"The Torture Garden", a 1898 novel from Octave Mirbeau. I was surprised that I had never heard of it before, let alone read it. And read it I certainly did, with mouth agape. It is apparently one of the most controversial books ever written. From the website Bookkake: "Once described as “the most sickening work of art of the nineteenth century”, Mirbeau’s sensual and disturbing novel follows a young man’s journey to the ends of desire and depravity in a grand Chinese palace garden where torture is enjoyed, and practiced, as a form of art itself."
And Mirbeau prefaces the novel with this ironic dedication: "To the priests, the soldiers, the judges, to those people who educate, instruct and govern men, I dedicate these pages of Murder and Blood."