This book traces the emergence of modern pessimism in nineteenth-century France and examines its aesthetic, epistemological, ethical, and political implications. It explores how, since pessimism as a worldview is not empirically verifiable, writers on pessimism shift the discussion to verisimilitude, opening up rich territory for cross-fertilization between philosophy and literature. The book traces debates on pessimism in the nineteenth century among French nonfiction writers who either lauded its promotion of compassion or condemned it for being a sick and unliveable attempt at renunciation. It then examines the way novelists and poets take up and transform these questions by portraying characters in lived situations that serve as testing grounds for the merits or limitations of pessimism. The debate on pessimism that emerged in the nineteenth century is still very much with us, and this book offers an interhistorical argument for embracing pessimism as a way of living well in the world, aesthetically, ethically, and politically.