Interviewing Evil, Ctd

A reader writes:

DiA took issue with your use of the label "evil" by noting that the bomber appears to be a rational actor. But doesn't his very rationality make him more evil? For me, that's the very difference between one who commits bad acts and one who is truly evil.
If one commits bad acts because of mental instability, we still punish him, but we might have sympathy for him and offer him medical help. If one reluctantly commits bad acts because of extenuating circumstances, we recognize those circumstances, especially if he shows remorse. But if one commits murder because he believes it is the rationally correct decision, if that person believes murder of children is morally permissible, that's evil. DiA's point was about the deep roots of these beliefs and the difficulty of dealing with them. I certainly agree, and we should do everything we can to understand their thought processes. But watching this video, if that's not evil, I don't know what is.