In April 2003 Aron Ralston, a 27-year-old hiker, fell and was trapped in a narrow crevasse, his right arm wedged against the rock wall by a boulder. Mr. Ralston's ordeal was a struggle for survival and a profound existential crisis. He had gone to Bluejohn Canyon, Utah for a rock-climbing weekend alone. Not telling anyone where he is going is part of the point: real freedom means getting a clean break from civilization and the burdens of family, friends,...