Against Nature, also known as Against the Grain, 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 retreats from society to indulge in his own aesthetic and sensual pleasures. The novel explores themes of artificiality, aestheticism, and the rejection of traditional values. Against Nature is a thought-provoking and controversial work that challenges societal norms and celebrates individualism.