 In the book but not the film, Denethor uses a "palantír" for knowledge of the Enemy, but Sauron weakens him through it.The film, lacking the palantír as an explanation of the change in Denethor, attributes his madness to grief over Boromir.The film depicts Denethor as self-indulgent, eating and drinking gluttonously as besiegers approach the city, whereas in the book he is sternly ascetic in his habits.