How have motives and circumstances figured into The Great Gatsby and to what effect?

To best answer this question, it might make sense to start by listing different examples of motivation and circumstances. Of course, these will naturally differ from character to character, and situation to situation. It could be said that motivation and circumstance are the two primary elements that move the plot forward in The Great Gatsby.

Gatsby's motivation is primarily centered on winning the love of Daisy. He believes that becoming wealthy will ensure her devotion to him, and this belief motivates his actions, from working with bootleggers to amass wealth, to acquiring his opulent mansion near Daisy's home, to throwing elaborate parties full of the kind of decadent people he thinks Daisy will like.

Daisy's motivation seems to be her own happiness and comfort; therefore, she rejects Gatsby's marriage proposal, because he is too poor to provide her with the kind of life she wants, and marries Tom Buchanan, whose wealth can provide her with the comforts and sophisticated lifestyle she hopes for. But these two are also motivated by the passionate love they shared in their youth, and this love motivates them again when they meet after five years apart.

Circumstance plays heavily into what becomes of these lovers. If Nick Caraway had not rented a house next door to Gatsby, and had not been a cousin to Daisy, Gatsby and Daisy might not have been reunited. If Daisy had not been unhappy about Tom's infidelity, she might not have been tempted to have an affair with Gatsby. More complicated circumstances, such as Tom's affair with Myrtle, and the mistaken identity that occurs when Myrtle's husband wants revenge for her accidental death, all contribute to the novel's eventual outcome.