The Winslow Boy takes us back to a time when honor was important and a family's good name was something worth fighting for.

Based on Terence Rattigan's classically constructed 1946 play, it's set in middle-class Edwardian London whose culture is often depicted today as hypocritical and psychologically repressive. Surprisingly, cutting-edge playwright and filmmaker David Mamet (The Spanish Prisoner) rejects these clichés and presents both the positive aspects of a traditional moral code as well as the often difficult costs of adhering to it.

The movie also intelligently examines contemporary issues such as the power of the media in promoting a cause and the relationship of individual rights to the public good.

Rattigan based his play on a real incident, and Mamet makes few changes from the original. The action is set in 1912, just before World War I when the prosperous, ordered life of Britain's middle classes seems threatened at home and abroad. Trade unions are striking, and women want the vote. Germany's Kaiser is building up his army, and the Balkans are ready to explode.

Against this ominous background, the Winslow family's personal drama unfolds. The opening lines set the tone. It's Sunday, and the Winslows are returning from church. The banker patriarch, Arthur (Nigel Hawthorne), is depicted as culturally somewhat behind the times.

“A gramophone is out of place in a civilized home,” he tells his pleasure-seeking older son, Dickie (Matthew Pidgeon). Arthur goes on to praise the sermon. He believes that “everything is a problem of ethics.”

His convictions are immediately put to the test. His younger son, 13-year-old Ronnie (Guy Edwards), makes an unexpected appearance after hiding out in the garden in the rain.

He's been kicked out of the Royal Naval Academy at Osbourne for allegedly stealing a 5-shilling postal order and cashing it. “If you tell me a lie, I shall know it,” the stern but kindly patriarch warns the child, “because a lie between you and me can't be hidden.”

The boy strongly proclaims his innocence. Arthur is convinced and vows to clear him and the family name no matter what the cost.

The movie establishes the weight of institutional traditions. Winslow's only daughter, Catherine (Rebecca Pidgeon), is engaged to an army officer, John Watherstone (Aden Gillette), who'll accept her working for women's suffrage but so trusts in the wisdom of the British navy that he doubts her younger brother's innocence.

The family solicitor, Desmond Curry (Colin Stinton), a champion cricketer, is also in love with Catherine, creating a genteel romantic triangle. But Curry is an honorable man and places the Winslows' interests above his own. Arthur is determined to challenge the admiralty in court, and the solicitor recommends they hire the country's top barrister, Sir Robert Morton (Jeremy Northam), to plead their cause.

Catherine disapproves of Sir Robert's pro-business politics and considers him too much of a calculating careerist to take such a small case. But after a harsh grilling of the young boy, he surprises her and agrees to do it.

The filmmaker hints that his attraction to Catherine may have been a factor, creating the possibility of further romantic intrigue.

Because of the complexity of British law, Sir Robert must defend the Winslow boy's honor before the admiralty, the Crown and Parliament before coming to trial. All this is expensive, and family resources are limited. To raise the necessary funds, the wastrel son, Dickie, is withdrawn from Oxford, and Catherine's dowry is eliminated, alienating her fiancé.

The case is depicted in the national press as the underdog vs. the establishment.

Cartoonists make fun of the admiralty, and satirical songs about the subject become popular, all of which advances the Winslows' cause.

Arthur and Rebecca continue to be willing to make sacrifices, but Mrs. Winslow (Gemma Jones) is not. She worries about the deterioration of her husband's health and regrets the decline in their standard of living.

“You've given your life,” she tells him. “For what?”

“For justice,” Arthur replies.

“For pride and self-importance,” she counters, suggesting the complexity of motives involved.

Although the family and Sir Robert still believe in Ronnie's innocence, the film, taking its cue from the play, plants some doubts. This means that the most moving moments spring from the emotional effects of the case on the family, not the plight of the boy.

“It's easy to do justice,” Sir Robert remarks. “Hard to do right.” The Winslow Boy makes the connections between these ideas and the concept of honor comes alive for contemporary audiences.

Arts & Culture correspondent John Prizer writes from Los Angeles.