Great moments stud Bernardo Bertolucci’s 1976 Marxist epic, but the end result is ambiguous. Robert De Niro is a landowner, Gerard Depardieu is a peasant; they share a birthday and most of the history of the 20th century—the fall of feudalism, the rise of fascism, and two world wars. In the film’s four-hour version, at least, the characterizations are hazy and the narrative seems jerky. Some scenes are banal and offensively simpleminded. But patience, ultimately, is rewarded with a welter of detail and some mighty fine camerawork. With Donald Sutherland, Burt Lancaster, Dominique Sanda, Stefania Sandrelli, and Sterling Hayden. 318 min.