"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.."

John Donne, "Devotions upon Emergent Occasions"