Zorba the Greek explores where and how to find meaning in life in a world where we are all fated to die. The novel questions how it is we should live, knowing we will all end up in the grave.
The intellectual narrator, the thirty-five-year-old Boss, goes to reopen a mine he owns in Crete, and to understand more directly the life of the common, working class person (though he takes his Dante with him and continues to view life through an intellectual prism). He falls in with Zorba the Greek, in many ways his opposite, an older man who lives pragmatically and largely unthinkingly in the world. Zorba is of a lower class than the narrator, has worked with his hands and been all over, and the narrator hires him as foreman for the mine. Zorba is hardworking and absorbed in living with gusto in the moment while the narrator tries to attain a Buddhist detachment.
Thus, Zorba is a hedonist, very different from the Boss. He says to the Boss, “To live—Do you know what that means? To undo your belt and look for trouble!”
As he ages and grow older to death, Zorba throws himself ever more fully into living. Unlike the Boss, he does not look for answers in religion or God, but in this world.
The major theme throughout Zorba the Greek is the exploration of the existentialist predicament. Existentialism is a philosophical school of thought that believes that there is no order or meaning in the universe.Thus humans either have to create meaning in their lives through their choices or wander aimlessly through a meaningless existence. Kazantakis looks at this predicament through the opposing characters of the narrator, "the Boss," a Buddhist ascetic, and Alexis Zorba, a worldly hedonist.
A second theme is the classic contrast between an Apollonian and Dionysian world view. The first is cerebral, based more in the thought; the second is more visceral, based on our physical bodies. According to Kazantakis both are necessary if we are to make any meaning out of life.