Rationalism in medicine

My mother told me an interesting story today. When she was young, her brother had tonsil problems. The doctors decided to do a tonsillectomy. They told her parents, "As long as we are doing one of your children, we might as well do both." And so they took out my mother's tonsils, even though she had had no problems with them whatsoever.

Of course, since then it has come to be understood the tonsils are a part of the immune system. But the attitude at the time is instructive: "If we experts do not see a reason for it, it must be useless, and therefore can be eliminated without harm."

This was an obvious violation of the "Chesterton's fence" principle: "In the matter of reforming things, as distinct from deforming them, there is one plain and simple principle; a principle which will probably be called a paradox. There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, 'I don’t see the use of this; let us clear it away.' To which the more intelligent type of reformer will do well to answer: 'If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.'"