Karadzic is the former president of the “Republika Srpska” and one of the chief architects of the brutal Bosnian war.

He brought the concentration camp back to Europe and ordered Europe’s worst massacre since World War II (in 1995, Bosnian-Serb forces slaughtered more than 7,000 unarmed Bosnian Muslim men and boys near Srebrenica). With Karadzic’s approval, torture and starvation became routine methods of prisoner control, organized mass rape became a spectator sport and snipers were authorized to fire on children during the siege of Sarajevo.

Karadzic’s arrest was long overdue. He was indicted by the U.N.’s International Criminal Tribunal for the Former Yugoslavia at The Hague 13 years ago, and since then, he had hidden in plain sight, protected by tolerant Serbian officials. He replaced his trademark bouffant hairdo with a jolly white beard, took up acupuncture and holistic medicine and opened a practice as a New Age healer.

The irony has been lost on no one. Here’s a man accused of the worst crimes devised by human ingenuity, and he calls himself a “healer”?

But this shouldn’t surprise us. The perpetrators of atrocities have always favored metaphors of healing. Just as a physician might use purges to rid a patient’s body of internal toxins, Stalin imagined that his purges would rid the Soviet body politic of dangerous internal corruption. Hitler saw the Jews as “a cancer on the breast of Germany” and was convinced that the extermination of the Jews was essential to restoring the health of the Aryan nation. For Karadzic as well, there was probably no sense of discontinuity between healing and destroying; one was essential to the other.

It’s easy to dismiss all this with a cynical snort. Karadzic and other perpetrators of atrocities may use metaphors of healing, but they can’t really believe that killing and healing can be reconciled, right?

I’m not so sure. All the evidence we have suggests that human beings are adept at self-deceit. We trick ourselves constantly, in countless tiny ways, into believing that the bad deeds of others are very bad indeed, while our own are necessary, minor, forgivable — or maybe not even bad at all.

In one recent study, for instance, Northeastern University psychologists Piercarlo Valdesolo and David DeSteno found that when subjects were asked to assign tasks to themselves and to strangers, nearly all gave themselves easy tasks while assigning unpleasant tasks to people they didn’t know.

When asked if their actions were fair, subjects were quick to find appealing rationales to justify saddling strangers with all the lousy jobs. But these same subjects were quick to condemn the same selfish behavior when they saw others engage in it.

Most of us aren’t all that different from Karadzic or any of the other killers who cloaked their atrocities in the soothing rhetoric of healing. We’re all moral hypocrites, willing to believe our own justifications for the rotten things we want to do.

There’s a depressing lesson here. Uplifting rhetoric can genuinely mask the true nature of bad deeds — even from those who carry them out. As a nation at war, it’s a lesson we should remember.

But there’s some intriguing and potentially good news as well from the world of social psychology: Valdesolo and DeSteno also found that when experimental subjects were asked to assess the fairness of their own selfish behavior while simultaneously engaging in some other difficult mental task (memorizing a long string of numbers), they judged their behavior far more harshly.

It seems, Valdesolo and DeSteno concluded, that if you tie up some cognitive capacity with a difficult task, there’s just not enough brain power left over to successfully lie to yourself.

And maybe that’s reason for optimism. If hypocrisy is created and sustained by mental effort, maybe it’s something that we — and even the worst moral hypocrites — can eventually learn to unlearn.

Rosa Brooks teaches at the Georgetown University Law Center and writes for the Los Angeles Times. Her e-mail address is rbrooks@latimescolumnists.com.