However, the fact that your actions are sanctioned by the state is obviously not a defense (a la Nuremberg), and so there's no point in adding "police officer" to the example.
Actually, I think there is. If you kill someone without "state sanction", as you put it, it's almost certainly Evil. If you kill someone that the local laws allow you to kill, it's much less likely to be Evil, because non-Evil reasons for killing, such as self-defense, tend to be accounted for in most legal systems. Anyway, I think I'm getting off the subject. Let me try rephrasing the general scenario:
You are a police officer. You have an arrest warrant for a suspected criminal. If you try to arrest the suspect, he is willing to use lethal force against you in order to prevent being captured. You also believe that, once the suspect has attempted to use lethal force against you, non-lethal force will prove to be insufficient to complete the arrest.
The way I see it, this could end in several ways:
1) Don't try to make an arrest attempt at all.
2) Attempt to make an arrest. The suspect responds by attempting to use lethal force against you. (He shoots at you with a low-caliber pistol, but you are protected by your bulletproof vest.) You believe that non-lethal force will most likely fail to subdue the suspect. Not willing to use lethal force and kill the suspect, you retreat, failing to make the arrest.
3) Attempt to make an arrest. The suspected criminal responds by attempting to use lethal force against you. (He shoots at you with a low-caliber pistol, but you are protected by your bulletproof vest.) You believe that non-lethal force will most likely fail to subdue the suspected criminal, but try anyway. (You start running at him, intending to wrestle the gun away from him with your bare hands.) The suspected criminal kills you. (He shoots you in the head.)
4) Attempt to make an arrest. The suspected criminal responds by attempting to use lethal force against you. (He shoots at you with a low-caliber pistol, but you are protected by your bulletproof vest.) You believe that non-lethal force will most likely fail to subdue the suspected criminal, so you resort to lethal force. (You shoot him with your own gun.) The suspected criminal is killed, and, when you are questioned about your actions, your lawyer says that you killed the suspect in self-defense. (Under U.S. law, this would indeed be the case - you would not be guilty of murder.)
Obviously Scenario 2 is a better outcome than Scenario 3, because in Scenario 3, you end up dead. However, if you know that you're not willing to use lethal force to begin with, and that non-lethal force is going to be insufficient, you're probably better off not making the arrest attempt at all, which is Scenario 1. Therefore Scenario 1 is better than Scenario 3. If you're going to make an arrest attempt at all, you are expecting Scenario 4 to occur. If you go through with Scenario 4, does that make you Evil? You initiated the use of force by making the arrest attempt, but the suspect could have chosen to submit to arrest rather than to fight against you - and he did, indeed, use lethal force before you did.
The way I see it, this could end in several ways:
I notice that you left off an outcome that if anything allows you to make your point stronger.
5) Attempt to make an arrest. You see that the suspected criminal has the capacity to use lethal force against you (he is armed) and you suspect that he will use it against you. You shoot the suspect. His use of lethal force against you is never more than counterfactual (ie. a valid suspicion).
For consistency some "6)" may be required in which the first "attempt to use lethal force against you&quo...
..fragments of a book that would never be written...
* * *
Captain Selena, late of the pirate ship Nemesis, quietly extended the very tip of her blade around the corner, staring at the tiny reflection on the metal. At once, but still silently, she pulled back the sword; and with her other hand made a complex gesture.
The translation spell told Hirou that the handsigns meant: "Orcs. Seven."
Dolf looked at Hirou. "My Prince," the wizard signed, "do not waste yourself against mundane opponents. Do not draw the Sword of Good as yet. Leave these to Selena."
Hirou's mouth was very dry. He didn't know if the translation spell could understand the difference between wanting to talk and wanting to make gestures; and so Hirou simply nodded.
Not for the first time, the thought occurred to Hirou that if he'd actually known he was going to be transported into a magical universe, informed he was the long-lost heir to the Throne of Bronze, handed the legendary Sword of Good, and told to fight evil, he would have spent less time reading fantasy novels. Joined the army, maybe. Taken fencing lessons, at least. If there was one thing that didn't prepare you for fantasy real life, it was sitting at home reading fantasy fiction.
Dolf and Selena were looking at Hirou, as if waiting for something more.
Oh. That's right. I'm the prince.
Hirou raised a finger and pointed it around the corner, trying to indicate that they should go ahead -
With a sudden burst of motion Selena plunged around the corner, Dolf following hard on her heels, and Hirou, startled and hardly thinking, moving after.
(This story ended up too long for a single LW post, so I put it on yudkowsky.net.
Do read the rest of the story there, before continuing to the Acknowledgments below.)
Acknowledgments:
I had the idea for this story during a conversation with Nick Bostrom and Robin Hanson about an awful little facet of human nature I call "suspension of moral disbelief". The archetypal case in my mind will always be the Passover Seder, watching my parents and family and sometimes friends reciting the Ten Plagues that God is supposed to have visited on Egypt. You take drops from the wine glass - or grape juice in my case - and drip them onto the plate, to symbolize your sadness at God slaughtering the first-born male children of the Egyptians. So the Seder actually points out the awfulness, and yet no one says: "This is wrong; God should not have done that to innocent families in retaliation for the actions of an unelected Pharaoh." I forget when I first realized how horrible that was - the real horror being not the Plagues, of course, since they never happened; the real horror is watching your family not notice that they're swearing allegiance to an evil God in a happy wholesome family Cthulhu-worshiping ceremony. Arbitrarily hideous evils can be wholly concealed by a social atmosphere in which no one is expected to point them out and it would seem awkward and out-of-place to do so.
In writing it's even simpler - the author gets to create the whole social universe, and the readers are immersed in the hero's own internal perspective. And so anything the heroes do, which no character notices as wrong, won't be noticed by the readers as unheroic. Genocide, mind-rape, eternal torture, anything.
Explicit inspiration was taken from this XKCD (warning: spoilers for The Princess Bride), this Boat Crime, and this Monty Python, not to mention that essay by David Brin and the entire Goblins webcomic. This Looking For Group helped inspire the story's title, and everything else flowed downhill from there.