The character of Zorba is reminiscent of several of the major comic characters in Western literature. He has been compared to Shakespeare's Falstaff, and to Cervantes's Sancho Panza. The latter comparison is inadequate, however; much of Zorba's idealism recalls the admirable "fool" who is Sancho's "boss," Don Quixote. Zorba is also an embodiment of philosopher Henri Bergson's elan vital. The novel as a whole depends much on the philosophical tradition of existentialism, and much of the dialogue has its source in the writings of Friedrich Nietzsche and his followers, thinkers who influenced Kazantzakis early in his life.