Alive is not “just” a cannibal movie – it actually delves into the ethical issues involved in eating other people. Most cannibal films assume that it is grotesque and taboo and generally yucky, and go on to treat the cannibal in the plot as simply a freak of nature, best destroyed ASAP. Except for Hannibal Lecter of course, who can see nothing much wrong with the idea.

Alive is the semi-fictional retelling of an actual event: the crash of a Uruguayan Air Force plane chartered by a football team in the Andes in 1972. The subject of cannibalism is not hidden: in case viewers missed the synopsis, reviews or word-of-mouth titillation, the film starts with Carlitos, a survivor of the crash (played by a chain-smoking John Malkovich), reflecting on his ordeal some twenty years earlier, and sharing the moral conclusions he drew from it. So many people, he complains, have told him they would have rather died than done that which he coyly does not name, but “until you’re in a situation like that, you have no idea how you’ll behave”. Wreathed in smoke, he explores the metaphysical lesson which we will hopefully glean from the tale, that the God he learnt about at school was not the God he met on the mountain: “the God that’s hidden by what surrounds us in this civilisation”. He caught a glimpse, it appears, of that savage and indifferent world of eat or be eaten, the inhuman universe that shocks those who have ever experienced the fury of nature.

The metaphorical nature of this tale is established at the beginning of the narrative. Two women play female stereotypical roles, one enthusing about, the other terrified of the mountains over and into which the plane bounces. They are the mother and sister of Nando (Ethan Hawke), who is to become the lead character when he finally awakens from his coma. The sister, Susana, thinks the mountains are beautiful, the mother replies that they look like “big teeth”. So the metaphor of incorporation is established, and so the plane and the mountain meet, in a feat of special effects impressive for 1993.

Nevertheless, we are 44 minutes into the film before the subject of cannibalism arises: Nando plans to walk over the mountains for help, but cannot do it on a piece of chocolate and a sip of wine (their only apparent food stores). “Then I’ll cut some meat off the pilots. After all they got us into this mess” he says. The others think he’s joking and go on reciting their rosaries, but by day nine, when his sister dies and they hear on the radio that the search has been called off, Nando calls them together and announces “We’re going to save ourselves”. His meaning is clear: they will have to eat the dead.

A crucial debate follows between those who “won’t do it” because it’s “disgusting” and those arguing in favour. These arguments boil down to the common themes of cannibal films. Revulsion: we sometimes have to do things that are disgusting, for example “if I had a wound that was rotting and needed washing out, wouldn’t you do it, even though it was disgusting?” The sanctity of life: “if the soul leaves the body when we die, then the body is just a carcass… What’s there in the snow is just meat, Antonio. Food.” Then of course the main theme: survival. Our families (and perhaps God too) would rather see us alive than morally pure. As they prepare to cut the first pieces of human flesh, one of them comments: “It’s like communion. From their deaths, we’ll live.” Nando, the instigator, hangs back from feeding until he is reassured they are not eating his sister’s body. Immediate family is hard to redefine as “just meat”.

It’s unusual, even in survival films, to see women cannibals (excepting comedies). Although the survival arguments have been fought and won, the last woman alive in the plane, Liliana, is still holding out, but decides that she wants another baby, will need nourishment, and accordingly agrees that tomorrow she will eat. That night an avalanche engulfs the wreckage and she is one of the victims, saved from abjection by death. Note: in the book upon which the film was based, she eats the flesh. Then gets killed.

In the bitter cold of the High Andes, the survivors are packed together in the wrecked interior of the plane, sharing their hopes and despairs, discussing ethics and strategies. We, the audience, are sitting among them, considering the same life and death questions, asking ourselves what we would do in their position. By contrast, the scenes outside in the dirty snow or struggling across the mountains to safety are remote: we are just observers, our distance confirmed by syrupy music.

Little attempt is made to show the physical effects of seventy days without (non-human) food: the men look ready for their next football match when rescue finally arrives. Roger Ebert admitted that he does not know what it would be like to huddle in a wrecked plane for ten weeks eating human flesh, but complains “I cannot imagine, and frankly this film doesn’t much help me”. It seems a minor quibble: the film was clearly a vehicle for Ethan Hawke, Vincent Spano and other Hollywood “young guns”: Newsweek stated that Hawke has “a face for which close-ups were invented”, suggesting that not everyone in the audience may have been there to struggle with ethical dilemmas.

Part of the attraction of the movies, particularly thrillers or horror movies, is the safety of recognising that we are anchored in a cinema watching actors on a set, and that realisation is never far away in watching Alive. Comfortable, warm and well-fed, we can watch our proxy desperadoes wrestle with fascinating questions of body and soul while ourselves munching thoughtfully on a choc-top. We may conclude that they would have been better to die in the crash, or that they made the heroic choice, but either way the genius of this iteration of the cannibal film is that we have watched the dehumanising of the human body, while allowing ethical ambiguity.