I was intrigued by the discussion about self-defense as an example of when it was right for one person to intentionally kill another. In the United States, self-defense justifies committing murder. For example, in Arizona,
“[a] person commits first degree murder if [i]ntending or knowing that the person’s conduct will cause death, the person causes the death of another person [plus some anti-abortion language],” but “a person is justified in threatening or using physical force against another when and to the extent a reasonable person would believe that physical force is immediately necessary to protect himself against the other’s use or attempted use of unlawful physical force.”
The language in bold gets a lot of attention. Although I am not a criminal lawyer, it seems to adopt Josh’s position that the question is whether the self-defender had a fear for his safety (subjective), not whether the target of the self-defense was in fact a threat to his safety (objective).
Pat noted that there is a difference between what we allow and what we should do. Here, I think it probably makes sense to use this standard, we’re tipping the scales in favor of the defendant (as in self-defense guy, and as in a potential defendant on murder charges) which is generally appropriate, and there is no social good served by making it safer to break into someone house. I do not think stealing merits the death penalty, and I would not want people to feel that they could kill people for taking their things. But, to the extent it is vague, fine.
The Bible seems to not say a whole heck of a lot about this topic. Perhaps, because it was just assumed that self-defense was appropriate. The Ten Commandments prohibit committing murder, not killing in general. Jesus taught to turn the other cheek, but I don’t think it follows directly from that that you should allow yourself to be killed. I came across a couple conservative articles ,  discussing the topic, they both quoted these as evidence of permitting self-defense: Luke 22:36 “He said to them, ‘But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one.'” and Exodus 22:2 “If a thief is caught breaking in and is struck so that he dies, the defender is not guilty of bloodshed; but if it happens after sunrise, he is guilty of bloodshed.”
If you follow the links, you will see that the Luke passage is taken completely out of context, and only a few versus later Jesus rebukes Peter using his sword to defend Jesus against the guys coming to arrest & crucify him. The Exodus scripture is totally on point. Although, it says that if I guy breaks into your house during the day, and you kill him, you are guilty of blood shed. So, as with may things, Exodus is more restrictive in the use of force than Arizona.
James, who is 12, is against intentionally killing someone even if that person is trying to kill him. James thinks you should try to stop the person, but not kill him on purpose. That seems to ignore the obvious problem of limited information that Josh addressed in consider the homeowner who has no way of knowing how armed the intruder is.
I think one should only use deadly force in self-defense when, to the best knowledge available to you at the time of the decision you believe there is no other way to prevent your death. Which, I guess is probably what everyone thinks in the end.