Not physically, but psychologically.
Say you were alone in your house and an attacker breaks in. He’s standing at the door of your bedroom with a knife. Because this takes place in Hypothetical Scenario Land, you’re psychic, and know with 100% accuracy that he will kill you if you don’t do anything in the next half of a minute. You, like everyone else in HSL, have a gun, and know how to shoot it with 100% accuracy, and it is always lethal. There is no immediate physical torture; he is simply menacingly moving towards your bed slow enough that it would be easy to reach for the gun near you and shoot him. You can’t merely disable him, either, the gun is always lethal and you’ll lose a hand-to-hand fight. There is nobody else in the house to worry about. Do you shoot?
I don’t think I could do it. Even if I knew I would be in the right to kill him, I don’t believe I could pull the trigger. I would probably be so frozen with fear that I wouldn’t even be thinking straight, and even if I was I would be considering the moral implications of killing him (“Does this person deserve to die just because they would kill? How do I know that there really isn’t such a thing as fate and that I deserve to die? Oh great, I’m dead.”) and wouldn’t think to reach for the gun. The only way I could see myself doing it is if there is someone else to protect that couldn’t protect themself (like a child), but even then it would be hard. I very much doubt that I could get over the initial fear reaction in the thirty second time frame; since I am not being immediately physically tortured as in a rape situation the endorphins wouldn’t kick in. I’d have time to think about it, and it’s that time that would kill me.
What say you?