Fernando Botero, Abu Ghraib, series. Image by Mark Barry, licensed under Creative Commons.

News that U.S. special forces had killed Osama bin Laden had barely hit the TV screens before former officials in the Bush administration were claiming that their policy of "enhanced interrogation" had been vindicated. The use of torture, they said, was key to finding bin Laden. Bush attorney general Michael Mukasey said that crucial information about the identity of bin Laden's courier had been gained by waterboarding Khalid Sheikh Mohammed, the alleged mastermind of 9/11.

But the New York Times reported in early May that "harsh techniques played a small role at most" in discovering bin Laden. In fact, prisoners who were harshly interrogated were more likely to offer misleading information. CIA director Leon Panetta reported that there was no one essential piece of information that led U.S. intelligence agencies to bin Laden and no evidence that enhanced interrogation had been key to the effort.

Senator John McCain, who was subjected to torture himself when he was a prisoner in North Vietnam, rejected Mukasey's conclusion, citing Panetta's report. McCain added, "I know from personal experience that the abuse of prisoners sometimes produces good intelligence but often produces bad intelligence, because under torture a person will say anything he thinks his captors want to hear—true or false—if he believes it will relieve his suffering."

The unreliability of forced confessions is hardly news. It has been assumed in Western law for centuries. Perhaps that is why those who rationalize torture look for every opportunity to construct an alternative narrative. And that narrative finds receptive ears—close to half of Americans think torture can often or sometimes be justified.

Given the utilitarian calculus that people bring to the issue of torture, it's useful to meet the argument that torture works with the empirically based counterargument: actually, there is not much evidence that it does.

In the end, however, the question is not whether torture is ever useful but whether it is morally permissible. Suppose bin Laden had been captured on the basis of information obtained from torture—that would not alter the moral case against torture.

Torture is wrong because it is an assault on human dignity. It humiliates those who are tortured and degrades those who torture. It is assault on a person's God-given dignity as a union of body, soul and mind. The practice of torture denies a fundamental truth that unifies the human family and is our only basis of peace: though sin may greatly deface and distort the image of God in a human being, it cannot fully erase it.