I read this book long ago in high school but from what I remember it is about society just after WWI. Everything was destroyed after the Great War- the social order, religious belief took a big hit, the economies of many countries, literally whole countries lay in ruins. The fabric that held everything together was gone. Young people didn't trust the people that led them into a war that killed many of them and destroyed the world and many of their prospects. There was nothing to cohere society but making money. This is what is being portrayed in The Sun Also Rises. Nick's physical impotence mirrors his emotional impotence and hope for his or future generations. They move from sensation to sensation with nothing to hold onto but the desire not to feel the emptiness that the world has no meaning except what you choose to give it. This is an existential novel. These young people have nothing to live for but hedonism and materialism in a world that destroyed itself. We are still reeling from the effects of WWI to this day.