It’s been four years since President Barack Obama signed an executive order banning torture and eight years since the CIA shelved the torture techniques euphemistically known as “enhanced interrogation.” But the debate over the U.S. government’s post-9/11 trip to “the dark side” — reignited most recently by “Zero Dark Thirty” — persists.

This week that debate moves to the Senate Intelligence Committee, where John O. Brennan, Obama’s pick to head the CIA, appears for his confirmation hearing. Before becoming Obama’s chief counterterrorism adviser, Brennan was deputy executive director of the CIA under George Tenet from 2001 to 2003. It was during that time that the agency began operating its “enhanced interrogation” program.

In light of Brennan’s CIA service during that period — as well as comments he made before joining the Obama administration in which he seemed to laud the effectiveness of the “enhanced interrogation” program — he should use his confirmation hearing as an opportunity to tackle torture head-on.

Senators on the Intelligence Committee should get clarity from Brennan on three important questions: One, what involvement — if any — did he have in the “enhanced interrogation” program? Two, what are his views of the arsenal of cruel, inhuman and degrading tactics — beyond waterboarding, which he has denounced — that the CIA used? And three, will he support declassification of the committee’s investigative report on CIA detention and interrogation — the most comprehensive record of the torture program to date?

Nuance about torture at the top reverberates throughout the national security apparatus as a license for abuse when the going gets tough. To some agents in the field, ambiguity reads as acceptance, which becomes a license to cut legal and ethical corners. The brave and dedicated public servants at the CIA deserve a leader who does not ask them to sacrifice their values and integrity in order to do their jobs.

Moral leadership is needed, and Brennan can use his hearing to demonstrate it publicly. He should renounce not just waterboarding but the whole “enhanced interrogation” program. And because his tenure as head of the CIA may outlive this administration, he should promise to resist political pressure to go soft on torture.

But the clearest, most important statement he can make is to express unambiguous support for releasing the Intelligence Committee’s 6,000-page report. According to Chairwoman Dianne Feinstein, D-Calif., and committee member Sen. Carl Levin, D-Mich., the report provides “a detailed, factual description of how interrogation techniques were used, the conditions under which detainees were held, and the intelligence that was — or wasn’t — gained from the program.” Feinstein also said it reveals that “abusive treatment of detainees … was far more systematic and widespread than we thought.”

The committee has approved the report and will vote on whether to make it public. But declassification will require the cooperation of the administration, including the CIA. On Thursday, Senators should secure Brennan’s commitment to support the report’s public release. By pledging to help make the report public, Brennan would go a long way toward demonstrating that despite past signs of ambivalence, he is squarely behind the president in rejecting torture. The report could also help to clear his name: Feinstein told the Washington Post that nothing in it suggests he played a significant role in the torture program.

Release of the report would not only allow Americans to see what their government did in their name; it would also trigger a public reckoning, which would, I’m confident, ensure that torture-as-official-policy remains an aberration. On the other hand, if the truth is suppressed, another terrorist attack or a new president could send us scurrying back to the dark side.

It may have been tempting to think that Obama’s executive order closed the book on torture. But we can’t close the book until we open it.

Elisa Massimino is president and CEO of Human Rights First.