"The third night that I roomed with Jack in our tiny double room, in the solid-tumor ward of the cancer clinic of the National Institute of Health in Maryland, a terrible thought occurred to me. Jack had a melanoma in his belly, a malignant solid tumor that the doctors guessed was the size of a softball. The doctors planned to remove the tumor, but they knew Jack would soon die. The cancer had now spread out to control. Jack, about 28, was in constant pain, and his doctor had prescribed an intravenous shot, a pain killer, and this would contr ....