Hemingway's theme in A Clean, Well-Lighted Place is a theme that runs through all of his literature: there is no God, no meaning to this world, and man must consequently find something to distract himself from his horrible truth.  For the older waiter, a clean, well-lighted café is such an escape.  This is an artificial light, made by man for man, yet it is the only way to step out of the darkness of reality: that life is filled with nothing meaningful. 

This completely nihilistic worldview glorifies individuals, like the veteran waiter and the elderly drinker, who find a method of coping with life's hardships in a graceful, dignified manner.  Though the old man is drunk, he isn't rude or unruly, but polite and well behaved.  Despite the obvious hardships in his life (since he attempts suicide), he doesn't lose his cool, but stays in control of himself, exhibiting grace under pressure.  Such grace, Hemingway asserts, should be the goal of every individual.