The fact that the cause is mental while the result is often physical, should cause no surprise. In the physiological realm we are used to the idea that cause and effect are often widely separated. A headache may be caused by faulty eyes, or it may result from trouble in the intestines. In the same way, we should not be too much surprised if the cause of nervous troubles is found to be even more remote, provided there is some connecting link between cause and effect. The difficulty in this case is the apparent gulf between the realm of the spirit and the realm of the body. It is hard to see how an intangible thing like a thought can produce a pain in the arm or nausea in the stomach. Philosophers are still arguing concerning the nature of the relation between mind and body, but no one denies that the closest relation does exist. Every year science is learning that ideas count and that they count physically, as well as spiritually. =Such Stuff as "Nerves" are Made Of.= Dr. Tom A. Williams in the little composite volume "Psychotherapeutics" says that the neuroses are based not on inherently weak nervous constitutions but on ignorance and on false ideas. What, then, are some of these erroneous ideas, these misconceptions, that cause so much trouble? We shall want to examine them more carefully in later chapters, but we might glance now at a few examples of these popular bugaboos that need to be slain by the sword of cold, hard fact. =Popular Misconceptions about the Body.= 1 "Eight hours' sleep is essential to health. All insomnia is dangerous and is incompatible with health. Nervous insomnia leads to shattered nerves and ultimately to insanity." 2 "Overwork leads to nervous breakdown. Fatigue accumulates from day to day and necessitates a long rest for recuperation." 3 "A carefully planned diet is essential to health, especially for the nervous person. A variety of food, eaten at the same time, is harmful. Acid and milk--for example, oranges and milk--are difficult to digest. Sour stomach is a sign of indigestion." 4 "Modern life is so strenuous that our nerves cannot stand the strain." 5 "Brain work is very fatiguing. It causes brain-fag and exhaustion." 6 "Constipation is at the root of most physical ailments and is caused by eating the wrong kind of food." Some of these misconceptions are household words and are so all but universally believed that the thought that they can be challenged is enough to bewilder one. However, it is ideas like this that furnish the material out of which many a nervous trouble is made. Based on a half-knowledge of the human body, on logical conclusions from faulty premises, on hastily swallowed notions passed on from one person to another, they tend by the very power of an idea to work themselves out to fulfilment. THE POWER BEHIND IDEAS