When a movie is about beautiful and hopeful things, we typically accept that it exists for its own sake. Darker tales seem to require justification: that made me feel bad, so did I value it?
I’ve been thinking lately about the challenge of finding value in something that can be vile or even punishing to watch- i.e., films in which people do bad things to each other. I suppose if I were making such a film, my first decision would be how much distance I wanted my audience to have from the brutality itself.
Psycho, for example, features murder that is just real enough to make you jump, 
maybe even distress you somewhat, but there is an deliberate understanding that you are watching an entertainment, and that allows you some distance so you can actually enjoy being scared.
Of course, brutality when presented differently can be tragic, sickening, or offensive. Jamie and I watched Gaspar Noe’s Irreversible one evening and couldn’t make it through the rape scene (I now regret turning it off, and suppose I may finish the film one day).
This type of violence is of course not entertaining, and sometimes provides no distance at all- even many critics can’t make it through Irreversible without closing their eyes or just walking out- yet a movie like Irreversible confronts and actually does justice to the reality of violence. So you give up safety, but you may be rewarded with catharsis, or an education.
Brutality can also merely live in a film to support an insight or an idea, as I believe it does in Dogtooth, a recent film from Greece. The grown children of the family in Dogtooth are trapped in the little dystopia their deranged father has made of his walled estate. They are the brainwashed victims as well as the most frightening characters of the story. It was difficult, waiting to see what grotesque animal thing they were going to do next to each other or to themselves, but I appreciated how the horror was used to ask questions about coercion and control: does any of this resemble what parents actually do to their children? (Put the sex stuff aside for a moment, if you can.) Is any of this merely a more intense degree of how parents limit their children, shape their perceptions, write a code of laws and then coerce their children to follow it?
When you see violence on film, you typically want to know as soon as possible what species it is. The most challenging horror films, then- to make, and to watch- would have to be those that take a multifaceted approach; a little entertainment value here, a little genuine tragedy there, some stylish violence (it can even be aesthetically interesting), basically a film that plays with the comfort level of the audience and with the very meaning of its material, and, hopefully, gets away with it. Let me mention here two examples of this approach, which find different levels of success.
I’m thinking first of Silent Night, Deadly Night, which I saw a couple of years ago (although in the 80’s I must have passed by that box on the Blockbuster s
helf 100 times without renting it) and was flummoxed by it- it made me feel bad, and I was kind of offended, but I couldn't say exactly how. In the film, a little boy is riding with his parents down a lonely highway on a snowy night (Christmas Eve, I think). I can’t remember why they stop the car, but a maniac dressed like Santa Claus kills the boy’s father, and rapes and kills his mother, in front of him (while Johnny Mathis or somebody continues to sing merrily on the radio). Later, as an institutionalized orphan, the boy is friendless, and treated cruelly by the adults in his life. All of this is the origin story for how he himself becomes a serial killer dressed as Santa Claus. What makes this so problematic for me is that once I am exhausted from having sympathy for this Job Junior, I am then a
sked to enjoy his career as a murderer the same way I might find entertainment in, say, watching Michael Myers plant a kitchen knife in someone’s head, as a fantasy that activates my imagination for casual entertainment- in short, a thrill. That fusion of tones seems flip and ugly, yet its novelty and boldness seem to hold potential. That is to say: the fact that the film is actually capable of shocking me with its approach suggests that it's moving in an untried direction, and that in itself is valuable. Who knows what a more intelligent foray in the same direction might yield?
More recently, we have I Saw the Devil, which at over two hours is even more exhausting than Silent Night, yet almost worth it. It is not as violent or as upsetting as Irreversible, but it is obsessively bloody, and earned from the audience, at its worst moments, some gasps and cries of disbelief. Far from being clear about the distance it wants to provide, it dances between objectified horror and intimate tragedy, yet with far more skill than the campy Silent Night. The virtuoso sequence I think of the most makes a struggle inside a fast-moving car look like bodies swirling in a giant Vitamix, throwing some implausible spectacle our way so we can sit at arm’s length and catch our breath. Other scenes, however, are as merciless and unpleasant as the deadpan killings in Summer of Sam.
It has good photography, nicely realized characters, and a high-energy performance from Choi Min-sik (he of the very nice sweater). But as technically assured as it might be, I can't tell if its tonal ambiguity is merely incidental, or if it's an incomplete attempt to transcend the horror genre by playing with our perception of violence. Either way, the amount of blood and sheer length of the film make the celebration of violence the center of the experience, drowning out any other possible concerns. Specifically, it's hard to experience the combo plate of dark and tragic feelings we're meant to have in the third act, because we are tired- and it's not emotional exhaustion as much as plain fatigue. Thematically, then, this lacks assurance- it has the chance to escape the label of "torture horror," but it piles on the brutality and increasingly facile spectacle, as though worried we could never love it for anything else.
