From Whom The Bell Tolls by John Donne

"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 friend's
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 bells tolls; it tolls for thee."

/from
Devotions upon Emergent Occasions, no. 17
(Meditation)
1624 (published)