Mark Jenkins has a fine essay in Outside on Aron Ralston — the hiker who ultimately had to amputate his own hand to survive — and on what survival requires.
It’s not being dead that scares us. The most frightening thing is being a witness to our own death. Watching it come, knowing we are trapped, alone, with no one to call for help. Perhaps most of all, though, fearing we may have a choice but may lack the courage to fight, or the resolve to tell death to go screw itself — whatever the cost.