>because in this case killing doesn't serve any purpose. Revenge comes from an emotion, that's why I'm saying it's not really rational. Rationality is a means

>because in this case killing doesn't serve any purpose. Revenge comes from an emotion, that's why I'm saying it's not really rational. Rationality is a means of achieving a goal. Rationality says nothing about what the ultimate goal should be. If one's system of ethics places value on punishing those who misbehave, then it would be perfectly rational to launch a revenge counterattack. And I think it is quite plausible that humans evolved to behave in accordance with a system of ethics that places value on retributive justice. Viewed from the perspective of game theory, being able to credibly pre-commit to punishing defectors even at one's own expense can be quite helpful in the long run. Perhaps you think that launching a revenge counterattack is wrong. But I contend that that is a question of ethics, not a question of rationality.