Miller wrote about his debt to Ibsen for fifty years and adapted An Enemy of the People the year after Salesman opened, which is as direct a statement of allegiance as a playwright makes. What he took is Ibsen's method: a household in an ordinary sitting room, a past that has been paid for in secret, and a play whose action is the arrival of the bill. Ibsen builds the whole of A Doll's House on a forged signature years old; Miller builds Salesman on Willy's Boston hotel room and Biff finding out. The difference Miller insisted on is the form. Ibsen keeps to the room and the clock; Salesman lets the past walk on stage and share it, which is the thing Ibsen made possible and did not do.