What is the conflict of a clean well lighted place?
The other waiter, who is older and more pessimistic, feels that life is meaningless and that there is nothing left to hope for. He sees only the darkness and despair that exist in the world, and finds no comfort in the café's light and warmth. He feels that death, rather than life, offers the only true peace.
The two waiters' discussion represents a conflict between the two opposing viewpoints that exist in the world: optimism and pessimism, hope and despair, light and darkness. Hemingway's story highlights the struggle between these two forces and leaves it open to the reader to decide which viewpoint they find most convincing.