Against Nature, also known as À rebours, is a novel by Joris-Karl Huysmans that epitomizes the decadent movement of the late 19th century. The protagonist, Jean des Esseintes, is a wealthy and eccentric aristocrat who withdraws from society to indulge in his extravagant and perverse desires. Huysmans' vivid descriptions of des Esseintes' luxurious lifestyle and his exploration of the limits of decadence make this book a fascinating read.