On the specific difficulty of adapting literary fiction and why most adaptations fail.

The problem with adapting literary fiction is not fidelity. The problem is that the things that make a novel a novel — interiority, duration, the accumulation of detail over hundreds of pages — are the things that cinema is worst equipped to represent.

A good adaptation is not a faithful adaptation. It's a translation: taking what the source material achieves in its own medium and finding a cinematic equivalent that achieves the same effect by completely different means. The Great Gatsby has been adapted many times; what it has never been adapted into is a film that achieves what Fitzgerald achieved, which is the simultaneous saturation and critique of a particular American dream.

The adaptations that work tend to find the cinematic core of a novel — the image or dynamic that is most translatable — and build outward from that. Jane Campion's The Piano is, technically, original material, but it understands what literary adaptation requires: finding the thing in the story that can only be expressed through the specific capabilities of cinema.

Sidney Lumet said that a film is good when you can't imagine it in any other form. That's the standard.