McCain, who was a prisoner of war in Vietnam, said on the Senate floor that his personal experience has shown abused prisoners offer up more bad than good, or even deliberately misleading, intelligence.
"Most of all, I know the use of torture compromises that which most distinguishes us from our enemies," he said. "Our belief that all people, even captured enemies, possess basic human rights which are protected by international conventions, [which] the United States not only joined but for the most part, authored."
McCain did acknowledge that the CIA resorted to extreme interrogation techniques with the goal of protecting Americans, but argued the ends didn't justify those means.
"I dispute wholeheartedly it was right for [CIA officers] to use these methods, which this report makes clear were neither in the best interest of justice, nor our security, nor the ideals we have sacrificed so much blood and treasure to defend," he said.