Fyodor Dostoyevsky said this quote
“ Whoever has experienced the power and the unrestrained ability to humiliate another human being automatically loses his own sensations. Tyranny is a habit, it has its own organic life, it develops finally into a disease. The habit can kill and coarsen the very best man or woman to the level of a beast. Blood and power intoxicate ... the return of the human dignity, repentance and regeneration becomes almost impossible. ”