CHAPTER XVIII
THE UNITY OF THE BODY
(Discusses the body as a whole, and shows that health is not a matter of many different organs and functions, but is one problem of one organism.)
The reader who has followed our argument this far will understand that we are seldom willing to think of the body as separate from the mind. The body is a machine, to be sure, but it is a machine that has a driver, and while it is possible for a sound machine to have a drunken and irresponsible driver, such a machine is not apt to remain sound very long. Frequently, when there is trouble with the machine, we find the fault to be with the driver; in other words, we find that what is needed for the body is a change in the mind.
If you wish to have a sound body, and to keep it sound as long as possible, the first problem for you to settle is what you want to make of your life; you must have a purpose, and confront the tasks of life with energy and interest. What is the use of talking about health to a man who has no moral purpose? He may answer—indeed, I have heard victims of alcoholism answer—"Let me alone. I have a right to go to hell in my own way."
I am aware, of course, that the opposite of the proposition is equally true. A man cannot enjoy much mental health while he has a sick body. It is a good deal like the old question, Which comes first, the hen or the egg? The mind and the body are bound up together, and you may try to deal with each by turn, but always you find yourself having to deal with both. Most physicians have a tendency to overlook the mind, and Christian Scientists make a religion of overlooking the body, and each pays the penalty in greatly reduced effectiveness.
My first criticism of medical science, as it exists today, is that it has a tendency to concentrate upon organs and functions, and to overlook the central unity of the system. You will find a doctor who specializes in the stomach and its diseases, and is apt to talk as if the stomach were a thing that went around in the world all by itself. He will discuss the question of what goes into your stomach, and overlook to point out to you that your stomach is nourished by your blood-stream, which is controlled by your nervous system, which in turn is controlled by hope, by ambition, by love, by all the spiritual elements of your being. A single pulse of anger or of fear may make more trouble with the contents of your stomach than the doctor's pepsins and digestive ferments can remedy in a week.
Of course, you may do yourself some purely local injury, and so for a time have a purely local problem. You may smash your finger, and that is a problem of a finger; but neglect it for a few days, and let blood poison set in, and you will be made aware that the human body is one organism, and also that, in spite of any metaphysical theories you may hold, your body does sometimes dominate and control your mind.
Some one has said that the blood is the life; and certainly the blood is both the symbol and the instrument of the body's unity. The blood penetrates to all parts of the body and maintains and renews them. If the blood is normal, the work of renewal does not often fail. If there is a failure of renewal—that is, a disease—we shall generally find an abnormal condition of the blood. The distribution of the blood is controlled by the heart, a great four-chambered pump. One chamber drives the blood to the lungs, a mass of fine porous membranes, where it comes into contact with the air, and gives off the poisons which it has accumulated in its course through the body, and takes up a fresh supply of oxygen. By another chamber of the heart the blood is then sucked out of the lungs, and by the next chamber it is driven to every corner of the body. It takes to every cell of the body the protein materials which are necessary for the body's renewal, and also the fuel materials which are to be burned to supply the body's energy; also it takes some thirty million millions of microscopic red corpuscles which are the carriers of oxygen, and an even greater number of the white corpuscles, which are the body's scavengers, its defenders from invasion by outside germs.
There are certain outer portions of the body, such as nails and the scales of the skin, which are dead matter, produced by the body and pushed out from it and no longer nourished by the blood. But all the still living parts of the body are fed at every instant by the stream of life. Each cell in the body takes the fuel which it needs for its activities, and combines it with the oxygen brought by the red corpuscles; and when the task of power-production has been achieved, the cell puts back into the blood-stream, not merely the carbon dioxide, but many complex chemical products—ammonia, uric acid, and the "fatigue poisons," indol, phenol and skatol. The blood-stream bears these along, and delivers some to the sweat glands to be thrown out, and some to the kidneys, and the rest to the lungs.
All of this complicated mass of activities is in normal health perfectly regulated and timed by the nervous system. You lie down to sleep, and your muscles rest, and the vital activities slow up, your heart beats only faintly; but let something frighten you, and you sit up, and these faculties leap into activity, your heart begins to pound, driving a fresh supply of blood and vital energy. You jump up and run, and these organs all set to work at top speed. If they did not do so, your muscles would have no fresh energy; they would become paralyzed by the fatigue poisons, and you would be, as we say, exhausted.