Personality and behavior are very important character traits, and must be analyzed in order to fully understand the underlying issues in a novel. F. Scott Fitzgerald uses the technique of conflicting, but somewhat similar characters in The Great Gatsby in order to demonstrate how pursuing one's desires can lead to both destruction and growth. He accomplishes this by using Gatsby, Tom, Nick, and Daisy to show the consequences of their unrestrained desires, and the actions they took to achieve these desires.
As the title infers, Jay Gatsby is nothing short of great. Gatsby has created his own society, a lonely and pseudo-upper class. This new class was built by Gatsby in order to help him cope with his own insecurities, especially the fact that he was not wealthy. His visions of becoming a "Dan Cody- have thoroughly encompassed his everyday life. His obsession with Daisy, and the fact that he believes that she left him because of his lower-class status, make him an ultimately mysterious man. Nobody knows how he became rich, nor do they know the motives behind his parties. Gatsby's modus operandi is unknown to the West Egg society, making him a unique spectacle for all to behold. Tom Buchanan is Gatsby's main enemy, his evil twin' if you will. Upon further investigation however, both appear to be much alike. Both Tom and Gatsby are motivated by a woman, whether it is Daisy and Myrtle for Tom or just Daisy for Gatsby. In addition, they are both extremely insecure about their social status. Tom expresses his insecurity in the form of racism and sexism, as well as excessive pride in himself. However, there are invariably always some differences. Tom is a very violent person, a classic case of football player aggression. He takes this aggression out on both his wife and mistress. He is also extremely hypocritical, condemning Gatsby's relationship with Daisy but having no qualms about his affair with Myrtle.