Suffering...

" 'The real power, the power we have to fight for night and day, is not power over things, but over men.’ He paused, and for a moment assumed again his air of a schoolmaster questioning a promising pupil: ‘How does one man assert his power over another, Winston?’

Winston thought. ‘By making him suffer,’ he said.

‘Exactly. By making him suffer. Obedience is not enough. Unless he is suffering, how can you be sure that he is obeying your will and not his own? Power is in inflicting pain and humiliation. Power is in tearing human minds to pieces and putting them together again in new shapes of your own choosing.' "

I will be impressed if you know which book this intoxicating passage is from without using a search engine.