes that man is psychical and physical, and intermingled as these two aspects are, endeavours to systematize and establish the psychic laws in relation to the physical. It is dawning on the East that to impress the West she must systematize her knowledge; for the Westerner, unlike the Eastern student, will not blindly follow in faith and rely on intuition that he is in the hands of the right teacher.
It may be this lack of intuitive perception that has prevented the West assimilating much the East is ready to give, but which it cannot give if the West questions its authority. Now that the knowledge of the East is being formulated on Western lines, Western science feels more inclined to accept and understand, and even to adapt Eastern wisdom to its own needs. This continuity of mind and body is shown in ways which we tend to pass over, but Sir B. W. Richardson indicates for us the common association of the emotion of love with the heart, irritability with the liver, and, significantly enough, the highest point of mental insight with the stomach—the solar plexus of the sympathetic system. Significantly, the great cosmic energy of the yogi, called Kundalini, is described as resting in the abdominal regions, and, when stimulated, gives super mental powers.