In his book Reaching for the Invisible God, Philip Yancey tells about a surgeon friend of his who performs delicate surgery to rebuild the human hand after a severe injury. Whenever he gets a call that there has been an accident, the doctor knows that he will be staring into a microscope and doing delicate surgery for six hours. And this can happen at all hours of the day or night.

On one occasion, he was called at 3 o'clock in the morning. He was worried about being able to concentrate enough during the surgery so he hit upon a novel approach that helped him. He ca…