Page "Pacifism" Paragraph 8

In contrast to the nonviolence principle stands the non-aggression principle which rejects the initiation of violence, but permits the use of violence for self-defense or delegated defense.

People supporting the non-aggression principle claim that the moral prohibition of the use of violence follows from argumentation ethics, which applies only when people are using argumentation to solve disputes.

So it does not apply when someone is subject to initiated violence, and hence self-defense is not morally rejected.

Another possible approach is a semantic one: the claim that defense and aggression are fundamentally different, a point that is obscured when using terms like " defensive violence " and " initiated violence "; that there is no moral prohibition on defense and no need to justify it or make an exception for it.