The analogy begins : You have just come from your annual medical checkup, where your doctor assures you that you are in robust health. Walking jauntily down t

The analogy begins : You have just come from your annual medical checkup, where your doctor assures you that you are in robust health. Walking jauntily down the street, you bump into a practitioner of alternative medicine. He takes one look at you and declares “You have a serious tumour! It must be removed or you will die”. You ignore him as you always have, and continue your merry way down the street. One day later, a stabbing pain suddenly cripples you, and you collapse to the pavement.