The word psyche means two things in Greek, his aunt said. Two very different but interesting things. Butterfly and soul. But when you stop and think about it carefully, butterfly and soul aren't so different, after all, are they? A butterfly starts out as a caterpillar, an ugly sort of earthbound, wormy nothing, and then one day the caterpillar builds a cocoon, and after a certain amount of time the cocoon opens and out comes the butterfly, the most beautiful creature in the world. That's what happens to souls as well, Archie. They struggle in the depths of darkness and ignorance, they suffer through trials and misfortunes, and bit by bit they become purified by those sufferings, strengthened by the hard things that happen to them, and one day, if the soul in question is a worthy soul, it will break out of its cocoon and soar through the air like a magnificent butterfly.
-- Paul Auster, 4 3 2 1