When the Justice Department publicly declared torture “abhorrent” in a legal opinion in December 2004, the Bush administration appeared to have abandoned its assertion of nearly unlimited presidential authority to order brutal interrogations.

But soon after Alberto R. Gonzales’s arrival as attorney general in February 2005, the Justice Department issued another opinion, this one in secret. It was a very different document, according to officials briefed on it, an expansive endorsement of the harshest interrogation techniques ever used by the Central Intelligence Agency.

The new opinion, the officials said, for the first time provided explicit authorization to barrage terror suspects with a combination of painful physical and psychological tactics, including head-slapping, simulated drowning and frigid temperatures.

Mr. Gonzales approved the legal memorandum on “combined effects” over the objections of James B. Comey, the deputy attorney general, who was leaving his job after bruising clashes with the White House. Disagreeing with what he viewed as the opinion’s overreaching legal reasoning, Mr. Comey told colleagues at the department that they would all be “ashamed” when the world eventually learned of it.

Later that year, as Congress moved toward outlawing “cruel, inhuman and degrading” treatment, the Justice Department issued another secret opinion, one most lawmakers did not know existed, current and former officials said. The Justice Department document declared that none of the C.I.A. interrogation methods violated that standard.

Labels: alberto gonzales, George Bush, torture