Terrance Tomkow in his blog:
If we have any rights, we surely have the right to self-defense. And yet self-defense has proven very puzzling to Rights theorists. To see why, take a simple case:
VILLAINOUS AGGRESSOR
There are two agents, AGGRESSOR and VICTIM: AGGRESSOR resents VICTIM for his sauve good looks and skill on the dance floor and has made it clear that he intends to kill him. One day AGGRESSOR shows up at the dance hall, gun in hand. He takes a shot at VICTIM but misses narrowly. He prepares to fire again, taking more careful aim, but VICTIM too has a gun and his only hope of surviving is to return fire and kill or disable AGGRESSOR.
Is it morally permissible for Victim to shoot aggressor? Of course! But now here's the puzzle. Rights Theorists have wanted to say:
- It is permissible for VICTIM to shoot AGGRESSOR because VICTIM has the right to self-defense.
- VICTIM has the right to self-defense because he, like everyone, has the right not to be killed or harmed. (That is why, if you are attempting to kill or harm him, you are doing something wrong.)
- In defending himself, VICTIM will kill or harm the AGGRESSOR.
- If the AGGRESSOR, had a right not to be killed or harmed, then it would be impermissible to kill or harm him.
The puzzle is: what happened to AGGRESSOR’s right not to be harmed?
It seems we must say that, by launching his attack, the attacker somehow loses his right not to be harmed. But where does it go?
More here.