Collider reports that Christopher Nolan remains irritated that the most famous line in *The Dark Knight* — “You either die a hero, or live long enough to see yourself become the villain” — was written by his brother and frequent collaborator, Jonathan Nolan. The line matters because it distils the film’s central concern with power, morality and Batman’s role as a vigilante, and has become one of the most widely recognised quotations in modern superhero cinema.

Harvey Dent, played by Aaron Eckhart, delivers the line during an early discussion with Rachel Dawes and Bruce Wayne about Batman’s legality and moral standing in Gotham. Jonathan Nolan also contributed to the stories or scripts for several Christopher Nolan films, including *Memento*, *The Prestige*, *The Dark Knight Rises* and *Interstellar*, before building his own television and producing career with projects such as *Westworld* and *Fallout*.