King Skule. And whom call you the unsound doubter?
Jatgeir. He who doubts of his own doubt.
King Skule (slowly). That methinks were death.
Jatgeir. 'T is worse; 't is neither day nor night.
King Skule (quickly, as if shaking off his thoughts). Where are my weapons? I will fight and act, not think.
IBSEN: The Pretenders, Act iv.
A gentleman once told me that he rarely passed another in the street without wondering if he had not accosted him in an improper manner. He knew very well that he had not, but the more he dwelt upon the possibility, the more doubtful he became, until the impulse to settle the question became so strong that he would retrace his steps and inquire. He asked if nux vomica would help this trouble! I told him he needed mental training.
"I have tried that," he answered. "I keep saying to myself, 'I will not think of it,' but it is no use; my head becomes hot, my sight blurred, my thoughts confused, and the only relief I find is to settle the question."
I tried to point out the direction in which he was tending, and told him he must remind himself that even if he had accosted another improperly, it was a trifling matter compared to the injury to himself of giving way to this compulsion; moreover, the impression he would make upon the other by going back would be even worse than that of having so accosted him; and, finally, he must dwell upon the probability that he had not offended the man, instead of the possibility that he had. Having pursued this line of thought, he must force himself to think of something else until the besetting impulse was obliterated. I suggested that if a baseball player should become incapacitated for the game, he would not lessen his disappointment by reiterating, "I will not think of baseball," but if he persistently turned his thoughts and his practice to billiards he might in time forget baseball.
"I never played baseball," he replied, "and don't even know the rules."