Time for the stoner ramble on my thoughts of some movies brought up. I was talking to somebody at work, and posted something similar to somebody via PM as well. IMO, the start of the "horror or not horror" conversation would start something like:
1. Is the violence/horror on screen or off?
2. Is the story about the people the horror is happening to, and are we with them in the movie?
3. What is the tone and atmosphere of the movie?
There are other things, but to me that starts to get at the core of what I am talking about. Thoughts on the movies talked about by name:
The Terminator: Watched it last night and I think it was the least horror of the examples. I forget how much time we are with Reese, how many times we are in the future, how many scenes are with the cops, how many car chases there are, etc.. I get what people are saying - there are definitely some jump scares and some shots look out of a horror movie - for example, the scene where Slider and Sarah's roommate get it. To me this is firmly sci-fi with scenes of horror. I imagine we will have a highly ranked example of a horror movie in a sci-fi setting on the countdown.
Se7en: I posted before this thing that I thought neither this or silence was horror. I am sticking with that for this one. Looking above, why I think it's not horror is we are largely following the detectives after the fact, the violence is off screen, and before the end the main scene with the killer was an action foot chase vs. a horror scene. Yes, it's a dark movie and has some horrific scenes and probably one of the best jump scares I've had in the theater (I heard on a pod that Sloth was a surprise to the actors too). That's why I posted earlier that it's as close to a horror a detective flick can get to a horror without being one. To me the mirror of Se7en would be something like Kill List. That felt like a horror movie shot in the style of a detective movie. Or...
Silence of the Lambs - Why I came around on Silence is again because of thinking of the above 3 things. First, I underestimate how gnarly the atmosphere and settings are. Mental institution, self storage rental, Bill's house and basement. We are also there for the abduction, Hannibal escape, in the house with Clarise at the end, etc.. We are there for the horror and with the people the horror is happening to -so much so that Demme has Hannibal staring straight into the camera at us.