For one human being to love another: that is perhaps the most difficult of all our tasks, the ultimate, the last test and proof, the work for which all other work is but preparation. Love is at first not anything that means merging, giving over, and uniting with another...it is a high inducement to the individual to ripen, to become something in himself, to become world for himself for another's sake, it is a great exacting claim upon him, something that chooses him out and calls him to vast things.  -- Rilke