Topics Ethics

Question Is it ethical to kill someone in self-defense? My instinct was yes at first, but upon further reflection, in a situation where it's "you or them", I can't seem to think of a reason to kill someone in self-defense, other than the fact that you simply want to live. After all, you're still taking a human life. (Also if you could explain why it is or isn't ethical would help me out a lot thanks!)

Accepted:
April 19, 2012

Comments

By "Is it ethical to kill someone in self-defense?" I take it you mean "Is it ever morally permissible to do so?" Consider a tidy case, in which you're morally innocent and in which, for all you can reasonably tell, it's certain you'll be killed unless you kill your attacker. If it's not morally permissible for you to kill the attacker, then it must be morally obligatory for you to allow yourself to be killed: permission and obligation are two sides of the same coin. Hence, unless it's morally obligatory for you to allow yourself to be killed, it's morally permissible for you to kill your attacker. I can't see how it could be morally obligatory for you to allow yourself to be killed in that situation, so I readily conclude that you're morally permitted to kill your attacker. (I recognize that some prominent figures have taken the opposite view, apparently including Jesus in Mt. 5:39.)

Your puzzlement seems to arise from the symmetry of the situation. One of you will die, each prefers his/her own survival to that of the other, and so on. Looking at it from an impartial standpoint, you see no good reason why either one of you should be preferred.

But there is a good reason: the other one -- not you -- is the cause of the problem, the cause of the need for one of you to die. You have a plausible reason for using force against the other, a reason that she lacks. While you cannot survive without using force against her, she can survive (could have survived) without using force against you.

To be sure, there are exceptional cases where the other must attack you to survive. She may be coerced by a third party aiming a gun at her, for example, or she may be unable to keep herself afloat without the only available life preserver which you are wearing and need just as urgently. And there are other exceptional cases where the other firmly believes -- falsely but on good grounds -- that you are trying to kill her. In such exceptional cases, I do see your ambivalence. As far as I know, the law of most countries permits self-defense in such cases as well, with deadly force if necessary. But, even if such self-defense is legally and even morally permissible, one might still wonder whether it is ethical in the sense of the morally best course of conduct. In the life preserver case, for example, if you are in your 80s and unlikely to survive hours in the water in any case, it would seem ethically better for you not to use your gun against a teenager who is attacking you in order to get the life jacket that you managed to snatch first when the ship sank.l

I would say: it is ethical to kill someone in self defence as long as their life is not more valuable than yours. In the unlikely event that the person attacking you is a terrific assset to the universe and you are not, then you must let them kill you rather than kill them.

My colleagues' examples show me that my intuitions aren't thoroughly consequentialist. I think an innocent person (and maybe any person) always has a right to lethal self-defense if needed to avoid a lethal threat. An innocent person's (and maybe any person's) sacrificing his/her life is always morally supererogatory.