A good novel is one that shows the complexity of individuals, and creates enough space for all these characters to have a voice; in this way a novel is called democratic - not that it advocates democracy but that by nature it is so. Empathy lies at the heart of Gatsby, like so many other great novels - the biggest sin is to be blind to others' problems and pains. Not seeing them means denying their existence.
Azar Nafisi (2003). “Reading Lolita in Tehran: A Memoir in Books”, p.132, Random House