"Life is like a box of chocolates: you never know what you're going to get." - Forrest Gump, by Robert Zemeckis

You know the plot: idiot grows up in Alabama and wanders through recent American history, witnessing astounding events and meeting great men (plus a few US Presidents). Academy Awards follow his every step.

I'm going to be criticising this film at length, so perhaps I should start by acknowledging its strengths. Robert Zemeckis knows how to craft a story, if nothing else, and Forrest Gump has an undeniable emotional impact. You can't help but engage with this simpleton and his naive nobility: Tom Hanks probably did not deserve his Oscar, but his empathetic performance is nevertheless a good one. There are good supporting performances, too, with Gary Sinise a real standout as Gump's commanding officer in Vietnam. The cast and direction together work miracles with the material, making an episodic and repetitive story engrossing and affecting. Technically, the film is close to flawless. Zemeckis has done himself a big favour by losing his regular cinematographer Dean Cundey, whose work I despise, and opting for Don Burgess; there are also some astounding special effects. (These effect scenes seem to work according to merit: the shots of Sinise without legs are flawless, but Gump's gratuitous meetings with presidents and celebrities are more obviously phoney). So my criticisms are qualified ones: I was moved by Forrest's story, and when Alan Silvestri's music fired up for the film's sentimental highpoints, I went with it. It might not stay with you after you see it (it's too lightweight for that), but it does provide an immediate emotional buzz.

Yet this can't disguise its fundamental vacuousness. I gather Groom's original novel was more satirical, and the film cries out for a more sensible approach to Gump's situation. His brainless homilies - many learnt from his mother, who should have known better - seem to be accepted by Zemeckis as some form of higher wisdom. "Life is like a box of chocolates - you never know what you're going to get" is bad enough, but "stupid is as stupid does?" Please! I might have bought a celebration of Gump's emotional sincerity (and the sequences that play on this are the film's best), but Zemeckis doesn't seem willing (or able) to deal with Gump's intellectual emptiness. When Gump receives a college degree, it's seen as a personal triumph rather than an opportunity for satire; it's a salute to the way sporting triumphs can cover for academic ability. He goes on to ever greater successes, becoming a war hero and a millionaire. In the process, it makes a nonsense of the great American myth of reward for effort. Forrest's fortune is made through dishonest acceptance of sponsorship money, the exploitation of monopoly profits, and a fortuitous investment on the stockmarket. This life story isn't a triumph of the worthy; it's a fluke that covers up the fact that in the real America Gump's prospects would be grim indeed (he' be sleeping on that park bench, probably).

Zemeckis could perhaps argue that this was irrelevant to the essential story that forms the film's core; yet the film's subject matter inevitably gives it a political charge. Gump's story is contrasted with that of his childhood friend Jenny, who joins the counterculture and takes a more participatory role in the history that Gump only observes. Perhaps this is just to widen our view of the times that we see, with Gump taking a traditional establishment course while Jenny drops out and explores the alternative. This is the Roger Ebert view: he adds that the couple's final reunion represents a "dream of reconciliation for [American] society." Yet Jenny's countercultural course is painted in stark contrast to Gump's upward mobility. Her politicised friends are stupid and hypocritical, and she suffers a constant barrage of misfortune. The anti-establishment left is punished, while Gump's conservative right is rewarded against all logic. The "reconciliation" Ebert talks of is in fact a surrender, with Jenny giving up her ideals and accepting the Gumpian ideal of life on the farm.