What can we do to increase vitality? "Old School" physicians and people in general seem to think that this can be done by consuming large quantities of nourishing food and drink and by the use of stimulants and tonics. The constant cry of patients is: "Doctor, if you could only prescribe some good tonic or some food that will give me strength, then I should be all right! I am sure that is all I need to be cured." We fully agree with the patient that he needs more vitality to overcome disease, but unfortunately this cannot be obtained from food and drink, from stimulants and tonics. Vitality, life, life force, whatever we may call it or whatever its aspect, is not something we can eat and drink. It is independent of the physical body and of material food. If the body should "fall dead," as we call it, the life force would continue to act just as vigorously in the spiritual body, which is the exact counterpart of the physical organism. The physical-material body as well as the spiritual-material body are only the instruments for the manifestation of the life force. They are no more life itself than the violin is the artist. But just as the violin must be kept in good condition in order to enable the artist to draw from it the harmonies of sound, so food and drink are necessary to keep the physical body in the best possible condition for the manifestation of vital force. The more normal our physical and spiritual bodies are in structure and function, the more harmonious our thought life and emotional life, the more abundant will be the influx of vital force into the twofold organism. This important subject has been treated more fully in Chapter IV. Ignorance of these simple truths leads to the most serious mistakes. Physicians and people in general do not stop to think that excessive eating and drinking tend to rob the body of vitality instead of supplying it. The processes of digestion, assimilation and elimination of food and drink in themselves require a considerable expenditure of vital force. Therefore all food taken in excess of the actual needs of the body consumes life force that should be available for other purposes, for the execution of physical and mental work. The Romans had a proverb: "Plenus venter non studet libenter"--"A full stomach does not like to study." The most wholesome food, if taken in excess, will clog the system with waste matter just as too much coal will dampen and extinguish the fire in the furnace. Furthermore, the morbid materials and systemic poisons produced by impure, unsuitable or wrongly combined foods will clog the cells and tissues of the body, cause unnecessary friction and obstruct the inflow and the operations of the vital energies, just as dust in a watch will clog and impede the movements of its mechanism.