Arthur Koestler, 'Darkness at Noon' (published 1940), an excerpt:
“When Rubashov capitulates,” said Ivanov, “it won’t be out of cowardice, but by logic. It is no use trying the hard method with him. He is made out of a certain material which becomes the tougher the more you hammer on it.”
“That is just talk,” said Gletkin. “Human beings able to resist any amount of physical pressure do not exist. I have never seen one. Experience shows me that the resistance of the human nerve system is limited by Nature.”
About 70 years later, from Mohamedou Ould Slahi, in his 'Guantanamo Diary' (published 2014), an excerpt:
There is nothing an interrogator could say to me that would be new; I’ve heard every variation. Each new interrogator would come up with the most ridiculous theories and lies, but you could tell they were all graduates of the same school... : "You haven’t driven a plane into a building; your involvement can be forgiven with just a five-minute talk. The US is the greatest country in the world; we would rather forgive than punish."... "I have nothing against Islam, I even have many Muslim friends."
____[censored and deleted by the US government] turned the air conditioner all the way down to bring me to freezing. This method had been practiced in the camp at least since August 2002. I had seen people who were exposed to the frozen room day after day; by then, the list was long. The consequences of the cold room are devastating, such as ______tism, but they show up only at a later age because it takes time until they work their way through the bones. The torture squad was so well trained that they were performing almost perfect crimes, avoiding leaving any obvious evidence. Nothing was left to chance. They hit in predefined places.
[Note: Twelve years later, Mohamedou Ould Slahi is still in Guantanamo.]