What is the relationship between the morality of self-defense and the morality of defending others? One natural view is that the two share the same underlying rationale, such that the permissibility of other-defense goes “hand-in-hand” with the permissibility of self-defense (Thomson 1991: 306). This seems most plausible in the case of liable attackers. Since the justification for harming such person’s rests on the “entirely impersonal” fact that they have forfeited their ordinary right against harm, it seems plausible that that any suitably situated person may act on that justification (Thomson 1991: 308).