I will now enter upon a study of the brain and its powers along these lines, to be enlivened by illustrative evidence. What reason and physiology had I with me that I should use methods in the sick-room wherein the entire medical world was against me, and with severest condemnation?
The head is the power-house of the human plant, with the brain the dynamo as the source of every possible human energy. We think, love, hate, admire, labor with our hands, taste, hear, smell, see, and feel through the brain. Broken bones and wounds heal, diseases are cured through energy evolved in the brain or the brain system as a whole. The other so-called vital organs and the muscles are only as so many machines that are run by the brain power, with the stomach an exceedingly important machine. That powers so rare do not originate in the bones, ligaments, muscles, or fats, does not need argument; that when the nerve-trunks that supply the arm or leg are severed power of movement and feeling is lost, is known to all; and equally would the power of the stomach be abolished were the nerve-trunks cut off. In a general way, then, it may be stated that the strength of the body is directly as the strength of the brain.
With this physiology, who in or out of the medical profession can fail to see clearly that the digestion of even an atom of food is a tax upon the strength of the brain for whatever of power needed by the stomach, the machine, for this purpose? Unless it can be proved that the stomach has powers not derived from the brain system, this will have to be admitted.
How is the strength kept up in the light of this physiology? The universal belief is that it is kept up by the daily food. In proportion to the prostration of sickness, so are physicians anxious to conserve the energies by working the stomach to the limit of its powers.
The impression that there must be something digested to support the vitality of the system is a belief, a conviction that has always been too self-evident to suggest a doubt.
If the well need food to keep up the strength, the sick need it all the more; this is the logic that has been displayed upon this question. Let us keep it clear in mind that, if the nerves going to the stomach are severed, paralysis will result as in the case of the arm, in order more definitely to conceive the stomach as a machine that requires power to run it even to a tiringout degree. This is strikingly illustrated by the exhausted feeling that invites the after-dinner nap for rest, which, however, does not rest overfilled stomachs, overfilled brains. The brain gets no rest while getting rid of food-masses with more of decomposition than of digestion.
If food really has power to keep up the strength, there should not be so much strength lost by the general activities—indeed, it would seem that fatigue should be impossible. But the fact remains that from the first wink in the morning to the last at night there is a gradual decline of strength no matter how much food is taken, nor how ample the powers of digestion; and that there comes a time with all when they must go to bed, and not to the dining-room, to recover lost strength. The loss of a night of sleep is never made up by any kind of care in eating on the following day, and none are so stupid as not to know that rest is the only means to recover from the exhaustion of excessive physical activity.
The brain is not only a self-feeding organ when necessary, but it is also a self-charging dynamo, regaining its exhausted energies entirely through rest and sleep. There is no movement so light, no thought or motion so trivial, that it does not cost brain power in its action—and this is true of even the slightest exercise of energy evolved in digestion.
Why, then, do we eat?
For two reasons, or perhaps three: we eat because we are hungry. We rarely fail to eat excessively to satisfy the sense of relish after the normal hunger sense has been dissipated; we may eat to satisfy relish as we eat ice cream, fruits, and the enticing extras that beguile us to put more food into the stomach after it is already overfilled for its working capacity. But our actual need of food, the best reason for taking it, is to make up for the wastes from the general activities; and this is a process in the order of Nature that actually tires the entire brain system, or, in the common phrase, the whole body, unless the stomach has powers not derived from the brain system.