Images of Osama bin Laden’s mangled face will not be beamed around the world. But it’s worth considering, as we think about the death of bin Laden, how his face looked in life.

It was not the face of a rabid or fulminating zealot. It was not even an angry face. On the contrary, in nearly every photograph, bin Laden bears a benign expression. There is a softness to his demeanor. He was reportedly soft-spoken (if intense) with colleagues, and reasonably kind, if distant, to his wives and children.

Yet he was the author of some of the greatest cruelties and crimes of the past two decades. Inspired and encouraged by him, al-Qaeda murdered thousands of innocent Americans in cold blood. The memory of human beings hurling themselves to their deaths out of windows at the World Trade Center rather than die in the inferno is etched into our psyches. It was al-Qaeda, possibly Khalid Sheikh Mohammad personally, who kidnapped, bound, and beheaded Daniel Pearl. It was al-Qaeda, bin Laden’s creation, that used a child with Down Syndrome as an unwitting suicide bomber in an attack on an Iraqi polling place in 2005. Perhaps running short on handicapped children to booby-trap, al-Qaeda used mentally impaired women to sow death and mayhem in Iraq in 2008. The AP reported: “Two mentally retarded women strapped with remote-control explosives — and possibly used as unwitting homicide bombers — brought carnage Friday to two pet bazaars, killing at least 91 people.”

When mentally impaired women were not available, al-Qaeda had other tactics. According to C. Christine Fair of Georgetown University, who authored a U.N. report on terrorism, al-Qaeda terrorists in Iraq would rape women and then hand them off to Samira Jassim, known as the Mother of Believers. Until her arrest in 2009, her job was to convince the shattered victims that the only way to redeem their honor was to die in a suicide mission. Paul Kix in the Daily Beast reports that 28 women did so.

Political theorist Hannah Arendt ignited decades of debate when she coined the expression “the banality of evil,” in reference to the architect of the Holocaust, Adolf Eichmann. He wasn’t extraordinary at all, she wrote, just a clerk doing his superior’s bidding without question.

But what of Hitler himself? There, if anywhere, was a face that personified evil, contorted as it so often was by rage. But his secretary remembered him as thoughtful and kind — he was solicitous about her health, for example. It took years for her to come to terms with his fathomless evil — and her own complicity.

None of the great monsters of the past 100 years — Lenin, Mao, Stalin, Hitler, Pol Pot — thought of themselves as evil. On the contrary, even when exhorting their followers to the worst extremes of human degradation, they did so in the name of a higher good. Hitler was purging the world of a dire threat, untermenschen (Jews, Gypsies, the mentally impaired, homosexuals, and Slavs) in order to usher in a golden age, the “Thousand-Year Reich.” Even in the very last moments of his life, Hitler pointed to his war against the Jews as his greatest achievement. He was proud of the Holocaust.

The Communists believed that in order to make an omelet, you had to break some eggs. In order to build the perfect society with universal prosperity and complete equality, some harsh measures would be necessary in the short term. But it was for a greater good. The brave dissident Vladimir Bukovsky noted mordantly that he had seen many broken eggs, but no one had ever tasted the omelet. One of Stalin’s henchmen recorded, “Our great goal was the universal triumph of communism, and for the sake of that goal, everything was permissible . . . to destroy hundreds of thousands or even millions of people . . . and to hesitate or doubt about all this was to give in to ‘intellectual squeamishness’ or ‘stupid liberalism.’” One hundred million people in the 20th century were sacrificed to that particular ideal.

Robert Heinlein said that “man is not a rational animal, he is a rationalizing animal.” Some are. Certainly those who commit tremendous crimes nearly always do so armed with elaborate self-justifications.

The unifying theme for the great killers is to dehumanize their victims first. Stalin targeted “kulaks” and “counterrevolutionaries.” Hitler despised “Jewish vermin.” Pol Pot loathed and derided “cosmopolitans.” The soft-spoken bin Laden, his quiet style notwithstanding, denied the humanity of his victims with the word “infidel.”

You cannot reliably detect evil in a face. But the attempt to dehumanize is always the precursor of dark crimes.National Review