What are the values and goals of the world described in The Great Gatsby? What kind of person survives in this world?
On the surface, wealth seems to be the most important value and goal in this world, and to a great extent that is true. Tom Buchanan's wealth, for example, brings him power. He impresses people with his huge house and string of polo ponies, and he is able to use his wealth to bully the little people, like George Wilson, and keep a mistress in Wilson's wife.
Gatsby understands the ethic of the world he lives in: he knows that if he wants to regain Daisy, he needs money and lots of it. He is willing to engage in a life of crime to earn the wealth he needs to attract her, and he is also willing to spend it freely.
As the contrast between Tom and Gatsby shows, however, it takes more than mere money to be a top dog in this culture. Gatsby has a vast amount of money, but he lacks Tom's pedigree: he hasn't inherited his wealth, he doesn't have the right connections, he doesn't horseback ride, he hasn't been to an Ivy League college, and his clothes and demeanor are just not quite right. He is the quintessential nouveau riche person, going up against established old money, and the deck is stacked against him.
The person who survives in this world is one very much like Tom Buchanan: someone with inherited money and connections who is not very bright and is willing to be completely ruthless. As Nick points out, Gatsby is too much a sensitive dreamer to survive amid the "foul dust" of this world.