Amputees often experience some sensation of a phantom limb. Somewhere, locked in their brains, a memory lingers of the nonexistent hand or leg. Invisible toes curl, imaginary hands grasp things, a "leg" feels so sturdy a patient may try to stand on it. For a few, the experience includes pain. Doctors watch helplessly, for the part of the body screaming for attention does not exist. One such patient was a medical school administrator, Mr. Barwick, who had a serious and painful circulation problem in his leg but refused to allow the recommended amputation.

As the pain grew worse, Barwick grew bitter. "I hate it!" he would mutter about the leg. At last he relented and told the doctor, "I can't stand it anymore. I'm through with that leg…