To keep my balance, I had to remember what Marty said: “It’s a love story. What’s important is the feeling, not the setting. Just nail the emotion and everything else will follow”. […] This was a love story requiring fineness and finesse, set among the first families and old order of New York. It was not something we were born to, but then, that might be an advantage. We could come to it without an agenda.
Both of us had responded to the quick of Wharton’ s novel – to the emotion – and not just to the decoration. We could both learn something from adapting suck a book – something, for example, about precision of plotting – and, as we did that, lend something of our own. We wanted to bring the novel together with the spirit of the older movies we admired and, sometimes, loved. […] Marty knew that the story, evocative of a particular and fascinating time, was not after all peculiar to it. “The setting’s important”, he said, “only to show why this love is impossible”. True, but the setting is seductive. I’d been seduced by it myself, immediately and irrevocably, when my college crony P.F. Kluge had passed the book along with a spare description of its splendors and a simple statement that it contained “one of the great last lines of dialogue”. I read the book right away. […] Each chapter flashed in front of me like reels of a film. But when I got around to giving Marty the book some years later, I let him find out about the dialogue himself. […] Then I waited a while. Marty put the novel on his shelf but put off reading it, as if by instinct, until an incident in his personal life sounded a resonance with Wharton’s narrative. Then, all at once, he picked it up and saw it all. Marty immediately saw those chapter-by-chapter reels, just as I did. And he saw more. He saw scenes. He saw shots. He saw camera moves. And he saw cuts. I think the whole movie was in his head by the time he turned the last page. […] Marty, with every new movie, was becoming ever more adept at rendering the shadings and exactitudes of various contemporary subcultures. His fierce eye for detail and his palpable evocation of social nuance would, I thought, have equally dazzling results turned to another time, a less familiar place. Here, I had an insider’s edge. I knew my friend was an avid reader of history and was fascinated, as well, with social forms and rituals. This put the New York of Edith Wharton much closer to his hand than most people, who knew him through his work – or thought they did – might realize.

Jay Cocks, in Martin Scorsese, Jay Cocks, The Age of Innocence, Newmarket Press, New York 1993