For Whom the Bell Tolls is a novel by Ernest Hemingway published in 1940. It tells the story of Robert Jordan, a young American volunteer attached to a Republican guerrilla unit during the Spanish Civil War. As a dynamiter, he is assigned to blow up a bridge during an attack on the city of Segovia.
True, but in this case I think the meme is referencing the poem by John Donne (which the Hemingway novel is named after):
No man is an island,
Entire of itself.
Each 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 thine own
Or of thine friend's were.
Each man's death diminishes me,
For I am involved in mankind.
Therefore, send not to know
For whom the bell tolls,
It tolls for thee.
