At those critical junctures, the question is not simply whether to live or die but what kind of life is worth living. Would you trade your ability—or your mother’s—to talk for a few extra months of mute life? The expansion of your visual blind spot in exchange for eliminating the small possibility of a fatal brain hemorrhage? Your right hand’s function to stop seizures? How much neurologic suffering would you let your child endure before saying that death is preferable?

