Read the following excerpt from a story.
The old lighthouse stood on a jagged tooth of rock, a lonely sentinel against the churning gray sea.
For fifty years, Elias had been its keeper.
He knew the rhythm of the waves like his own heartbeat, the cry of the gulls as the voices of old friends.
Tonight was his last watch.
A new automated light, a sterile, pulsing eye of technology, was to be activated at dawn.
He polished the great lens, its glass cool beneath his weathered hands.
It wasn't just a lamp to him; it was a heart, and he was its final beat.
The foghorn blew, a long, mournful sigh that seemed to echo the feeling in his own chest.
Which of the following sentences best states a theme of the passage?
