The Odyssey . . . . The third allegory uses the surface story to symbolize the main themes of Nietzsche's Thus Spake Zarathustra . This allegory, the main one, again deals with evolution, so it shares considerable symbolism with the with the second allegory. But now there are just two evolutionary leaps - ape to man, man to overman. Between man and overman is a major subplot in which God stands in man's way.
Wheat analyzes the three allegories in detail.
Arthur Clarke is not only coauthor of 2001 's screenplay but author of both the short story on which the movie is loosely based, The Sentinel , and the novel that is based on the movie. Together, Hal and Discovery constitute an essential living organism that symbolizes a hypothetical new humanoid species, humanoid machines. The author also explains the surface story and the meaning of the four monoliths. In 2001, each monolith has four meanings - one for the surface story and one for each of the three allegories. These are just a few examples of Wheat's analysis.