No man is an island, entire of itself every man is a piece of the continent, a part of the main
if a clod be washed away by the sea, Europe is the less, as well as if a promontory were,
as well as if a manor of thy friends or of thine own were any man's death diminishes me,
because I am involved in mankind and therefore never send to know for whom the bell tolls
it tolls for thee.

- John Donne (1572-1631)
http://www.online-literature.com/donne/409/