Pre-emptive rules and the scope of defensive rights

This essay advances a morality of defensive harm, which I call “Rule-SD.” Rule-SD resolves in a new way two types of difficult cases. It entails that if certain conditions are met, a defender has the right to kill a man who is innocently falling on her, if this is necessary for her survival. Moreover, Rule-SD yields the “free competition resolution” in some symmetrical cases; it implies that two people who innocently threaten each other might have a right to kill each other if necessary for their survival. Rule-SD’s core claim is that a defender’s right of self-defense might arise from a “pre-emptive rule” rather than from facts about the liability of the attacker. In those cases, the defender is subject to a rule that permits self-preference.