John Donne. Meditation 17. [No man is an island... For whom the bell tolls, etc.]

This is where the passage is found that Thomas Merton used (No Man Is An
Island) and Ernest Hemmingway (For Whom the Bells Toll). It was a
meditation of John Donne's during an illness.

http://www.luminarium.org/sevenlit/donne/meditation17.php