President Obama's decision to release Bush administration memos on harsh interrogation techniques raises an inevitable question: What now?

In his news conference Wednesday night, Obama took care to say only that he believes waterboarding is torture -- stopping short, barely, of laying an accusation at the door of George W. Bush. What is the country supposed to do with this knowledge about its agencies' efforts to pry information out of suspected terrorists? It is a hard problem, because much of what we do know leads to questions about what we don't, and because we are a long way from consensus about whether torture -- if, in fact, this was torture -- has any justifiable role in the defense of the United States.

Why did interrogators choose to employ such measures? What were their orders? What information were they trying to obtain? What intelligence did they actually get, and did that intelligence save lives? And, more vexing: If torture did save lives, does that mean it was the right thing to do?

To get closer to a consensus -- not to mention a coherent policy -- the country will have to undergo a difficult process of discovery. The best way to begin is with the appointment of a commission to investigate U.S. interrogation practices since 2001.

Another way to do it would be to launch criminal investigations, but Obama has shown appropriate distaste for that idea. However satisfying some might find such an exercise, the prosecution of Bush administration figures would tend to split the population along partisan lines. Too many of America's problems have been allowed to become wedges that widen that divide; from the Iraq war to health care to tax policy, the public's view has been filtered through a broken pair of glasses, one lens pointing left and the other right. What's needed now is not talk of war crimes and prison time but a national conversation about the ethical treatment of prisoners, with no flavor of partisanship and no hint of vengeance. Neither party can pretend that it holds an exclusive lease on the moral high ground.

As others have suggested, the inquiry should be designed along the lines of the 9/11 commission, which did valuable service investigating the terrorist attacks of 2001. This panel, similarly, must be a nonpartisan, blue-ribbon commission of unimpeachable integrity and neutrality. Its goal should be not merely to chronicle what U.S. interrogators did, but to help establish the context in which those interrogators worked.

Former Vice President Dick Cheney says he has seen documents that detail the valuable information acquired in the interrogation program, and has asked the government to release them. He is not alone in suggesting that the tactics accomplished useful objectives; Dennis Blair, Obama's intelligence director, says as much. Obama, who has seen the documents too, insists that interrogators could have gotten the information in other ways. We agree that those documents should be made public, as Cheney suggests. But even if they show what he says they do, they will not settle the question of whether the ends justified such means. If moral questions were so simple, philosophy classes would be an easier A.

From the more complicated landscape of the interrogation chamber, at least two questions cry out for further discussion: Is it possible, as some suggest, that radical Islamic militants actually need to endure suffering before they consider themselves free to speak? And what of the allegation that torture was a means to get suspects to say something they, and their questioners, knew was not true: that Iraq had a connection to the attacks on 9/11? Whether they are credible insights or sensational allegations, such assertions deserve public airing and debate.

Other countries, notably South Africa, have demonstrated the value of commissions that shine daylight on painful truths. Few truths are as painful as the thought of people being waterboarded on our behalf, or slammed into walls, or subjected to insects or sleep deprivation. It would be easier to avert our eyes, but these things were done in our name. We have to look.