Suppose, in fact, the doubter has made a mistake; how shall he banish the worry? By reminding himself that others have made mistakes, why should not he, and that it is somewhat egotistic on his part to insist that, whatever others may do, _he_ must do everything right. If this line of reasoning fails to console him, let him think of the greater mistakes he might have made. A financial magnate was once asked how he succeeded in keeping his mind free from worry. He replied, by contemplating the two worst things that could happen to him: losing all his property and going to jail. He had learned the lesson that _one thought can be driven out only by another_.
With regard to immediate doubts. If the over-scrupulous business or professional man, worn out after an exacting day's work, will stop and reflect, he will realize that much of his exhaustion is due to his having filled the day with such doubts as whether he is doing the wrong thing, or the right thing at the wrong time, whether he or someone else will miss an appointment or fail to meet obligations, and whether he or his assistants may make blunders.
Let him resolve some morning that he will proceed that day from task to task without allowing such thoughts to intrude. If he does so he will find that he has succeeded in his work at least as well as usual, and that he is comparatively fresh in the evening.
So far we have only considered the most obvious and simple among the evidences of doubting folly. A still more obstinate tendency of the doubter is the insistent habit interminably to argue over the simplest proposition, particularly regarding matters pertaining to the health, comfort, and life of the individual himself. A certain patient, of this type, attempts to describe to his physician a peculiar, hitherto undescribed, and even now indescribable sensation "through his right lung." He traces this sensation to what he believes to have been the absorption of a poison some years ago. His line of reasoning is somewhat as follows: 1. The drug was a poison. 2. If he absorbed it he must have been poisoned. 3. If he was poisoned then, he is poisoned now. 4. There is no proof that such a poison cannot produce such a sensation. 5. He has the sensation. Conclusion: He is suffering from poison. In support of this proposition he will spend hours with anyone who will listen. The physician who allows himself to be drawn into the controversy speedily finds himself, instead of giving advice to listening ears, involved in a battle of wits in which he is quite likely to come off second best. He assures the patient, for example, that, as far as scientific methods can establish the fact, the lung is sound.