Erin has written this fantastic post on, well, evil in films that ties together Chigurh (from No Country for Old Men), Hannibal Lecter, and black widow spiders. You should read it because, like I said, it's fantastic. If the line "It takes a man to style himself like a seven-year-old girl" doesn't have you wanting to read it right now, then nothing will.
I wrote a comment on Erin's blog, and wanted to repeat myself here, just a little bit. In comparing these three, Erin labels them "creature[s] of nature", though she rightly qualifies and complicates Hannibal a bit - but, at least in Silence of the Lambs, Hannibal has no history, and this is just as good as being a creature purely of nature. She also notes that it would be unsatisfying to 'explain' Chigurh, just as the origin provided in the novels set chronologically before Silence of the Lambs only seem to damage Hannibal's character. It seems as if art's most persuasive and frightening villains are diminished in being understandable - in being made human.
For instance, from the pilot of Family Guy, we get this 'origin' for Adolf Hitler:
It's particularly absurd, but I think it manages to express, in 10 seconds, what was wrong-headed about trying to 'explain' where Hannibal Lecter comes from. No matter the explanation, the origin will always be too banal and too mundane, even too relatable or too sympathetic - nothing short of showing Hitler emerging from Hell itself will be satisfying, because we don't want our villains to be explicable - we want them to be exceptional.
And this expectation and satisfaction is horribly problematic. Because this is exactly how politicians and pundits get away with constructing The Terrorists as evil entities that exist somehow outside politics and history. Because our art teaches us that we shouldn't want to know where evil comes from, and that in any case it emerges directly from nature and is merely acting on that nature, like a black widow or a tornado. We don't need to know why a suicide bomber is a suicide bomber anymore than we need to know why Chigurh kills - they just do.
I don't remember where or when, but Geoff once made the comment on his blog that there was something in the hypervisible misogynistic violence of the Sin City film that he found appealing, and it was a bit troubling because it was so gratifying as a film experience and obviously disgusting as a gender politics. And I feel the same sort of unresolvable ambivalence about these evil characters in No Country for Old Men and Silence of the Lambs.