This book presents a collection of digitally processed Polaroid images and Polaroid collages by Anna & Bernhard Blume, produced between 1988 and 2000. The series, entitled Principle of Cruelty, was a central focus of their work during the nineties. The Cologne artist couple, both halves of which were born in 1937, followed their first photographs with a series of works that developed from restrained, experimental early works to a lusty, orgiastic massacre of physiognomic deformation and destruction. Here artists’ faces are tortured and distorted by trivial plastic objects, coat hangers, and brightly colored household utensils. The honorable, classical genre of the artist self-portrait is transformed into a sequence of shameless distortions that, in the words of Anna & Bernhard Blume, “put to rest the myth of the portrait and the autonomy of the subject it seeks to convey.” In the interplay of the blood-red Polaroid images and adjacent statements inspired by French philosopher Cl ment Rosset, we recognize the sarcastic denial of all comforting metaphysical theories and a villainous pleasure in catastrophe: Joy knows no mercy.